diff -burN jfreechart-original/pom.xml jfreechart-after-maintenance/pom.xml
--- jfreechart-original/pom.xml	2022-03-07 09:23:25.000000000 +0100
+++ jfreechart-after-maintenance/pom.xml	2022-04-17 18:12:48.000000000 +0200
@@ -66,6 +66,16 @@
             <version>4.11</version>
             <scope>test</scope>
         </dependency>
+
+        <!-- https://mvnrepository.com/artifact/org.mockito/mockito-core -->
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>4.4.0</version>
+            <scope>test</scope>
+        </dependency>
+
+
     </dependencies>
 
     <distributionManagement>
diff -burN jfreechart-original/src/main/java/org/jfree/chart/axis/DateAxis.java jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/DateAxis.java
--- jfreechart-original/src/main/java/org/jfree/chart/axis/DateAxis.java	2022-03-07 09:23:25.000000000 +0100
+++ jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/DateAxis.java	2022-04-17 18:12:48.000000000 +0200
@@ -181,7 +181,7 @@
  * For example, this allows you to create a date axis that only contains
  * working days.
  */
-public class DateAxis extends ValueAxis implements Cloneable, Serializable {
+public class DateAxis extends DatePeriodCommon implements Cloneable, Serializable {
 
     /** For serialization. */
     private static final long serialVersionUID = -1013460999649007604L;
@@ -758,32 +758,7 @@
         DateRange range = (DateRange) getRange();
         double axisMin = this.timeline.toTimelineValue(range.getLowerMillis());
         double axisMax = this.timeline.toTimelineValue(range.getUpperMillis());
-        double result = 0.0;
-        if (RectangleEdge.isTopOrBottom(edge)) {
-            double minX = area.getX();
-            double maxX = area.getMaxX();
-            if (isInverted()) {
-                result = maxX + ((value - axisMin) / (axisMax - axisMin))
-                         * (minX - maxX);
-            }
-            else {
-                result = minX + ((value - axisMin) / (axisMax - axisMin))
-                         * (maxX - minX);
-            }
-        }
-        else if (RectangleEdge.isLeftOrRight(edge)) {
-            double minY = area.getMinY();
-            double maxY = area.getMaxY();
-            if (isInverted()) {
-                result = minY + (((value - axisMin) / (axisMax - axisMin))
-                         * (maxY - minY));
-            }
-            else {
-                result = maxY - (((value - axisMin) / (axisMax - axisMin))
-                         * (maxY - minY));
-            }
-        }
-        return result;
+        return getCoordinates(value, area, edge, axisMin, axisMax);
     }
 
     /**
@@ -1399,21 +1374,21 @@
      * just look at two values: the lower bound and the upper bound for the
      * axis.  These two values will usually be representative.
      *
+     * @param resultInitialValue
      * @param g2  the graphics device.
      * @param unit  the tick unit to use for calculation.
      *
      * @return The estimated maximum width of the tick labels.
      */
-    private double estimateMaximumTickLabelWidth(Graphics2D g2, 
-            DateTickUnit unit) {
+    private double estimateMaximumTickLabelDimension(Graphics2D g2,
+                                                     DateTickUnit unit, boolean verticalOrHorizontal, double resultInitialValue) {
 
-        RectangleInsets tickLabelInsets = getTickLabelInsets();
-        double result = tickLabelInsets.getLeft() + tickLabelInsets.getRight();
+        double result = resultInitialValue;
 
         Font tickLabelFont = getTickLabelFont();
         FontRenderContext frc = g2.getFontRenderContext();
         LineMetrics lm = tickLabelFont.getLineMetrics("ABCxyz", frc);
-        if (isVerticalTickLabels()) {
+        if (verticalOrHorizontal) {
             // all tick labels have the same width (equal to the height of
             // the font)...
             result += lm.getHeight();
@@ -1456,42 +1431,32 @@
      *
      * @return The estimated maximum width of the tick labels.
      */
-    private double estimateMaximumTickLabelHeight(Graphics2D g2,
+    private double estimateMaximumTickLabelWidth(Graphics2D g2,
             DateTickUnit unit) {
 
         RectangleInsets tickLabelInsets = getTickLabelInsets();
-        double result = tickLabelInsets.getTop() + tickLabelInsets.getBottom();
+        return estimateMaximumTickLabelDimension(g2, unit, isVerticalTickLabels(), tickLabelInsets.getLeft() + tickLabelInsets.getRight());
 
-        Font tickLabelFont = getTickLabelFont();
-        FontRenderContext frc = g2.getFontRenderContext();
-        LineMetrics lm = tickLabelFont.getLineMetrics("ABCxyz", frc);
-        if (!isVerticalTickLabels()) {
-            // all tick labels have the same width (equal to the height of
-            // the font)...
-            result += lm.getHeight();
-        }
-        else {
-            // look at lower and upper bounds...
-            DateRange range = (DateRange) getRange();
-            Date lower = range.getLowerDate();
-            Date upper = range.getUpperDate();
-            String lowerStr, upperStr;
-            DateFormat formatter = getDateFormatOverride();
-            if (formatter != null) {
-                lowerStr = formatter.format(lower);
-                upperStr = formatter.format(upper);
-            }
-            else {
-                lowerStr = unit.dateToString(lower);
-                upperStr = unit.dateToString(upper);
-            }
-            FontMetrics fm = g2.getFontMetrics(tickLabelFont);
-            double w1 = fm.stringWidth(lowerStr);
-            double w2 = fm.stringWidth(upperStr);
-            result += Math.max(w1, w2);
         }
 
-        return result;
+    /**
+     * Estimates the maximum width of the tick labels, assuming the specified
+     * tick unit is used.
+     * <P>
+     * Rather than computing the string bounds of every tick on the axis, we
+     * just look at two values: the lower bound and the upper bound for the
+     * axis.  These two values will usually be representative.
+     *
+     * @param g2  the graphics device.
+     * @param unit  the tick unit to use for calculation.
+     *
+     * @return The estimated maximum width of the tick labels.
+     */
+    private double estimateMaximumTickLabelHeight(Graphics2D g2,
+            DateTickUnit unit) {
+
+        RectangleInsets tickLabelInsets = getTickLabelInsets();
+        return estimateMaximumTickLabelDimension(g2, unit, !isVerticalTickLabels(), tickLabelInsets.getTop() + tickLabelInsets.getBottom());
 
     }
 
@@ -1555,6 +1520,30 @@
     protected List refreshTicksHorizontal(Graphics2D g2,
                 Rectangle2D dataArea, RectangleEdge edge) {
 
+        DateTickUnit unit = getTickUnit();
+        Date tickDate = calculateLowestVisibleTickValue(unit);
+        return refreshTicksRefactored(g2, dataArea, edge, unit, tickDate, TextAnchor.CENTER_RIGHT, RectangleEdge.TOP, Math.PI, - Math.PI, TextAnchor.BOTTOM_CENTER, TextAnchor.TOP_CENTER);
+
+    }
+
+    /**
+     * Recalculates the ticks for the date axis.
+     *
+     * @param g2  the graphics device.
+     * @param dataArea  the area in which the plot should be drawn.
+     * @param edge  the location of the axis.
+     *
+     * @return A list of ticks.
+     */
+    protected List refreshTicksVertical(Graphics2D g2,
+                                        Rectangle2D dataArea, RectangleEdge edge) {
+
+        DateTickUnit unit = getTickUnit();
+        Date tickDate = calculateLowestVisibleTickValue(unit);
+        return refreshTicksRefactored(g2, dataArea, edge, unit, tickDate, TextAnchor.BOTTOM_CENTER, RectangleEdge.LEFT, - Math.PI, Math.PI, TextAnchor.CENTER_RIGHT, TextAnchor.CENTER_LEFT);
+    }
+
+    private List refreshTicksRefactored(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge, DateTickUnit unit, Date tickDate, TextAnchor originAnchor, RectangleEdge rectangleEdge, double pi, double pi1, TextAnchor oneCenter, TextAnchor otherCenter) {
         List result = new java.util.ArrayList();
 
         Font tickLabelFont = getTickLabelFont();
@@ -1564,8 +1553,6 @@
             selectAutoTickUnit(g2, dataArea, edge);
         }
 
-        DateTickUnit unit = getTickUnit();
-        Date tickDate = calculateLowestVisibleTickValue(unit);
         Date upperDate = getMaximumDate();
 
         boolean hasRolled = false;
@@ -1596,39 +1583,7 @@
 
             if (!isHiddenValue(tickDate.getTime())) {
                 // work out the value, label and position
-                String tickLabel;
-                DateFormat formatter = getDateFormatOverride();
-                if (formatter != null) {
-                    tickLabel = formatter.format(tickDate);
-                }
-                else {
-                    tickLabel = this.tickUnit.dateToString(tickDate);
-                }
-                TextAnchor anchor, rotationAnchor;
-                double angle = 0.0;
-                if (isVerticalTickLabels()) {
-                    anchor = TextAnchor.CENTER_RIGHT;
-                    rotationAnchor = TextAnchor.CENTER_RIGHT;
-                    if (edge == RectangleEdge.TOP) {
-                        angle = Math.PI / 2.0;
-                    }
-                    else {
-                        angle = -Math.PI / 2.0;
-                    }
-                }
-                else {
-                    if (edge == RectangleEdge.TOP) {
-                        anchor = TextAnchor.BOTTOM_CENTER;
-                        rotationAnchor = TextAnchor.BOTTOM_CENTER;
-                    }
-                    else {
-                        anchor = TextAnchor.TOP_CENTER;
-                        rotationAnchor = TextAnchor.TOP_CENTER;
-                    }
-                }
-
-                Tick tick = new DateTick(tickDate, tickLabel, anchor,
-                        rotationAnchor, angle);
+                Tick tick = getTickRefreshed(originAnchor, edge, rectangleEdge, pi, pi1, oneCenter, otherCenter, tickDate);
                 result.add(tick);
                 hasRolled = false;
 
@@ -1658,61 +1613,9 @@
 
         }
         return result;
-
-    }
-
-    /**
-     * Recalculates the ticks for the date axis.
-     *
-     * @param g2  the graphics device.
-     * @param dataArea  the area in which the plot should be drawn.
-     * @param edge  the location of the axis.
-     *
-     * @return A list of ticks.
-     */
-    protected List refreshTicksVertical(Graphics2D g2,
-            Rectangle2D dataArea, RectangleEdge edge) {
-
-        List result = new java.util.ArrayList();
-
-        Font tickLabelFont = getTickLabelFont();
-        g2.setFont(tickLabelFont);
-
-        if (isAutoTickUnitSelection()) {
-            selectAutoTickUnit(g2, dataArea, edge);
-        }
-        DateTickUnit unit = getTickUnit();
-        Date tickDate = calculateLowestVisibleTickValue(unit);
-        Date upperDate = getMaximumDate();
-
-        boolean hasRolled = false;
-        while (tickDate.before(upperDate)) {
-
-            // could add a flag to make the following correction optional...
-            if (!hasRolled) {
-                tickDate = correctTickDateForPosition(tickDate, unit,
-                    this.tickMarkPosition);
             }
 
-            long lowestTickTime = tickDate.getTime();
-            long distance = unit.addToDate(tickDate, this.timeZone).getTime()
-                    - lowestTickTime;
-            int minorTickSpaces = getMinorTickCount();
-            if (minorTickSpaces <= 0) {
-                minorTickSpaces = unit.getMinorTickCount();
-            }
-            for (int minorTick = 1; minorTick < minorTickSpaces; minorTick++) {
-                long minorTickTime = lowestTickTime - distance
-                        * minorTick / minorTickSpaces;
-                if (minorTickTime > 0 && getRange().contains(minorTickTime)
-                        && (!isHiddenValue(minorTickTime))) {
-                    result.add(new DateTick(TickType.MINOR,
-                            new Date(minorTickTime), "", TextAnchor.TOP_CENTER,
-                            TextAnchor.CENTER, 0.0));
-                }
-            }
-            if (!isHiddenValue(tickDate.getTime())) {
-                // work out the value, label and position
+    private Tick getTickRefreshed(TextAnchor originAnchor, RectangleEdge edge, RectangleEdge top, double pi, double PI, TextAnchor oneCenter, TextAnchor otherCenter, Date tickDate) {
                 String tickLabel;
                 DateFormat formatter = getDateFormatOverride();
                 if (formatter != null) {
@@ -1724,54 +1627,29 @@
                 TextAnchor anchor, rotationAnchor;
                 double angle = 0.0;
                 if (isVerticalTickLabels()) {
-                    anchor = TextAnchor.BOTTOM_CENTER;
-                    rotationAnchor = TextAnchor.BOTTOM_CENTER;
-                    if (edge == RectangleEdge.LEFT) {
-                        angle = -Math.PI / 2.0;
+            anchor = originAnchor;
+            rotationAnchor = originAnchor;
+            if (edge == top) {
+                angle = pi / 2.0;
                     }
                     else {
-                        angle = Math.PI / 2.0;
+                angle = PI / 2.0;
                     }
                 }
                 else {
-                    if (edge == RectangleEdge.LEFT) {
-                        anchor = TextAnchor.CENTER_RIGHT;
-                        rotationAnchor = TextAnchor.CENTER_RIGHT;
+            if (edge == top) {
+                anchor = oneCenter;
+                rotationAnchor = oneCenter;
                     }
                     else {
-                        anchor = TextAnchor.CENTER_LEFT;
-                        rotationAnchor = TextAnchor.CENTER_LEFT;
+                anchor = otherCenter;
+                rotationAnchor = otherCenter;
                     }
                 }
 
                 Tick tick = new DateTick(tickDate, tickLabel, anchor,
                         rotationAnchor, angle);
-                result.add(tick);
-                hasRolled = false;
-
-                long currentTickTime = tickDate.getTime();
-                tickDate = unit.addToDate(tickDate, this.timeZone);
-                long nextTickTime = tickDate.getTime();
-                for (int minorTick = 1; minorTick < minorTickSpaces;
-                        minorTick++) {
-                    long minorTickTime = currentTickTime
-                            + (nextTickTime - currentTickTime)
-                            * minorTick / minorTickSpaces;
-                    if (getRange().contains(minorTickTime)
-                            && (!isHiddenValue(minorTickTime))) {
-                        result.add(new DateTick(TickType.MINOR,
-                                new Date(minorTickTime), "",
-                                TextAnchor.TOP_CENTER, TextAnchor.CENTER,
-                                0.0));
-                    }
-                }
-            }
-            else {
-                tickDate = unit.rollDate(tickDate, this.timeZone);
-                hasRolled = true;
-            }
-        }
-        return result;
+        return tick;
     }
 
     /**
diff -burN jfreechart-original/src/main/java/org/jfree/chart/axis/DatePeriodCommon.java jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/DatePeriodCommon.java
--- jfreechart-original/src/main/java/org/jfree/chart/axis/DatePeriodCommon.java	1970-01-01 01:00:00.000000000 +0100
+++ jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/DatePeriodCommon.java	2022-04-17 18:12:48.000000000 +0200
@@ -0,0 +1,49 @@
+package org.jfree.chart.axis;
+
+import org.jfree.chart.ui.RectangleEdge;
+
+import java.awt.geom.Rectangle2D;
+
+public abstract class DatePeriodCommon extends ValueAxis {
+
+    /**
+     * Constructs a value axis.
+     *
+     * @param label             the axis label ({@code null} permitted).
+     * @param standardTickUnits the source for standard tick units
+     *                          ({@code null} permitted).
+     */
+    protected DatePeriodCommon(String label, TickUnitSource standardTickUnits) {
+        super(label, standardTickUnits);
+    }
+
+    protected double getCoordinates(double value, Rectangle2D area, RectangleEdge edge, double axisMin, double axisMax) {
+        double result = 0.0;
+        if (RectangleEdge.isTopOrBottom(edge)) {
+            double minX = area.getX();
+            double maxX = area.getMaxX();
+            if (isInverted()) {
+                result = maxX + ((value - axisMin) / (axisMax - axisMin))
+                        * (minX - maxX);
+            }
+            else {
+                result = minX + ((value - axisMin) / (axisMax - axisMin))
+                        * (maxX - minX);
+            }
+        }
+        else if (RectangleEdge.isLeftOrRight(edge)) {
+            double minY = area.getMinY();
+            double maxY = area.getMaxY();
+            double v = ((value - axisMin) / (axisMax - axisMin))
+                    * (maxY - minY);
+            if (isInverted()) {
+                result = minY + v;
+            }
+            else {
+                result = maxY - v;
+            }
+        }
+        return result;
+    }
+
+}
diff -burN jfreechart-original/src/main/java/org/jfree/chart/axis/LogarithmicAxis.java jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/LogarithmicAxis.java
--- jfreechart-original/src/main/java/org/jfree/chart/axis/LogarithmicAxis.java	2022-03-07 09:23:25.000000000 +0100
+++ jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/LogarithmicAxis.java	2022-04-17 18:12:48.000000000 +0200
@@ -836,32 +836,7 @@
 
                 if (currentTickValue >= lowerBoundVal - SMALL_LOG_VALUE) {
                     //tick value not below lowest data value
-                    TextAnchor anchor;
-                    TextAnchor rotationAnchor;
-                    double angle = 0.0;
-                    if (isVerticalTickLabels()) {
-                        anchor = TextAnchor.CENTER_RIGHT;
-                        rotationAnchor = TextAnchor.CENTER_RIGHT;
-                        if (edge == RectangleEdge.TOP) {
-                            angle = Math.PI / 2.0;
-                        }
-                        else {
-                            angle = -Math.PI / 2.0;
-                        }
-                    }
-                    else {
-                        if (edge == RectangleEdge.TOP) {
-                            anchor = TextAnchor.BOTTOM_CENTER;
-                            rotationAnchor = TextAnchor.BOTTOM_CENTER;
-                        }
-                        else {
-                            anchor = TextAnchor.TOP_CENTER;
-                            rotationAnchor = TextAnchor.TOP_CENTER;
-                        }
-                    }
-
-                    Tick tick = new NumberTick(new Double(currentTickValue),
-                            tickLabel, anchor, rotationAnchor, angle);
+                    Tick tick = getTickHorizontallyRefreshed(edge, currentTickValue, tickLabel);
                     ticks.add(tick);
                 }
             }
@@ -1026,34 +1001,8 @@
 
                 if (tickVal >= lowerBoundVal - SMALL_LOG_VALUE) {
                     //tick value not below lowest data value
-                    TextAnchor anchor;
-                    TextAnchor rotationAnchor;
-                    double angle = 0.0;
-                    if (isVerticalTickLabels()) {
-                        if (edge == RectangleEdge.LEFT) {
-                            anchor = TextAnchor.BOTTOM_CENTER;
-                            rotationAnchor = TextAnchor.BOTTOM_CENTER;
-                            angle = -Math.PI / 2.0;
-                        }
-                        else {
-                            anchor = TextAnchor.BOTTOM_CENTER;
-                            rotationAnchor = TextAnchor.BOTTOM_CENTER;
-                            angle = Math.PI / 2.0;
-                        }
-                    }
-                    else {
-                        if (edge == RectangleEdge.LEFT) {
-                            anchor = TextAnchor.CENTER_RIGHT;
-                            rotationAnchor = TextAnchor.CENTER_RIGHT;
-                        }
-                        else {
-                            anchor = TextAnchor.CENTER_LEFT;
-                            rotationAnchor = TextAnchor.CENTER_LEFT;
-                        }
-                    }
                     //create tick object and add to list:
-                    ticks.add(new NumberTick(new Double(tickVal), tickLabel,
-                            anchor, rotationAnchor, angle));
+                    ticks.add(getTickVerticallyRefreshed(edge, tickVal, tickLabel));
                 }
             }
         }
diff -burN jfreechart-original/src/main/java/org/jfree/chart/axis/LogAxis.java jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/LogAxis.java
--- jfreechart-original/src/main/java/org/jfree/chart/axis/LogAxis.java	2022-03-07 09:23:25.000000000 +0100
+++ jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/LogAxis.java	2022-04-17 18:12:48.000000000 +0200
@@ -97,7 +97,7 @@
  *
  * @since 1.0.7
  */
-public class LogAxis extends ValueAxis {
+public class LogAxis extends NumberLogCommon {
 
     /** The logarithm base. */
     private double base = 10.0;
@@ -120,9 +120,6 @@
     /**  The smallest value permitted on the axis. */
     private double smallestValue = 1E-100;
 
-    /** The current tick unit. */
-    private NumberTickUnit tickUnit;
-
     /** The override number format. */
     private NumberFormat numberFormatOverride;
 
@@ -254,57 +251,6 @@
         fireChangeEvent();
     }
 
-    /**
-     * Returns the current tick unit.
-     *
-     * @return The current tick unit.
-     *
-     * @see #setTickUnit(NumberTickUnit)
-     */
-    public NumberTickUnit getTickUnit() {
-        return this.tickUnit;
-    }
-
-    /**
-     * Sets the tick unit for the axis and sends an {@link AxisChangeEvent} to
-     * all registered listeners.  A side effect of calling this method is that
-     * the "auto-select" feature for tick units is switched off (you can
-     * restore it using the {@link ValueAxis#setAutoTickUnitSelection(boolean)}
-     * method).
-     *
-     * @param unit  the new tick unit ({@code null} not permitted).
-     *
-     * @see #getTickUnit()
-     */
-    public void setTickUnit(NumberTickUnit unit) {
-        // defer argument checking...
-        setTickUnit(unit, true, true);
-    }
-
-    /**
-     * Sets the tick unit for the axis and, if requested, sends an
-     * {@link AxisChangeEvent} to all registered listeners.  In addition, an
-     * option is provided to turn off the "auto-select" feature for tick units
-     * (you can restore it using the
-     * {@link ValueAxis#setAutoTickUnitSelection(boolean)} method).
-     *
-     * @param unit  the new tick unit ({@code null} not permitted).
-     * @param notify  notify listeners?
-     * @param turnOffAutoSelect  turn off the auto-tick selection?
-     *
-     * @see #getTickUnit()
-     */
-    public void setTickUnit(NumberTickUnit unit, boolean notify,
-            boolean turnOffAutoSelect) {
-        Args.nullNotPermitted(unit, "unit");
-        this.tickUnit = unit;
-        if (turnOffAutoSelect) {
-            setAutoTickUnitSelection(false, false);
-        }
-        if (notify) {
-            fireChangeEvent();
-        }
-    }
 
     /**
      * Returns the number format override.  If this is non-{@code null}, 
@@ -513,47 +459,6 @@
     }
 
     /**
-     * Draws the axis on a Java 2D graphics device (such as the screen or a
-     * printer).
-     *
-     * @param g2  the graphics device ({@code null} not permitted).
-     * @param cursor  the cursor location (determines where to draw the axis).
-     * @param plotArea  the area within which the axes and plot should be drawn.
-     * @param dataArea  the area within which the data should be drawn.
-     * @param edge  the axis location ({@code null} not permitted).
-     * @param plotState  collects information about the plot ({@code null} 
-     *         permitted).
-     *
-     * @return The axis state (never {@code null}).
-     */
-    @Override
-    public AxisState draw(Graphics2D g2, double cursor, Rectangle2D plotArea,
-            Rectangle2D dataArea, RectangleEdge edge,
-            PlotRenderingInfo plotState) {
-
-        AxisState state;
-        // if the axis is not visible, don't draw it...
-        if (!isVisible()) {
-            state = new AxisState(cursor);
-            // even though the axis is not visible, we need ticks for the
-            // gridlines...
-            List ticks = refreshTicks(g2, state, dataArea, edge);
-            state.setTicks(ticks);
-            return state;
-        }
-        state = drawTickMarksAndLabels(g2, cursor, plotArea, dataArea, edge);
-        if (getAttributedLabel() != null) {
-            state = drawAttributedLabel(getAttributedLabel(), g2, plotArea, 
-                    dataArea, edge, state);
-            
-        } else {
-            state = drawLabel(getLabel(), g2, plotArea, dataArea, edge, state);
-        }
-        createAndAddEntity(cursor, state, dataArea, edge, plotState);
-        return state;
-    }
-
-    /**
      * Calculates the positions of the tick labels for the axis, storing the
      * results in the tick label list (ready for drawing).
      *
@@ -863,25 +768,6 @@
     }
 
     /**
-     * Estimates the maximum tick label height.
-     *
-     * @param g2  the graphics device.
-     *
-     * @return The maximum height.
-     *
-     * @since 1.0.7
-     */
-    protected double estimateMaximumTickLabelHeight(Graphics2D g2) {
-        RectangleInsets tickLabelInsets = getTickLabelInsets();
-        double result = tickLabelInsets.getTop() + tickLabelInsets.getBottom();
-
-        Font tickLabelFont = getTickLabelFont();
-        FontRenderContext frc = g2.getFontRenderContext();
-        result += tickLabelFont.getLineMetrics("123", frc).getHeight();
-        return result;
-    }
-
-    /**
      * Estimates the maximum width of the tick labels, assuming the specified
      * tick unit is used.
      * <P>
diff -burN jfreechart-original/src/main/java/org/jfree/chart/axis/NumberAxis.java jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/NumberAxis.java
--- jfreechart-original/src/main/java/org/jfree/chart/axis/NumberAxis.java	2022-03-07 09:23:25.000000000 +0100
+++ jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/NumberAxis.java	2022-04-17 18:12:48.000000000 +0200
@@ -119,7 +119,6 @@
 
 import org.jfree.chart.event.AxisChangeEvent;
 import org.jfree.chart.plot.Plot;
-import org.jfree.chart.plot.PlotRenderingInfo;
 import org.jfree.chart.plot.ValueAxisPlot;
 import org.jfree.chart.ui.RectangleEdge;
 import org.jfree.chart.ui.RectangleInsets;
@@ -140,7 +139,7 @@
  * The {@code NumberAxis} class has a mechanism for automatically
  * selecting a tick unit that is appropriate for the current axis range.
  */
-public class NumberAxis extends ValueAxis implements Cloneable, Serializable {
+public class NumberAxis extends NumberLogCommon implements Cloneable, Serializable {
 
     /** For serialization. */
     private static final long serialVersionUID = 2805933088476185789L;
@@ -178,9 +177,6 @@
      */
     private boolean autoRangeStickyZero;
 
-    /** The tick unit for the axis. */
-    private NumberTickUnit tickUnit;
-
     /** The override number format. */
     private NumberFormat numberFormatOverride;
 
@@ -204,7 +200,6 @@
         this.rangeType = RangeType.FULL;
         this.autoRangeIncludesZero = DEFAULT_AUTO_RANGE_INCLUDES_ZERO;
         this.autoRangeStickyZero = DEFAULT_AUTO_RANGE_STICKY_ZERO;
-        this.tickUnit = DEFAULT_TICK_UNIT;
         this.numberFormatOverride = null;
         this.markerBand = null;
     }
@@ -297,65 +292,6 @@
     }
 
     /**
-     * Returns the tick unit for the axis.
-     * <p>
-     * Note: if the {@code autoTickUnitSelection} flag is
-     * {@code true} the tick unit may be changed while the axis is being
-     * drawn, so in that case the return value from this method may be
-     * irrelevant if the method is called before the axis has been drawn.
-     *
-     * @return The tick unit for the axis.
-     *
-     * @see #setTickUnit(NumberTickUnit)
-     * @see ValueAxis#isAutoTickUnitSelection()
-     */
-    public NumberTickUnit getTickUnit() {
-        return this.tickUnit;
-    }
-
-    /**
-     * Sets the tick unit for the axis and sends an {@link AxisChangeEvent} to
-     * all registered listeners.  A side effect of calling this method is that
-     * the "auto-select" feature for tick units is switched off (you can
-     * restore it using the {@link ValueAxis#setAutoTickUnitSelection(boolean)}
-     * method).
-     *
-     * @param unit  the new tick unit ({@code null} not permitted).
-     *
-     * @see #getTickUnit()
-     * @see #setTickUnit(NumberTickUnit, boolean, boolean)
-     */
-    public void setTickUnit(NumberTickUnit unit) {
-        // defer argument checking...
-        setTickUnit(unit, true, true);
-    }
-
-    /**
-     * Sets the tick unit for the axis and, if requested, sends an
-     * {@link AxisChangeEvent} to all registered listeners.  In addition, an
-     * option is provided to turn off the "auto-select" feature for tick units
-     * (you can restore it using the
-     * {@link ValueAxis#setAutoTickUnitSelection(boolean)} method).
-     *
-     * @param unit  the new tick unit ({@code null} not permitted).
-     * @param notify  notify listeners?
-     * @param turnOffAutoSelect  turn off the auto-tick selection?
-     */
-    public void setTickUnit(NumberTickUnit unit, boolean notify,
-            boolean turnOffAutoSelect) {
-
-        Args.nullNotPermitted(unit, "unit");
-        this.tickUnit = unit;
-        if (turnOffAutoSelect) {
-            setAutoTickUnitSelection(false, false);
-        }
-        if (notify) {
-            notifyListeners(new AxisChangeEvent(this));
-        }
-
-    }
-
-    /**
      * Returns the number format override.  If this is non-null, then it will
      * be used to format the numbers on the axis.
      *
@@ -632,53 +568,6 @@
     }
 
     /**
-     * Draws the axis on a Java 2D graphics device (such as the screen or a
-     * printer).
-     *
-     * @param g2  the graphics device ({@code null} not permitted).
-     * @param cursor  the cursor location.
-     * @param plotArea  the area within which the axes and data should be drawn
-     *                  ({@code null} not permitted).
-     * @param dataArea  the area within which the data should be drawn
-     *                  ({@code null} not permitted).
-     * @param edge  the location of the axis ({@code null} not permitted).
-     * @param plotState  collects information about the plot
-     *                   ({@code null} permitted).
-     *
-     * @return The axis state (never {@code null}).
-     */
-    @Override
-    public AxisState draw(Graphics2D g2, double cursor, Rectangle2D plotArea,
-            Rectangle2D dataArea, RectangleEdge edge,
-            PlotRenderingInfo plotState) {
-
-        AxisState state;
-        // if the axis is not visible, don't draw it...
-        if (!isVisible()) {
-            state = new AxisState(cursor);
-            // even though the axis is not visible, we need ticks for the
-            // gridlines...
-            List ticks = refreshTicks(g2, state, dataArea, edge);
-            state.setTicks(ticks);
-            return state;
-        }
-
-        // draw the tick marks and labels...
-        state = drawTickMarksAndLabels(g2, cursor, plotArea, dataArea, edge);
-
-        if (getAttributedLabel() != null) {
-            state = drawAttributedLabel(getAttributedLabel(), g2, plotArea, 
-                    dataArea, edge, state);
-            
-        } else {
-            state = drawLabel(getLabel(), g2, plotArea, dataArea, edge, state);
-        }
-        createAndAddEntity(cursor, state, dataArea, edge, plotState);
-        return state;
-
-    }
-
-    /**
      * Creates the standard tick units.
      * <P>
      * If you don't like these defaults, create your own instance of TickUnits
@@ -742,23 +631,6 @@
     }
 
     /**
-     * Estimates the maximum tick label height.
-     *
-     * @param g2  the graphics device.
-     *
-     * @return The maximum height.
-     */
-    protected double estimateMaximumTickLabelHeight(Graphics2D g2) {
-        RectangleInsets tickLabelInsets = getTickLabelInsets();
-        double result = tickLabelInsets.getTop() + tickLabelInsets.getBottom();
-
-        Font tickLabelFont = getTickLabelFont();
-        FontRenderContext frc = g2.getFontRenderContext();
-        result += tickLabelFont.getLineMetrics("123", frc).getHeight();
-        return result;
-    }
-
-    /**
      * Estimates the maximum width of the tick labels, assuming the specified
      * tick unit is used.
      * <P>
@@ -942,10 +814,39 @@
      *
      * @return A list of ticks.
      */
-    protected List refreshTicksHorizontal(Graphics2D g2,
-            Rectangle2D dataArea, RectangleEdge edge) {
+    protected List refreshTicksHorizontal(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge) {
+        return refreshTicksRefactored(g2, dataArea, edge, false);
+    }
+
+    /**
+     * Calculates the positions of the tick labels for the axis, storing the
+     * results in the tick label list (ready for drawing).
+     *
+     * @param g2  the graphics device.
+     * @param dataArea  the area in which the plot should be drawn.
+     * @param edge  the location of the axis.
+     *
+     * @return A list of ticks.
+     */
+    protected List refreshTicksVertical(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge) {
+        return refreshTicksRefactored(g2, dataArea, edge, true);
+    }
+
+    /**
+     * Calculates the positions of the tick labels for the axis, storing the
+     * results in the tick label list (ready for drawing).
+     *
+     * @param g2  the graphics device.
+     * @param dataArea  the area in which the data should be drawn.
+     * @param edge  the location of the axis.
+     * @param vertical  boolean, true if vertical refresh, false if horizontal
+     *
+     * @return A list of ticks.
+     */
+    protected List refreshTicksRefactored(Graphics2D g2, Rectangle2D dataArea, RectangleEdge edge, boolean vertical) {
 
         List result = new java.util.ArrayList();
+        if(vertical) result.clear();
 
         Font tickLabelFont = getTickLabelFont();
         g2.setFont(tickLabelFont);
@@ -983,31 +884,7 @@
                 else {
                     tickLabel = getTickUnit().valueToString(currentTickValue);
                 }
-                TextAnchor anchor, rotationAnchor;
-                double angle = 0.0;
-                if (isVerticalTickLabels()) {
-                    anchor = TextAnchor.CENTER_RIGHT;
-                    rotationAnchor = TextAnchor.CENTER_RIGHT;
-                    if (edge == RectangleEdge.TOP) {
-                        angle = Math.PI / 2.0;
-                    }
-                    else {
-                        angle = -Math.PI / 2.0;
-                    }
-                }
-                else {
-                    if (edge == RectangleEdge.TOP) {
-                        anchor = TextAnchor.BOTTOM_CENTER;
-                        rotationAnchor = TextAnchor.BOTTOM_CENTER;
-                    }
-                    else {
-                        anchor = TextAnchor.TOP_CENTER;
-                        rotationAnchor = TextAnchor.TOP_CENTER;
-                    }
-                }
-
-                Tick tick = new NumberTick(new Double(currentTickValue),
-                        tickLabel, anchor, rotationAnchor, angle);
+                Tick tick = refreshTick(edge, vertical, currentTickValue, tickLabel);
                 result.add(tick);
                 double nextTickValue = lowestTickValue + ((i + 1) * size);
                 for (int minorTick = 1; minorTick < minorTickSpaces;
@@ -1027,61 +904,46 @@
 
     }
 
-    /**
-     * Calculates the positions of the tick labels for the axis, storing the
-     * results in the tick label list (ready for drawing).
-     *
-     * @param g2  the graphics device.
-     * @param dataArea  the area in which the plot should be drawn.
-     * @param edge  the location of the axis.
-     *
-     * @return A list of ticks.
-     */
-    protected List refreshTicksVertical(Graphics2D g2,
-            Rectangle2D dataArea, RectangleEdge edge) {
 
-        List result = new java.util.ArrayList();
-        result.clear();
 
-        Font tickLabelFont = getTickLabelFont();
-        g2.setFont(tickLabelFont);
-        if (isAutoTickUnitSelection()) {
-            selectAutoTickUnit(g2, dataArea, edge);
+    private Tick refreshTick(RectangleEdge edge, boolean vertical, double currentTickValue, String tickLabel) {
+        if(vertical) {
+            return getTickVerticallyRefreshed(edge, currentTickValue, tickLabel);
+        } else {
+            return getTickHorizontallyRefreshed(edge, currentTickValue, tickLabel);
+        }
         }
 
-        TickUnit tu = getTickUnit();
-        double size = tu.getSize();
-        int count = calculateVisibleTickCount();
-        double lowestTickValue = calculateLowestVisibleTickValue();
-
-        if (count <= ValueAxis.MAXIMUM_TICK_COUNT) {
-            int minorTickSpaces = getMinorTickCount();
-            if (minorTickSpaces <= 0) {
-                minorTickSpaces = tu.getMinorTickCount();
+    protected Tick getTickHorizontallyRefreshed(RectangleEdge edge, double currentTickValue, String tickLabel) {
+        TextAnchor anchor, rotationAnchor;
+        double angle = 0.0;
+        if (isVerticalTickLabels()) {
+            anchor = TextAnchor.CENTER_RIGHT;
+            rotationAnchor = TextAnchor.CENTER_RIGHT;
+            if (edge == RectangleEdge.TOP) {
+                angle = Math.PI / 2.0;
             }
-            for (int minorTick = 1; minorTick < minorTickSpaces; minorTick++) {
-                double minorTickValue = lowestTickValue
-                        - size * minorTick / minorTickSpaces;
-                if (getRange().contains(minorTickValue)) {
-                    result.add(new NumberTick(TickType.MINOR, minorTickValue,
-                            "", TextAnchor.TOP_CENTER, TextAnchor.CENTER,
-                            0.0));
+            else {
+                angle = -Math.PI / 2.0;
                 }
             }
-
-            for (int i = 0; i < count; i++) {
-                double currentTickValue = lowestTickValue + (i * size);
-                String tickLabel;
-                NumberFormat formatter = getNumberFormatOverride();
-                if (formatter != null) {
-                    tickLabel = formatter.format(currentTickValue);
+        else {
+            if (edge == RectangleEdge.TOP) {
+                anchor = TextAnchor.BOTTOM_CENTER;
+                rotationAnchor = TextAnchor.BOTTOM_CENTER;
                 }
                 else {
-                    tickLabel = getTickUnit().valueToString(currentTickValue);
+                anchor = TextAnchor.TOP_CENTER;
+                rotationAnchor = TextAnchor.TOP_CENTER;
+            }
+        }
+        Tick tick = new NumberTick(new Double(currentTickValue),
+                tickLabel, anchor, rotationAnchor, angle);
+        return tick;
                 }
 
-                TextAnchor anchor;
-                TextAnchor rotationAnchor;
+    protected Tick getTickVerticallyRefreshed(RectangleEdge edge, double currentTickValue, String tickLabel) {
+        TextAnchor anchor, rotationAnchor;
                 double angle = 0.0;
                 if (isVerticalTickLabels()) {
                     if (edge == RectangleEdge.LEFT) {
@@ -1105,27 +967,9 @@
                         rotationAnchor = TextAnchor.CENTER_LEFT;
                     }
                 }
-
                 Tick tick = new NumberTick(new Double(currentTickValue),
                         tickLabel, anchor, rotationAnchor, angle);
-                result.add(tick);
-
-                double nextTickValue = lowestTickValue + ((i + 1) * size);
-                for (int minorTick = 1; minorTick < minorTickSpaces;
-                        minorTick++) {
-                    double minorTickValue = currentTickValue
-                            + (nextTickValue - currentTickValue)
-                            * minorTick / minorTickSpaces;
-                    if (getRange().contains(minorTickValue)) {
-                        result.add(new NumberTick(TickType.MINOR,
-                                minorTickValue, "", TextAnchor.TOP_CENTER,
-                                TextAnchor.CENTER, 0.0));
-                    }
-                }
-            }
-        }
-        return result;
-
+        return tick;
     }
 
     /**
diff -burN jfreechart-original/src/main/java/org/jfree/chart/axis/NumberLogCommon.java jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/NumberLogCommon.java
--- jfreechart-original/src/main/java/org/jfree/chart/axis/NumberLogCommon.java	1970-01-01 01:00:00.000000000 +0100
+++ jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/NumberLogCommon.java	2022-04-17 18:12:48.000000000 +0200
@@ -0,0 +1,150 @@
+package org.jfree.chart.axis;
+
+import org.jfree.chart.event.AxisChangeEvent;
+import org.jfree.chart.plot.PlotRenderingInfo;
+import org.jfree.chart.ui.RectangleEdge;
+import org.jfree.chart.ui.RectangleInsets;
+import org.jfree.chart.util.Args;
+
+import java.awt.*;
+import java.awt.font.FontRenderContext;
+import java.awt.geom.Rectangle2D;
+import java.util.List;
+
+import static org.jfree.chart.axis.NumberAxis.DEFAULT_TICK_UNIT;
+
+public abstract class NumberLogCommon extends ValueAxis {
+
+    /** The tick unit for the axis. */
+    protected TickUnit tickUnit;
+
+    /**
+     * Constructs a value axis.
+     *
+     * @param label             the axis label ({@code null} permitted).
+     * @param standardTickUnits the source for standard tick units
+     *                          ({@code null} permitted).
+     */
+    protected NumberLogCommon(String label, TickUnitSource standardTickUnits) {
+        super(label, standardTickUnits);
+        this.tickUnit = DEFAULT_TICK_UNIT;
+    }
+
+    /**
+     * Returns the current tick unit.
+     *
+     * @return The current tick unit.
+     *
+     * @see #setTickUnit(NumberTickUnit)
+     */
+    public TickUnit getTickUnit() {
+        return this.tickUnit;
+    }
+
+    /**
+     * Sets the tick unit for the axis and sends an {@link AxisChangeEvent} to
+     * all registered listeners.  A side effect of calling this method is that
+     * the "auto-select" feature for tick units is switched off (you can
+     * restore it using the {@link ValueAxis#setAutoTickUnitSelection(boolean)}
+     * method).
+     *
+     * @param unit  the new tick unit ({@code null} not permitted).
+     *
+     * @see #getTickUnit()
+     */
+    public void setTickUnit(NumberTickUnit unit) {
+        // defer argument checking...
+        setTickUnit(unit, true, true);
+    }
+
+    /**
+     * Sets the tick unit for the axis and, if requested, sends an
+     * {@link AxisChangeEvent} to all registered listeners.  In addition, an
+     * option is provided to turn off the "auto-select" feature for tick units
+     * (you can restore it using the
+     * {@link ValueAxis#setAutoTickUnitSelection(boolean)} method).
+     *
+     * @param unit  the new tick unit ({@code null} not permitted).
+     * @param notify  notify listeners?
+     * @param turnOffAutoSelect  turn off the auto-tick selection?
+     *
+     * @see #getTickUnit()
+     */
+    public void setTickUnit(NumberTickUnit unit, boolean notify,
+                            boolean turnOffAutoSelect) {
+        Args.nullNotPermitted(unit, "unit");
+        this.tickUnit = unit;
+        if (turnOffAutoSelect) {
+            setAutoTickUnitSelection(false, false);
+        }
+        if (notify) {
+            fireChangeEvent();
+        }
+    }
+
+    /**
+     * Draws the axis on a Java 2D graphics device (such as the screen or a
+     * printer).
+     *
+     * @param g2  the graphics device ({@code null} not permitted).
+     * @param cursor  the cursor location.
+     * @param plotArea  the area within which the axes and data should be drawn
+     *                  ({@code null} not permitted).
+     * @param dataArea  the area within which the data should be drawn
+     *                  ({@code null} not permitted).
+     * @param edge  the location of the axis ({@code null} not permitted).
+     * @param plotState  collects information about the plot
+     *                   ({@code null} permitted).
+     *
+     * @return The axis state (never {@code null}).
+     */
+    @Override
+    public AxisState draw(Graphics2D g2, double cursor, Rectangle2D plotArea,
+                          Rectangle2D dataArea, RectangleEdge edge,
+                          PlotRenderingInfo plotState) {
+
+        AxisState state;
+        // if the axis is not visible, don't draw it...
+        if (!isVisible()) {
+            state = new AxisState(cursor);
+            // even though the axis is not visible, we need ticks for the
+            // gridlines...
+            List ticks = refreshTicks(g2, state, dataArea, edge);
+            state.setTicks(ticks);
+            return state;
+        }
+
+        // draw the tick marks and labels...
+        state = drawTickMarksAndLabels(g2, cursor, plotArea, dataArea, edge);
+
+        if (getAttributedLabel() != null) {
+            state = drawAttributedLabel(getAttributedLabel(), g2, plotArea,
+                    dataArea, edge, state);
+
+        } else {
+            state = drawLabel(getLabel(), g2, plotArea, dataArea, edge, state);
+        }
+        createAndAddEntity(cursor, state, dataArea, edge, plotState);
+        return state;
+
+    }
+
+    /**
+     * Estimates the maximum tick label height.
+     *
+     * @param g2  the graphics device.
+     *
+     * @return The maximum height.
+     *
+     * @since 1.0.7
+     */
+    protected double estimateMaximumTickLabelHeight(Graphics2D g2) {
+        RectangleInsets tickLabelInsets = getTickLabelInsets();
+        double result = tickLabelInsets.getTop() + tickLabelInsets.getBottom();
+
+        Font tickLabelFont = getTickLabelFont();
+        FontRenderContext frc = g2.getFontRenderContext();
+        result += tickLabelFont.getLineMetrics("123", frc).getHeight();
+        return result;
+    }
+}
diff -burN jfreechart-original/src/main/java/org/jfree/chart/axis/PeriodAxis.java jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/PeriodAxis.java
--- jfreechart-original/src/main/java/org/jfree/chart/axis/PeriodAxis.java	2022-03-07 09:23:25.000000000 +0100
+++ jfreechart-after-maintenance/src/main/java/org/jfree/chart/axis/PeriodAxis.java	2022-04-17 18:12:48.000000000 +0200
@@ -111,7 +111,7 @@
  * displayed across the bottom or top of a plot, but is broken for display at
  * the left or right of charts.
  */
-public class PeriodAxis extends ValueAxis
+public class PeriodAxis extends DatePeriodCommon
         implements Cloneable, PublicCloneable, Serializable {
 
     /** For serialization. */
@@ -966,35 +966,9 @@
     public double valueToJava2D(double value, Rectangle2D area,
             RectangleEdge edge) {
 
-        double result = Double.NaN;
         double axisMin = this.first.getFirstMillisecond();
         double axisMax = this.last.getLastMillisecond();
-        if (RectangleEdge.isTopOrBottom(edge)) {
-            double minX = area.getX();
-            double maxX = area.getMaxX();
-            if (isInverted()) {
-                result = maxX + ((value - axisMin) / (axisMax - axisMin))
-                         * (minX - maxX);
-            }
-            else {
-                result = minX + ((value - axisMin) / (axisMax - axisMin))
-                         * (maxX - minX);
-            }
-        }
-        else if (RectangleEdge.isLeftOrRight(edge)) {
-            double minY = area.getMinY();
-            double maxY = area.getMaxY();
-            if (isInverted()) {
-                result = minY + (((value - axisMin) / (axisMax - axisMin))
-                         * (maxY - minY));
-            }
-            else {
-                result = maxY - (((value - axisMin) / (axisMax - axisMin))
-                         * (maxY - minY));
-            }
-        }
-        return result;
-
+        return getCoordinates(value, area, edge, axisMin, axisMax);
     }
 
     /**
diff -burN jfreechart-original/src/main/java/org/jfree/chart/ChartPanel.java jfreechart-after-maintenance/src/main/java/org/jfree/chart/ChartPanel.java
--- jfreechart-original/src/main/java/org/jfree/chart/ChartPanel.java	2022-03-07 09:23:25.000000000 +0100
+++ jfreechart-after-maintenance/src/main/java/org/jfree/chart/ChartPanel.java	2022-04-17 18:12:48.000000000 +0200
@@ -219,7 +219,6 @@
 import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Method;
 import java.util.EventListener;
-import java.util.Iterator;
 import java.util.List;
 import java.util.ResourceBundle;
 
@@ -1403,7 +1402,7 @@
         String result = null;
         if (this.info != null) {
             EntityCollection entities = this.info.getEntityCollection();
-            if (entities != null) {
+            if ((entities != null) && (entities.getEntityCount() > 0)) {
                 Insets insets = getInsets();
                 ChartEntity entity = entities.getEntity(
                         (int) ((e.getX() - insets.left) / this.scaleX),
@@ -1761,6 +1760,10 @@
      */
     @Override
     public void mouseEntered(MouseEvent e) {
+        mouseEnteredAction();
+    }
+
+    void mouseEnteredAction() {
         if (!this.ownToolTipDelaysActive) {
             ToolTipManager ttm = ToolTipManager.sharedInstance();
 
@@ -1786,6 +1789,10 @@
      */
     @Override
     public void mouseExited(MouseEvent e) {
+        mouseExitedAction();
+    }
+
+    void mouseExitedAction() {
         if (this.ownToolTipDelaysActive) {
             // restore original tooltip dealys
             ToolTipManager ttm = ToolTipManager.sharedInstance();
@@ -1806,23 +1813,27 @@
      */
     @Override
     public void mousePressed(MouseEvent e) {
+        mousePressedAction(e.getX(), e.getY(), e.getPoint(), e.isPopupTrigger(), e.getModifiers());
+    }
+
+    void mousePressedAction(int cursorX, int cursorY, Point cursorPoint, boolean popupTrigger, int cursorModifiers) {
         if (this.chart == null) {
             return;
         }
         Plot plot = this.chart.getPlot();
-        int mods = e.getModifiers();
+        int mods = cursorModifiers;
         if ((mods & this.panMask) == this.panMask) {
             // can we pan this plot?
             if (plot instanceof Pannable) {
                 Pannable pannable = (Pannable) plot;
                 if (pannable.isDomainPannable() || pannable.isRangePannable()) {
-                    Rectangle2D screenDataArea = getScreenDataArea(e.getX(),
-                            e.getY());
+                    Rectangle2D screenDataArea = getScreenDataArea(cursorX,
+                            cursorY);
                     if (screenDataArea != null && screenDataArea.contains(
-                            e.getPoint())) {
+                            cursorPoint)) {
                         this.panW = screenDataArea.getWidth();
                         this.panH = screenDataArea.getHeight();
-                        this.panLast = e.getPoint();
+                        this.panLast = cursorPoint;
                         setCursor(Cursor.getPredefinedCursor(
                                 Cursor.MOVE_CURSOR));
                     }
@@ -1832,17 +1843,17 @@
             }
         }
         else if (this.zoomRectangle == null) {
-            Rectangle2D screenDataArea = getScreenDataArea(e.getX(), e.getY());
+            Rectangle2D screenDataArea = getScreenDataArea(cursorX, cursorY);
             if (screenDataArea != null) {
-                this.zoomPoint = getPointInRectangle(e.getX(), e.getY(),
+                this.zoomPoint = getPointInRectangle(cursorX, cursorY,
                         screenDataArea);
             }
             else {
                 this.zoomPoint = null;
             }
-            if (e.isPopupTrigger()) {
+            if (popupTrigger) {
                 if (this.popup != null) {
-                    displayPopupMenu(e.getX(), e.getY());
+                    displayPopupMenu(cursorX, cursorY);
                 }
             }
         }
@@ -1858,7 +1869,7 @@
      *
      * @return A point within the rectangle.
      */
-    private Point2D getPointInRectangle(int x, int y, Rectangle2D area) {
+    Point2D getPointInRectangle(int x, int y, Rectangle2D area) {
         double xx = Math.max(area.getMinX(), Math.min(x, area.getMaxX()));
         double yy = Math.max(area.getMinY(), Math.min(y, area.getMaxY()));
         return new Point2D.Double(xx, yy);
@@ -1879,30 +1890,7 @@
 
         // handle panning if we have a start point
         if (this.panLast != null) {
-            double dx = e.getX() - this.panLast.getX();
-            double dy = e.getY() - this.panLast.getY();
-            if (dx == 0.0 && dy == 0.0) {
-                return;
-            }
-            double wPercent = -dx / this.panW;
-            double hPercent = dy / this.panH;
-            boolean old = this.chart.getPlot().isNotify();
-            this.chart.getPlot().setNotify(false);
-            Pannable p = (Pannable) this.chart.getPlot();
-            if (p.getOrientation() == PlotOrientation.VERTICAL) {
-                p.panDomainAxes(wPercent, this.info.getPlotInfo(),
-                        this.panLast);
-                p.panRangeAxes(hPercent, this.info.getPlotInfo(),
-                        this.panLast);
-            }
-            else {
-                p.panDomainAxes(hPercent, this.info.getPlotInfo(),
-                        this.panLast);
-                p.panRangeAxes(wPercent, this.info.getPlotInfo(),
-                        this.panLast);
-            }
-            this.panLast = e.getPoint();
-            this.chart.getPlot().setNotify(old);
+            mouseDraggedHandlePanning(e.getX(), e.getY(), e.getPoint());
             return;
         }
 
@@ -1920,6 +1908,22 @@
             drawZoomRectangle(g2, true);
         }
 
+        setZoomRectangle(e.getX(), e.getY(), this.zoomPoint);
+
+        // Draw the new zoom rectangle...
+        if (this.useBuffer) {
+            repaint();
+        }
+        else {
+            // with no buffer, we use XOR to draw the rectangle "over" the
+            // chart...
+            drawZoomRectangle(g2, true);
+        }
+        g2.dispose();
+
+    }
+
+    void setZoomRectangle(int x, int y, Point2D zoomPoint) {
         boolean hZoom, vZoom;
         if (this.orientation == PlotOrientation.HORIZONTAL) {
             hZoom = this.rangeZoomable;
@@ -1930,39 +1934,54 @@
             vZoom = this.rangeZoomable;
         }
         Rectangle2D scaledDataArea = getScreenDataArea(
-                (int) this.zoomPoint.getX(), (int) this.zoomPoint.getY());
+                (int) zoomPoint.getX(), (int) zoomPoint.getY());
         if (hZoom && vZoom) {
             // selected rectangle shouldn't extend outside the data area...
-            double xmax = Math.min(e.getX(), scaledDataArea.getMaxX());
-            double ymax = Math.min(e.getY(), scaledDataArea.getMaxY());
+            double xmax = Math.min(x, scaledDataArea.getMaxX());
+            double ymax = Math.min(y, scaledDataArea.getMaxY());
             this.zoomRectangle = new Rectangle2D.Double(
-                    this.zoomPoint.getX(), this.zoomPoint.getY(),
-                    xmax - this.zoomPoint.getX(), ymax - this.zoomPoint.getY());
+                    zoomPoint.getX(), zoomPoint.getY(),
+                    xmax - zoomPoint.getX(), ymax - zoomPoint.getY());
         }
         else if (hZoom) {
-            double xmax = Math.min(e.getX(), scaledDataArea.getMaxX());
+            double xmax = Math.min(x, scaledDataArea.getMaxX());
             this.zoomRectangle = new Rectangle2D.Double(
-                    this.zoomPoint.getX(), scaledDataArea.getMinY(),
-                    xmax - this.zoomPoint.getX(), scaledDataArea.getHeight());
+                    zoomPoint.getX(), scaledDataArea.getMinY(),
+                    xmax - zoomPoint.getX(), scaledDataArea.getHeight());
         }
         else if (vZoom) {
-            double ymax = Math.min(e.getY(), scaledDataArea.getMaxY());
+            double ymax = Math.min(y, scaledDataArea.getMaxY());
             this.zoomRectangle = new Rectangle2D.Double(
-                    scaledDataArea.getMinX(), this.zoomPoint.getY(),
-                    scaledDataArea.getWidth(), ymax - this.zoomPoint.getY());
+                    scaledDataArea.getMinX(), zoomPoint.getY(),
+                    scaledDataArea.getWidth(), ymax - zoomPoint.getY());
+        }
         }
 
-        // Draw the new zoom rectangle...
-        if (this.useBuffer) {
-            repaint();
+    void mouseDraggedHandlePanning(int x, int y, Point point) {
+        double dx = x - this.panLast.getX();
+        double dy = y - this.panLast.getY();
+        if (dx == 0.0 && dy == 0.0) {
+            return;
+        }
+        double wPercent = -dx / this.panW;
+        double hPercent = dy / this.panH;
+        boolean old = this.chart.getPlot().isNotify();
+        this.chart.getPlot().setNotify(false);
+        Pannable p = (Pannable) this.chart.getPlot();
+        if (p.getOrientation() == PlotOrientation.VERTICAL) {
+            p.panDomainAxes(wPercent, this.info.getPlotInfo(),
+                    this.panLast);
+            p.panRangeAxes(hPercent, this.info.getPlotInfo(),
+                    this.panLast);
         }
         else {
-            // with no buffer, we use XOR to draw the rectangle "over" the
-            // chart...
-            drawZoomRectangle(g2, true);
+            p.panDomainAxes(hPercent, this.info.getPlotInfo(),
+                    this.panLast);
+            p.panRangeAxes(wPercent, this.info.getPlotInfo(),
+                    this.panLast);
         }
-        g2.dispose();
-
+        this.panLast = point;
+        this.chart.getPlot().setNotify(old);
     }
 
     /**
@@ -1975,6 +1994,11 @@
     @Override
     public void mouseReleased(MouseEvent e) {
 
+        mouseReleasedAction(e.getX(), e.getY(), e.isPopupTrigger(), this.zoomPoint);
+
+    }
+
+    void mouseReleasedAction(int x, int y, boolean popupTrigger, Point2D zoomPoint) {
         // if we've been panning, we need to reset now that the mouse is 
         // released...
         if (this.panLast != null) {
@@ -1993,48 +2017,17 @@
                 vZoom = this.rangeZoomable;
             }
 
-            boolean zoomTrigger1 = hZoom && Math.abs(e.getX()
-                - this.zoomPoint.getX()) >= this.zoomTriggerDistance;
-            boolean zoomTrigger2 = vZoom && Math.abs(e.getY()
-                - this.zoomPoint.getY()) >= this.zoomTriggerDistance;
+            boolean zoomTrigger1 = hZoom && Math.abs(x
+                - zoomPoint.getX()) >= this.zoomTriggerDistance;
+            boolean zoomTrigger2 = vZoom && Math.abs(y
+                - zoomPoint.getY()) >= this.zoomTriggerDistance;
             if (zoomTrigger1 || zoomTrigger2) {
-                if ((hZoom && (e.getX() < this.zoomPoint.getX()))
-                    || (vZoom && (e.getY() < this.zoomPoint.getY()))) {
+                if ((hZoom && (x < zoomPoint.getX()))
+                    || (vZoom && (y < zoomPoint.getY()))) {
                     restoreAutoBounds();
                 }
                 else {
-                    double x, y, w, h;
-                    Rectangle2D screenDataArea = getScreenDataArea(
-                            (int) this.zoomPoint.getX(),
-                            (int) this.zoomPoint.getY());
-                    double maxX = screenDataArea.getMaxX();
-                    double maxY = screenDataArea.getMaxY();
-                    // for mouseReleased event, (horizontalZoom || verticalZoom)
-                    // will be true, so we can just test for either being false;
-                    // otherwise both are true
-                    if (!vZoom) {
-                        x = this.zoomPoint.getX();
-                        y = screenDataArea.getMinY();
-                        w = Math.min(this.zoomRectangle.getWidth(),
-                                maxX - this.zoomPoint.getX());
-                        h = screenDataArea.getHeight();
-                    }
-                    else if (!hZoom) {
-                        x = screenDataArea.getMinX();
-                        y = this.zoomPoint.getY();
-                        w = screenDataArea.getWidth();
-                        h = Math.min(this.zoomRectangle.getHeight(),
-                                maxY - this.zoomPoint.getY());
-                    }
-                    else {
-                        x = this.zoomPoint.getX();
-                        y = this.zoomPoint.getY();
-                        w = Math.min(this.zoomRectangle.getWidth(),
-                                maxX - this.zoomPoint.getX());
-                        h = Math.min(this.zoomRectangle.getHeight(),
-                                maxY - this.zoomPoint.getY());
-                    }
-                    Rectangle2D zoomArea = new Rectangle2D.Double(x, y, w, h);
+                    Rectangle2D zoomArea = getZoomArea(hZoom, vZoom, zoomPoint, this.zoomRectangle);
                     zoom(zoomArea);
                 }
                 this.zoomPoint = null;
@@ -2056,12 +2049,47 @@
 
         }
 
-        else if (e.isPopupTrigger()) {
+        else if (popupTrigger) {
             if (this.popup != null) {
-                displayPopupMenu(e.getX(), e.getY());
+                displayPopupMenu(x, y);
+            }
             }
         }
 
+    Rectangle2D getZoomArea(boolean hZoom, boolean vZoom, Point2D zoomPoint, Rectangle2D zoomRectangle) {
+        double x, y, w, h;
+        Rectangle2D screenDataArea = getScreenDataArea(
+                (int) zoomPoint.getX(),
+                (int) zoomPoint.getY());
+        double maxX = screenDataArea.getMaxX();
+        double maxY = screenDataArea.getMaxY();
+        // for mouseReleased event, (horizontalZoom || verticalZoom)
+        // will be true, so we can just test for either being false;
+        // otherwise both are true
+        if (! vZoom) {
+            x = zoomPoint.getX();
+            y = screenDataArea.getMinY();
+            w = Math.min(zoomRectangle.getWidth(),
+                    maxX - zoomPoint.getX());
+            h = screenDataArea.getHeight();
+        }
+        else if (! hZoom) {
+            x = screenDataArea.getMinX();
+            y = zoomPoint.getY();
+            w = screenDataArea.getWidth();
+            h = Math.min(zoomRectangle.getHeight(),
+                    maxY - zoomPoint.getY());
+        }
+        else {
+            x = zoomPoint.getX();
+            y = zoomPoint.getY();
+            w = Math.min(zoomRectangle.getWidth(),
+                    maxX - zoomPoint.getX());
+            h = Math.min(zoomRectangle.getHeight(),
+                    maxY - zoomPoint.getY());
+        }
+        Rectangle2D zoomArea = new Rectangle2D.Double(x, y, w, h);
+        return zoomArea;
     }
 
     /**
@@ -2685,12 +2713,7 @@
      * @throws IOException if there is an I/O error.
      */
     public void doSaveAs() throws IOException {
-        JFileChooser fileChooser = new JFileChooser();
-        fileChooser.setCurrentDirectory(this.defaultDirectoryForSaveAs);
-        FileNameExtensionFilter filter = new FileNameExtensionFilter(
-                    localizationResources.getString("PNG_Image_Files"), "png");
-        fileChooser.addChoosableFileFilter(filter);
-        fileChooser.setFileFilter(filter);
+        JFileChooser fileChooser = createFileChooser("PNG_Image_Files", "png");
 
         int option = fileChooser.showSaveDialog(this);
         if (option == JFileChooser.APPROVE_OPTION) {
@@ -2711,37 +2734,13 @@
      * if the JFreeSVG library is on the classpath...if this library is not 
      * present, the method will fail.
      */
-    private void saveAsSVG(File f) throws IOException {
+    void saveAsSVG(File f) throws IOException {
         File file = f;
         if (file == null) {
-            JFileChooser fileChooser = new JFileChooser();
-            fileChooser.setCurrentDirectory(this.defaultDirectoryForSaveAs);
-            FileNameExtensionFilter filter = new FileNameExtensionFilter(
-                    localizationResources.getString("SVG_Files"), "svg");
-            fileChooser.addChoosableFileFilter(filter);
-            fileChooser.setFileFilter(filter);
+            JFileChooser fileChooser = createFileChooser("SVG_Files", "svg");
 
             int option = fileChooser.showSaveDialog(this);
-            if (option == JFileChooser.APPROVE_OPTION) {
-                String filename = fileChooser.getSelectedFile().getPath();
-                if (isEnforceFileExtensions()) {
-                    if (!filename.endsWith(".svg")) {
-                        filename = filename + ".svg";
-                    }
-                }
-                file = new File(filename);
-                if (file.exists()) {
-                    String fileExists = localizationResources.getString(
-                            "FILE_EXISTS_CONFIRM_OVERWRITE");
-                    int response = JOptionPane.showConfirmDialog(this, 
-                            fileExists,
-                            localizationResources.getString("Save_as_SVG"),
-                            JOptionPane.OK_CANCEL_OPTION);
-                    if (response == JOptionPane.CANCEL_OPTION) {
-                        file = null;
-                    }
-                }
-            }
+            file = saveFile(option, fileChooser, ".svg", file, "Save_as_SVG");
         }
         
         if (file != null) {
@@ -2766,6 +2765,43 @@
         }
     }
     
+    File saveFile(int option, JFileChooser fileChooser, String suffix, File file, String saveAs) {
+        if (option == JFileChooser.APPROVE_OPTION) {
+            String filename = fileChooser.getSelectedFile().getPath();
+            if (isEnforceFileExtensions()) {
+                if (!filename.endsWith(suffix)) {
+                    filename = filename + suffix;
+                }
+            }
+            file = new File(filename);
+            if (file.exists()) {
+                file = dealWithExistingFile(file, JOptionPane.showConfirmDialog(this,
+                        localizationResources.getString(
+                                "FILE_EXISTS_CONFIRM_OVERWRITE"),
+                        localizationResources.getString(saveAs),
+                        JOptionPane.OK_CANCEL_OPTION));
+            }
+        }
+        return file;
+    }
+
+    File dealWithExistingFile(File file, int response) {
+        if (response == JOptionPane.CANCEL_OPTION) {
+            file = null;
+        }
+        return file;
+    }
+
+    JFileChooser createFileChooser(String description, String extension) {
+        JFileChooser fileChooser = new JFileChooser();
+        fileChooser.setCurrentDirectory(this.defaultDirectoryForSaveAs);
+        FileNameExtensionFilter filter = new FileNameExtensionFilter(
+                localizationResources.getString(description), extension);
+        fileChooser.addChoosableFileFilter(filter);
+        fileChooser.setFileFilter(filter);
+        return fileChooser;
+    }
+
     /**
      * Generates a string containing a rendering of the chart in SVG format.
      * This feature is only supported if the JFreeSVG library is included on 
@@ -2775,7 +2811,7 @@
      *     {@code null} if there is a problem with the method invocation
      *     by reflection.
      */
-    private String generateSVG(int width, int height) {
+    String generateSVG(int width, int height) {
         Graphics2D g2 = createSVGGraphics2D(width, height);
         if (g2 == null) {
             throw new IllegalStateException("JFreeSVG library is not present.");
@@ -2834,34 +2870,10 @@
     private void saveAsPDF(File f) {
         File file = f;
         if (file == null) {
-            JFileChooser fileChooser = new JFileChooser();
-            fileChooser.setCurrentDirectory(this.defaultDirectoryForSaveAs);
-            FileNameExtensionFilter filter = new FileNameExtensionFilter(
-                    localizationResources.getString("PDF_Files"), "pdf");
-            fileChooser.addChoosableFileFilter(filter);
-            fileChooser.setFileFilter(filter);
+            JFileChooser fileChooser = createFileChooser("PDF_Files", "pdf");
 
             int option = fileChooser.showSaveDialog(this);
-            if (option == JFileChooser.APPROVE_OPTION) {
-                String filename = fileChooser.getSelectedFile().getPath();
-                if (isEnforceFileExtensions()) {
-                    if (!filename.endsWith(".pdf")) {
-                        filename = filename + ".pdf";
-                    }
-                }
-                file = new File(filename);
-                if (file.exists()) {
-                    String fileExists = localizationResources.getString(
-                            "FILE_EXISTS_CONFIRM_OVERWRITE");
-                    int response = JOptionPane.showConfirmDialog(this, 
-                            fileExists,
-                            localizationResources.getString("Save_as_PDF"),
-                            JOptionPane.OK_CANCEL_OPTION);
-                    if (response == JOptionPane.CANCEL_OPTION) {
-                        file = null;
-                    }
-                }
-            }
+            file = saveFile(option, fileChooser, ".pdf", file, "Save_as_PDF");
         }
         
         if (file != null) {
@@ -3320,4 +3332,24 @@
 
     }
 
+    public boolean isOwnToolTipDelaysActive() {
+        return ownToolTipDelaysActive;
+    }
+
+    public Point getPanLast() {
+        return panLast;
+    }
+
+    public void setPanLast(Point panLast) {
+        this.panLast = panLast;
+    }
+
+    public Point2D getZoomPoint() {
+        return zoomPoint;
+    }
+
+    public Rectangle2D getZoomRectangle() {
+        return zoomRectangle;
+    }
+
 }
diff -burN jfreechart-original/src/main/java/org/jfree/chart/plot/CategoryPlot.java jfreechart-after-maintenance/src/main/java/org/jfree/chart/plot/CategoryPlot.java
--- jfreechart-original/src/main/java/org/jfree/chart/plot/CategoryPlot.java	2022-03-07 09:23:25.000000000 +0100
+++ jfreechart-after-maintenance/src/main/java/org/jfree/chart/plot/CategoryPlot.java	2022-04-17 18:12:48.000000000 +0200
@@ -219,6 +219,7 @@
 import java.util.TreeMap;
 import org.jfree.chart.JFreeChart;
 import org.jfree.chart.LegendItemCollection;
+import org.jfree.chart.LegendItemSource;
 import org.jfree.chart.annotations.Annotation;
 import org.jfree.chart.annotations.CategoryAnnotation;
 import org.jfree.chart.axis.Axis;
@@ -233,11 +234,9 @@
 import org.jfree.chart.axis.ValueTick;
 import org.jfree.chart.event.AnnotationChangeEvent;
 import org.jfree.chart.event.AnnotationChangeListener;
-import org.jfree.chart.event.ChartChangeEventType;
 import org.jfree.chart.event.PlotChangeEvent;
 import org.jfree.chart.event.RendererChangeEvent;
 import org.jfree.chart.event.RendererChangeListener;
-import org.jfree.chart.renderer.category.AbstractCategoryItemRenderer;
 import org.jfree.chart.renderer.category.CategoryItemRenderer;
 import org.jfree.chart.renderer.category.CategoryItemRendererState;
 import org.jfree.chart.ui.Layer;
@@ -262,7 +261,7 @@
  * A general plotting class that uses data from a {@link CategoryDataset} and
  * renders each data item using a {@link CategoryItemRenderer}.
  */
-public class CategoryPlot extends Plot implements ValueAxisPlot, Pannable,
+public class CategoryPlot extends CategoryXYCommon implements ValueAxisPlot, Pannable,
         Zoomable, AnnotationChangeListener, RendererChangeListener,
         Cloneable, PublicCloneable, Serializable {
 
@@ -320,29 +319,15 @@
             = ResourceBundleWrapper.getBundle(
             "org.jfree.chart.plot.LocalizationBundle");
 
-    /** The plot orientation. */
-    private PlotOrientation orientation;
-
-    /** The offset between the data area and the axes. */
-    private RectangleInsets axisOffset;
-
     /** Storage for the domain axes. */
     private Map<Integer, CategoryAxis> domainAxes;
 
-    /** Storage for the domain axis locations. */
-    private Map<Integer, AxisLocation> domainAxisLocations;
-
     /**
      * A flag that controls whether or not the shared domain axis is drawn
      * (only relevant when the plot is being used as a subplot).
      */
     private boolean drawSharedDomainAxis;
 
-    /** Storage for the range axes. */
-    private Map<Integer, ValueAxis> rangeAxes;
-
-    /** Storage for the range axis locations. */
-    private Map<Integer, AxisLocation> rangeAxisLocations;
 
     /** Storage for the datasets. */
     private Map<Integer, CategoryDataset> datasets;
@@ -417,40 +402,6 @@
      */
     private transient Paint rangeZeroBaselinePaint;
 
-    /**
-     * A flag that controls whether the grid-lines for the range axis are
-     * visible.
-     */
-    private boolean rangeGridlinesVisible;
-
-    /** The stroke used to draw the range axis grid-lines. */
-    private transient Stroke rangeGridlineStroke;
-
-    /** The paint used to draw the range axis grid-lines. */
-    private transient Paint rangeGridlinePaint;
-
-    /**
-     * A flag that controls whether or not gridlines are shown for the minor
-     * tick values on the primary range axis.
-     *
-     * @since 1.0.13
-     */
-    private boolean rangeMinorGridlinesVisible;
-
-    /**
-     * The stroke used to draw the range minor grid-lines.
-     *
-     * @since 1.0.13
-     */
-    private transient Stroke rangeMinorGridlineStroke;
-
-    /**
-     * The paint used to draw the range minor grid-lines.
-     *
-     * @since 1.0.13
-     */
-    private transient Paint rangeMinorGridlinePaint;
-
     /** The anchor value. */
     private double anchorValue;
 
@@ -515,17 +466,6 @@
      */
     private boolean rangeCrosshairLockedOnData = true;
 
-    /** A map containing lists of markers for the domain axes. */
-    private Map foregroundDomainMarkers;
-
-    /** A map containing lists of markers for the domain axes. */
-    private Map backgroundDomainMarkers;
-
-    /** A map containing lists of markers for the range axes. */
-    private Map foregroundRangeMarkers;
-
-    /** A map containing lists of markers for the range axes. */
-    private Map backgroundRangeMarkers;
 
     /**
      * A (possibly empty) list of annotations for the plot.  The list should
@@ -859,100 +799,6 @@
     }
 
     /**
-     * Returns the domain axis location for the primary domain axis.
-     *
-     * @return The location (never {@code null}).
-     *
-     * @see #getRangeAxisLocation()
-     */
-    public AxisLocation getDomainAxisLocation() {
-        return getDomainAxisLocation(0);
-    }
-
-    /**
-     * Returns the location for a domain axis.
-     *
-     * @param index  the axis index.
-     *
-     * @return The location.
-     *
-     * @see #setDomainAxisLocation(int, AxisLocation)
-     */
-    public AxisLocation getDomainAxisLocation(int index) {
-        AxisLocation result = this.domainAxisLocations.get(index);
-        if (result == null) {
-            result = AxisLocation.getOpposite(getDomainAxisLocation(0));
-        }
-        return result;
-    }
-
-    /**
-     * Sets the location of the domain axis and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @param location  the axis location ({@code null} not permitted).
-     *
-     * @see #getDomainAxisLocation()
-     * @see #setDomainAxisLocation(int, AxisLocation)
-     */
-    public void setDomainAxisLocation(AxisLocation location) {
-        // delegate...
-        setDomainAxisLocation(0, location, true);
-    }
-
-    /**
-     * Sets the location of the domain axis and, if requested, sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param location  the axis location ({@code null} not permitted).
-     * @param notify  a flag that controls whether listeners are notified.
-     */
-    public void setDomainAxisLocation(AxisLocation location, boolean notify) {
-        // delegate...
-        setDomainAxisLocation(0, location, notify);
-    }
-
-    /**
-     * Sets the location for a domain axis and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @param index  the axis index.
-     * @param location  the location.
-     *
-     * @see #getDomainAxisLocation(int)
-     * @see #setRangeAxisLocation(int, AxisLocation)
-     */
-    public void setDomainAxisLocation(int index, AxisLocation location) {
-        // delegate...
-        setDomainAxisLocation(index, location, true);
-    }
-
-    /**
-     * Sets the location for a domain axis and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @param index  the axis index.
-     * @param location  the location.
-     * @param notify  notify listeners?
-     *
-     * @since 1.0.5
-     *
-     * @see #getDomainAxisLocation(int)
-     * @see #setRangeAxisLocation(int, AxisLocation, boolean)
-     */
-    public void setDomainAxisLocation(int index, AxisLocation location,
-            boolean notify) {
-        if (index == 0 && location == null) {
-            throw new IllegalArgumentException(
-                    "Null 'location' for index 0 not permitted.");
-        }
-        this.domainAxisLocations.put(index, location);
-        if (notify) {
-            fireChangeEvent();
-        }
-    }
-
-    /**
      * Returns the domain axis edge.  This is derived from the axis location
      * and the plot orientation.
      *
@@ -1014,16 +860,6 @@
         }
     }
 
-    /**
-     * Returns the range axis for the plot.  If the range axis for this plot is
-     * null, then the method will return the parent plot's range axis (if there
-     * is a parent plot).
-     *
-     * @return The range axis (possibly {@code null}).
-     */
-    public ValueAxis getRangeAxis() {
-        return getRangeAxis(0);
-    }
 
     /**
      * Returns a range axis.
@@ -1032,6 +868,7 @@
      *
      * @return The axis ({@code null} possible).
      */
+    @Override
     public ValueAxis getRangeAxis(int index) {
         ValueAxis result = this.rangeAxes.get(index);
         if (result == null) {
@@ -1050,6 +887,7 @@
      *
      * @param axis  the axis ({@code null} permitted).
      */
+    @Override
     public void setRangeAxis(ValueAxis axis) {
         setRangeAxis(0, axis);
     }
@@ -1065,31 +903,6 @@
         setRangeAxis(index, axis, true);
     }
 
-    /**
-     * Sets a range axis and, if requested, sends a {@link PlotChangeEvent} to
-     * all registered listeners.
-     *
-     * @param index  the axis index.
-     * @param axis  the axis.
-     * @param notify  notify listeners?
-     */
-    public void setRangeAxis(int index, ValueAxis axis, boolean notify) {
-        ValueAxis existing = this.rangeAxes.get(index);
-        if (existing != null) {
-            existing.removeChangeListener(this);
-        }
-        if (axis != null) {
-            axis.setPlot(this);
-        }
-        this.rangeAxes.put(index, axis);
-        if (axis != null) {
-            axis.configure();
-            axis.addChangeListener(this);
-        }
-        if (notify) {
-            fireChangeEvent();
-        }
-    }
 
     /**
      * Sets the range axes for this plot and sends a {@link PlotChangeEvent}
@@ -1132,104 +945,6 @@
         return result;
     }
 
-    private int findRangeAxisIndex(ValueAxis axis) {
-        for (Entry<Integer, ValueAxis> entry : this.rangeAxes.entrySet()) {
-            if (entry.getValue() == axis) {
-                return entry.getKey();
-            }
-        }
-        return -1;
-    }
-    
-    /**
-     * Returns the range axis location.
-     *
-     * @return The location (never {@code null}).
-     */
-    public AxisLocation getRangeAxisLocation() {
-        return getRangeAxisLocation(0);
-    }
-
-    /**
-     * Returns the location for a range axis.
-     *
-     * @param index  the axis index.
-     *
-     * @return The location.
-     *
-     * @see #setRangeAxisLocation(int, AxisLocation)
-     */
-    public AxisLocation getRangeAxisLocation(int index) {
-        AxisLocation result = this.rangeAxisLocations.get(index);
-        if (result == null) {
-            result = AxisLocation.getOpposite(getRangeAxisLocation(0));
-        }
-        return result;
-    }
-
-    /**
-     * Sets the location of the range axis and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @param location  the location ({@code null} not permitted).
-     *
-     * @see #setRangeAxisLocation(AxisLocation, boolean)
-     * @see #setDomainAxisLocation(AxisLocation)
-     */
-    public void setRangeAxisLocation(AxisLocation location) {
-        // defer argument checking...
-        setRangeAxisLocation(location, true);
-    }
-
-    /**
-     * Sets the location of the range axis and, if requested, sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param location  the location ({@code null} not permitted).
-     * @param notify  notify listeners?
-     *
-     * @see #setDomainAxisLocation(AxisLocation, boolean)
-     */
-    public void setRangeAxisLocation(AxisLocation location, boolean notify) {
-        setRangeAxisLocation(0, location, notify);
-    }
-
-    /**
-     * Sets the location for a range axis and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @param index  the axis index.
-     * @param location  the location.
-     *
-     * @see #getRangeAxisLocation(int)
-     * @see #setRangeAxisLocation(int, AxisLocation, boolean)
-     */
-    public void setRangeAxisLocation(int index, AxisLocation location) {
-        setRangeAxisLocation(index, location, true);
-    }
-
-    /**
-     * Sets the location for a range axis and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @param index  the axis index.
-     * @param location  the location.
-     * @param notify  notify listeners?
-     *
-     * @see #getRangeAxisLocation(int)
-     * @see #setDomainAxisLocation(int, AxisLocation, boolean)
-     */
-    public void setRangeAxisLocation(int index, AxisLocation location,
-            boolean notify) {
-        if (index == 0 && location == null) {
-            throw new IllegalArgumentException(
-                    "Null 'location' for index 0 not permitted.");
-        }
-        this.rangeAxisLocations.put(index, location);
-        if (notify) {
-            fireChangeEvent();
-        }
-    }
 
     /**
      * Returns the edge where the primary range axis is located.
@@ -1252,39 +967,6 @@
         return Plot.resolveRangeAxisLocation(location, this.orientation);
     }
 
-    /**
-     * Returns the number of range axes.
-     *
-     * @return The axis count.
-     */
-    public int getRangeAxisCount() {
-        return this.rangeAxes.size();
-    }
-
-    /**
-     * Clears the range axes from the plot and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     */
-    public void clearRangeAxes() {
-        for (ValueAxis yAxis : this.rangeAxes.values()) {
-            if (yAxis != null) {
-                yAxis.removeChangeListener(this);
-            }
-        }
-        this.rangeAxes.clear();
-        fireChangeEvent();
-    }
-
-    /**
-     * Configures the range axes.
-     */
-    public void configureRangeAxes() {
-        for (ValueAxis yAxis : this.rangeAxes.values()) {
-            if (yAxis != null) {
-                yAxis.configure();
-            }
-        }
-    }
 
     /**
      * Returns the primary dataset for the plot.
@@ -1973,177 +1655,6 @@
     }
 
     /**
-     * Returns the flag that controls whether the range grid-lines are visible.
-     *
-     * @return The flag.
-     *
-     * @see #setRangeGridlinesVisible(boolean)
-     */
-    public boolean isRangeGridlinesVisible() {
-        return this.rangeGridlinesVisible;
-    }
-
-    /**
-     * Sets the flag that controls whether or not grid-lines are drawn against
-     * the range axis.  If the flag changes value, a {@link PlotChangeEvent} is
-     * sent to all registered listeners.
-     *
-     * @param visible  the new value of the flag.
-     *
-     * @see #isRangeGridlinesVisible()
-     */
-    public void setRangeGridlinesVisible(boolean visible) {
-        if (this.rangeGridlinesVisible != visible) {
-            this.rangeGridlinesVisible = visible;
-            fireChangeEvent();
-        }
-    }
-
-    /**
-     * Returns the stroke used to draw the grid-lines against the range axis.
-     *
-     * @return The stroke (never {@code null}).
-     *
-     * @see #setRangeGridlineStroke(Stroke)
-     */
-    public Stroke getRangeGridlineStroke() {
-        return this.rangeGridlineStroke;
-    }
-
-    /**
-     * Sets the stroke used to draw the grid-lines against the range axis and
-     * sends a {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param stroke  the stroke ({@code null} not permitted).
-     *
-     * @see #getRangeGridlineStroke()
-     */
-    public void setRangeGridlineStroke(Stroke stroke) {
-        Args.nullNotPermitted(stroke, "stroke");
-        this.rangeGridlineStroke = stroke;
-        fireChangeEvent();
-    }
-
-    /**
-     * Returns the paint used to draw the grid-lines against the range axis.
-     *
-     * @return The paint (never {@code null}).
-     *
-     * @see #setRangeGridlinePaint(Paint)
-     */
-    public Paint getRangeGridlinePaint() {
-        return this.rangeGridlinePaint;
-    }
-
-    /**
-     * Sets the paint used to draw the grid lines against the range axis and
-     * sends a {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param paint  the paint ({@code null} not permitted).
-     *
-     * @see #getRangeGridlinePaint()
-     */
-    public void setRangeGridlinePaint(Paint paint) {
-        Args.nullNotPermitted(paint, "paint");
-        this.rangeGridlinePaint = paint;
-        fireChangeEvent();
-    }
-
-    /**
-     * Returns {@code true} if the range axis minor grid is visible, and
-     * {@code false} otherwise.
-     *
-     * @return A boolean.
-     *
-     * @see #setRangeMinorGridlinesVisible(boolean)
-     *
-     * @since 1.0.13
-     */
-    public boolean isRangeMinorGridlinesVisible() {
-        return this.rangeMinorGridlinesVisible;
-    }
-
-    /**
-     * Sets the flag that controls whether or not the range axis minor grid
-     * lines are visible.
-     * <p>
-     * If the flag value is changed, a {@link PlotChangeEvent} is sent to all
-     * registered listeners.
-     *
-     * @param visible  the new value of the flag.
-     *
-     * @see #isRangeMinorGridlinesVisible()
-     *
-     * @since 1.0.13
-     */
-    public void setRangeMinorGridlinesVisible(boolean visible) {
-        if (this.rangeMinorGridlinesVisible != visible) {
-            this.rangeMinorGridlinesVisible = visible;
-            fireChangeEvent();
-        }
-    }
-
-    /**
-     * Returns the stroke for the minor grid lines (if any) plotted against the
-     * range axis.
-     *
-     * @return The stroke (never {@code null}).
-     *
-     * @see #setRangeMinorGridlineStroke(Stroke)
-     *
-     * @since 1.0.13
-     */
-    public Stroke getRangeMinorGridlineStroke() {
-        return this.rangeMinorGridlineStroke;
-    }
-
-    /**
-     * Sets the stroke for the minor grid lines plotted against the range axis,
-     * and sends a {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param stroke  the stroke ({@code null} not permitted).
-     *
-     * @see #getRangeMinorGridlineStroke()
-     *
-     * @since 1.0.13
-     */
-    public void setRangeMinorGridlineStroke(Stroke stroke) {
-        Args.nullNotPermitted(stroke, "stroke");
-        this.rangeMinorGridlineStroke = stroke;
-        fireChangeEvent();
-    }
-
-    /**
-     * Returns the paint for the minor grid lines (if any) plotted against the
-     * range axis.
-     *
-     * @return The paint (never {@code null}).
-     *
-     * @see #setRangeMinorGridlinePaint(Paint)
-     *
-     * @since 1.0.13
-     */
-    public Paint getRangeMinorGridlinePaint() {
-        return this.rangeMinorGridlinePaint;
-    }
-
-    /**
-     * Sets the paint for the minor grid lines plotted against the range axis
-     * and sends a {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param paint  the paint ({@code null} not permitted).
-     *
-     * @see #getRangeMinorGridlinePaint()
-     *
-     * @since 1.0.13
-     */
-    public void setRangeMinorGridlinePaint(Paint paint) {
-        Args.nullNotPermitted(paint, "paint");
-        this.rangeMinorGridlinePaint = paint;
-        fireChangeEvent();
-    }
-
-    /**
      * Returns the fixed legend items, if any.
      *
      * @return The legend items (possibly {@code null}).
@@ -2273,18 +1784,8 @@
      */
     @Override
     public void datasetChanged(DatasetChangeEvent event) {
-        for (ValueAxis yAxis : this.rangeAxes.values()) {
-            if (yAxis != null) {
-                yAxis.configure();
-            }
-        }
-        if (getParent() != null) {
-            getParent().datasetChanged(event);
-        } else {
-            PlotChangeEvent e = new PlotChangeEvent(this);
-            e.setType(ChartChangeEventType.DATASET_UPDATED);
-            notifyListeners(e);
-        }
+        configureRangeAxes();
+        dealWithEventWhenDatasetChanges(event);
 
     }
 
@@ -2361,261 +1862,6 @@
     }
 
     /**
-     * Adds a marker for display by a particular renderer and, if requested,
-     * sends a {@link PlotChangeEvent} to all registered listeners.
-     * <P>
-     * Typically a marker will be drawn by the renderer as a line perpendicular
-     * to a domain axis, however this is entirely up to the renderer.
-     *
-     * @param index  the renderer index.
-     * @param marker  the marker ({@code null} not permitted).
-     * @param layer  the layer ({@code null} not permitted).
-     * @param notify  notify listeners?
-     *
-     * @since 1.0.10
-     *
-     * @see #removeDomainMarker(int, Marker, Layer, boolean)
-     */
-    public void addDomainMarker(int index, CategoryMarker marker, Layer layer,
-            boolean notify) {
-        Args.nullNotPermitted(marker, "marker");
-        Args.nullNotPermitted(layer, "layer");
-        Collection markers;
-        if (layer == Layer.FOREGROUND) {
-            markers = (Collection) this.foregroundDomainMarkers.get(
-                    new Integer(index));
-            if (markers == null) {
-                markers = new java.util.ArrayList();
-                this.foregroundDomainMarkers.put(new Integer(index), markers);
-            }
-            markers.add(marker);
-        } else if (layer == Layer.BACKGROUND) {
-            markers = (Collection) this.backgroundDomainMarkers.get(
-                    new Integer(index));
-            if (markers == null) {
-                markers = new java.util.ArrayList();
-                this.backgroundDomainMarkers.put(new Integer(index), markers);
-            }
-            markers.add(marker);
-        }
-        marker.addChangeListener(this);
-        if (notify) {
-            fireChangeEvent();
-        }
-    }
-
-    /**
-     * Clears all the domain markers for the plot and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @see #clearRangeMarkers()
-     */
-    public void clearDomainMarkers() {
-        if (this.backgroundDomainMarkers != null) {
-            Set keys = this.backgroundDomainMarkers.keySet();
-            Iterator iterator = keys.iterator();
-            while (iterator.hasNext()) {
-                Integer key = (Integer) iterator.next();
-                clearDomainMarkers(key.intValue());
-            }
-            this.backgroundDomainMarkers.clear();
-        }
-        if (this.foregroundDomainMarkers != null) {
-            Set keys = this.foregroundDomainMarkers.keySet();
-            Iterator iterator = keys.iterator();
-            while (iterator.hasNext()) {
-                Integer key = (Integer) iterator.next();
-                clearDomainMarkers(key.intValue());
-            }
-            this.foregroundDomainMarkers.clear();
-        }
-        fireChangeEvent();
-    }
-
-    /**
-     * Returns the list of domain markers (read only) for the specified layer.
-     *
-     * @param layer  the layer (foreground or background).
-     *
-     * @return The list of domain markers.
-     */
-    public Collection getDomainMarkers(Layer layer) {
-        return getDomainMarkers(0, layer);
-    }
-
-    /**
-     * Returns a collection of domain markers for a particular renderer and
-     * layer.
-     *
-     * @param index  the renderer index.
-     * @param layer  the layer.
-     *
-     * @return A collection of markers (possibly {@code null}).
-     */
-    public Collection getDomainMarkers(int index, Layer layer) {
-        Collection result = null;
-        Integer key = new Integer(index);
-        if (layer == Layer.FOREGROUND) {
-            result = (Collection) this.foregroundDomainMarkers.get(key);
-        }
-        else if (layer == Layer.BACKGROUND) {
-            result = (Collection) this.backgroundDomainMarkers.get(key);
-        }
-        if (result != null) {
-            result = Collections.unmodifiableCollection(result);
-        }
-        return result;
-    }
-
-    /**
-     * Clears all the domain markers for the specified renderer.
-     *
-     * @param index  the renderer index.
-     *
-     * @see #clearRangeMarkers(int)
-     */
-    public void clearDomainMarkers(int index) {
-        Integer key = new Integer(index);
-        if (this.backgroundDomainMarkers != null) {
-            Collection markers
-                = (Collection) this.backgroundDomainMarkers.get(key);
-            if (markers != null) {
-                Iterator iterator = markers.iterator();
-                while (iterator.hasNext()) {
-                    Marker m = (Marker) iterator.next();
-                    m.removeChangeListener(this);
-                }
-                markers.clear();
-            }
-        }
-        if (this.foregroundDomainMarkers != null) {
-            Collection markers
-                = (Collection) this.foregroundDomainMarkers.get(key);
-            if (markers != null) {
-                Iterator iterator = markers.iterator();
-                while (iterator.hasNext()) {
-                    Marker m = (Marker) iterator.next();
-                    m.removeChangeListener(this);
-                }
-                markers.clear();
-            }
-        }
-        fireChangeEvent();
-    }
-
-    /**
-     * Removes a marker for the domain axis and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @param marker  the marker.
-     *
-     * @return A boolean indicating whether or not the marker was actually
-     *         removed.
-     *
-     * @since 1.0.7
-     */
-    public boolean removeDomainMarker(Marker marker) {
-        return removeDomainMarker(marker, Layer.FOREGROUND);
-    }
-
-    /**
-     * Removes a marker for the domain axis in the specified layer and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param marker the marker ({@code null} not permitted).
-     * @param layer the layer (foreground or background).
-     *
-     * @return A boolean indicating whether or not the marker was actually
-     *         removed.
-     *
-     * @since 1.0.7
-     */
-    public boolean removeDomainMarker(Marker marker, Layer layer) {
-        return removeDomainMarker(0, marker, layer);
-    }
-
-    /**
-     * Removes a marker for a specific dataset/renderer and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param index the dataset/renderer index.
-     * @param marker the marker.
-     * @param layer the layer (foreground or background).
-     *
-     * @return A boolean indicating whether or not the marker was actually
-     *         removed.
-     *
-     * @since 1.0.7
-     */
-    public boolean removeDomainMarker(int index, Marker marker, Layer layer) {
-        return removeDomainMarker(index, marker, layer, true);
-    }
-
-    /**
-     * Removes a marker for a specific dataset/renderer and, if requested,
-     * sends a {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param index the dataset/renderer index.
-     * @param marker the marker.
-     * @param layer the layer (foreground or background).
-     * @param notify  notify listeners?
-     *
-     * @return A boolean indicating whether or not the marker was actually
-     *         removed.
-     *
-     * @since 1.0.10
-     */
-    public boolean removeDomainMarker(int index, Marker marker, Layer layer,
-            boolean notify) {
-        ArrayList markers;
-        if (layer == Layer.FOREGROUND) {
-            markers = (ArrayList) this.foregroundDomainMarkers.get(new Integer(
-                    index));
-        } else {
-            markers = (ArrayList) this.backgroundDomainMarkers.get(new Integer(
-                    index));
-        }
-        if (markers == null) {
-            return false;
-        }
-        boolean removed = markers.remove(marker);
-        if (removed && notify) {
-            fireChangeEvent();
-        }
-        return removed;
-    }
-
-    /**
-     * Adds a marker for display (in the foreground) against the range axis and
-     * sends a {@link PlotChangeEvent} to all registered listeners. Typically a
-     * marker will be drawn by the renderer as a line perpendicular to the
-     * range axis, however this is entirely up to the renderer.
-     *
-     * @param marker  the marker ({@code null} not permitted).
-     *
-     * @see #removeRangeMarker(Marker)
-     */
-    public void addRangeMarker(Marker marker) {
-        addRangeMarker(marker, Layer.FOREGROUND);
-    }
-
-    /**
-     * Adds a marker for display against the range axis and sends a
-     * {@link PlotChangeEvent} to all registered listeners.  Typically a marker
-     * will be drawn by the renderer as a line perpendicular to the range axis,
-     * however this is entirely up to the renderer.
-     *
-     * @param marker  the marker ({@code null} not permitted).
-     * @param layer  the layer (foreground or background) ({@code null}
-     *               not permitted).
-     *
-     * @see #removeRangeMarker(Marker, Layer)
-     */
-    public void addRangeMarker(Marker marker, Layer layer) {
-        addRangeMarker(0, marker, layer);
-    }
-
-    /**
      * Adds a marker for display by a particular renderer and sends a
      * {@link PlotChangeEvent} to all registered listeners.
      * <P>
@@ -2675,34 +1921,6 @@
     }
 
     /**
-     * Clears all the range markers for the plot and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @see #clearDomainMarkers()
-     */
-    public void clearRangeMarkers() {
-        if (this.backgroundRangeMarkers != null) {
-            Set keys = this.backgroundRangeMarkers.keySet();
-            Iterator iterator = keys.iterator();
-            while (iterator.hasNext()) {
-                Integer key = (Integer) iterator.next();
-                clearRangeMarkers(key.intValue());
-            }
-            this.backgroundRangeMarkers.clear();
-        }
-        if (this.foregroundRangeMarkers != null) {
-            Set keys = this.foregroundRangeMarkers.keySet();
-            Iterator iterator = keys.iterator();
-            while (iterator.hasNext()) {
-                Integer key = (Integer) iterator.next();
-                clearRangeMarkers(key.intValue());
-            }
-            this.foregroundRangeMarkers.clear();
-        }
-        fireChangeEvent();
-    }
-
-    /**
      * Returns the list of range markers (read only) for the specified layer.
      *
      * @param layer  the layer (foreground or background).
@@ -2740,96 +1958,6 @@
     }
 
     /**
-     * Clears all the range markers for the specified renderer.
-     *
-     * @param index  the renderer index.
-     *
-     * @see #clearDomainMarkers(int)
-     */
-    public void clearRangeMarkers(int index) {
-        Integer key = new Integer(index);
-        if (this.backgroundRangeMarkers != null) {
-            Collection markers
-                = (Collection) this.backgroundRangeMarkers.get(key);
-            if (markers != null) {
-                Iterator iterator = markers.iterator();
-                while (iterator.hasNext()) {
-                    Marker m = (Marker) iterator.next();
-                    m.removeChangeListener(this);
-                }
-                markers.clear();
-            }
-        }
-        if (this.foregroundRangeMarkers != null) {
-            Collection markers
-                = (Collection) this.foregroundRangeMarkers.get(key);
-            if (markers != null) {
-                Iterator iterator = markers.iterator();
-                while (iterator.hasNext()) {
-                    Marker m = (Marker) iterator.next();
-                    m.removeChangeListener(this);
-                }
-                markers.clear();
-            }
-        }
-        fireChangeEvent();
-    }
-
-    /**
-     * Removes a marker for the range axis and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @param marker the marker.
-     *
-     * @return A boolean indicating whether or not the marker was actually
-     *         removed.
-     *
-     * @since 1.0.7
-     *
-     * @see #addRangeMarker(Marker)
-     */
-    public boolean removeRangeMarker(Marker marker) {
-        return removeRangeMarker(marker, Layer.FOREGROUND);
-    }
-
-    /**
-     * Removes a marker for the range axis in the specified layer and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param marker the marker ({@code null} not permitted).
-     * @param layer the layer (foreground or background).
-     *
-     * @return A boolean indicating whether or not the marker was actually
-     *         removed.
-     *
-     * @since 1.0.7
-     *
-     * @see #addRangeMarker(Marker, Layer)
-     */
-    public boolean removeRangeMarker(Marker marker, Layer layer) {
-        return removeRangeMarker(0, marker, layer);
-    }
-
-    /**
-     * Removes a marker for a specific dataset/renderer and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param index the dataset/renderer index.
-     * @param marker the marker.
-     * @param layer the layer (foreground or background).
-     *
-     * @return A boolean indicating whether or not the marker was actually
-     *         removed.
-     *
-     * @since 1.0.7
-     *
-     * @see #addRangeMarker(int, Marker, Layer)
-     */
-    public boolean removeRangeMarker(int index, Marker marker, Layer layer) {
-        return removeRangeMarker(index, marker, layer, true);
-    }
-
-    /**
      * Removes a marker for a specific dataset/renderer and sends a
      * {@link PlotChangeEvent} to all registered listeners.
      *
@@ -3425,13 +2553,7 @@
             }
         } else {
             // reserve space for the range axes (if any)...
-            for (ValueAxis yAxis : this.rangeAxes.values()) {
-                if (yAxis != null) {
-                    int i = findRangeAxisIndex(yAxis);
-                    RectangleEdge edge = getRangeAxisEdge(i);
-                    space = yAxis.reserveSpace(g2, this, plotArea, edge, space);
-                }
-            }
+            space = reserveSpaceForTheRangeAxes(g2, plotArea, space);
         }
         return space;
 
@@ -3511,7 +2633,7 @@
         // calculate the data area...
         AxisSpace space = calculateAxisSpace(g2, area);
         Rectangle2D dataArea = space.shrink(area, null);
-        this.axisOffset.trim(dataArea);
+        trimAxisOffset(dataArea);
         dataArea = integerise(dataArea);
         if (dataArea.isEmpty()) {
             return;
@@ -3769,7 +2891,7 @@
      *
      * @return A map containing the axis states.
      */
-    protected Map drawAxes(Graphics2D g2, Rectangle2D plotArea, 
+    protected Map<Axis, AxisState> drawAxes(Graphics2D g2, Rectangle2D plotArea,
             Rectangle2D dataArea, PlotRenderingInfo plotState) {
 
         AxisCollection axisCollection = new AxisCollection();
@@ -3782,73 +2904,7 @@
             }
         }
 
-        // add range axes to lists...
-        for (ValueAxis yAxis : this.rangeAxes.values()) {
-            if (yAxis != null) {
-                int index = findRangeAxisIndex(yAxis);
-                axisCollection.add(yAxis, getRangeAxisEdge(index));
-            }
-        }
-
-        Map axisStateMap = new HashMap();
-
-        // draw the top axes
-        double cursor = dataArea.getMinY() - this.axisOffset.calculateTopOutset(
-                dataArea.getHeight());
-        Iterator iterator = axisCollection.getAxesAtTop().iterator();
-        while (iterator.hasNext()) {
-            Axis axis = (Axis) iterator.next();
-            if (axis != null) {
-                AxisState axisState = axis.draw(g2, cursor, plotArea, dataArea,
-                        RectangleEdge.TOP, plotState);
-                cursor = axisState.getCursor();
-                axisStateMap.put(axis, axisState);
-            }
-        }
-
-        // draw the bottom axes
-        cursor = dataArea.getMaxY()
-                 + this.axisOffset.calculateBottomOutset(dataArea.getHeight());
-        iterator = axisCollection.getAxesAtBottom().iterator();
-        while (iterator.hasNext()) {
-            Axis axis = (Axis) iterator.next();
-            if (axis != null) {
-                AxisState axisState = axis.draw(g2, cursor, plotArea, dataArea,
-                        RectangleEdge.BOTTOM, plotState);
-                cursor = axisState.getCursor();
-                axisStateMap.put(axis, axisState);
-            }
-        }
-
-        // draw the left axes
-        cursor = dataArea.getMinX()
-                 - this.axisOffset.calculateLeftOutset(dataArea.getWidth());
-        iterator = axisCollection.getAxesAtLeft().iterator();
-        while (iterator.hasNext()) {
-            Axis axis = (Axis) iterator.next();
-            if (axis != null) {
-                AxisState axisState = axis.draw(g2, cursor, plotArea, dataArea,
-                        RectangleEdge.LEFT, plotState);
-                cursor = axisState.getCursor();
-                axisStateMap.put(axis, axisState);
-            }
-        }
-
-        // draw the right axes
-        cursor = dataArea.getMaxX()
-                 + this.axisOffset.calculateRightOutset(dataArea.getWidth());
-        iterator = axisCollection.getAxesAtRight().iterator();
-        while (iterator.hasNext()) {
-            Axis axis = (Axis) iterator.next();
-            if (axis != null) {
-                AxisState axisState = axis.draw(g2, cursor, plotArea, dataArea,
-                        RectangleEdge.RIGHT, plotState);
-                cursor = axisState.getCursor();
-                axisStateMap.put(axis, axisState);
-            }
-        }
-
-        return axisStateMap;
+        return extractedDraw(g2, plotArea, dataArea, plotState, axisCollection);
 
     }
 
@@ -4689,24 +3745,8 @@
     public void zoomRangeAxes(double factor, PlotRenderingInfo info,
                               Point2D source, boolean useAnchor) {
 
-        // perform the zoom on each range axis
-        for (ValueAxis rangeAxis : this.rangeAxes.values()) {
-            if (rangeAxis == null) {
-                continue;
-            }
-            if (useAnchor) {
-                // get the relevant source coordinate given the plot orientation
-                double sourceY = source.getY();
-                if (this.orientation.isHorizontal()) {
-                    sourceY = source.getX();
-                }
-                double anchorY = rangeAxis.java2DToValue(sourceY,
-                        info.getDataArea(), getRangeAxisEdge());
-                rangeAxis.resizeRange2(factor, anchorY);
-            } else {
-                rangeAxis.resizeRange(factor);
-            }
-        }
+        zoomRangeAxesWithFactor(factor, info, source, useAnchor);
+
     }
 
     /**
@@ -4720,13 +3760,10 @@
     @Override
     public void zoomRangeAxes(double lowerPercent, double upperPercent,
             PlotRenderingInfo state, Point2D source) {
-        for (ValueAxis yAxis : this.rangeAxes.values()) {
-            if (yAxis != null) {
-                yAxis.zoomRange(lowerPercent, upperPercent);
-            }
-        }
+        zoomRangeAxesDefault(lowerPercent, upperPercent);
     }
 
+
     /**
      * Returns the anchor value.
      *
diff -burN jfreechart-original/src/main/java/org/jfree/chart/plot/CategoryXYCommon.java jfreechart-after-maintenance/src/main/java/org/jfree/chart/plot/CategoryXYCommon.java
--- jfreechart-original/src/main/java/org/jfree/chart/plot/CategoryXYCommon.java	1970-01-01 01:00:00.000000000 +0100
+++ jfreechart-after-maintenance/src/main/java/org/jfree/chart/plot/CategoryXYCommon.java	2022-04-17 18:12:48.000000000 +0200
@@ -0,0 +1,1026 @@
+package org.jfree.chart.plot;
+
+import org.jfree.chart.axis.*;
+import org.jfree.chart.event.ChartChangeEventType;
+import org.jfree.chart.event.PlotChangeEvent;
+import org.jfree.chart.ui.Layer;
+import org.jfree.chart.ui.RectangleEdge;
+import org.jfree.chart.ui.RectangleInsets;
+import org.jfree.chart.util.Args;
+import org.jfree.data.general.DatasetChangeEvent;
+
+import java.awt.*;
+import java.awt.geom.Point2D;
+import java.awt.geom.Rectangle2D;
+import java.util.*;
+
+public abstract class CategoryXYCommon extends Plot {
+
+
+    /** Storage for the range axes. */
+    protected Map<Integer, ValueAxis> rangeAxes;
+
+    /** Storage for the range axis locations. */
+    protected Map<Integer, AxisLocation> rangeAxisLocations;
+
+    /** The offset between the data area and the axes. */
+    protected RectangleInsets axisOffset;
+
+    /** The plot orientation. */
+    protected PlotOrientation orientation;
+
+    /** Storage for the domain axis locations. */
+    protected Map<Integer, AxisLocation> domainAxisLocations;
+    /**
+     * The stroke used to draw the range minor grid-lines.
+     *
+     * @since 1.0.13
+     */
+    protected transient Stroke rangeMinorGridlineStroke;
+    /**
+     * The paint used to draw the range minor grid-lines.
+     *
+     * @since 1.0.13
+     */
+    protected transient Paint rangeMinorGridlinePaint;
+    /**
+     * A flag that controls whether the grid-lines for the range axis are
+     * visible.
+     */
+    protected boolean rangeGridlinesVisible;
+
+    /** A map containing lists of markers for the domain axes. */
+    protected Map foregroundDomainMarkers;
+
+    /** A map containing lists of markers for the domain axes. */
+    protected Map backgroundDomainMarkers;
+
+    /** A map containing lists of markers for the range axes. */
+    protected Map foregroundRangeMarkers;
+
+    /** A map containing lists of markers for the range axes. */
+    protected Map backgroundRangeMarkers;
+
+    /**
+     * A flag that controls whether or not gridlines are shown for the minor
+     * tick values on the primary range axis.
+     *
+     * @since 1.0.13
+     */
+    protected boolean rangeMinorGridlinesVisible;
+
+    /** The stroke used to draw the range axis grid-lines. */
+    protected transient Stroke rangeGridlineStroke;
+
+    /** The paint used to draw the range axis grid-lines. */
+    protected transient Paint rangeGridlinePaint;
+
+
+    /**
+     * Returns the range axis for the plot.  If the range axis for this plot is
+     * null, then the method will return the parent plot's range axis (if there
+     * is a parent plot).
+     *
+     * @return The range axis (possibly {@code null}).
+     */
+    public ValueAxis getRangeAxis() {
+        return getRangeAxis(0);
+    }
+
+    public abstract ValueAxis getRangeAxis(int index);
+    public abstract void setRangeAxis(ValueAxis axis);
+
+
+    /**
+     * Returns the number of range axes.
+     *
+     * @return The axis count.
+     */
+    public int getRangeAxisCount() {
+        return this.rangeAxes.size();
+    }
+
+
+    /**
+     * Clears the range axes from the plot and sends a {@link PlotChangeEvent}
+     * to all registered listeners.
+     */
+    public void clearRangeAxes() {
+        for (ValueAxis axis : this.rangeAxes.values()) {
+            if (axis != null) {
+                axis.removeChangeListener(this);
+            }
+        }
+        this.rangeAxes.clear();
+        fireChangeEvent();
+    }
+
+    /**
+     * Configures the range axes.
+     */
+    public void configureRangeAxes() {
+        for (ValueAxis axis : this.rangeAxes.values()) {
+            if (axis != null) {
+                axis.configure();
+            }
+        }
+    }
+
+
+    protected void dealWithEventWhenDatasetChanges(DatasetChangeEvent event) {
+        if (getParent() != null) {
+            getParent().datasetChanged(event);
+        } else {
+            PlotChangeEvent e = new PlotChangeEvent(this);
+            e.setType(ChartChangeEventType.DATASET_UPDATED);
+            notifyListeners(e);
+        }
+    }
+
+    /**
+     * Sets a range axis and, if requested, sends a {@link PlotChangeEvent} to
+     * all registered listeners.
+     *
+     * @param index  the axis index.
+     * @param axis  the axis.
+     * @param notify  notify listeners?
+     */
+    public void setRangeAxis(int index, ValueAxis axis, boolean notify) {
+        ValueAxis existing = this.rangeAxes.get(index);
+        if (existing != null) {
+            existing.removeChangeListener(this);
+        }
+        if (axis != null) {
+            axis.setPlot(this);
+        }
+        this.rangeAxes.put(index, axis);
+        if (axis != null) {
+            axis.configure();
+            axis.addChangeListener(this);
+        }
+        if (notify) {
+            fireChangeEvent();
+        }
+    }
+
+    /**
+     * Sets the location for a range axis and sends a {@link PlotChangeEvent}
+     * to all registered listeners.
+     *
+     * @param index  the axis index.
+     * @param location  the location.
+     *
+     * @see #getRangeAxisLocation(int)
+     * @see #setRangeAxisLocation(int, AxisLocation, boolean)
+     */
+    public void setRangeAxisLocation(int index, AxisLocation location) {
+        setRangeAxisLocation(index, location, true);
+    }
+
+    /**
+     * Sets the location for a range axis and sends a {@link PlotChangeEvent}
+     * to all registered listeners.
+     *
+     * @param index  the axis index.
+     * @param location  the location.
+     * @param notify  notify listeners?
+     *
+     * @see #getRangeAxisLocation(int)
+     * @see #setDomainAxisLocation(int, AxisLocation, boolean)
+     */
+    public void setRangeAxisLocation(int index, AxisLocation location,
+                                     boolean notify) {
+        if (index == 0 && location == null) {
+            throw new IllegalArgumentException(
+                    "Null 'location' for index 0 not permitted.");
+        }
+        this.rangeAxisLocations.put(index, location);
+        if (notify) {
+            fireChangeEvent();
+        }
+    }
+    /**
+     * Sets the location of the range axis and sends a {@link PlotChangeEvent}
+     * to all registered listeners.
+     *
+     * @param location  the location ({@code null} not permitted).
+     *
+     * @see #setRangeAxisLocation(AxisLocation, boolean)
+     * @see #setDomainAxisLocation(AxisLocation)
+     */
+    public void setRangeAxisLocation(AxisLocation location) {
+        // defer argument checking...
+        setRangeAxisLocation(location, true);
+    }
+
+    /**
+     * Sets the location of the range axis and, if requested, sends a
+     * {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @param location  the location ({@code null} not permitted).
+     * @param notify  notify listeners?
+     *
+     * @see #setDomainAxisLocation(AxisLocation, boolean)
+     */
+    public void setRangeAxisLocation(AxisLocation location, boolean notify) {
+        setRangeAxisLocation(0, location, notify);
+    }
+
+    /**
+     * Returns the location for a range axis.
+     *
+     * @param index  the axis index.
+     *
+     * @return The location.
+     *
+     * @see #setRangeAxisLocation(int, AxisLocation)
+     */
+    public AxisLocation getRangeAxisLocation(int index) {
+        AxisLocation result = this.rangeAxisLocations.get(index);
+        if (result == null) {
+            result = AxisLocation.getOpposite(getRangeAxisLocation(0));
+        }
+        return result;
+    }
+
+    protected int findRangeAxisIndex(ValueAxis axis) {
+        for (Map.Entry<Integer, ValueAxis> entry : this.rangeAxes.entrySet()) {
+            if (entry.getValue() == axis) {
+                return entry.getKey();
+            }
+        }
+        return -1;
+    }
+
+    /**
+     * Returns the range axis location.
+     *
+     * @return The location (never {@code null}).
+     */
+    public AxisLocation getRangeAxisLocation() {
+        return getRangeAxisLocation(0);
+    }
+
+
+    /**
+     * Sets the location of the domain axis and sends a {@link PlotChangeEvent}
+     * to all registered listeners.
+     *
+     * @param location  the axis location ({@code null} not permitted).
+     *
+     * @see #getDomainAxisLocation()
+     * @see #setDomainAxisLocation(int, AxisLocation)
+     */
+    public void setDomainAxisLocation(AxisLocation location) {
+        // delegate...
+        setDomainAxisLocation(0, location, true);
+    }
+
+    /**
+     * Sets the location of the domain axis and, if requested, sends a
+     * {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @param location  the axis location ({@code null} not permitted).
+     * @param notify  a flag that controls whether listeners are notified.
+     */
+    public void setDomainAxisLocation(AxisLocation location, boolean notify) {
+        // delegate...
+        setDomainAxisLocation(0, location, notify);
+    }
+
+
+    /**
+     * Sets the location for a domain axis and sends a {@link PlotChangeEvent}
+     * to all registered listeners.
+     *
+     * @param index  the axis index.
+     * @param location  the location.
+     *
+     * @see #getDomainAxisLocation(int)
+     * @see #setRangeAxisLocation(int, AxisLocation)
+     */
+    public void setDomainAxisLocation(int index, AxisLocation location) {
+        // delegate...
+        setDomainAxisLocation(index, location, true);
+    }
+
+    /**
+     * Returns the location for a domain axis.  If this hasn't been set
+     * explicitly, the method returns the location that is opposite to the
+     * primary domain axis location.
+     *
+     * @param index  the axis index (must be &gt;= 0).
+     *
+     * @return The location (never {@code null}).
+     *
+     * @see #setDomainAxisLocation(int, AxisLocation)
+     */
+    public AxisLocation getDomainAxisLocation(int index) {
+        AxisLocation result = this.domainAxisLocations.get(index);
+        if (result == null) {
+            result = AxisLocation.getOpposite(getDomainAxisLocation());
+        }
+        return result;
+    }
+
+
+    /**
+     * Returns the domain axis location for the primary domain axis.
+     *
+     * @return The location (never {@code null}).
+     *
+     * @see #getRangeAxisLocation()
+     */
+    public AxisLocation getDomainAxisLocation() {
+        return getDomainAxisLocation(0);
+    }
+
+    /**
+     * Sets the location for a domain axis and sends a {@link PlotChangeEvent}
+     * to all registered listeners.
+     *
+     * @param index  the axis index.
+     * @param location  the location.
+     * @param notify  notify listeners?
+     *
+     * @since 1.0.5
+     *
+     * @see #getDomainAxisLocation(int)
+     * @see #setRangeAxisLocation(int, AxisLocation, boolean)
+     */
+    public void setDomainAxisLocation(int index, AxisLocation location,
+                                      boolean notify) {
+        if (index == 0 && location == null) {
+            throw new IllegalArgumentException(
+                    "Null 'location' for index 0 not permitted.");
+        }
+        this.domainAxisLocations.put(index, location);
+        if (notify) {
+            fireChangeEvent();
+        }
+    }
+
+    protected AxisSpace reserveSpaceForTheRangeAxes(Graphics2D g2, Rectangle2D plotArea, AxisSpace space) {
+        for (ValueAxis yAxis : this.rangeAxes.values()) {
+            if (yAxis != null) {
+                int i = findRangeAxisIndex(yAxis);
+                RectangleEdge edge = getRangeAxisEdge(i);
+                space = yAxis.reserveSpace(g2, this, plotArea, edge, space);
+            }
+        }
+        return space;
+    }
+
+    protected abstract RectangleEdge getRangeAxisEdge(int i);
+
+
+    protected void addRangesToList(AxisCollection axisCollection) {
+        for (ValueAxis axis : this.rangeAxes.values()) {
+            if (axis != null) {
+                int index = findRangeAxisIndex(axis);
+                axisCollection.add(axis, getRangeAxisEdge(index));
+            }
+        }
+    }
+
+    protected Map<Axis, AxisState> extractedDraw(Graphics2D g2, Rectangle2D plotArea, Rectangle2D dataArea, PlotRenderingInfo plotState, AxisCollection axisCollection) {
+        // add range axes to lists...
+        addRangesToList(axisCollection);
+
+        Map<Axis, AxisState> axisStateMap = new HashMap<Axis, AxisState>();
+
+        // draw the top axes
+        Iterator iterator = axisCollection.getAxesAtTop().iterator();
+        double cursor = dataArea.getMinY() - this.axisOffset.calculateTopOutset(dataArea.getHeight());
+        drawTheAxes(iterator, cursor, g2, plotArea, dataArea, plotState, axisStateMap, RectangleEdge.TOP);
+
+        // draw the bottom axes
+        iterator = axisCollection.getAxesAtBottom().iterator();
+        cursor = dataArea.getMaxY() + this.axisOffset.calculateBottomOutset(dataArea.getHeight());
+        drawTheAxes(iterator, cursor, g2, plotArea, dataArea, plotState, axisStateMap, RectangleEdge.BOTTOM);
+
+        // draw the left axes
+        iterator = axisCollection.getAxesAtLeft().iterator();
+        cursor = dataArea.getMinX() - this.axisOffset.calculateLeftOutset(dataArea.getWidth());
+        drawTheAxes(iterator, cursor, g2, plotArea, dataArea, plotState, axisStateMap, RectangleEdge.LEFT);
+
+        // draw the right axes
+        iterator = axisCollection.getAxesAtRight().iterator();
+        cursor = dataArea.getMaxX() + this.axisOffset.calculateRightOutset(dataArea.getWidth());
+        drawTheAxes(iterator, cursor, g2, plotArea, dataArea, plotState, axisStateMap, RectangleEdge.RIGHT);
+
+        return axisStateMap;
+    }
+
+
+    private void drawTheAxes(Iterator iterator, double cursor, Graphics2D g2, Rectangle2D plotArea, Rectangle2D dataArea, PlotRenderingInfo plotState, Map<Axis, AxisState> axisStateMap, RectangleEdge rectangleEdge) {
+        while (iterator.hasNext()) {
+            Axis axis = (Axis) iterator.next();
+            if (axis != null) {
+                AxisState axisState = axis.draw(g2, cursor, plotArea, dataArea,
+                        rectangleEdge, plotState);
+                cursor = axisState.getCursor();
+                axisStateMap.put(axis, axisState);
+            }
+        }
+    }
+
+    protected void trimAxisOffset(Rectangle2D dataArea) {
+        this.axisOffset.trim(dataArea);
+    }
+
+    protected void zoomRangeAxesWithFactor(double factor, PlotRenderingInfo info, Point2D source, boolean useAnchor) {
+        // perform the zoom on each range axis
+        for (ValueAxis rangeAxis : this.rangeAxes.values()) {
+            if (rangeAxis == null) {
+                continue;
+            }
+            if (useAnchor) {
+                // get the relevant source coordinate given the plot orientation
+                double sourceY = source.getY();
+                if (this.orientation.isHorizontal()) {
+                    sourceY = source.getX();
+                }
+                double anchorY = rangeAxis.java2DToValue(sourceY,
+                        info.getDataArea(), getRangeAxisEdge());
+                rangeAxis.resizeRange2(factor, anchorY);
+            } else {
+                rangeAxis.resizeRange(factor);
+            }
+        }
+    }
+
+    protected abstract RectangleEdge getRangeAxisEdge();
+
+    protected void zoomRangeAxesDefault(double lowerPercent, double upperPercent) {
+        for (ValueAxis yAxis : this.rangeAxes.values()) {
+            if (yAxis != null) {
+                yAxis.zoomRange(lowerPercent, upperPercent);
+            }
+        }
+    }
+
+    /**
+     * Returns the stroke used to draw the grid-lines against the range axis.
+     *
+     * @return The stroke (never {@code null}).
+     *
+     * @see #setRangeGridlineStroke(Stroke)
+     */
+    public Stroke getRangeGridlineStroke() {
+        return this.rangeGridlineStroke;
+    }
+
+    /**
+     * Sets the stroke used to draw the grid-lines against the range axis and
+     * sends a {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @param stroke  the stroke ({@code null} not permitted).
+     *
+     * @see #getRangeGridlineStroke()
+     */
+    public void setRangeGridlineStroke(Stroke stroke) {
+        Args.nullNotPermitted(stroke, "stroke");
+        this.rangeGridlineStroke = stroke;
+        fireChangeEvent();
+    }
+
+    /**
+     * Returns the paint used to draw the grid-lines against the range axis.
+     *
+     * @return The paint (never {@code null}).
+     *
+     * @see #setRangeGridlinePaint(Paint)
+     */
+    public Paint getRangeGridlinePaint() {
+        return this.rangeGridlinePaint;
+    }
+
+    /**
+     * Sets the paint used to draw the grid lines against the range axis and
+     * sends a {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @param paint  the paint ({@code null} not permitted).
+     *
+     * @see #getRangeGridlinePaint()
+     */
+    public void setRangeGridlinePaint(Paint paint) {
+        Args.nullNotPermitted(paint, "paint");
+        this.rangeGridlinePaint = paint;
+        fireChangeEvent();
+    }
+
+    /**
+     * Returns {@code true} if the range axis minor grid is visible, and
+     * {@code false} otherwise.
+     *
+     * @return A boolean.
+     *
+     * @see #setRangeMinorGridlinesVisible(boolean)
+     *
+     * @since 1.0.13
+     */
+    public boolean isRangeMinorGridlinesVisible() {
+        return this.rangeMinorGridlinesVisible;
+    }
+
+    /**
+     * Sets the flag that controls whether or not the range axis minor grid
+     * lines are visible.
+     * <p>
+     * If the flag value is changed, a {@link PlotChangeEvent} is sent to all
+     * registered listeners.
+     *
+     * @param visible  the new value of the flag.
+     *
+     * @see #isRangeMinorGridlinesVisible()
+     *
+     * @since 1.0.13
+     */
+    public void setRangeMinorGridlinesVisible(boolean visible) {
+        if (this.rangeMinorGridlinesVisible != visible) {
+            this.rangeMinorGridlinesVisible = visible;
+            fireChangeEvent();
+        }
+    }
+
+    /**
+     * Returns the stroke for the minor grid lines (if any) plotted against the
+     * range axis.
+     *
+     * @return The stroke (never {@code null}).
+     *
+     * @see #setRangeMinorGridlineStroke(Stroke)
+     *
+     * @since 1.0.13
+     */
+    public Stroke getRangeMinorGridlineStroke() {
+        return this.rangeMinorGridlineStroke;
+    }
+
+    /**
+     * Sets the stroke for the minor grid lines plotted against the range axis,
+     * and sends a {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @param stroke  the stroke ({@code null} not permitted).
+     *
+     * @see #getRangeMinorGridlineStroke()
+     *
+     * @since 1.0.13
+     */
+    public void setRangeMinorGridlineStroke(Stroke stroke) {
+        Args.nullNotPermitted(stroke, "stroke");
+        this.rangeMinorGridlineStroke = stroke;
+        fireChangeEvent();
+    }
+
+    /**
+     * Returns the paint for the minor grid lines (if any) plotted against the
+     * range axis.
+     *
+     * @return The paint (never {@code null}).
+     *
+     * @see #setRangeMinorGridlinePaint(Paint)
+     *
+     * @since 1.0.13
+     */
+    public Paint getRangeMinorGridlinePaint() {
+        return this.rangeMinorGridlinePaint;
+    }
+
+    /**
+     * Sets the paint for the minor grid lines plotted against the range axis
+     * and sends a {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @param paint  the paint ({@code null} not permitted).
+     *
+     * @see #getRangeMinorGridlinePaint()
+     *
+     * @since 1.0.13
+     */
+    public void setRangeMinorGridlinePaint(Paint paint) {
+        Args.nullNotPermitted(paint, "paint");
+        this.rangeMinorGridlinePaint = paint;
+        fireChangeEvent();
+    }
+
+
+    /**
+     * Clears all the domain markers for the plot and sends a
+     * {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @see #clearRangeMarkers()
+     */
+    public void clearDomainMarkers() {
+        if (this.backgroundDomainMarkers != null) {
+            Set keys = this.backgroundDomainMarkers.keySet();
+            Iterator iterator = keys.iterator();
+            while (iterator.hasNext()) {
+                Integer key = (Integer) iterator.next();
+                clearDomainMarkers(key.intValue());
+            }
+            this.backgroundDomainMarkers.clear();
+        }
+        if (this.foregroundDomainMarkers != null) {
+            Set keys = this.foregroundDomainMarkers.keySet();
+            Iterator iterator = keys.iterator();
+            while (iterator.hasNext()) {
+                Integer key = (Integer) iterator.next();
+                clearDomainMarkers(key.intValue());
+            }
+            this.foregroundDomainMarkers.clear();
+        }
+        fireChangeEvent();
+    }
+    /**
+     * Clears all the domain markers for the specified renderer.
+     *
+     * @param index  the renderer index.
+     *
+     * @see #clearRangeMarkers(int)
+     */
+    public void clearDomainMarkers(int index) {
+        Integer key = new Integer(index);
+        if (this.backgroundDomainMarkers != null) {
+            Collection markers
+                    = (Collection) this.backgroundDomainMarkers.get(key);
+            if (markers != null) {
+                Iterator iterator = markers.iterator();
+                while (iterator.hasNext()) {
+                    Marker m = (Marker) iterator.next();
+                    m.removeChangeListener(this);
+                }
+                markers.clear();
+            }
+        }
+        if (this.foregroundDomainMarkers != null) {
+            Collection markers
+                    = (Collection) this.foregroundDomainMarkers.get(key);
+            if (markers != null) {
+                Iterator iterator = markers.iterator();
+                while (iterator.hasNext()) {
+                    Marker m = (Marker) iterator.next();
+                    m.removeChangeListener(this);
+                }
+                markers.clear();
+            }
+        }
+        fireChangeEvent();
+    }
+
+    /**
+     * Adds a marker for display by a particular renderer and, if requested,
+     * sends a {@link PlotChangeEvent} to all registered listeners.
+     * <P>
+     * Typically a marker will be drawn by the renderer as a line perpendicular
+     * to a domain axis, however this is entirely up to the renderer.
+     *
+     * @param index  the renderer index.
+     * @param marker  the marker ({@code null} not permitted).
+     * @param layer  the layer ({@code null} not permitted).
+     * @param notify  notify listeners?
+     *
+     * @since 1.0.10
+     *
+     * @see #removeDomainMarker(int, Marker, Layer, boolean)
+     */
+    public void addDomainMarker(int index, CategoryMarker marker, Layer layer,
+                                boolean notify) {
+        Args.nullNotPermitted(marker, "marker");
+        Args.nullNotPermitted(layer, "layer");
+        Collection markers;
+        if (layer == Layer.FOREGROUND) {
+            markers = (Collection) this.foregroundDomainMarkers.get(
+                    new Integer(index));
+            if (markers == null) {
+                markers = new java.util.ArrayList();
+                this.foregroundDomainMarkers.put(new Integer(index), markers);
+            }
+            markers.add(marker);
+        } else if (layer == Layer.BACKGROUND) {
+            markers = (Collection) this.backgroundDomainMarkers.get(
+                    new Integer(index));
+            if (markers == null) {
+                markers = new java.util.ArrayList();
+                this.backgroundDomainMarkers.put(new Integer(index), markers);
+            }
+            markers.add(marker);
+        }
+        marker.addChangeListener(this);
+        if (notify) {
+            fireChangeEvent();
+        }
+    }
+
+
+    /**
+     * Returns the list of domain markers (read only) for the specified layer.
+     *
+     * @param layer  the layer (foreground or background).
+     *
+     * @return The list of domain markers.
+     */
+    public Collection getDomainMarkers(Layer layer) {
+        return getDomainMarkers(0, layer);
+    }
+
+    /**
+     * Returns a collection of domain markers for a particular renderer and
+     * layer.
+     *
+     * @param index  the renderer index.
+     * @param layer  the layer.
+     *
+     * @return A collection of markers (possibly {@code null}).
+     */
+    public Collection getDomainMarkers(int index, Layer layer) {
+        Collection result = null;
+        Integer key = new Integer(index);
+        if (layer == Layer.FOREGROUND) {
+            result = (Collection) this.foregroundDomainMarkers.get(key);
+        }
+        else if (layer == Layer.BACKGROUND) {
+            result = (Collection) this.backgroundDomainMarkers.get(key);
+        }
+        if (result != null) {
+            result = Collections.unmodifiableCollection(result);
+        }
+        return result;
+    }
+
+    /**
+     * Removes a marker for the domain axis and sends a {@link PlotChangeEvent}
+     * to all registered listeners.
+     *
+     * @param marker  the marker.
+     *
+     * @return A boolean indicating whether or not the marker was actually
+     *         removed.
+     *
+     * @since 1.0.7
+     */
+    public boolean removeDomainMarker(Marker marker) {
+        return removeDomainMarker(marker, Layer.FOREGROUND);
+    }
+
+    /**
+     * Removes a marker for the domain axis in the specified layer and sends a
+     * {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @param marker the marker ({@code null} not permitted).
+     * @param layer the layer (foreground or background).
+     *
+     * @return A boolean indicating whether or not the marker was actually
+     *         removed.
+     *
+     * @since 1.0.7
+     */
+    public boolean removeDomainMarker(Marker marker, Layer layer) {
+        return removeDomainMarker(0, marker, layer);
+    }
+
+    /**
+     * Removes a marker for a specific dataset/renderer and sends a
+     * {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @param index the dataset/renderer index.
+     * @param marker the marker.
+     * @param layer the layer (foreground or background).
+     *
+     * @return A boolean indicating whether or not the marker was actually
+     *         removed.
+     *
+     * @since 1.0.7
+     */
+    public boolean removeDomainMarker(int index, Marker marker, Layer layer) {
+        return removeDomainMarker(index, marker, layer, true);
+    }
+
+    /**
+     * Removes a marker for a specific dataset/renderer and, if requested,
+     * sends a {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @param index the dataset/renderer index.
+     * @param marker the marker.
+     * @param layer the layer (foreground or background).
+     * @param notify  notify listeners?
+     *
+     * @return A boolean indicating whether or not the marker was actually
+     *         removed.
+     *
+     * @since 1.0.10
+     */
+    public boolean removeDomainMarker(int index, Marker marker, Layer layer,
+                                      boolean notify) {
+        ArrayList markers;
+        if (layer == Layer.FOREGROUND) {
+            markers = (ArrayList) this.foregroundDomainMarkers.get(new Integer(
+                    index));
+        } else {
+            markers = (ArrayList) this.backgroundDomainMarkers.get(new Integer(
+                    index));
+        }
+        if (markers == null) {
+            return false;
+        }
+        boolean removed = markers.remove(marker);
+        if (removed && notify) {
+            fireChangeEvent();
+        }
+        return removed;
+    }
+
+    /**
+     * Adds a marker for display (in the foreground) against the range axis and
+     * sends a {@link PlotChangeEvent} to all registered listeners. Typically a
+     * marker will be drawn by the renderer as a line perpendicular to the
+     * range axis, however this is entirely up to the renderer.
+     *
+     * @param marker  the marker ({@code null} not permitted).
+     *
+     * @see #removeRangeMarker(Marker)
+     */
+    public void addRangeMarker(Marker marker) {
+        addRangeMarker(marker, Layer.FOREGROUND);
+    }
+
+    /**
+     * Adds a marker for display against the range axis and sends a
+     * {@link PlotChangeEvent} to all registered listeners.  Typically a marker
+     * will be drawn by the renderer as a line perpendicular to the range axis,
+     * however this is entirely up to the renderer.
+     *
+     * @param marker  the marker ({@code null} not permitted).
+     * @param layer  the layer (foreground or background) ({@code null}
+     *               not permitted).
+     *
+     * @see #removeRangeMarker(Marker, Layer)
+     */
+    public void addRangeMarker(Marker marker, Layer layer) {
+        addRangeMarker(0, marker, layer);
+    }
+
+    /**
+     * Adds a marker for a specific dataset/renderer and sends a
+     * {@link PlotChangeEvent} to all registered listeners.
+     * <P>
+     * Typically a marker will be drawn by the renderer as a line perpendicular
+     * to the range axis, however this is entirely up to the renderer.
+     *
+     * @param index  the dataset/renderer index.
+     * @param marker  the marker.
+     * @param layer  the layer (foreground or background).
+     *
+     * @see #clearRangeMarkers(int)
+     * @see #addDomainMarker(int, Marker, Layer)
+     */
+    public void addRangeMarker(int index, Marker marker, Layer layer) {
+        addRangeMarker(index, marker, layer, true);
+    }
+
+    protected abstract void addRangeMarker(int index, Marker marker, Layer layer, boolean notify);
+
+    /**
+     * Clears all the range markers and sends a {@link PlotChangeEvent} to all
+     * registered listeners.
+     *
+     * @see #clearRangeMarkers()
+     */
+    public void clearRangeMarkers() {
+        if (this.backgroundRangeMarkers != null) {
+            Set<Integer> keys = this.backgroundRangeMarkers.keySet();
+            for (Integer key : keys) {
+                clearRangeMarkers(key);
+            }
+            this.backgroundRangeMarkers.clear();
+        }
+        if (this.foregroundRangeMarkers != null) {
+            Set<Integer> keys = this.foregroundRangeMarkers.keySet();
+            for (Integer key : keys) {
+                clearRangeMarkers(key);
+            }
+            this.foregroundRangeMarkers.clear();
+        }
+        fireChangeEvent();
+    }
+
+    /**
+     * Clears all the range markers for the specified renderer.
+     *
+     * @param index  the renderer index.
+     *
+     * @see #clearDomainMarkers(int)
+     */
+    public void clearRangeMarkers(int index) {
+        Integer key = new Integer(index);
+        if (this.backgroundRangeMarkers != null) {
+            Collection markers
+                    = (Collection) this.backgroundRangeMarkers.get(key);
+            if (markers != null) {
+                Iterator iterator = markers.iterator();
+                while (iterator.hasNext()) {
+                    Marker m = (Marker) iterator.next();
+                    m.removeChangeListener(this);
+                }
+                markers.clear();
+            }
+        }
+        if (this.foregroundRangeMarkers != null) {
+            Collection markers
+                    = (Collection) this.foregroundRangeMarkers.get(key);
+            if (markers != null) {
+                Iterator iterator = markers.iterator();
+                while (iterator.hasNext()) {
+                    Marker m = (Marker) iterator.next();
+                    m.removeChangeListener(this);
+                }
+                markers.clear();
+            }
+        }
+        fireChangeEvent();
+    }
+
+    /**
+     * Removes a marker for the range axis and sends a {@link PlotChangeEvent}
+     * to all registered listeners.
+     *
+     * @param marker the marker.
+     *
+     * @return A boolean indicating whether or not the marker was actually
+     *         removed.
+     *
+     * @since 1.0.7
+     *
+     * @see #addRangeMarker(Marker)
+     */
+    public boolean removeRangeMarker(Marker marker) {
+        return removeRangeMarker(marker, Layer.FOREGROUND);
+    }
+
+    /**
+     * Removes a marker for the range axis in the specified layer and sends a
+     * {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @param marker the marker ({@code null} not permitted).
+     * @param layer the layer (foreground or background).
+     *
+     * @return A boolean indicating whether or not the marker was actually
+     *         removed.
+     *
+     * @since 1.0.7
+     *
+     * @see #addRangeMarker(Marker, Layer)
+     */
+    public boolean removeRangeMarker(Marker marker, Layer layer) {
+        return removeRangeMarker(0, marker, layer);
+    }
+
+    /**
+     * Removes a marker for a specific dataset/renderer and sends a
+     * {@link PlotChangeEvent} to all registered listeners.
+     *
+     * @param index the dataset/renderer index.
+     * @param marker the marker.
+     * @param layer the layer (foreground or background).
+     *
+     * @return A boolean indicating whether or not the marker was actually
+     *         removed.
+     *
+     * @since 1.0.7
+     *
+     * @see #addRangeMarker(int, Marker, Layer)
+     */
+    public boolean removeRangeMarker(int index, Marker marker, Layer layer) {
+        return removeRangeMarker(index, marker, layer, true);
+    }
+
+    protected abstract boolean removeRangeMarker(int index, Marker marker, Layer layer, boolean notify);
+
+    /**
+     * Returns {@code true} if the range axis grid is visible, and
+     * {@code false} otherwise.
+     *
+     * @return A boolean.
+     *
+     * @see #setRangeGridlinesVisible(boolean)
+     */
+    public boolean isRangeGridlinesVisible() {
+        return this.rangeGridlinesVisible;
+    }
+
+    /**
+     * Sets the flag that controls whether or not grid-lines are drawn against
+     * the range axis.  If the flag changes value, a {@link PlotChangeEvent} is
+     * sent to all registered listeners.
+     *
+     * @param visible  the new value of the flag.
+     *
+     * @see #isRangeGridlinesVisible()
+     */
+    public void setRangeGridlinesVisible(boolean visible) {
+        if (this.rangeGridlinesVisible != visible) {
+            this.rangeGridlinesVisible = visible;
+            fireChangeEvent();
+        }
+    }
+}
diff -burN jfreechart-original/src/main/java/org/jfree/chart/plot/XYPlot.java jfreechart-after-maintenance/src/main/java/org/jfree/chart/plot/XYPlot.java
--- jfreechart-original/src/main/java/org/jfree/chart/plot/XYPlot.java	2022-03-07 09:23:25.000000000 +0100
+++ jfreechart-after-maintenance/src/main/java/org/jfree/chart/plot/XYPlot.java	2022-04-17 18:12:48.000000000 +0200
@@ -281,7 +281,6 @@
 import org.jfree.chart.axis.ValueAxis;
 import org.jfree.chart.axis.ValueTick;
 import org.jfree.chart.event.AnnotationChangeEvent;
-import org.jfree.chart.event.ChartChangeEventType;
 import org.jfree.chart.event.PlotChangeEvent;
 import org.jfree.chart.event.RendererChangeEvent;
 import org.jfree.chart.event.RendererChangeListener;
@@ -316,7 +315,7 @@
  * The {@link org.jfree.chart.ChartFactory} class contains static methods for
  * creating pre-configured charts.
  */
-public class XYPlot extends Plot implements ValueAxisPlot, Pannable, Zoomable,
+public class XYPlot extends CategoryXYCommon implements ValueAxisPlot, Pannable, Zoomable,
         RendererChangeListener, Cloneable, PublicCloneable, Serializable {
 
     /** For serialization. */
@@ -345,24 +344,9 @@
             = ResourceBundleWrapper.getBundle(
                     "org.jfree.chart.plot.LocalizationBundle");
 
-    /** The plot orientation. */
-    private PlotOrientation orientation;
-
-    /** The offset between the data area and the axes. */
-    private RectangleInsets axisOffset;
-
     /** The domain axis / axes (used for the x-values). */
     private Map<Integer, ValueAxis> domainAxes;
 
-    /** The domain axis locations. */
-    private Map<Integer, AxisLocation> domainAxisLocations;
-
-    /** The range axis (used for the y-values). */
-    private Map<Integer, ValueAxis> rangeAxes;
-
-    /** The range axis location. */
-    private Map<Integer, AxisLocation> rangeAxisLocations;
-
     /** Storage for the datasets. */
     private Map<Integer, XYDataset> datasets;
 
@@ -405,15 +389,6 @@
     /** The paint used to draw the domain grid-lines. */
     private transient Paint domainGridlinePaint;
 
-    /** A flag that controls whether the range grid-lines are visible. */
-    private boolean rangeGridlinesVisible;
-
-    /** The stroke used to draw the range grid-lines. */
-    private transient Stroke rangeGridlineStroke;
-
-    /** The paint used to draw the range grid-lines. */
-    private transient Paint rangeGridlinePaint;
-
     /**
      * A flag that controls whether the domain minor grid-lines are visible.
      *
@@ -436,27 +411,6 @@
     private transient Paint domainMinorGridlinePaint;
 
     /**
-     * A flag that controls whether the range minor grid-lines are visible.
-     *
-     * @since 1.0.12
-     */
-    private boolean rangeMinorGridlinesVisible;
-
-    /**
-     * The stroke used to draw the range minor grid-lines.
-     *
-     * @since 1.0.12
-     */
-    private transient Stroke rangeMinorGridlineStroke;
-
-    /**
-     * The paint used to draw the range minor grid-lines.
-     *
-     * @since 1.0.12
-     */
-    private transient Paint rangeMinorGridlinePaint;
-
-    /**
      * A flag that controls whether or not the zero baseline against the domain
      * axis is visible.
      *
@@ -526,18 +480,6 @@
      */
     private boolean rangeCrosshairLockedOnData = true;
 
-    /** A map of lists of foreground markers (optional) for the domain axes. */
-    private Map foregroundDomainMarkers;
-
-    /** A map of lists of background markers (optional) for the domain axes. */
-    private Map backgroundDomainMarkers;
-
-    /** A map of lists of foreground markers (optional) for the range axes. */
-    private Map foregroundRangeMarkers;
-
-    /** A map of lists of background markers (optional) for the range axes. */
-    private Map backgroundRangeMarkers;
-
     /**
      * A (possibly empty) list of annotations for the plot.  The list should
      * be initialised in the constructor and never allowed to be
@@ -887,44 +829,6 @@
     }
 
     /**
-     * Returns the location of the primary domain axis.
-     *
-     * @return The location (never {@code null}).
-     *
-     * @see #setDomainAxisLocation(AxisLocation)
-     */
-    public AxisLocation getDomainAxisLocation() {
-        return (AxisLocation) this.domainAxisLocations.get(0);
-    }
-
-    /**
-     * Sets the location of the primary domain axis and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param location  the location ({@code null} not permitted).
-     *
-     * @see #getDomainAxisLocation()
-     */
-    public void setDomainAxisLocation(AxisLocation location) {
-        // delegate...
-        setDomainAxisLocation(0, location, true);
-    }
-
-    /**
-     * Sets the location of the domain axis and, if requested, sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param location  the location ({@code null} not permitted).
-     * @param notify  notify listeners?
-     *
-     * @see #getDomainAxisLocation()
-     */
-    public void setDomainAxisLocation(AxisLocation location, boolean notify) {
-        // delegate...
-        setDomainAxisLocation(0, location, notify);
-    }
-
-    /**
      * Returns the edge for the primary domain axis (taking into account the
      * plot's orientation).
      *
@@ -977,66 +881,6 @@
     }
 
     /**
-     * Returns the location for a domain axis.  If this hasn't been set
-     * explicitly, the method returns the location that is opposite to the
-     * primary domain axis location.
-     *
-     * @param index  the axis index (must be &gt;= 0).
-     *
-     * @return The location (never {@code null}).
-     *
-     * @see #setDomainAxisLocation(int, AxisLocation)
-     */
-    public AxisLocation getDomainAxisLocation(int index) {
-        AxisLocation result = this.domainAxisLocations.get(index);
-        if (result == null) {
-            result = AxisLocation.getOpposite(getDomainAxisLocation());
-        }
-        return result;
-    }
-
-    /**
-     * Sets the location for a domain axis and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @param index  the axis index.
-     * @param location  the location ({@code null} not permitted for index
-     *     0).
-     *
-     * @see #getDomainAxisLocation(int)
-     */
-    public void setDomainAxisLocation(int index, AxisLocation location) {
-        // delegate...
-        setDomainAxisLocation(index, location, true);
-    }
-
-    /**
-     * Sets the axis location for a domain axis and, if requested, sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param index  the axis index (must be &gt;= 0).
-     * @param location  the location ({@code null} not permitted for
-     *     index 0).
-     * @param notify  notify listeners?
-     *
-     * @since 1.0.5
-     *
-     * @see #getDomainAxisLocation(int)
-     * @see #setRangeAxisLocation(int, AxisLocation, boolean)
-     */
-    public void setDomainAxisLocation(int index, AxisLocation location,
-            boolean notify) {
-        if (index == 0 && location == null) {
-            throw new IllegalArgumentException(
-                    "Null 'location' for index 0 not permitted.");
-        }
-        this.domainAxisLocations.put(index, location);
-        if (notify) {
-            fireChangeEvent();
-        }
-    }
-
-    /**
      * Returns the edge for a domain axis.
      *
      * @param index  the axis index.
@@ -1073,6 +917,7 @@
      * @see #getRangeAxis()
      * @see #setRangeAxis(int, ValueAxis)
      */
+    @Override
     public void setRangeAxis(ValueAxis axis)  {
         if (axis != null) {
             axis.setPlot(this);
@@ -1091,43 +936,17 @@
     }
 
     /**
-     * Returns the location of the primary range axis.
+     * Returns the location for a range axis.
      *
-     * @return The location (never {@code null}).
-     *
-     * @see #setRangeAxisLocation(AxisLocation)
-     */
-    public AxisLocation getRangeAxisLocation() {
-        return (AxisLocation) this.rangeAxisLocations.get(0);
-    }
-
-    /**
-     * Sets the location of the primary range axis and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param location  the location ({@code null} not permitted).
-     *
-     * @see #getRangeAxisLocation()
-     */
-    public void setRangeAxisLocation(AxisLocation location) {
-        // delegate...
-        setRangeAxisLocation(0, location, true);
-    }
-
-    /**
-     * Sets the location of the primary range axis and, if requested, sends a
-     * {@link PlotChangeEvent} to all registered listeners.
+     * @param index  the axis index.
      *
-     * @param location  the location ({@code null} not permitted).
-     * @param notify  notify listeners?
+     * @return The location.
      *
-     * @see #getRangeAxisLocation()
+     * @see #setRangeAxisLocation(int, AxisLocation)
      */
-    public void setRangeAxisLocation(AxisLocation location, boolean notify) {
-        // delegate...
-        setRangeAxisLocation(0, location, notify);
+    public AxisLocation getRangeAxisLocation(int index) {
+        return this.rangeAxisLocations.get(0);
     }
-
     /**
      * Returns the edge for the primary range axis.
      *
@@ -1151,6 +970,7 @@
      *
      * @see #setRangeAxis(int, ValueAxis)
      */
+    @Override
     public ValueAxis getRangeAxis(int index) {
         ValueAxis result = this.rangeAxes.get(index);
         if (result == null) {
@@ -1220,105 +1040,6 @@
     }
 
     /**
-     * Returns the number of range axes.
-     *
-     * @return The axis count.
-     *
-     * @see #getDomainAxisCount()
-     */
-    public int getRangeAxisCount() {
-        return this.rangeAxes.size();
-    }
-
-    /**
-     * Clears the range axes from the plot and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @see #clearDomainAxes()
-     */
-    public void clearRangeAxes() {
-        for (ValueAxis axis: this.rangeAxes.values()) {
-            if (axis != null) {
-                axis.removeChangeListener(this);
-            }
-        }
-        this.rangeAxes.clear();
-        fireChangeEvent();
-    }
-
-    /**
-     * Configures the range axes.
-     *
-     * @see #configureDomainAxes()
-     */
-    public void configureRangeAxes() {
-        for (ValueAxis axis: this.rangeAxes.values()) {
-            if (axis != null) {
-                axis.configure();
-            }
-        }
-    }
-
-    /**
-     * Returns the location for a range axis.  If this hasn't been set
-     * explicitly, the method returns the location that is opposite to the
-     * primary range axis location.
-     *
-     * @param index  the axis index (must be &gt;= 0).
-     *
-     * @return The location (never {@code null}).
-     *
-     * @see #setRangeAxisLocation(int, AxisLocation)
-     */
-    public AxisLocation getRangeAxisLocation(int index) {
-        AxisLocation result = this.rangeAxisLocations.get(index);
-        if (result == null) {
-            result = AxisLocation.getOpposite(getRangeAxisLocation());
-        }
-        return result;
-    }
-
-    /**
-     * Sets the location for a range axis and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @param index  the axis index.
-     * @param location  the location ({@code null} permitted).
-     *
-     * @see #getRangeAxisLocation(int)
-     */
-    public void setRangeAxisLocation(int index, AxisLocation location) {
-        // delegate...
-        setRangeAxisLocation(index, location, true);
-    }
-
-    /**
-     * Sets the axis location for a domain axis and, if requested, sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param index  the axis index.
-     * @param location  the location ({@code null} not permitted for
-     *     index 0).
-     * @param notify  notify listeners?
-     *
-     * @since 1.0.5
-     *
-     * @see #getRangeAxisLocation(int)
-     * @see #setDomainAxisLocation(int, AxisLocation, boolean)
-     */
-    public void setRangeAxisLocation(int index, AxisLocation location,
-            boolean notify) {
-        if (index == 0 && location == null) {
-            throw new IllegalArgumentException(
-                    "Null 'location' for index 0 not permitted.");
-        }
-        this.rangeAxisLocations.put(index, location);
-        if (notify) {
-            fireChangeEvent();
-        }
-    }
-
-    /**
      * Returns the edge for a range axis.
      *
      * @param index  the axis index.
@@ -1930,183 +1651,6 @@
         this.domainMinorGridlinePaint = paint;
         fireChangeEvent();
     }
-
-    /**
-     * Returns {@code true} if the range axis grid is visible, and
-     * {@code false} otherwise.
-     *
-     * @return A boolean.
-     *
-     * @see #setRangeGridlinesVisible(boolean)
-     */
-    public boolean isRangeGridlinesVisible() {
-        return this.rangeGridlinesVisible;
-    }
-
-    /**
-     * Sets the flag that controls whether or not the range axis grid lines
-     * are visible.
-     * <p>
-     * If the flag value is changed, a {@link PlotChangeEvent} is sent to all
-     * registered listeners.
-     *
-     * @param visible  the new value of the flag.
-     *
-     * @see #isRangeGridlinesVisible()
-     */
-    public void setRangeGridlinesVisible(boolean visible) {
-        if (this.rangeGridlinesVisible != visible) {
-            this.rangeGridlinesVisible = visible;
-            fireChangeEvent();
-        }
-    }
-
-    /**
-     * Returns the stroke for the grid lines (if any) plotted against the
-     * range axis.
-     *
-     * @return The stroke (never {@code null}).
-     *
-     * @see #setRangeGridlineStroke(Stroke)
-     */
-    public Stroke getRangeGridlineStroke() {
-        return this.rangeGridlineStroke;
-    }
-
-    /**
-     * Sets the stroke for the grid lines plotted against the range axis,
-     * and sends a {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param stroke  the stroke ({@code null} not permitted).
-     *
-     * @see #getRangeGridlineStroke()
-     */
-    public void setRangeGridlineStroke(Stroke stroke) {
-        Args.nullNotPermitted(stroke, "stroke");
-        this.rangeGridlineStroke = stroke;
-        fireChangeEvent();
-    }
-
-    /**
-     * Returns the paint for the grid lines (if any) plotted against the range
-     * axis.
-     *
-     * @return The paint (never {@code null}).
-     *
-     * @see #setRangeGridlinePaint(Paint)
-     */
-    public Paint getRangeGridlinePaint() {
-        return this.rangeGridlinePaint;
-    }
-
-    /**
-     * Sets the paint for the grid lines plotted against the range axis and
-     * sends a {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param paint  the paint ({@code null} not permitted).
-     *
-     * @see #getRangeGridlinePaint()
-     */
-    public void setRangeGridlinePaint(Paint paint) {
-        Args.nullNotPermitted(paint, "paint");
-        this.rangeGridlinePaint = paint;
-        fireChangeEvent();
-    }
-
-    /**
-     * Returns {@code true} if the range axis minor grid is visible, and
-     * {@code false} otherwise.
-     *
-     * @return A boolean.
-     *
-     * @see #setRangeMinorGridlinesVisible(boolean)
-     *
-     * @since 1.0.12
-     */
-    public boolean isRangeMinorGridlinesVisible() {
-        return this.rangeMinorGridlinesVisible;
-    }
-
-    /**
-     * Sets the flag that controls whether or not the range axis minor grid
-     * lines are visible.
-     * <p>
-     * If the flag value is changed, a {@link PlotChangeEvent} is sent to all
-     * registered listeners.
-     *
-     * @param visible  the new value of the flag.
-     *
-     * @see #isRangeMinorGridlinesVisible()
-     *
-     * @since 1.0.12
-     */
-    public void setRangeMinorGridlinesVisible(boolean visible) {
-        if (this.rangeMinorGridlinesVisible != visible) {
-            this.rangeMinorGridlinesVisible = visible;
-            fireChangeEvent();
-        }
-    }
-
-    /**
-     * Returns the stroke for the minor grid lines (if any) plotted against the
-     * range axis.
-     *
-     * @return The stroke (never {@code null}).
-     *
-     * @see #setRangeMinorGridlineStroke(Stroke)
-     *
-     * @since 1.0.12
-     */
-    public Stroke getRangeMinorGridlineStroke() {
-        return this.rangeMinorGridlineStroke;
-    }
-
-    /**
-     * Sets the stroke for the minor grid lines plotted against the range axis,
-     * and sends a {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param stroke  the stroke ({@code null} not permitted).
-     *
-     * @see #getRangeMinorGridlineStroke()
-     *
-     * @since 1.0.12
-     */
-    public void setRangeMinorGridlineStroke(Stroke stroke) {
-        Args.nullNotPermitted(stroke, "stroke");
-        this.rangeMinorGridlineStroke = stroke;
-        fireChangeEvent();
-    }
-
-    /**
-     * Returns the paint for the minor grid lines (if any) plotted against the
-     * range axis.
-     *
-     * @return The paint (never {@code null}).
-     *
-     * @see #setRangeMinorGridlinePaint(Paint)
-     *
-     * @since 1.0.12
-     */
-    public Paint getRangeMinorGridlinePaint() {
-        return this.rangeMinorGridlinePaint;
-    }
-
-    /**
-     * Sets the paint for the minor grid lines plotted against the range axis
-     * and sends a {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param paint  the paint ({@code null} not permitted).
-     *
-     * @see #getRangeMinorGridlinePaint()
-     *
-     * @since 1.0.12
-     */
-    public void setRangeMinorGridlinePaint(Paint paint) {
-        Args.nullNotPermitted(paint, "paint");
-        this.rangeMinorGridlinePaint = paint;
-        fireChangeEvent();
-    }
-
     /**
      * Returns a flag that controls whether or not a zero baseline is
      * displayed for the domain axis.
@@ -2654,48 +2198,6 @@
     }
 
     /**
-     * Clears all the range markers and sends a {@link PlotChangeEvent} to all
-     * registered listeners.
-     *
-     * @see #clearRangeMarkers()
-     */
-    public void clearRangeMarkers() {
-        if (this.backgroundRangeMarkers != null) {
-            Set<Integer> keys = this.backgroundRangeMarkers.keySet();
-            for (Integer key : keys) {
-                clearRangeMarkers(key);
-            }
-            this.backgroundRangeMarkers.clear();
-        }
-        if (this.foregroundRangeMarkers != null) {
-            Set<Integer> keys = this.foregroundRangeMarkers.keySet();
-            for (Integer key : keys) {
-                clearRangeMarkers(key);
-            }
-            this.foregroundRangeMarkers.clear();
-        }
-        fireChangeEvent();
-    }
-
-    /**
-     * Adds a marker for a specific dataset/renderer and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     * <P>
-     * Typically a marker will be drawn by the renderer as a line perpendicular
-     * to the range axis, however this is entirely up to the renderer.
-     *
-     * @param index  the dataset/renderer index.
-     * @param marker  the marker.
-     * @param layer  the layer (foreground or background).
-     *
-     * @see #clearRangeMarkers(int)
-     * @see #addDomainMarker(int, Marker, Layer)
-     */
-    public void addRangeMarker(int index, Marker marker, Layer layer) {
-        addRangeMarker(index, marker, layer, true);
-    }
-
-    /**
      * Adds a marker for a specific dataset/renderer and, if requested, sends a
      * {@link PlotChangeEvent} to all registered listeners.
      * <P>
@@ -2736,103 +2238,6 @@
         }
     }
 
-    /**
-     * Clears the (foreground and background) range markers for a particular
-     * renderer.
-     *
-     * @param index  the renderer index.
-     */
-    public void clearRangeMarkers(int index) {
-        Integer key = new Integer(index);
-        if (this.backgroundRangeMarkers != null) {
-            Collection markers
-                = (Collection) this.backgroundRangeMarkers.get(key);
-            if (markers != null) {
-                Iterator iterator = markers.iterator();
-                while (iterator.hasNext()) {
-                    Marker m = (Marker) iterator.next();
-                    m.removeChangeListener(this);
-                }
-                markers.clear();
-            }
-        }
-        if (this.foregroundRangeMarkers != null) {
-            Collection markers
-                = (Collection) this.foregroundRangeMarkers.get(key);
-            if (markers != null) {
-                Iterator iterator = markers.iterator();
-                while (iterator.hasNext()) {
-                    Marker m = (Marker) iterator.next();
-                    m.removeChangeListener(this);
-                }
-                markers.clear();
-            }
-        }
-        fireChangeEvent();
-    }
-
-    /**
-     * Removes a marker for the range axis and sends a {@link PlotChangeEvent}
-     * to all registered listeners.
-     *
-     * @param marker the marker.
-     *
-     * @return A boolean indicating whether or not the marker was actually
-     *         removed.
-     *
-     * @since 1.0.7
-     */
-    public boolean removeRangeMarker(Marker marker) {
-        return removeRangeMarker(marker, Layer.FOREGROUND);
-    }
-
-    /**
-     * Removes a marker for the range axis in the specified layer and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param marker the marker ({@code null} not permitted).
-     * @param layer the layer (foreground or background).
-     *
-     * @return A boolean indicating whether or not the marker was actually
-     *         removed.
-     *
-     * @since 1.0.7
-     */
-    public boolean removeRangeMarker(Marker marker, Layer layer) {
-        return removeRangeMarker(0, marker, layer);
-    }
-
-    /**
-     * Removes a marker for a specific dataset/renderer and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param index the dataset/renderer index.
-     * @param marker the marker ({@code null} not permitted).
-     * @param layer the layer (foreground or background).
-     *
-     * @return A boolean indicating whether or not the marker was actually
-     *         removed.
-     *
-     * @since 1.0.7
-     */
-    public boolean removeRangeMarker(int index, Marker marker, Layer layer) {
-        return removeRangeMarker(index, marker, layer, true);
-    }
-
-    /**
-     * Removes a marker for a specific dataset/renderer and sends a
-     * {@link PlotChangeEvent} to all registered listeners.
-     *
-     * @param index  the dataset/renderer index.
-     * @param marker  the marker ({@code null} not permitted).
-     * @param layer  the layer (foreground or background) ({@code null} not permitted).
-     * @param notify  notify listeners?
-     *
-     * @return A boolean indicating whether or not the marker was actually
-     *         removed.
-     *
-     * @since 1.0.10
-     */
     public boolean removeRangeMarker(int index, Marker marker, Layer layer,
             boolean notify) {
         Args.nullNotPermitted(marker, "marker");
@@ -3070,13 +2475,7 @@
         }
         else {
             // reserve space for the range axes...
-            for (ValueAxis axis: this.rangeAxes.values()) {
-                if (axis != null) {
-                    RectangleEdge edge = getRangeAxisEdge(
-                            findRangeAxisIndex(axis));
-                    space = axis.reserveSpace(g2, this, plotArea, edge, space);
-                }
-            }
+            space = reserveSpaceForTheRangeAxes(g2, plotArea, space);
         }
         return space;
 
@@ -3131,7 +2530,7 @@
 
         AxisSpace space = calculateAxisSpace(g2, area);
         Rectangle2D dataArea = space.shrink(area, null);
-        this.axisOffset.trim(dataArea);
+        trimAxisOffset(dataArea);
 
         dataArea = integerise(dataArea);
         if (dataArea.isEmpty()) {
@@ -3614,65 +3013,8 @@
             }
         }
 
-        // add range axes to lists...
-        for (ValueAxis axis : this.rangeAxes.values()) {
-            if (axis != null) {
-                int axisIndex = findRangeAxisIndex(axis);
-                axisCollection.add(axis, getRangeAxisEdge(axisIndex));
-            }
-        }
-
-        Map axisStateMap = new HashMap();
-
-        // draw the top axes
-        double cursor = dataArea.getMinY() - this.axisOffset.calculateTopOutset(
-                dataArea.getHeight());
-        Iterator iterator = axisCollection.getAxesAtTop().iterator();
-        while (iterator.hasNext()) {
-            ValueAxis axis = (ValueAxis) iterator.next();
-            AxisState info = axis.draw(g2, cursor, plotArea, dataArea,
-                    RectangleEdge.TOP, plotState);
-            cursor = info.getCursor();
-            axisStateMap.put(axis, info);
-        }
-
-        // draw the bottom axes
-        cursor = dataArea.getMaxY()
-                 + this.axisOffset.calculateBottomOutset(dataArea.getHeight());
-        iterator = axisCollection.getAxesAtBottom().iterator();
-        while (iterator.hasNext()) {
-            ValueAxis axis = (ValueAxis) iterator.next();
-            AxisState info = axis.draw(g2, cursor, plotArea, dataArea,
-                    RectangleEdge.BOTTOM, plotState);
-            cursor = info.getCursor();
-            axisStateMap.put(axis, info);
-        }
+        return extractedDraw(g2, plotArea, dataArea, plotState, axisCollection);
 
-        // draw the left axes
-        cursor = dataArea.getMinX()
-                 - this.axisOffset.calculateLeftOutset(dataArea.getWidth());
-        iterator = axisCollection.getAxesAtLeft().iterator();
-        while (iterator.hasNext()) {
-            ValueAxis axis = (ValueAxis) iterator.next();
-            AxisState info = axis.draw(g2, cursor, plotArea, dataArea,
-                    RectangleEdge.LEFT, plotState);
-            cursor = info.getCursor();
-            axisStateMap.put(axis, info);
-        }
-
-        // draw the right axes
-        cursor = dataArea.getMaxX()
-                 + this.axisOffset.calculateRightOutset(dataArea.getWidth());
-        iterator = axisCollection.getAxesAtRight().iterator();
-        while (iterator.hasNext()) {
-            ValueAxis axis = (ValueAxis) iterator.next();
-            AxisState info = axis.draw(g2, cursor, plotArea, dataArea,
-                    RectangleEdge.RIGHT, plotState);
-            cursor = info.getCursor();
-            axisStateMap.put(axis, info);
-        }
-
-        return axisStateMap;
     }
 
     /**
@@ -4389,14 +3731,6 @@
         return result;
     }
 
-    private int findRangeAxisIndex(ValueAxis axis) {
-        for (Map.Entry<Integer, ValueAxis> entry : this.rangeAxes.entrySet()) {
-            if (entry.getValue() == axis) {
-                return entry.getKey();
-            }
-        }
-        return -1;
-    }
 
     /**
      * Returns the range for the specified axis.
@@ -4532,14 +3866,7 @@
     public void datasetChanged(DatasetChangeEvent event) {
         configureDomainAxes();
         configureRangeAxes();
-        if (getParent() != null) {
-            getParent().datasetChanged(event);
-        }
-        else {
-            PlotChangeEvent e = new PlotChangeEvent(this);
-            e.setType(ChartChangeEventType.DATASET_UPDATED);
-            notifyListeners(e);
-        }
+        dealWithEventWhenDatasetChanges(event);
     }
 
     /**
@@ -5154,24 +4481,8 @@
     public void zoomRangeAxes(double factor, PlotRenderingInfo info,
                               Point2D source, boolean useAnchor) {
 
-        // perform the zoom on each range axis
-        for (ValueAxis yAxis : this.rangeAxes.values()) {
-            if (yAxis == null) {
-                continue;
-            }
-            if (useAnchor) {
-                // get the relevant source coordinate given the plot orientation
-                double sourceY = source.getY();
-                if (this.orientation == PlotOrientation.HORIZONTAL) {
-                    sourceY = source.getX();
-                }
-                double anchorY = yAxis.java2DToValue(sourceY,
-                        info.getDataArea(), getRangeAxisEdge());
-                yAxis.resizeRange2(factor, anchorY);
-            } else {
-                yAxis.resizeRange(factor);
-            }
-        }
+        zoomRangeAxesWithFactor(factor, info, source, useAnchor);
+
     }
 
     /**
@@ -5187,11 +4498,7 @@
     @Override
     public void zoomRangeAxes(double lowerPercent, double upperPercent,
                               PlotRenderingInfo info, Point2D source) {
-        for (ValueAxis yAxis : this.rangeAxes.values()) {
-            if (yAxis != null) {
-                yAxis.zoomRange(lowerPercent, upperPercent);
-            }
-        }
+        zoomRangeAxesDefault(lowerPercent, upperPercent);
     }
 
     /**
diff -burN jfreechart-original/src/test/java/org/jfree/chart/ChartPanelTest.java jfreechart-after-maintenance/src/test/java/org/jfree/chart/ChartPanelTest.java
--- jfreechart-original/src/test/java/org/jfree/chart/ChartPanelTest.java	2022-03-07 09:23:25.000000000 +0100
+++ jfreechart-after-maintenance/src/test/java/org/jfree/chart/ChartPanelTest.java	2022-04-17 18:12:48.000000000 +0200
@@ -41,22 +41,37 @@
 
 package org.jfree.chart;
 
-import static org.junit.Assert.assertEquals;
-import static org.junit.Assert.assertTrue;
-import static org.junit.Assert.assertFalse;
-import java.awt.geom.Rectangle2D;
-import java.util.EventListener;
-import java.util.List;
-
-import javax.swing.event.CaretListener;
-
 import org.jfree.chart.axis.NumberAxis;
 import org.jfree.chart.event.ChartChangeEvent;
 import org.jfree.chart.event.ChartChangeListener;
+import org.jfree.chart.event.PlotChangeEvent;
+import org.jfree.chart.event.PlotChangeListener;
+import org.jfree.chart.panel.CrosshairOverlay;
+import org.jfree.chart.plot.Crosshair;
 import org.jfree.chart.plot.PlotOrientation;
+import org.jfree.chart.plot.ThermometerPlot;
 import org.jfree.chart.plot.XYPlot;
+import org.jfree.data.general.DefaultPieDataset;
 import org.jfree.data.xy.DefaultXYDataset;
 import org.junit.Test;
+import org.mockito.invocation.InvocationOnMock;
+import org.mockito.stubbing.Answer;
+
+import javax.swing.*;
+import javax.swing.event.CaretListener;
+import java.awt.*;
+import java.awt.datatransfer.Clipboard;
+import java.awt.event.ActionEvent;
+import java.awt.geom.Point2D;
+import java.awt.geom.Rectangle2D;
+import java.awt.image.BufferedImage;
+import java.io.File;
+import java.util.EventListener;
+import java.util.List;
+
+import static org.jfree.chart.ChartPanel.*;
+import static org.junit.Assert.*;
+import static org.mockito.Mockito.*;
 
 /**
  * Tests for the {@link ChartPanel} class.
@@ -117,8 +132,7 @@
         boolean pass = false;
         try {
             listeners = p.getListeners((Class) null);
-        }
-        catch (NullPointerException e) {
+        } catch (NullPointerException e) {
             pass = true;
         }
         assertTrue(pass);
@@ -127,8 +141,7 @@
         pass = false;
         try {
             listeners = p.getListeners(Integer.class);
-        }
-        catch (ClassCastException e) {
+        } catch (ClassCastException e) {
             pass = true;
         }
         assertTrue(pass);
@@ -343,4 +356,523 @@
         panel.setMouseWheelEnabled(false);
         assertFalse(panel.isMouseWheelEnabled());
     }
+
+    @Test
+    public void testGetToolTipText() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = new ChartPanel(chart);
+        assertEquals(null, panel.getToolTipText(null));
+        // TODO test with a real MouseEvent
+    }
+
+    @Test
+    public void testScale() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = new ChartPanel(chart);
+        // scale is 0.0 by default and is only set by paintComponent
+        BufferedImage bi = new BufferedImage(300, 200, BufferedImage.TYPE_INT_ARGB);
+        Graphics2D g2 = bi.createGraphics();
+        panel.setSize(300, 200);
+        panel.paintComponent(g2);
+        // Insets are (0,0,0,0)
+        assertEquals(1.0, panel.getScaleX(), 0.1);
+        assertEquals(1.0, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        panel.setSize(150, 50);
+        panel.paintComponent(g2);
+        assertEquals(0.5, panel.getScaleX(), 0.1);
+        assertEquals(0.25, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(5.0, 5.0, 15.0, 10.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        panel.setMaximumDrawWidth(500);
+        panel.setSize(600, 400);
+        panel.paintComponent(g2);
+        assertEquals(1.2, panel.getScaleX(), 0.1);
+        assertEquals(1.0, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(12.0, 20.0, 36.0, 40.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        panel.setMaximumDrawHeight(200);
+        panel.setSize(600, 400);
+        panel.paintComponent(g2);
+        assertEquals(1.2, panel.getScaleX(), 0.1);
+        assertEquals(2.0, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(12.0, 40.0, 36.0, 80.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        g2.dispose();
+    }
+
+    /**
+     * Same test as the previous one, but specifying no buffer to check that it has the same behaviour.
+     */
+    @Test
+    public void testPaintComponentNoBuffer() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = new ChartPanel(chart, false);
+        // scale is 0.0 by default and is only set by paintComponent
+        BufferedImage bi = new BufferedImage(300, 200, BufferedImage.TYPE_INT_ARGB);
+        Graphics2D g2 = bi.createGraphics();
+        panel.setSize(300, 200);
+        panel.paintComponent(g2);
+        // Insets are (0,0,0,0)
+        assertEquals(1.0, panel.getScaleX(), 0.1);
+        assertEquals(1.0, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        panel.setSize(150, 50);
+        panel.paintComponent(g2);
+        assertEquals(0.5, panel.getScaleX(), 0.1);
+        assertEquals(0.25, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(5.0, 5.0, 15.0, 10.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        panel.setMaximumDrawWidth(500);
+        panel.setSize(600, 400);
+        panel.paintComponent(g2);
+        assertEquals(1.2, panel.getScaleX(), 0.1);
+        assertEquals(1.0, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(12.0, 20.0, 36.0, 40.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        panel.setMaximumDrawHeight(200);
+        panel.setSize(600, 400);
+        panel.paintComponent(g2);
+        assertEquals(1.2, panel.getScaleX(), 0.1);
+        assertEquals(2.0, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(12.0, 40.0, 36.0, 80.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        g2.dispose();
+    }
+
+    @Test
+    public void testPaintComponentNullChart() {
+        ChartPanel panel = new ChartPanel(null);
+        // scale is 0.0 by default and is only set by paintComponent
+        BufferedImage bi = new BufferedImage(300, 200, BufferedImage.TYPE_INT_ARGB);
+        Graphics2D g2 = bi.createGraphics();
+        panel.setSize(300, 200);
+        panel.paintComponent(g2);
+
+    }
+
+    /**
+     * Same test as the previous one, but specifying no buffer to check that it has the same behaviour.
+     */
+    @Test
+    public void testPaintComponentWithOverlays() {
+        CrosshairOverlay overlay = new CrosshairOverlay();
+        overlay.addDomainCrosshair(new Crosshair());
+        overlay.addRangeCrosshair(new Crosshair());
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = new ChartPanel(chart, false);
+        panel.addOverlay(overlay);
+        // scale is 0.0 by default and is only set by paintComponent
+        BufferedImage bi = new BufferedImage(300, 200, BufferedImage.TYPE_INT_ARGB);
+        Graphics2D g2 = bi.createGraphics();
+        panel.setSize(300, 200);
+        panel.paintComponent(g2);
+        // Insets are (0,0,0,0)
+        assertEquals(1.0, panel.getScaleX(), 0.1);
+        assertEquals(1.0, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        panel.setSize(150, 50);
+        panel.paintComponent(g2);
+        assertEquals(0.5, panel.getScaleX(), 0.1);
+        assertEquals(0.25, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(5.0, 5.0, 15.0, 10.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        panel.setMaximumDrawWidth(500);
+        panel.setSize(600, 400);
+        panel.paintComponent(g2);
+        assertEquals(1.2, panel.getScaleX(), 0.1);
+        assertEquals(1.0, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(12.0, 20.0, 36.0, 40.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        panel.setMaximumDrawHeight(200);
+        panel.setSize(600, 400);
+        panel.paintComponent(g2);
+        assertEquals(1.2, panel.getScaleX(), 0.1);
+        assertEquals(2.0, panel.getScaleY(), 0.1);
+        assertEquals(new Rectangle2D.Double(12.0, 40.0, 36.0, 80.0),
+                panel.scale(new Rectangle2D.Double(10.0, 20.0, 30.0, 40.0)));
+        g2.dispose();
+    }
+
+    @Test
+    public void testActionPerformed() {
+        final boolean[] plotChanged = {false};
+
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        chart.getPlot().addChangeListener(new PlotChangeListener() {
+            @Override
+            public void plotChanged(PlotChangeEvent event) {
+                plotChanged[0] = true;
+            }
+        });
+
+        ChartPanel panel = new ChartPanel(chart);
+
+        ActionEvent event = new ActionEvent(new Object(), 0, ZOOM_IN_BOTH_COMMAND);
+        panel.actionPerformed(event);
+        assertTrue(plotChanged[0]);
+
+        plotChanged[0] = false;
+        event = new ActionEvent(new Object(), 0, ZOOM_IN_DOMAIN_COMMAND);
+        panel.actionPerformed(event);
+        assertTrue(plotChanged[0]);
+
+        plotChanged[0] = false;
+        event = new ActionEvent(new Object(), 0, ZOOM_IN_RANGE_COMMAND);
+        panel.actionPerformed(event);
+        assertTrue(plotChanged[0]);
+
+        event = new ActionEvent(new Object(), 0, ZOOM_OUT_BOTH_COMMAND);
+        panel.actionPerformed(event);
+        assertTrue(plotChanged[0]);
+
+        plotChanged[0] = false;
+        event = new ActionEvent(new Object(), 0, ZOOM_OUT_DOMAIN_COMMAND);
+        panel.actionPerformed(event);
+        assertTrue(plotChanged[0]);
+
+        plotChanged[0] = false;
+        event = new ActionEvent(new Object(), 0, ZOOM_OUT_RANGE_COMMAND);
+        panel.actionPerformed(event);
+        assertTrue(plotChanged[0]);
+
+        event = new ActionEvent(new Object(), 0, ZOOM_RESET_BOTH_COMMAND);
+        panel.actionPerformed(event);
+        assertTrue(plotChanged[0]);
+
+        plotChanged[0] = false;
+        event = new ActionEvent(new Object(), 0, ZOOM_RESET_BOTH_COMMAND);
+        panel.actionPerformed(event);
+        assertTrue(plotChanged[0]);
+
+        plotChanged[0] = false;
+        event = new ActionEvent(new Object(), 0, ZOOM_RESET_BOTH_COMMAND);
+        panel.actionPerformed(event);
+        assertTrue(plotChanged[0]);
+
+        event = new ActionEvent(new Object(), 0, COPY_COMMAND);
+        panel.actionPerformed(event);
+        Clipboard systemClipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
+        assertEquals("image/x-java-image; class=java.awt.Image", systemClipboard.getContents(this).getTransferDataFlavors()[0].getMimeType());
+
+    }
+
+    @Test
+    public void testMouseEnteredExitedInteractions() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = new ChartPanel(chart);
+        panel.mouseEnteredAction();
+        assertTrue(panel.isOwnToolTipDelaysActive());
+        panel.mouseExitedAction();
+        assertFalse(panel.isOwnToolTipDelaysActive());
+    }
+
+    @Test
+    public void testMousePressedPannableButNotDomainNorRange() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = new ChartPanel(chart);
+        Point cursorPoint = new Point(10, 20);
+        panel.mousePressedAction(10, 20, cursorPoint, false, 2);
+        assertNull(panel.getPanLast());
+    }
+
+    @Test
+    public void testMousePressedPannable() {
+        XYPlot plot = mock(XYPlot.class);
+        when(plot.isDomainPannable()).thenReturn(true);
+        when(plot.isRangePannable()).thenReturn(true);
+        JFreeChart chart = new JFreeChart(plot);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        when(panel.getScreenDataArea(anyInt(),anyInt())).thenReturn(new Rectangle(10,10));
+        Point cursorPoint = new Point(0, 0);
+        panel.mousePressedAction(0, 0, cursorPoint, false, 2);
+        assertEquals(cursorPoint, panel.getPanLast());
+    }
+
+    @Test
+    public void testMousePressedNonPannable() {
+        DefaultPieDataset dataset = new DefaultPieDataset();
+        JFreeChart chart = ChartFactory.createPieChart("TestChart", dataset);
+        ChartPanel panel = new ChartPanel(chart);
+        panel.mouseEnteredAction();
+        assertTrue(panel.isOwnToolTipDelaysActive());
+        panel.mouseExitedAction();
+        assertFalse(panel.isOwnToolTipDelaysActive());
+    }
+
+    @Test
+    public void testMousePressedNoModifiersZoomRectangle() {
+        DefaultPieDataset dataset = new DefaultPieDataset();
+        JFreeChart chart = ChartFactory.createPieChart("TestChart", dataset);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        when(panel.getScreenDataArea(anyInt(), anyInt())).thenReturn(new Rectangle(10,10));
+        Point cursorPoint = new Point(0, 0);
+        panel.mousePressedAction(0, 0, cursorPoint, false, 1);
+        assertEquals(cursorPoint, panel.getZoomPoint());
+    }
+
+    @Test
+    public void testMousePressedNoModifiersZoomRectangleNullScreenDataArea() {
+        DefaultPieDataset dataset = new DefaultPieDataset();
+        JFreeChart chart = ChartFactory.createPieChart("TestChart", dataset);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        when(panel.getScreenDataArea(anyInt(), anyInt())).thenReturn(null);
+        Point cursorPoint = new Point(0, 0);
+        panel.mousePressedAction(0, 0, cursorPoint, false, 1);
+        assertNull(panel.getZoomPoint());
+    }
+
+    @Test
+    public void testMousePressedNoModifiersPopupTrigger() {
+        DefaultPieDataset dataset = new DefaultPieDataset();
+        JFreeChart chart = ChartFactory.createPieChart("TestChart", dataset);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        when(panel.getScreenDataArea(anyInt(), anyInt())).thenReturn(new Rectangle(10,10));
+        final boolean[] displayPopupCalled = {false};
+        doAnswer(new Answer<Void>() {
+            @Override
+            public Void answer(InvocationOnMock invocationOnMock) {
+                displayPopupCalled[0] = true;
+                return null;
+            }
+        }).when(panel).displayPopupMenu(anyInt(), anyInt());
+        Point cursorPoint = new Point(0, 0);
+        panel.mousePressedAction(0, 0, cursorPoint, true, 1);
+        assertTrue(displayPopupCalled[0]);
+    }
+
+    @Test
+    public void testGetPointInRectangle() {
+        DefaultPieDataset dataset = new DefaultPieDataset();
+        JFreeChart chart = ChartFactory.createPieChart("TestChart", dataset);
+        ChartPanel panel = new ChartPanel(chart);
+        Rectangle2D r2d = mock(Rectangle2D.class);
+        when(r2d.getMaxX()).thenReturn(100d);
+        when(r2d.getMaxY()).thenReturn(50d);
+
+        Point2D pointInRectangle = panel.getPointInRectangle(10, 20, r2d);
+        assertEquals(pointInRectangle.getX(), 10, 0.1);
+        assertEquals(pointInRectangle.getY(), 20, 0.1);
+
+        pointInRectangle = panel.getPointInRectangle(100, 200, r2d);
+        assertEquals(pointInRectangle.getX(), 100, 0.1);
+        assertEquals(pointInRectangle.getY(), 50, 0.1);
+
+        pointInRectangle = panel.getPointInRectangle(200, 200, r2d);
+        assertEquals(pointInRectangle.getX(), 100, 0.1);
+        assertEquals(pointInRectangle.getY(), 50, 0.1);
+    }
+
+    @Test
+    public void testSetZoomRectangleNoZoomable() {
+        DefaultPieDataset dataset = new DefaultPieDataset();
+        JFreeChart chart = ChartFactory.createPieChart("TestChart", dataset);
+        ChartPanel panel = new ChartPanel(chart);
+        panel.setZoomRectangle(10, 20, new Point(10, 20));
+        assertNull(panel.getZoomRectangle());
+    }
+
+    @Test
+    public void testSetZoomRectangleVerticalPlotZoomable() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = new ChartPanel(chart);
+        panel.setZoomRectangle(10, 20, new Point(10, 20));
+        assertEquals(new Rectangle2D.Double(10d, 20d, -10d, -20d), panel.getZoomRectangle());
+    }
+
+    @Test
+    public void testSetZoomRectangleHorizontalPlotZoomable() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.HORIZONTAL, false, false, false);
+        ChartPanel panel = new ChartPanel(chart);
+        panel.setZoomRectangle(10, 20, new Point(10, 20));
+        assertEquals(new Rectangle2D.Double(10d, 20d, -10d, -20d), panel.getZoomRectangle());
+    }
+
+    @Test
+    public void testSetZoomRectanglePlotZoomableRange() {
+        JFreeChart chart = new JFreeChart(new ThermometerPlot());
+        ChartPanel panel = new ChartPanel(chart);
+        panel.setZoomRectangle(10, 20, new Point(10, 20));
+        assertEquals(new Rectangle2D.Double(0d, 20d, 0d, -20d), panel.getZoomRectangle());
+    }
+
+    @Test
+    public void testhandlePanningVertical() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = new ChartPanel(chart);
+        panel.setPanLast(new Point(15, 15));
+        Point point = new Point(20, 30);
+        panel.mouseDraggedHandlePanning(10, 20, point);
+        assertEquals(point, panel.getPanLast());
+    }
+
+    @Test
+    public void testhandlePanningHorizontal() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.HORIZONTAL, false, false, false);
+        ChartPanel panel = new ChartPanel(chart);
+        panel.setPanLast(new Point(15, 15));
+        Point point = new Point(20, 30);
+        panel.mouseDraggedHandlePanning(10, 20, point);
+        assertEquals(point, panel.getPanLast());
+    }
+
+    @Test
+    public void testMouseReleasedNotNullPanLast() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.HORIZONTAL, false, false, false);
+        ChartPanel panel = new ChartPanel(chart);
+        panel.setPanLast(new Point(15, 15));
+        Point point = new Point(20, 30);
+        panel.mouseDraggedHandlePanning(10, 20, point);
+        assertEquals(point, panel.getPanLast());
+    }
+
+    @Test
+    public void testGetZoomAreaDoubleZoom() {
+        JFreeChart chart = new JFreeChart(new ThermometerPlot());
+        ChartPanel panel = new ChartPanel(chart);
+        Rectangle2D zoomArea = panel.getZoomArea(true, true, new Point(10, 10), new Rectangle(15, 30));
+        assertEquals(new Rectangle2D.Double(10d, 10d, -10d, -10d), zoomArea);
+    }
+
+    @Test
+    public void testGetZoomAreaHZoom() {
+        JFreeChart chart = new JFreeChart(new ThermometerPlot());
+        ChartPanel panel = new ChartPanel(chart);
+        Rectangle2D zoomArea = panel.getZoomArea(true, false, new Point(10, 10), new Rectangle(15, 30));
+//        when(panel.getScreenDataArea(anyInt(),anyInt())).thenReturn(new Rectangle(10,10));
+        assertEquals(new Rectangle2D.Double(10d, 0d, -10d, 0d), zoomArea);
+    }
+
+    @Test
+    public void testGetZoomAreaVZoom() {
+        JFreeChart chart = new JFreeChart(new ThermometerPlot());
+        ChartPanel panel = new ChartPanel(chart);
+        Rectangle2D zoomArea = panel.getZoomArea(false, true, new Point(10, 10), new Rectangle(15, 30));
+//        when(panel.getScreenDataArea(anyInt(),anyInt())).thenReturn(new Rectangle(10,10));
+        assertEquals(new Rectangle2D.Double(0d, 10d, 0d, -10d), zoomArea);
+    }
+
+    @Test
+    public void testMouseReleasedPopupTrigger() {
+        DefaultPieDataset dataset = new DefaultPieDataset();
+        JFreeChart chart = ChartFactory.createPieChart("TestChart", dataset);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        when(panel.getScreenDataArea(anyInt(), anyInt())).thenReturn(new Rectangle(10,10));
+        final boolean[] displayPopupCalled = {false};
+        doAnswer(new Answer<Void>() {
+            @Override
+            public Void answer(InvocationOnMock invocationOnMock) {
+                displayPopupCalled[0] = true;
+                return null;
+            }
+        }).when(panel).displayPopupMenu(anyInt(), anyInt());
+        panel.mouseReleasedAction(0, 0, true, new Point(10, 10));
+        assertTrue(displayPopupCalled[0]);
+    }
+
+    @Test
+    public void testMouseReleasedPanLast() {
+        DefaultPieDataset dataset = new DefaultPieDataset();
+        JFreeChart chart = ChartFactory.createPieChart("TestChart", dataset);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        panel.setPanLast(new Point(15, 15));
+        panel.mouseReleasedAction(0, 0, true, new Point(10, 10));
+        assertNull(panel.getPanLast());
+    }
+
+    @Test
+    public void testMouseReleasedZoomRectangle() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        panel.setPanLast(null);
+        panel.setZoomRectangle(10, 20, new Point(10, 20));
+        doNothing().when(panel).displayPopupMenu(anyInt(), anyInt());
+        panel.mouseReleasedAction(0, 0, true, new Point(10, 10));
+        assertNull(panel.getZoomRectangle());
+    }
+
+    @Test(expected = IllegalStateException.class)
+    public void testGenerateSVGNull() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        panel.generateSVG(100, 200);
+    }
+
+    @Test
+    public void testSaveNullFile() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        JFileChooser jFileChooser = mock(JFileChooser.class);
+        when(jFileChooser.getSelectedFile()).thenReturn(new File("/test/path"));
+        File file = panel.saveFile(JFileChooser.APPROVE_OPTION, jFileChooser, ".ext", null, "save_as");
+        assertEquals("/test/path.ext", file.getPath());
+    }
+
+    @Test
+    public void testDealWithExistingFileCancel() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        File file = mock(File.class);
+        File fileToSave = panel.dealWithExistingFile(file, JOptionPane.CANCEL_OPTION);
+        assertNull(fileToSave);
+    }
+
+    @Test
+    public void testDealWithExistingFileNotCancel() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        File file = mock(File.class);
+        File fileToSave = panel.dealWithExistingFile(file, JOptionPane.OK_OPTION);
+        assertEquals(file, fileToSave);
+    }
+
+    @Test
+    public void testCreateFileChooser() {
+        DefaultXYDataset dataset = new DefaultXYDataset();
+        JFreeChart chart = ChartFactory.createXYLineChart("TestChart", "X",
+                "Y", dataset, PlotOrientation.VERTICAL, false, false, false);
+        ChartPanel panel = spy(new ChartPanel(chart));
+        JFileChooser fileChooser = panel.createFileChooser("PDF_Files", "ext");
+        assertTrue(fileChooser.getFileFilter().accept(new File("test.ext")));
+        assertFalse(fileChooser.getFileFilter().accept(new File("test.other")));
+    }
+
+
 }
diff -burN jfreechart-original/src/test/java/org/jfree/chart/entity/ChartEntityTest.java jfreechart-after-maintenance/src/test/java/org/jfree/chart/entity/ChartEntityTest.java
--- jfreechart-original/src/test/java/org/jfree/chart/entity/ChartEntityTest.java	1970-01-01 01:00:00.000000000 +0100
+++ jfreechart-after-maintenance/src/test/java/org/jfree/chart/entity/ChartEntityTest.java	2022-04-17 18:12:48.000000000 +0200
@@ -0,0 +1,76 @@
+package org.jfree.chart.entity;
+
+import org.jfree.chart.imagemap.StandardToolTipTagFragmentGenerator;
+import org.jfree.chart.imagemap.StandardURLTagFragmentGenerator;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.awt.*;
+
+import static org.junit.Assert.*;
+
+public class ChartEntityTest {
+
+    private ChartEntity chartEntityRect, chartEntityPoly;
+
+    @Before
+    public void setUp() throws Exception {
+        chartEntityRect = new ChartEntity(new Rectangle(1, 2, 3, 4));
+        chartEntityPoly = new ChartEntity(new Polygon(new int[]{1, 2, 3, 4, 5}, new int[]{1, 2, 3, 4, 5},5));
+    }
+
+    @Test
+    public void testgetShapeType() {
+        assertEquals("rect", chartEntityRect.getShapeType());
+        assertEquals("poly", chartEntityPoly.getShapeType());
+    }
+
+    @Test
+    public void testgetShapeCoords() {
+        assertEquals("1,2,4,6", chartEntityRect.getShapeCoords());
+        assertEquals("1,1,2,2,3,3,4,4,5,5,5,5", chartEntityPoly.getShapeCoords());
+    }
+
+    @Test
+    public void testgetImageMapAreaTag() {
+        StandardToolTipTagFragmentGenerator toolTipGenerator = new StandardToolTipTagFragmentGenerator();
+        StandardURLTagFragmentGenerator urlTagGenerator = new StandardURLTagFragmentGenerator();
+        assertEquals("", chartEntityRect.getImageMapAreaTag(toolTipGenerator, urlTagGenerator));
+        chartEntityRect.setToolTipText(" a nice rectangle");
+        assertEquals("<area shape=\"rect\" coords=\"1,2,4,6\" title=\" a nice rectangle\" alt=\"\" nohref=\"nohref\"/>",
+                chartEntityRect.getImageMapAreaTag(toolTipGenerator, urlTagGenerator));
+        chartEntityRect.setURLText("http://www.example.com/jfreechart");
+        assertEquals("<area shape=\"rect\" coords=\"1,2,4,6\" title=\" a nice rectangle\" alt=\"\" href=\"http://www.example.com/jfreechart\"/>",
+                chartEntityRect.getImageMapAreaTag(toolTipGenerator, urlTagGenerator));
+        chartEntityPoly.setURLText("http://www.example.com/jfreechart");
+        assertEquals("<area shape=\"poly\" coords=\"1,1,2,2,3,3,4,4,5,5,5,5\" href=\"http://www.example.com/jfreechart\" alt=\"\"/>",
+                chartEntityPoly.getImageMapAreaTag(toolTipGenerator, urlTagGenerator));
+    }
+
+    @Test
+    public void testToString() {
+        assertEquals("ChartEntity: tooltip = null", chartEntityRect.toString());
+        chartEntityRect.setToolTipText(" a nice rectangle");
+        assertEquals("ChartEntity: tooltip =  a nice rectangle", chartEntityRect.toString());
+    }
+
+    @Test
+    public void testEquals() {
+        assertNotEquals(chartEntityRect,null);
+        assertEquals(chartEntityRect,chartEntityRect);
+        assertNotEquals(chartEntityRect,chartEntityPoly);
+        assertEquals(chartEntityRect, new ChartEntity(new Rectangle(1, 2, 3, 4)));
+        assertNotEquals(chartEntityRect, new ChartEntity(new Rectangle(2, 2, 3, 4)));
+        assertNotEquals(chartEntityRect, new ChartEntity(new Rectangle(1, 2, 3, 5)));
+        assertNotEquals(chartEntityPoly, new ChartEntity(new Polygon(new int[]{1, 2, 3, 4}, new int[]{1, 2, 3, 4},4)));
+        assertNotEquals(chartEntityPoly, new ChartEntity(new Polygon(new int[]{1, 2, 3, 4, 6}, new int[]{1, 2, 3, 4, 6},5)));
+        ChartEntity rectToolTip = new ChartEntity(new Rectangle(1, 2, 3, 4),"toolTip");
+        assertNotEquals(chartEntityRect, rectToolTip);
+        assertEquals(rectToolTip, new ChartEntity(new Rectangle(1, 2, 3, 4),"toolTip"));
+        ChartEntity rectToolUrl = new ChartEntity(new Rectangle(1, 2, 3, 4),"toolTip", "http://www.example.com/jfreechart");
+        assertNotEquals(chartEntityRect, rectToolUrl);
+        assertNotEquals(rectToolTip,rectToolUrl);
+    }
+
+
+}
\ No newline at end of file