Axis: expose method to recompute transformation cache

If the axis gets changed multiple times during event handling, but the
cache is only updated during layout, axes transforms from the event
handlers use outdated transformations.

This has the effect that e.g. panning only applies the first mouse event
in each pulse and the panning is a lot slower than the actual mouse
movement.

This adds a method to the axes which can be called by plugins which use
and update the axis range.

chartfx-chart/src/main/java/io/fair_acc/chartfx/axes/Axis.java

@@ -361,4 +361,11 @@ public interface Axis extends AxisDescription {
      * @return the canvas of the axis
      */
     Canvas getCanvas();
+
+    /**
+     * Hook to manually update the cached axis transforms outside of the render loop.
+     * This is needed e.g. when plugins adjust the axes and at the same time need to perform
+     * transformations with the modified ranges.
+     */
+    default void updateCachedTransforms() {};
 }

chartfx-chart/src/main/java/io/fair_acc/chartfx/axes/spi/AbstractAxis.java

@@ -250,7 +250,7 @@ protected void updateAxisRange(double length) {
         updateScaleAndUnitPrefix();
 
         // Update the cache to the new range
-        updateCachedVariables();
+        updateCachedTransforms();
 
         // Compute new tick marks and locations
         updateMajorTickMarks(range);

chartfx-chart/src/main/java/io/fair_acc/chartfx/axes/spi/AbstractAxisParameter.java

@@ -4,7 +4,6 @@
 import java.util.Objects;
 
 import io.fair_acc.chartfx.ui.css.*;
-import io.fair_acc.chartfx.ui.layout.ChartPane;
 import io.fair_acc.chartfx.utils.PropUtil;
 import io.fair_acc.dataset.events.BitState;
 import io.fair_acc.dataset.events.ChartBits;
@@ -15,10 +14,7 @@
 import javafx.css.*;
 import javafx.scene.layout.Pane;
 import javafx.scene.layout.Region;
-import javafx.scene.paint.Color;
-import javafx.scene.paint.Paint;
 import javafx.scene.text.Font;
-import javafx.scene.text.TextAlignment;
 import javafx.util.StringConverter;
 
 import io.fair_acc.chartfx.Chart;
@@ -360,7 +356,8 @@ public String getUserAgentStylesheet() {
     /**
      * to be overwritten by derived class that want to cache variables for efficiency reasons
      */
-    protected void updateCachedVariables() { // NOPMD by rstein function can but does not have to be overwritten
+    @Override
+    public void updateCachedTransforms() { // NOPMD by rstein function can but does not have to be overwritten
         // called once new axis parameters have been established
         cachedOffset = getSide().isHorizontal() ? 0 : getLength();
     }
@@ -816,7 +813,8 @@ public ObjectProperty<AxisLabelOverlapPolicy> overlapPolicyProperty() {
 
     @Override
     public boolean set(final double min, final double max) {
-        return PropUtil.set(minProp, min) | PropUtil.set(maxProp, max);
+        final boolean result = PropUtil.set(minProp, min) | PropUtil.set(maxProp, max);
+        return result;
     }
 
     @Override

chartfx-chart/src/main/java/io/fair_acc/chartfx/axes/spi/DefaultNumericAxis.java

@@ -1,10 +1,5 @@
 package io.fair_acc.chartfx.axes.spi;
 
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.Collections;
-import java.util.List;
-
 import io.fair_acc.chartfx.utils.PropUtil;
 import io.fair_acc.dataset.spi.fastutil.DoubleArrayList;
 import javafx.beans.property.BooleanProperty;
@@ -540,8 +535,8 @@ protected double computeTickUnit(final double rawTickUnit) {
     }
 
     @Override
-    protected void updateCachedVariables() {
-        super.updateCachedVariables();
+    public void updateCachedTransforms() {
+        super.updateCachedTransforms();
         if (cache == null) { // lgtm [java/useless-null-check] NOPMD NOSONAR -- called from static initializer
             return;
         }

chartfx-chart/src/main/java/io/fair_acc/chartfx/axes/spi/OscilloscopeAxis.java

@@ -372,8 +372,8 @@ protected void recomputeClampedRange() {
     }
 
     @Override
-    protected void updateCachedVariables() {
-        super.updateCachedVariables();
+    public void updateCachedTransforms() {
+        super.updateCachedTransforms();
         if (cache == null) { // lgtm [java/useless-null-check] NOPMD NOSONAR -- called from static initializer
             return;
         }

chartfx-chart/src/test/java/io/fair_acc/chartfx/axes/spi/DefaultNumericAxisTests.java

@@ -80,7 +80,7 @@ public void parameterTests() {
         assertTrue(axis.isLogAxis());
         assertEquals(LogAxisType.LOG10_SCALE, axis.getLogAxisType());
         axis.setMin(0.1);
-        axis.updateCachedVariables();
+        axis.updateCachedTransforms();
         axis.layoutChildren();
         assertEquals(axis.getZeroPosition(), axis.getDisplayPosition(axis.getMin()));
         assertEquals(10, axis.getLogarithmBase());
@@ -89,7 +89,7 @@ public void parameterTests() {
 
         axis.setLogAxis(false);
         assertFalse(axis.isLogAxis());
-        axis.updateCachedVariables();
+        axis.updateCachedTransforms();
         tickValues.clear();
         axis.calculateMinorTickValues(tickValues);
     }

chartfx-chart/src/test/java/io/fair_acc/chartfx/axes/spi/OscilloscopeAxisTests.java

@@ -86,7 +86,7 @@ public void identityTests() {
         final OscilloscopeAxis axis = new OscilloscopeAxis("axis title", 0.0, 100.0, 10.0);
 
         assertDoesNotThrow(() -> axis.setSide(Side.BOTTOM));
-        assertDoesNotThrow(axis::updateCachedVariables);
+        assertDoesNotThrow(axis::updateCachedTransforms);
 
         final double zero = axis.getDisplayPosition(axis.getValueForDisplay(0));
         assertEquals(0.0, zero);
@@ -167,13 +167,13 @@ public void setterGetterTests() {
         axis.setTickUnitSupplier(testTickUnitSupplier);
         assertEquals(testTickUnitSupplier, axis.getTickUnitSupplier());
 
-        assertDoesNotThrow(axis::updateCachedVariables);
+        assertDoesNotThrow(axis::updateCachedTransforms);
 
         assertDoesNotThrow(() -> axis.setSide(Side.BOTTOM));
-        assertDoesNotThrow(axis::updateCachedVariables);
+        assertDoesNotThrow(axis::updateCachedTransforms);
 
         assertDoesNotThrow(() -> axis.setSide(Side.LEFT));
-        assertDoesNotThrow(axis::updateCachedVariables);
+        assertDoesNotThrow(axis::updateCachedTransforms);
 
         assertNotNull(axis.getAxisTransform());