8349091: Charts: exception initializing in a background thread

Reviewed-by: kizune, kcr

Author: Andy Goryachev

Diff for: modules/javafx.controls/src/main/java/javafx/scene/chart/AreaChart.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,24 +25,33 @@
 
 package javafx.scene.chart;
 
-import java.util.*;
-
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
 import javafx.animation.FadeTransition;
 import javafx.animation.Interpolator;
 import javafx.animation.KeyFrame;
 import javafx.animation.KeyValue;
 import javafx.animation.Timeline;
-import javafx.application.Platform;
 import javafx.beans.NamedArg;
 import javafx.beans.property.BooleanProperty;
 import javafx.beans.property.DoubleProperty;
 import javafx.beans.property.SimpleDoubleProperty;
 import javafx.collections.FXCollections;
 import javafx.collections.ListChangeListener;
 import javafx.collections.ObservableList;
+import javafx.css.CssMetaData;
+import javafx.css.Styleable;
+import javafx.css.StyleableBooleanProperty;
+import javafx.css.StyleableProperty;
+import javafx.css.converter.BooleanConverter;
 import javafx.scene.AccessibleRole;
 import javafx.scene.Group;
 import javafx.scene.Node;
+import javafx.scene.chart.LineChart.SortingPolicy;
 import javafx.scene.layout.StackPane;
 import javafx.scene.shape.ClosePath;
 import javafx.scene.shape.LineTo;
@@ -51,14 +60,7 @@
 import javafx.scene.shape.PathElement;
 import javafx.scene.shape.StrokeLineJoin;
 import javafx.util.Duration;
-
 import com.sun.javafx.charts.Legend.LegendItem;
-import javafx.css.converter.BooleanConverter;
-import javafx.css.CssMetaData;
-import javafx.css.Styleable;
-import javafx.css.StyleableBooleanProperty;
-import javafx.css.StyleableProperty;
-import javafx.scene.chart.LineChart.SortingPolicy;
 
 /**
  * AreaChart - Plots the area between the line that connects the data points and
@@ -541,7 +543,7 @@ private Node createSymbol(Series<X,Y> series, int seriesIndex, final Data<X,Y> i
             symbol = new StackPane();
             symbol.setAccessibleRole(AccessibleRole.TEXT);
             symbol.setAccessibleRoleDescription("Point");
-            symbol.focusTraversableProperty().bind(Platform.accessibilityActiveProperty());
+            symbol.setFocusTraversable(isAccessibilityActive());
             item.setNode(symbol);
         }
         // set symbol styles

Diff for: modules/javafx.controls/src/main/java/javafx/scene/chart/BarChart.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -25,38 +25,38 @@
 
 package javafx.scene.chart;
 
-import java.util.*;
-
-import javafx.scene.AccessibleRole;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
 import javafx.animation.Animation;
 import javafx.animation.FadeTransition;
 import javafx.animation.Interpolator;
 import javafx.animation.KeyFrame;
 import javafx.animation.KeyValue;
 import javafx.animation.ParallelTransition;
 import javafx.animation.Timeline;
-import javafx.application.Platform;
 import javafx.beans.NamedArg;
 import javafx.beans.property.DoubleProperty;
 import javafx.collections.FXCollections;
+import javafx.collections.ListChangeListener;
 import javafx.collections.ObservableList;
+import javafx.css.CssMetaData;
+import javafx.css.PseudoClass;
+import javafx.css.Styleable;
+import javafx.css.StyleableDoubleProperty;
+import javafx.css.StyleableProperty;
+import javafx.css.converter.SizeConverter;
 import javafx.geometry.Orientation;
+import javafx.scene.AccessibleRole;
 import javafx.scene.Node;
 import javafx.scene.layout.StackPane;
 import javafx.util.Duration;
-
 import com.sun.javafx.charts.Legend.LegendItem;
 
-import javafx.css.StyleableDoubleProperty;
-import javafx.css.CssMetaData;
-import javafx.css.PseudoClass;
-
-import javafx.css.converter.SizeConverter;
-import javafx.collections.ListChangeListener;
-
-import javafx.css.Styleable;
-import javafx.css.StyleableProperty;
-
 /**
  * A chart that plots bars indicating data values for a category. The bars can be vertical or horizontal depending on
  * which axis is a category axis.
@@ -559,7 +559,7 @@ private Node createBar(Series<X,Y> series, int seriesIndex, final Data<X,Y> item
             bar = new StackPane();
             bar.setAccessibleRole(AccessibleRole.TEXT);
             bar.setAccessibleRoleDescription("Bar");
-            bar.focusTraversableProperty().bind(Platform.accessibilityActiveProperty());
+            bar.setFocusTraversable(isAccessibilityActive());
             item.setNode(bar);
         }
         bar.getStyleClass().setAll("chart-bar", "series" + seriesIndex, "data" + itemIndex, series.defaultColorStyleClass);

Diff for: modules/javafx.controls/src/main/java/javafx/scene/chart/BubbleChart.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,10 +28,8 @@
 import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
-
 import javafx.animation.FadeTransition;
 import javafx.animation.ParallelTransition;
-import javafx.application.Platform;
 import javafx.beans.NamedArg;
 import javafx.collections.FXCollections;
 import javafx.collections.ObservableList;
@@ -41,7 +39,6 @@
 import javafx.scene.layout.StackPane;
 import javafx.scene.shape.Ellipse;
 import javafx.util.Duration;
-
 import com.sun.javafx.charts.Legend.LegendItem;
 
 /**
@@ -270,7 +267,7 @@ public Object queryAccessibleAttribute(AccessibleAttribute attribute, Object...
             };
             bubble.setAccessibleRole(AccessibleRole.TEXT);
             bubble.setAccessibleRoleDescription("Bubble");
-            bubble.focusTraversableProperty().bind(Platform.accessibilityActiveProperty());
+            bubble.setFocusTraversable(isAccessibilityActive());
             item.setNode(bubble);
         }
         // set bubble styles

Diff for: modules/javafx.controls/src/main/java/javafx/scene/chart/Chart.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2022, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,9 +28,6 @@
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
-
-import com.sun.javafx.scene.control.skin.Utils;
-
 import javafx.animation.Animation;
 import javafx.animation.KeyFrame;
 import javafx.application.Platform;
@@ -40,28 +37,30 @@
 import javafx.beans.property.SimpleBooleanProperty;
 import javafx.beans.property.StringProperty;
 import javafx.beans.property.StringPropertyBase;
+import javafx.beans.value.ChangeListener;
+import javafx.beans.value.ObservableValue;
 import javafx.beans.value.WritableValue;
 import javafx.collections.ObservableList;
+import javafx.css.CssMetaData;
+import javafx.css.Styleable;
+import javafx.css.StyleableBooleanProperty;
+import javafx.css.StyleableObjectProperty;
+import javafx.css.StyleableProperty;
+import javafx.css.converter.BooleanConverter;
+import javafx.css.converter.EnumConverter;
 import javafx.geometry.Pos;
 import javafx.geometry.Side;
 import javafx.scene.Node;
+import javafx.scene.Scene;
 import javafx.scene.control.Label;
 import javafx.scene.layout.Pane;
 import javafx.scene.layout.Region;
-
+import javafx.stage.Window;
+import javafx.util.Subscription;
 import com.sun.javafx.charts.ChartLayoutAnimator;
 import com.sun.javafx.charts.Legend;
 import com.sun.javafx.scene.NodeHelper;
-
-import javafx.css.StyleableBooleanProperty;
-import javafx.css.StyleableObjectProperty;
-import javafx.css.CssMetaData;
-
-import javafx.css.converter.BooleanConverter;
-import javafx.css.converter.EnumConverter;
-
-import javafx.css.Styleable;
-import javafx.css.StyleableProperty;
+import com.sun.javafx.scene.control.skin.Utils;
 
 /**
  * Base class for all charts. It has 3 parts the title, legend and chartContent. The chart content is populated by the
@@ -104,6 +103,9 @@ public abstract class Chart extends Region {
     /** Animator for animating stuff on the chart */
     private final ChartLayoutAnimator animator = new ChartLayoutAnimator(chartContent);
 
+    // SimpleBooleanProperty or Subscription
+    private volatile Object accessibilityActive;
+
     // -------------- PUBLIC PROPERTIES --------------------------------------------------------------------------------
 
     /** The chart title */
@@ -274,7 +276,6 @@ protected ObservableList<Node> getChartChildren() {
      */
     public Chart() {
         titleLabel.setAlignment(Pos.CENTER);
-        titleLabel.focusTraversableProperty().bind(Platform.accessibilityActiveProperty());
         getChildren().addAll(titleLabel, chartContent);
         getStyleClass().add("chart");
         titleLabel.getStyleClass().add("chart-title");
@@ -511,6 +512,62 @@ public StyleableProperty<Boolean> getStyleableProperty(Chart node) {
         return getClassCssMetaData();
     }
 
-}
+    private void handleAccessibilityActive(boolean on) {
+        titleLabel.setFocusTraversable(on);
+        updateSymbolFocusable(on);
+    }
 
+    /**
+     * Invoked in the FX application thread when accessibility active platform property changes.
+     * The child classes should override this method to set focus traversable flag on every symbol, as well as
+     * other elements that need to be focusable.
+     * @param on whether the accessibility is active
+     */
+    // package protected: custom charts must handle accessbility on their own
+    void updateSymbolFocusable(boolean on) {
+    }
 
+    /**
+     * When called from JavaFX application thread, returns the value of the property.
+     * When called from any other thread, returns false and sets up the machinery to
+     * invoke {@code updateSymbolFocusable()} when needed.
+     * The chart implementations should use this method to set focus travesable flags on the nodes
+     * which needs to be focus traversable when accessibility is on.
+     * @return
+     */
+    // package protected: custom charts must handle accessbility on their own
+    final boolean isAccessibilityActive() {
+        if (Platform.isFxApplicationThread()) {
+            if (accessibilityActive instanceof SimpleBooleanProperty p) {
+                return p.get();
+            } else {
+                if (accessibilityActive instanceof Subscription sub) {
+                    sub.unsubscribe();
+                }
+                SimpleBooleanProperty active = new SimpleBooleanProperty();
+                accessibilityActive = active;
+                active.addListener((src, prev, on) -> {
+                    handleAccessibilityActive(on);
+                });
+                active.bind(Platform.accessibilityActiveProperty());
+                return active.get();
+            }
+        } else {
+            // chart and its data are allowed to be constructed in a background thread
+            if (accessibilityActive == null) {
+                // set up a subscription to be fired once the chart becomes a part of the scene graph
+                accessibilityActive = sceneProperty()
+                    .flatMap(Scene::windowProperty)
+                    .subscribe((w) -> {
+                        if (w != null) {
+                            // will unsubscribe when appears in a window, in the fx app thread
+                            if (isAccessibilityActive()) {
+                                handleAccessibilityActive(true);
+                            }
+                        }
+                    });
+            }
+            return false;
+        }
+    }
+}

Diff for: modules/javafx.controls/src/main/java/javafx/scene/chart/LineChart.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2010, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2010, 2025, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -26,17 +26,16 @@
 package javafx.scene.chart;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-
+import javafx.animation.Animation;
 import javafx.animation.FadeTransition;
 import javafx.animation.Interpolator;
 import javafx.animation.KeyFrame;
 import javafx.animation.KeyValue;
 import javafx.animation.Timeline;
-import javafx.animation.Animation;
-import javafx.application.Platform;
 import javafx.beans.NamedArg;
 import javafx.beans.property.BooleanProperty;
 import javafx.beans.property.DoubleProperty;
@@ -46,26 +45,20 @@
 import javafx.collections.FXCollections;
 import javafx.collections.ListChangeListener;
 import javafx.collections.ObservableList;
+import javafx.css.CssMetaData;
+import javafx.css.Styleable;
+import javafx.css.StyleableBooleanProperty;
+import javafx.css.StyleableProperty;
+import javafx.css.converter.BooleanConverter;
 import javafx.scene.AccessibleRole;
 import javafx.scene.Node;
 import javafx.scene.layout.StackPane;
 import javafx.scene.shape.LineTo;
 import javafx.scene.shape.Path;
 import javafx.scene.shape.StrokeLineJoin;
 import javafx.util.Duration;
-
 import com.sun.javafx.charts.Legend.LegendItem;
 
-import javafx.css.StyleableBooleanProperty;
-import javafx.css.CssMetaData;
-
-import javafx.css.converter.BooleanConverter;
-
-import java.util.*;
-
-import javafx.css.Styleable;
-import javafx.css.StyleableProperty;
-
 /**
  * Line Chart plots a line connecting the data points in a series. The data points
  * themselves can be represented by symbols optionally. Line charts are usually used
@@ -530,7 +523,7 @@ private Node createSymbol(Series<X, Y> series, int seriesIndex, final Data<X,Y>
             symbol = new StackPane();
             symbol.setAccessibleRole(AccessibleRole.TEXT);
             symbol.setAccessibleRoleDescription("Point");
-            symbol.focusTraversableProperty().bind(Platform.accessibilityActiveProperty());
+            symbol.setFocusTraversable(isAccessibilityActive());
             item.setNode(symbol);
         }
         // set symbol styles