8370446: Support dialogs with StageStyle.EXTENDED

modules/javafx.controls/src/main/java/javafx/scene/control/Dialog.java

@@ -43,6 +43,7 @@
 import javafx.event.EventType;
 import javafx.scene.Node;
 import javafx.scene.control.ButtonBar.ButtonData;
+import javafx.scene.layout.HeaderBar;
 import javafx.stage.Modality;
 import javafx.stage.Stage;
 import javafx.stage.StageStyle;
@@ -461,10 +462,10 @@ public final Modality getModality() {
     }
 
     /**
-     * Specifies the style for this dialog. This must be done prior to making
-     * the dialog visible. The style is one of: StageStyle.DECORATED,
-     * StageStyle.UNDECORATED, StageStyle.TRANSPARENT, StageStyle.UTILITY,
-     * or StageStyle.UNIFIED.
+     * Specifies the style for this dialog. This must be done prior to making the dialog visible.
+     * <p>
+     * Note that a dialog with the {@link StageStyle#EXTENDED} style should also specify a {@link HeaderBar} with
+     * the {@link DialogPane#setHeaderBar(HeaderBar)} method, as otherwise the dialog window will not be draggable.
      *
      * @param style the style for this dialog.
      *

modules/javafx.controls/src/main/java/javafx/scene/control/DialogPane.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2014, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2014, 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
@@ -31,6 +31,8 @@
 import java.util.Map;
 import java.util.WeakHashMap;
 
+import com.sun.javafx.PreviewFeature;
+import com.sun.javafx.css.StyleManager;
 import com.sun.javafx.scene.control.skin.Utils;
 import com.sun.javafx.scene.control.skin.resources.ControlResources;
 import javafx.beans.DefaultProperty;
@@ -51,22 +53,24 @@
 import javafx.css.StyleableObjectProperty;
 import javafx.css.StyleableProperty;
 import javafx.css.StyleableStringProperty;
+import javafx.css.converter.StringConverter;
 import javafx.event.ActionEvent;
+import javafx.geometry.HPos;
 import javafx.geometry.Pos;
+import javafx.geometry.VPos;
 import javafx.scene.AccessibleRole;
 import javafx.scene.Node;
 import javafx.scene.control.ButtonBar.ButtonData;
 import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
 import javafx.scene.layout.ColumnConstraints;
 import javafx.scene.layout.GridPane;
+import javafx.scene.layout.HeaderBar;
 import javafx.scene.layout.Pane;
 import javafx.scene.layout.Priority;
 import javafx.scene.layout.Region;
 import javafx.scene.layout.StackPane;
-
-import com.sun.javafx.css.StyleManager;
-import javafx.css.converter.StringConverter;
+import javafx.stage.StageStyle;
 
 /**
  * DialogPane should be considered to be the root node displayed within a
@@ -213,11 +217,15 @@ public DialogPane() {
         setAccessibleRole(AccessibleRole.DIALOG);
 
         headerTextPanel = new GridPane();
+        headerTextPanel.setVisible(false);
+        headerTextPanel.setManaged(false);
         getChildren().add(headerTextPanel);
 
         graphicContainer = new StackPane();
 
         contentLabel = createContentLabel("");
+        contentLabel.setVisible(false);
+        contentLabel.setManaged(false);
         getChildren().add(contentLabel);
 
         // Add this listener before calling #createButtonBar, so that the listener added in #createButtonBar will run
@@ -430,6 +438,74 @@ public CssMetaData<DialogPane,String> getCssMetaData() {
         return imageUrl;
     }
 
+    // --- header bar
+    private ObjectProperty<HeaderBar> headerBar;
+
+    /**
+     * Specifies the {@link HeaderBar} for the dialog. The {@code HeaderBar} will be placed at the
+     * top of the dialog window, and extend the entire width of the window. This property will only
+     * be used if the dialog window is configured with the {@link StageStyle#EXTENDED} style; it has
+     * no effect for other styles.
+     *
+     * @return the {@code headerBar} property
+     * @defaultValue {@code null}
+     * @since 26
+     * @deprecated This is a preview feature which may be changed or removed in a future release.
+     */
+    @Deprecated(since = "26")
+    public final ObjectProperty<HeaderBar> headerBarProperty() {
+        if (headerBar == null) {
+            PreviewFeature.HEADER_BAR.checkEnabled();
+            headerBar = new SimpleObjectProperty<>(this, "headerBar") {
+                WeakReference<HeaderBar> wref = new WeakReference<>(null);
+
+                @Override
+                protected void invalidated() {
+                    HeaderBar oldValue = wref.get();
+                    if (oldValue != null) {
+                        getChildren().remove(oldValue);
+                    }
+
+                    HeaderBar newValue = get();
+                    if (newValue != null) {
+                        getChildren().add(newValue);
+                    }
+
+                    wref = new WeakReference<>(newValue);
+                }
+            };
+        }
+
+        return headerBar;
+    }
+
+    /**
+     * Gets the value of the {@link #headerBarProperty() headerBar} property.
+     *
+     * @return the {@code HeaderBar}
+     * @since 26
+     * @deprecated This is a preview feature which may be changed or removed in a future release.
+     */
+    @Deprecated(since = "26")
+    public final HeaderBar getHeaderBar() {
+        PreviewFeature.HEADER_BAR.checkEnabled();
+        return headerBar != null ? headerBar.get() : null;
+    }
+
+    /**
+     * Sets the value of the {@link #headerBarProperty() headerBar} property.
+     *
+     * @param value the new value
+     * @since 26
+     * @deprecated This is a preview feature which may be changed or removed in a future release.
+     */
+    @Deprecated(since = "26")
+    public final void setHeaderBar(HeaderBar value) {
+        PreviewFeature.HEADER_BAR.checkEnabled();
+        if (headerBar != null || value != null) {
+            headerBarProperty().set(value);
+        }
+    }
 
     // --- header
     private final ObjectProperty<Node> header = new SimpleObjectProperty<>(null) {
@@ -878,11 +954,15 @@ protected Node createDetailsButton() {
         final Node content = getActualContent();
         final Node graphic = getActualGraphic();
         final Node expandableContent = getExpandableContent();
+        final HeaderBar headerBar = getHeaderBar();
 
         final double graphicPrefWidth = hasHeader || graphic == null ? 0 : graphic.prefWidth(-1);
         final double headerPrefHeight = hasHeader ? header.prefHeight(w) : 0;
         final double buttonBarPrefHeight = buttonBar == null ? 0 : buttonBar.prefHeight(w);
         final double graphicPrefHeight = hasHeader || graphic == null ? 0 : graphic.prefHeight(-1);
+        final double headerBarPrefHeight = headerBar != null
+            ? Utils.boundedSize(headerBar.prefHeight(w), headerBar.minHeight(w), headerBar.maxHeight(w))
+            : 0;
 
         final double expandableContentPrefHeight;
         final double contentAreaHeight;
@@ -894,16 +974,20 @@ protected Node createDetailsButton() {
             // precedence goes to content and then expandable content
             contentAreaHeight = isExpanded() ? content.prefHeight(availableContentWidth) : 0;
             contentAndGraphicHeight = hasHeader ? contentAreaHeight : Math.max(graphicPrefHeight, contentAreaHeight);
-            expandableContentPrefHeight = h - (headerPrefHeight + contentAndGraphicHeight + buttonBarPrefHeight);
+            expandableContentPrefHeight = h - (headerBarPrefHeight + headerPrefHeight + contentAndGraphicHeight + buttonBarPrefHeight);
         } else {
             // content gets the lowest precedence
             expandableContentPrefHeight = isExpanded() ? expandableContent.prefHeight(w) : 0;
-            contentAreaHeight = h - (headerPrefHeight + expandableContentPrefHeight + buttonBarPrefHeight);
+            contentAreaHeight = h - (headerBarPrefHeight + headerPrefHeight + expandableContentPrefHeight + buttonBarPrefHeight);
             contentAndGraphicHeight = hasHeader ? contentAreaHeight : Math.max(graphicPrefHeight, contentAreaHeight);
         }
 
+        if (headerBar != null) {
+            layoutInArea(headerBar, 0, 0, w, headerBarPrefHeight, 0, HPos.LEFT, VPos.TOP);
+        }
+
         double x = leftPadding;
-        double y = topPadding;
+        double y = topPadding + headerBarPrefHeight;
 
         if (! hasHeader) {
             if (graphic != null) {
@@ -933,6 +1017,7 @@ protected Node createDetailsButton() {
 
     /** {@inheritDoc} */
     @Override protected double computeMinWidth(double height) {
+        double headerBarMinWidth = getHeaderBar() instanceof HeaderBar hb ? hb.minWidth(height) : 0;
         double headerMinWidth = hasHeader() ? getActualHeader().minWidth(height) + 10 : 0;
         double contentMinWidth = getActualContent().minWidth(height);
         double buttonBarMinWidth = buttonBar == null ? 0 : buttonBar.minWidth(height);
@@ -949,13 +1034,14 @@ protected Node createDetailsButton() {
                 Math.max(Math.max(headerMinWidth, expandableContentMinWidth), Math.max(contentMinWidth, buttonBarMinWidth)) +
                 snappedRightInset();
 
-        return snapSizeX(minWidth);
+        return snapSizeX(Math.max(minWidth, headerBarMinWidth));
     }
 
     /** {@inheritDoc} */
     @Override protected double computeMinHeight(double width) {
         final boolean hasHeader = hasHeader();
 
+        double headerBarMinHeight = getHeaderBar() instanceof HeaderBar hb ? hb.minHeight(width) : 0;
         double headerMinHeight = hasHeader ? getActualHeader().minHeight(width) : 0;
         double buttonBarMinHeight = buttonBar == null ? 0 : buttonBar.minHeight(width);
 
@@ -976,6 +1062,7 @@ protected Node createDetailsButton() {
         }
 
         double minHeight = snappedTopInset() +
+                headerBarMinHeight +
                 headerMinHeight +
                 Math.max(graphicMinHeight, contentMinHeight) +
                 expandableContentMinHeight +
@@ -991,6 +1078,8 @@ protected Node createDetailsButton() {
         double contentPrefWidth = getActualContent().prefWidth(height);
         double buttonBarPrefWidth = buttonBar == null ? 0 : buttonBar.prefWidth(height);
         double graphicPrefWidth = getActualGraphic().prefWidth(height);
+        double headerBarPrefWidth = getHeaderBar() instanceof HeaderBar hb
+            ? Utils.boundedSize(hb.prefWidth(height), hb.minWidth(height), hb.maxWidth(height)) : 0;
 
         double expandableContentPrefWidth = 0;
         final Node expandableContent = getExpandableContent();
@@ -1003,7 +1092,7 @@ protected Node createDetailsButton() {
                Math.max(Math.max(headerPrefWidth, expandableContentPrefWidth), Math.max(contentPrefWidth, buttonBarPrefWidth)) +
                snappedRightInset();
 
-        return snapSizeX(prefWidth);
+        return snapSizeX(Math.max(prefWidth, headerBarPrefWidth));
     }
 
     /** {@inheritDoc} */
@@ -1012,6 +1101,8 @@ protected Node createDetailsButton() {
 
         double headerPrefHeight = hasHeader ? getActualHeader().prefHeight(width) : 0;
         double buttonBarPrefHeight = buttonBar == null ? 0 : buttonBar.prefHeight(width);
+        double headerBarPrefHeight = getHeaderBar() instanceof HeaderBar hb
+            ? Utils.boundedSize(hb.prefHeight(width), hb.minHeight(width), hb.maxHeight(width)) : 0;
 
         Node graphic = getActualGraphic();
         double graphicPrefWidth = hasHeader ? 0 : graphic.prefWidth(-1);
@@ -1029,6 +1120,7 @@ protected Node createDetailsButton() {
         }
 
         double prefHeight = snappedTopInset() +
+               headerBarPrefHeight +
                headerPrefHeight +
                Math.max(graphicPrefHeight, contentPrefHeight) +
                expandableContentPrefHeight +

modules/javafx.controls/src/test/java/test/javafx/scene/control/DialogPaneTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 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
@@ -25,9 +25,11 @@
 
 package test.javafx.scene.control;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.*;
+
 import javafx.collections.ObservableList;
 import javafx.css.PseudoClass;
+import javafx.geometry.BoundingBox;
 import javafx.geometry.Bounds;
 import javafx.geometry.Insets;
 import javafx.scene.Node;
@@ -37,6 +39,7 @@
 import javafx.scene.image.Image;
 import javafx.scene.image.ImageView;
 import javafx.scene.layout.BorderPane;
+import javafx.scene.layout.HeaderBar;
 import javafx.scene.layout.StackPane;
 import javafx.scene.shape.Rectangle;
 import javafx.scene.text.Font;
@@ -151,4 +154,27 @@ private void verifyIdOfButtonInButtonBar(String id) {
             }
         }
     }
+
+    @Test
+    public void headerBarIsLocatedAtTopOfDialogPane() {
+        var headerBar = new HeaderBar();
+        headerBar.setMinHeight(20);
+        headerBar.setPrefHeight(20);
+        dialogPane.setHeaderBar(headerBar);
+        dialogPane.resize(1000, 1000);
+        dialogPane.applyCss();
+        dialogPane.layout();
+
+        assertEquals(
+            new BoundingBox(0, 0, 1000, 20),
+            dialogPane.lookup("HeaderBar").getLayoutBounds());
+
+        dialogPane.getChildren().stream()
+            .filter(Node::isVisible)
+            .filter(c -> c != headerBar)
+            .forEach(child ->
+                assertTrue(child.getLayoutY() >= headerBar.getHeight(), () ->
+                    child.getClass().getSimpleName() + " must be located below HeaderBar, layoutY = " + child.getLayoutBounds())
+            );
+    }
 }

modules/javafx.controls/src/test/java/test/javafx/scene/control/DialogTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 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
@@ -102,6 +102,17 @@ public void testDialogPrefHeight() {
         assertEquals(prefHeight, dialog.getDialogPane().getPrefHeight(), 0);
     }
 
+    @Test
+    public void testInitialDialogPaneIsAttachedToScene() {
+        class TestDialog extends Dialog<ButtonType> {
+            TestDialog() {
+                assertNotNull(getDialogPane().getScene());
+            }
+        }
+
+        assertDoesNotThrow(TestDialog::new);
+    }
+
     @Test
     public void testAddAndRemoveEventHandler() {
         var handler = new TestHandler();