8357067: Platform preference change can emit multiple notifications

modules/javafx.graphics/src/main/java/com/sun/glass/ui/Application.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
@@ -84,7 +84,7 @@ public void handleOpenFilesAction(Application app, long time, String files[]) {
         // currently used only on Mac OS X
         public void handleQuitAction(Application app, long time) {
         }
-        public void handlePreferencesChanged(Map<String, Object> preferences) {
+        public void handlePreferencesChanged(Map<String, Object> preferences, int suggestedDelayMillis) {
         }
     }
 
@@ -255,10 +255,10 @@ protected void notifyWillResignActive() {
         }
     }
 
-    protected void notifyPreferencesChanged(Map<String, Object> preferences) {
+    protected void notifyPreferencesChanged(Map<String, Object> preferences, int suggestedDelayMillis) {
         EventHandler handler = getEventHandler();
         if (handler != null) {
-            handler.handlePreferencesChanged(preferences);
+            handler.handlePreferencesChanged(preferences, suggestedDelayMillis);
         }
     }
 

modules/javafx.graphics/src/main/java/com/sun/javafx/application/PlatformImpl.java

@@ -28,6 +28,7 @@
 import com.sun.javafx.PlatformUtil;
 import com.sun.javafx.PreviewFeature;
 import com.sun.javafx.SecurityUtil;
+import com.sun.javafx.application.preferences.DelayedChangeAggregator;
 import com.sun.javafx.application.preferences.PlatformPreferences;
 import com.sun.javafx.application.preferences.PreferenceMapping;
 import com.sun.javafx.css.StyleManager;
@@ -57,6 +58,7 @@
 import javafx.application.ConditionalFeature;
 import javafx.beans.property.BooleanProperty;
 import javafx.beans.property.SimpleBooleanProperty;
+import javafx.collections.MapChangeListener;
 import javafx.scene.Scene;
 
 public class PlatformImpl {
@@ -918,6 +920,7 @@ private static boolean isSupportedImpl(ConditionalFeature feature) {
     }
 
     private static PlatformPreferences platformPreferences;
+    private static DelayedChangeAggregator platformPreferencesAggregator;
 
     public static PlatformPreferences getPlatformPreferences() {
         if (platformPreferences == null) {
@@ -937,7 +940,12 @@ public static void initPreferences(Map<String, Class<?>> platformKeys,
                                        Map<String, PreferenceMapping<?, ?>> platformKeyMappings,
                                        Map<String, Object> preferences) {
         platformPreferences = new PlatformPreferences(platformKeys, platformKeyMappings);
+        platformPreferences.addListener(PlatformImpl::checkHighContrastThemeChanged);
         platformPreferences.update(preferences);
+        platformPreferencesAggregator = new DelayedChangeAggregator(
+            platformPreferences::update,
+            Toolkit.getToolkit().getPrimaryTimer()::nanos,
+            PlatformImpl::runLater);
     }
 
     /**
@@ -948,17 +956,19 @@ public static void initPreferences(Map<String, Class<?>> platformKeys,
      * was removed, the corresponding key is mapped to {@code null}.
      *
      * @param preferences a map that includes the changed preferences
+     * @param suggestedDelayMillis a suggestion from the native implementation to delay the publication of
+     *                             changed preferences for the specified amount of time, because more changes
+     *                             may be coming
      */
-    public static void updatePreferences(Map<String, Object> preferences) {
+    public static void updatePreferences(Map<String, Object> preferences, int suggestedDelayMillis) {
         if (isFxApplicationThread()) {
-            checkHighContrastThemeChanged(preferences);
-            platformPreferences.update(preferences);
+            platformPreferencesAggregator.update(preferences, suggestedDelayMillis);
         } else {
             // Make a defensive copy in case the caller of this method decides to re-use or
             // modify its preferences map after the method returns. Don't use Map.copyOf
             // because the preferences map may contain null values.
             Map<String, Object> preferencesCopy = new HashMap<>(preferences);
-            runLater(() -> updatePreferences(preferencesCopy));
+            runLater(() -> updatePreferences(preferencesCopy, suggestedDelayMillis));
         }
     }
 
@@ -974,11 +984,15 @@ public static void checkPreferencesSupport() {
     }
 
     // This method will be removed when StyleThemes are added.
-    private static void checkHighContrastThemeChanged(Map<String, Object> preferences) {
-        if (Boolean.TRUE.equals(preferences.get("Windows.SPI.HighContrast"))) {
-            setAccessibilityTheme(preferences.get("Windows.SPI.HighContrastColorScheme") instanceof String s ? s : null);
-        } else {
-            setAccessibilityTheme(null);
+    private static void checkHighContrastThemeChanged(MapChangeListener.Change<? extends String, ?> change) {
+        if (change.getKey().equals("Windows.SPI.HighContrast")
+                || change.getKey().equals("Windows.SPI.HighContrastColorScheme")) {
+            setAccessibilityTheme(
+                platformPreferences
+                    .getBoolean("Windows.SPI.HighContrast")
+                    .filter(Boolean::booleanValue)
+                    .flatMap(_ -> platformPreferences.getString("Windows.SPI.HighContrastColorScheme"))
+                    .orElse(null));
         }
     }
 

modules/javafx.graphics/src/main/java/com/sun/javafx/application/preferences/DelayedChangeAggregator.java

@@ -0,0 +1,89 @@
+/*
+ * Copyright (c) 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package com.sun.javafx.application.preferences;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.concurrent.Executor;
+import java.util.function.Consumer;
+import java.util.function.LongSupplier;
+
+/**
+ * Aggregates multiple subsequent sets of changes into a single changeset, and notifies a consumer.
+ * Due to its delayed nature, the consumer may not be notified immediately when a changeset arrives.
+ * <p>
+ * This class is not thread-safe and can only safely be used on a single thread; this applies to the
+ * {@link #update(Map, int)}} method as well as the delayed executor.
+ */
+public final class DelayedChangeAggregator {
+
+    private final Executor delayedExecutor;
+    private final LongSupplier nanoTimeSupplier;
+    private final Consumer<Map<String, Object>> changeConsumer;
+    private final Map<String, Object> currentChangeSet;
+    private long elapsedTimeNanos;
+    private int serial;
+
+    public DelayedChangeAggregator(Consumer<Map<String, Object>> changeConsumer,
+                                   LongSupplier nanoTimeSupplier,
+                                   Executor delayedExecutor) {
+        this.changeConsumer = changeConsumer;
+        this.nanoTimeSupplier = nanoTimeSupplier;
+        this.delayedExecutor = delayedExecutor;
+        this.currentChangeSet = new HashMap<>();
+    }
+
+    /**
+     * Integrates the specified changeset into the current changeset, and applies the current changeset
+     * after the specified delay period. The delay is added to the current time, but will not elapse
+     * before any previous delays are scheduled to elapse.
+     *
+     * @param changeset the changeset
+     * @param delayMillis the delay period, in milliseconds
+     */
+    public void update(Map<String, Object> changeset, int delayMillis) {
+        if (delayMillis > 0 || !currentChangeSet.isEmpty()) {
+            int currentSerial = ++serial;
+            long newElapsedTimeNanos = nanoTimeSupplier.getAsLong() + (long)delayMillis * 1000000;
+            elapsedTimeNanos = Math.max(elapsedTimeNanos, newElapsedTimeNanos);
+            currentChangeSet.putAll(changeset);
+            delayedExecutor.execute(() -> update(currentSerial));
+        } else {
+            changeConsumer.accept(changeset);
+        }
+    }
+
+    private void update(int expectedSerial) {
+        if (expectedSerial == serial) {
+            if (nanoTimeSupplier.getAsLong() < elapsedTimeNanos) {
+                delayedExecutor.execute(() -> update(expectedSerial));
+            } else {
+                changeConsumer.accept(currentChangeSet);
+                currentChangeSet.clear();
+            }
+        }
+    }
+}

modules/javafx.graphics/src/main/java/com/sun/javafx/tk/quantum/QuantumToolkit.java

@@ -365,8 +365,8 @@ void runToolkit() {
                 }
 
                 @Override
-                public void handlePreferencesChanged(Map<String, Object> preferences) {
-                    PlatformImpl.updatePreferences(preferences);
+                public void handlePreferencesChanged(Map<String, Object> preferences, int suggestedDelayMillis) {
+                    PlatformImpl.updatePreferences(preferences, suggestedDelayMillis);
                 }
             });
         }

modules/javafx.graphics/src/main/native-glass/gtk/PlatformSupport.cpp

@@ -189,7 +189,7 @@ void PlatformSupport::updatePreferences() const {
             jCollectionsCls, jCollectionsUnmodifiableMap, newPreferences);
 
         if (!EXCEPTION_OCCURED(env)) {
-            env->CallVoidMethod(application, jApplicationNotifyPreferencesChanged, unmodifiablePreferences);
+            env->CallVoidMethod(application, jApplicationNotifyPreferencesChanged, unmodifiablePreferences, 0);
             EXCEPTION_OCCURED(env);
 
             env->DeleteLocalRef(unmodifiablePreferences);

modules/javafx.graphics/src/main/native-glass/gtk/glass_general.cpp

@@ -350,7 +350,7 @@ JNI_OnLoad(JavaVM *jvm, void *reserved)
     if (env->ExceptionCheck()) return JNI_ERR;
     jApplicationGetName = env->GetMethodID(jApplicationCls, "getName", "()Ljava/lang/String;");
     if (env->ExceptionCheck()) return JNI_ERR;
-    jApplicationNotifyPreferencesChanged = env->GetMethodID(jApplicationCls, "notifyPreferencesChanged", "(Ljava/util/Map;)V");
+    jApplicationNotifyPreferencesChanged = env->GetMethodID(jApplicationCls, "notifyPreferencesChanged", "(Ljava/util/Map;I)V");
     if (env->ExceptionCheck()) return JNI_ERR;
 
     clazz = env->FindClass("java/lang/Object");

modules/javafx.graphics/src/main/native-glass/gtk/glass_general.h

@@ -227,7 +227,7 @@ struct jni_exception: public std::exception {
     extern jmethodID jApplicationReportException; // reportException(Ljava/lang/Throwable;)V
     extern jmethodID jApplicationGetApplication; // GetApplication()()Lcom/sun/glass/ui/Application;
     extern jmethodID jApplicationGetName; // getName()Ljava/lang/String;
-    extern jmethodID jApplicationNotifyPreferencesChanged; // notifyPreferencesChanged(Ljava/util/Map;)V
+    extern jmethodID jApplicationNotifyPreferencesChanged; // notifyPreferencesChanged(Ljava/util/Map;I)V
 
     extern jclass jObjectCls; // java.lang.Object
     extern jmethodID jObjectEquals; // java.lang.Object#equals(Ljava/lang/Object;)Z

modules/javafx.graphics/src/main/native-glass/mac/GlassApplication.m

@@ -967,7 +967,7 @@ + (BOOL)syncRenderingDisabled {
     if ((*env)->ExceptionCheck(env)) return;
 
     javaIDs.MacApplication.notifyPreferencesChanged = (*env)->GetMethodID(
-            env, jClass, "notifyPreferencesChanged", "(Ljava/util/Map;)V");
+            env, jClass, "notifyPreferencesChanged", "(Ljava/util/Map;I)V");
     if ((*env)->ExceptionCheck(env)) return;
 
     if (jRunnableRun == NULL)

modules/javafx.graphics/src/main/native-glass/mac/PlatformSupport.m

@@ -307,7 +307,7 @@ - (void)updatePreferences {
             (*env)->CallVoidMethod(
                 env, application,
                 javaIDs.MacApplication.notifyPreferencesChanged,
-                unmodifiablePreferences);
+                unmodifiablePreferences, 0);
             GLASS_CHECK_EXCEPTION(env);
 
             (*env)->DeleteLocalRef(env, unmodifiablePreferences);

modules/javafx.graphics/src/main/native-glass/win/GlassApplication.cpp

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2011, 2024, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2011, 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
@@ -182,9 +182,11 @@ LRESULT GlassApplication::WindowProc(UINT msg, WPARAM wParam, LPARAM lParam)
         case WM_THEMECHANGED:
         case WM_SYSCOLORCHANGE:
         case WM_DWMCOLORIZATIONCOLORCHANGED:
+            // Usually, the WM_THEMECHANGED and WM_SYSCOLORCHANGE messages are followed by other
+            // messages or WinRT callbacks that may change platform preferences.
             if (m_platformSupport.updatePreferences(
-                    PlatformSupport::PreferenceType(PlatformSupport::PT_SYSTEM_COLORS |
-                                                    PlatformSupport::PT_UI_SETTINGS))) {
+                    PlatformSupport::PreferenceType(PlatformSupport::PT_SYSTEM_COLORS | PlatformSupport::PT_SYSTEM_PARAMS),
+                    /* delayedChangesExpected: */ msg == WM_THEMECHANGED || msg == WM_SYSCOLORCHANGE)) {
                 return 0;
             }
             break;
@@ -332,7 +334,7 @@ JNIEXPORT void JNICALL Java_com_sun_glass_ui_win_WinApplication_initIDs
     if (CheckAndClearException(env)) return;
 
     javaIDs.Application.notifyPreferencesChangedMID =
-        env->GetMethodID(cls, "notifyPreferencesChanged", "(Ljava/util/Map;)V");
+        env->GetMethodID(cls, "notifyPreferencesChanged", "(Ljava/util/Map;I)V");
     ASSERT(javaIDs.Application.notifyPreferencesChangedMID);
     if (CheckAndClearException(env)) return;