Add CefBrowserSettings.windowless_frame_rate (see chromiumembedded#459)

Also adds methods to dynamically set/get the frame rate and fixes
some pre-existing compile issues.

java/org/cef/CefBrowserSettings.java

@@ -0,0 +1,31 @@
+// Copyright (c) 2024 The Chromium Embedded Framework Authors. All rights
+// reserved. Use of this source code is governed by a BSD-style license that
+// can be found in the LICENSE file.
+
+package org.cef;
+
+/**
+ * Browser initialization settings. Specify NULL or 0 to get the recommended
+ * default values. The consequences of using custom values may not be well
+ * tested. Many of these and other settings can also configured using command-
+ * line switches.
+ */
+public class CefBrowserSettings {
+    /**
+     * The maximum rate in frames per second (fps) that CefRenderHandler::OnPaint
+     * will be called for a windowless browser. The actual fps may be lower if
+     * the browser cannot generate frames at the requested rate. The minimum
+     * value is 1 and the maximum value is 60 (default 30). This value can also
+     * be changed dynamically via {@code CefBrowser#setWindowlessFrameRate}
+     */
+    public int windowless_frame_rate = 0;
+
+    public CefBrowserSettings() {}
+
+    @Override
+    public CefBrowserSettings clone() {
+        CefBrowserSettings tmp = new CefBrowserSettings();
+        tmp.windowless_frame_rate = windowless_frame_rate;
+        return tmp;
+    }
+}

java/org/cef/CefClient.java

@@ -4,11 +4,7 @@
 
 package org.cef;
 
-import org.cef.browser.CefBrowser;
-import org.cef.browser.CefBrowserFactory;
-import org.cef.browser.CefFrame;
-import org.cef.browser.CefMessageRouter;
-import org.cef.browser.CefRequestContext;
+import org.cef.browser.*;
 import org.cef.callback.CefAuthCallback;
 import org.cef.callback.CefBeforeDownloadCallback;
 import org.cef.callback.CefCallback;
@@ -60,6 +56,7 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.Vector;
+import java.util.function.Consumer;
 
 import javax.swing.SwingUtilities;
 
@@ -141,7 +138,16 @@ public CefBrowser createBrowser(String url, boolean isOffscreenRendered, boolean
             CefRequestContext context) {
         if (isDisposed_)
             throw new IllegalStateException("Can't create browser. CefClient is disposed");
-        return CefBrowserFactory.create(this, url, isOffscreenRendered, isTransparent, context);
+        return CefBrowserFactory.create(
+                this, url, isOffscreenRendered, isTransparent, context, null);
+    }
+
+    public CefBrowser createBrowser(String url, boolean isOffscreenRendered, boolean isTransparent,
+            CefRequestContext context, CefBrowserSettings settings) {
+        if (isDisposed_)
+            throw new IllegalStateException("Can't create browser. CefClient is disposed");
+        return CefBrowserFactory.create(
+                this, url, isOffscreenRendered, isTransparent, context, settings);
     }
 
     @Override
@@ -753,6 +759,15 @@ public void onPaint(CefBrowser browser, boolean popup, Rectangle[] dirtyRects,
             realHandler.onPaint(browser, popup, dirtyRects, buffer, width, height);
     }
 
+    @Override
+    public void addOnPaintListener(Consumer<CefPaintEvent> listener) {}
+
+    @Override
+    public void setOnPaintListener(Consumer<CefPaintEvent> listener) {}
+
+    @Override
+    public void removeOnPaintListener(Consumer<CefPaintEvent> listener) {}
+
     @Override
     public boolean startDragging(CefBrowser browser, CefDragData dragData, int mask, int x, int y) {
         if (browser == null) return false;

java/org/cef/browser/CefBrowser.java

@@ -390,4 +390,26 @@ public void runFileDialog(FileDialogMode mode, String title, String defaultFileP
      * @throws UnsupportedOperationException if not supported
      */
     public CompletableFuture<BufferedImage> createScreenshot(boolean nativeResolution);
+
+    /**
+     * Set the maximum rate in frames per second (fps) that {@code CefRenderHandler::onPaint}
+     * will be called for a windowless browser. The actual fps may be
+     * lower if the browser cannot generate frames at the requested rate. The
+     * minimum value is 1, and the maximum value is 60 (default 30).
+     *
+     * @param frameRate the maximum frame rate
+     * @throws UnsupportedOperationException if not supported
+     */
+    public void setWindowlessFrameRate(int frameRate);
+
+    /**
+     * Returns the maximum rate in frames per second (fps) that {@code CefRenderHandler::onPaint}
+     * will be called for a windowless browser. The actual fps may be lower if the browser cannot
+     * generate frames at the requested rate. The minimum value is 1, and the maximum value is 60
+     * (default 30).
+     *
+     * @return the framerate, 0 if an error occurs
+     * @throws UnsupportedOperationException if not supported
+     */
+    public CompletableFuture<Integer> getWindowlessFrameRate();
 }

java/org/cef/browser/CefBrowserFactory.java

@@ -4,15 +4,17 @@
 
 package org.cef.browser;
 
+import org.cef.CefBrowserSettings;
 import org.cef.CefClient;
 
 /**
  * Creates a new instance of CefBrowser according the passed values
  */
 public class CefBrowserFactory {
     public static CefBrowser create(CefClient client, String url, boolean isOffscreenRendered,
-            boolean isTransparent, CefRequestContext context) {
-        if (isOffscreenRendered) return new CefBrowserOsr(client, url, isTransparent, context);
-        return new CefBrowserWr(client, url, context);
+            boolean isTransparent, CefRequestContext context, CefBrowserSettings settings) {
+        if (isOffscreenRendered)
+            return new CefBrowserOsr(client, url, isTransparent, context, settings);
+        return new CefBrowserWr(client, url, context, settings);
     }
 }

java/org/cef/browser/CefBrowserOsr.java

@@ -15,6 +15,7 @@
 import com.jogamp.opengl.awt.GLCanvas;
 import com.jogamp.opengl.util.GLBuffers;
 
+import org.cef.CefBrowserSettings;
 import org.cef.CefClient;
 import org.cef.OS;
 import org.cef.callback.CefDragData;
@@ -89,13 +90,15 @@ class CefBrowserOsr extends CefBrowser_N implements CefRenderHandler {
     private CopyOnWriteArrayList<Consumer<CefPaintEvent>> onPaintListeners =
             new CopyOnWriteArrayList<>();
 
-    CefBrowserOsr(CefClient client, String url, boolean transparent, CefRequestContext context) {
-        this(client, url, transparent, context, null, null);
+    CefBrowserOsr(CefClient client, String url, boolean transparent, CefRequestContext context,
+            CefBrowserSettings settings) {
+        this(client, url, transparent, context, null, null, settings);
     }
 
     private CefBrowserOsr(CefClient client, String url, boolean transparent,
-            CefRequestContext context, CefBrowserOsr parent, Point inspectAt) {
-        super(client, url, context, parent, inspectAt);
+            CefRequestContext context, CefBrowserOsr parent, Point inspectAt,
+            CefBrowserSettings settings) {
+        super(client, url, context, parent, inspectAt, settings);
         isTransparent_ = transparent;
         renderer_ = new CefRenderer(transparent);
         createGLCanvas();
@@ -122,7 +125,7 @@ public CefRenderHandler getRenderHandler() {
     protected CefBrowser_N createDevToolsBrowser(CefClient client, String url,
             CefRequestContext context, CefBrowser_N parent, Point inspectAt) {
         return new CefBrowserOsr(
-                client, url, isTransparent_, context, (CefBrowserOsr) this, inspectAt);
+                client, url, isTransparent_, context, (CefBrowserOsr) this, inspectAt, null);
     }
 
     private synchronized long getWindowHandle() {

java/org/cef/browser/CefBrowserWr.java

@@ -4,6 +4,7 @@
 
 package org.cef.browser;
 
+import org.cef.CefBrowserSettings;
 import org.cef.CefClient;
 import org.cef.OS;
 import org.cef.handler.CefWindowHandler;
@@ -166,14 +167,15 @@ public int getClickCount(int event, int button) {
         }
     };
 
-    CefBrowserWr(CefClient client, String url, CefRequestContext context) {
-        this(client, url, context, null, null);
+    CefBrowserWr(
+            CefClient client, String url, CefRequestContext context, CefBrowserSettings settings) {
+        this(client, url, context, null, null, settings);
     }
 
     @SuppressWarnings("serial")
     private CefBrowserWr(CefClient client, String url, CefRequestContext context,
-            CefBrowserWr parent, Point inspectAt) {
-        super(client, url, context, parent, inspectAt);
+            CefBrowserWr parent, Point inspectAt, CefBrowserSettings settings) {
+        super(client, url, context, parent, inspectAt, settings);
         delayedUpdate_.setRepeats(false);
 
         // Disabling lightweight of popup menu is required because
@@ -318,7 +320,7 @@ public CefWindowHandler getWindowHandler() {
     @Override
     protected CefBrowser_N createDevToolsBrowser(CefClient client, String url,
             CefRequestContext context, CefBrowser_N parent, Point inspectAt) {
-        return new CefBrowserWr(client, url, context, (CefBrowserWr) this, inspectAt);
+        return new CefBrowserWr(client, url, context, (CefBrowserWr) this, inspectAt, null);
     }
 
     private synchronized long getWindowHandle() {
@@ -421,4 +423,16 @@ private boolean createBrowserIfRequired(boolean hasParent) {
     public CompletableFuture<BufferedImage> createScreenshot(boolean nativeResolution) {
         throw new UnsupportedOperationException("Unsupported for windowed rendering");
     }
+
+    @Override
+    public void setWindowlessFrameRate(int frameRate) {
+        throw new UnsupportedOperationException(
+                "You can only set windowless framerate on OSR browser");
+    }
+
+    @Override
+    public CompletableFuture<Integer> getWindowlessFrameRate() {
+        throw new UnsupportedOperationException(
+                "You can only get windowless framerate on OSR browser");
+    }
 }

java/org/cef/browser/CefBrowser_N.java

@@ -4,6 +4,7 @@
 
 package org.cef.browser;
 
+import org.cef.CefBrowserSettings;
 import org.cef.CefClient;
 import org.cef.browser.CefDevToolsClient.DevToolsException;
 import org.cef.callback.CefDragData;
@@ -49,14 +50,19 @@ abstract class CefBrowser_N extends CefNativeAdapter implements CefBrowser {
     private boolean closeAllowed_ = false;
     private volatile boolean isClosed_ = false;
     private volatile boolean isClosing_ = false;
+    private final CefBrowserSettings settings_;
 
     protected CefBrowser_N(CefClient client, String url, CefRequestContext context,
-            CefBrowser_N parent, Point inspectAt) {
+            CefBrowser_N parent, Point inspectAt, CefBrowserSettings settings) {
         client_ = client;
         url_ = url;
         request_context_ = context;
         parent_ = parent;
         inspectAt_ = inspectAt;
+        if (settings != null)
+            settings_ = settings.clone();
+        else
+            settings_ = new CefBrowserSettings();
     }
 
     protected String getUrl() {
@@ -162,7 +168,7 @@ public synchronized CefDevToolsClient getDevToolsClient() {
 
     CompletableFuture<Integer> executeDevToolsMethod(String method, String parametersAsJson) {
         CompletableFuture<Integer> future = new CompletableFuture<>();
-        N_ExecuteDevToolsMethod(method, parametersAsJson, new DevToolsMethodCallback() {
+        N_ExecuteDevToolsMethod(method, parametersAsJson, new IntCallback() {
             @Override
             public void onComplete(int generatedMessageId) {
                 if (generatedMessageId <= 0) {
@@ -190,8 +196,8 @@ protected void createBrowser(CefClientHandler clientHandler, long windowHandle,
             boolean osr, boolean transparent, Component canvas, CefRequestContext context) {
         if (getNativeRef("CefBrowser") == 0 && !isPending_) {
             try {
-                N_CreateBrowser(
-                        clientHandler, windowHandle, url, osr, transparent, canvas, context);
+                N_CreateBrowser(clientHandler, windowHandle, url, osr, transparent, canvas, context,
+                        settings_);
             } catch (UnsatisfiedLinkError err) {
                 err.printStackTrace();
             }
@@ -789,17 +795,36 @@ protected final void notifyMoveOrResizeStarted() {
         }
     }
 
-    private interface DevToolsMethodCallback {
-        void onComplete(int generatedMessageId);
+    public void setWindowlessFrameRate(int frameRate) {
+        try {
+            N_SetWindowlessFrameRate(frameRate);
+        } catch (UnsatisfiedLinkError ule) {
+            ule.printStackTrace();
+        }
+    }
+
+    public CompletableFuture<Integer> getWindowlessFrameRate() {
+        final CompletableFuture<Integer> future = new CompletableFuture<>();
+        try {
+            N_GetWindowlessFrameRate(future::complete);
+        } catch (UnsatisfiedLinkError ule) {
+            ule.printStackTrace();
+            future.complete(0);
+        }
+        return future;
+    }
+
+    private interface IntCallback {
+        void onComplete(int value);
     }
 
     private final native boolean N_CreateBrowser(CefClientHandler clientHandler, long windowHandle,
             String url, boolean osr, boolean transparent, Component canvas,
-            CefRequestContext context);
+            CefRequestContext context, CefBrowserSettings settings);
     private final native boolean N_CreateDevTools(CefBrowser parent, CefClientHandler clientHandler,
             long windowHandle, boolean osr, boolean transparent, Component canvas, Point inspectAt);
     private final native void N_ExecuteDevToolsMethod(
-            String method, String parametersAsJson, DevToolsMethodCallback callback);
+            String method, String parametersAsJson, IntCallback callback);
     private final native CefRegistration N_AddDevToolsMessageObserver(
             CefDevToolsMessageObserver observer);
     private final native long N_GetWindowHandle(long surfaceHandle);
@@ -860,4 +885,6 @@ private final native void N_DragTargetDragEnter(
     private final native void N_UpdateUI(Rectangle contentRect, Rectangle browserRect);
     private final native void N_SetParent(long windowHandle, Component canvas);
     private final native void N_NotifyMoveOrResizeStarted();
+    private final native void N_SetWindowlessFrameRate(int frameRate);
+    private final native void N_GetWindowlessFrameRate(IntCallback frameRateCallback);
 }

java/tests/detailed/MainFrame.java

@@ -6,6 +6,7 @@
 
 import org.cef.CefApp;
 import org.cef.CefApp.CefVersion;
+import org.cef.CefBrowserSettings;
 import org.cef.CefClient;
 import org.cef.CefSettings;
 import org.cef.CefSettings.ColorType;
@@ -58,6 +59,7 @@ public static void main(String[] args) {
         boolean osrEnabledArg = false;
         boolean transparentPaintingEnabledArg = false;
         boolean createImmediately = false;
+        int windowless_frame_rate = 0;
         for (String arg : args) {
             arg = arg.toLowerCase();
             if (arg.equals("--off-screen-rendering-enabled")) {
@@ -66,17 +68,30 @@ public static void main(String[] args) {
                 transparentPaintingEnabledArg = true;
             } else if (arg.equals("--create-immediately")) {
                 createImmediately = true;
+            } else if (arg.equals("--windowless-frame-rate-60")) {
+                windowless_frame_rate = 60;
             }
         }
 
         System.out.println("Offscreen rendering " + (osrEnabledArg ? "enabled" : "disabled"));
 
         // MainFrame keeps all the knowledge to display the embedded browser
         // frame.
-        final MainFrame frame = new MainFrame(
-                osrEnabledArg, transparentPaintingEnabledArg, createImmediately, args);
+        final MainFrame frame = new MainFrame(osrEnabledArg, transparentPaintingEnabledArg,
+                createImmediately, windowless_frame_rate, args);
         frame.setSize(800, 600);
         frame.setVisible(true);
+
+        if (osrEnabledArg && windowless_frame_rate != 0) {
+            frame.getBrowser().getWindowlessFrameRate().thenAccept(
+                    framerate -> System.out.println("Framerate is:" + framerate));
+
+            frame.getBrowser().setWindowlessFrameRate(2);
+            frame.getBrowser().getWindowlessFrameRate().thenAccept(
+                    framerate -> System.out.println("Framerate is:" + framerate));
+
+            frame.getBrowser().setWindowlessFrameRate(windowless_frame_rate);
+        }
     }
 
     private final CefClient client_;
@@ -88,7 +103,7 @@ public static void main(String[] args) {
     private boolean transparent_painting_enabled_;
 
     public MainFrame(boolean osrEnabled, boolean transparentPaintingEnabled,
-            boolean createImmediately, String[] args) {
+            boolean createImmediately, int windowless_frame_rate, String[] args) {
         this.osr_enabled_ = osrEnabled;
         this.transparent_painting_enabled_ = transparentPaintingEnabled;
 
@@ -200,9 +215,12 @@ public void onLoadError(CefBrowser browser, CefFrame frame, ErrorCode errorCode,
             }
         });
 
+        CefBrowserSettings browserSettings = new CefBrowserSettings();
+        browserSettings.windowless_frame_rate = windowless_frame_rate;
+
         // Create the browser.
-        CefBrowser browser = client_.createBrowser(
-                "http://www.google.com", osrEnabled, transparentPaintingEnabled, null);
+        CefBrowser browser = client_.createBrowser("http://www.google.com", osrEnabled,
+                transparentPaintingEnabled, null, browserSettings);
         setBrowser(browser);
 
         // Set up the UI for this example implementation.