[PageLifecycle] Implement hide event for normal and nonCompositedWebGL.

Author: magomez

Source/WebCore/html/canvas/WebGLRenderingContextBase.cpp

@@ -1211,8 +1211,11 @@ void WebGLRenderingContextBase::addActivityStateChangeObserverIfNecessary()
 
     // We are only interested in visibility changes for contexts
     // that are using the high-performance GPU.
+    // We also use the activityState changes when nonCompositedWebGL is enabled, but not
+    // if we're using PageLifecycle, as we don't hide to transparent there.
     m_nonCompositedWebGLEnabled = canvas->document().frame()->settings().nonCompositedWebGLEnabled();
-    if (!isHighPerformanceContext(m_context) && !m_nonCompositedWebGLEnabled)
+    m_usingPageLifecycle = canvas->document().frame()->settings().pageLifecycleAPIEnabled();
+    if (!isHighPerformanceContext(m_context) && (!m_nonCompositedWebGLEnabled || m_usingPageLifecycle))
         return;
 
     auto* page = canvas->document().page();

Source/WebCore/html/canvas/WebGLRenderingContextBase.h

@@ -1206,6 +1206,7 @@ class WebGLRenderingContextBase : public GraphicsContextGL::Client, public GPUBa
     Timer m_checkForContextLossHandlingTimer;
     bool m_isSuspended { false };
     bool m_nonCompositedWebGLEnabled { false };
+    bool m_usingPageLifecycle { false };
 
 #if ENABLE(WEBXR)
     bool m_isXRCompatible { false };

Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.cpp

@@ -57,6 +57,7 @@ DrawingAreaCoordinatedGraphics::DrawingAreaCoordinatedGraphics(WebPage& webPage,
     , m_discardPreviousLayerTreeHostTimer(RunLoop::main(), this, &DrawingAreaCoordinatedGraphics::discardPreviousLayerTreeHost)
     , m_supportsAsyncScrolling(parameters.store.getBoolValueForKey(WebPreferencesKey::threadedScrollingEnabledKey()))
     , m_displayTimer(RunLoop::main(), this, &DrawingAreaCoordinatedGraphics::displayTimerFired)
+    , m_usingPageLifecycle(parameters.store.getBoolValueForKey(WebPreferencesKey::pageLifecycleAPIEnabledKey()))
 {
 #if USE(GLIB_EVENT_LOOP)
     m_discardPreviousLayerTreeHostTimer.setPriority(RunLoopSourcePriority::ReleaseUnusedResourcesTimer);
@@ -398,34 +399,49 @@ RefPtr<DisplayRefreshMonitor> DrawingAreaCoordinatedGraphics::createDisplayRefre
 
 void DrawingAreaCoordinatedGraphics::activityStateDidChange(OptionSet<ActivityState::Flag> changed, ActivityStateChangeID, CompletionHandler<void()>&& completionHandler)
 {
-    // We use calls to suspendPainting() and resumePainting() to stop the compositor loop and paint the content transparent
-    // so nothing gets rendered. There are 2 exceptions to this that need to be handled separately:
-    // - WebGL in nonCompositedWebGL: we're not using the compositor in this case. WebGLRenderingContextBase will observe the activity
-    //   state changes and paint the content transparent when the view is suspended or hidden.
-    // - MediaPlayer videoSink window when using the GStreamer holepunch: HTMLMediaElement will perform calls to the MediaPlayer
-    //   to set an empty rectangle when it detects that the view has become hidden or suspended.
+    if (m_usingPageLifecycle) {
+        // Implementation for the Page Lifecycle events.
 
-    // Handle hide/show functionality.
-    if (changed & ActivityState::IsVisible && !m_isViewSuspended) {
-        if (m_webPage.corePage()->isVisible())
-            resumePainting();
-        else
-            suspendPainting();
-    }
+        // Handle hide/show functionality.
+        if (changed & ActivityState::IsVisible) {
+            if (m_webPage.corePage()->isVisible())
+                resumePainting();
+            else
+                suspendPainting();
+        }
 
-    // Handle suspend/resume functionality. Besides stopping the rendering, we stop active DOM objects and media playback.
-    if (changed & ActivityState::IsInWindow) {
-        if (m_isViewSuspended) {
-            m_webPage.corePage()->resumeActiveDOMObjectsAndAnimations();
-            m_webPage.corePage()->resumeAllMediaPlayback();
+    } else {
+        // Implementation for the old suspend/resume/hide/show functionality
+
+        // We use calls to suspendPainting() and resumePainting() to stop the compositor loop and paint the content transparent
+        // so nothing gets rendered. There are 2 exceptions to this that need to be handled separately:
+        // - WebGL in nonCompositedWebGL: we're not using the compositor in this case. WebGLRenderingContextBase will observe the activity
+        //   state changes and paint the content transparent when the view is suspended or hidden.
+        // - MediaPlayer videoSink window when using the GStreamer holepunch: HTMLMediaElement will perform calls to the MediaPlayer
+        //   to set an empty rectangle when it detects that the view has become hidden or suspended.
+
+        // Handle hide/show functionality.
+        if (changed & ActivityState::IsVisible && !m_isViewSuspended) {
             if (m_webPage.corePage()->isVisible())
                 resumePainting();
-            m_isViewSuspended = false;
-        } else {
-            suspendPainting();
-            m_webPage.corePage()->suspendAllMediaPlayback();
-            m_webPage.corePage()->suspendActiveDOMObjectsAndAnimations();
-            m_isViewSuspended = true;
+            else
+                suspendPainting();
+        }
+
+        // Handle suspend/resume functionality. Besides stopping the rendering, we stop active DOM objects and media playback.
+        if (changed & ActivityState::IsInWindow) {
+            if (m_isViewSuspended) {
+                m_webPage.corePage()->resumeActiveDOMObjectsAndAnimations();
+                m_webPage.corePage()->resumeAllMediaPlayback();
+                if (m_webPage.corePage()->isVisible())
+                    resumePainting();
+                m_isViewSuspended = false;
+            } else {
+                suspendPainting();
+                m_webPage.corePage()->suspendAllMediaPlayback();
+                m_webPage.corePage()->suspendActiveDOMObjectsAndAnimations();
+                m_isViewSuspended = true;
+            }
         }
     }
 
@@ -632,7 +648,7 @@ void DrawingAreaCoordinatedGraphics::suspendPainting()
         return;
 
     if (m_layerTreeHost)
-        m_layerTreeHost->pauseRendering();
+        m_layerTreeHost->pauseRendering(!m_usingPageLifecycle);
     else
         m_displayTimer.stop();
 

Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/DrawingAreaCoordinatedGraphics.h

@@ -165,6 +165,8 @@ class DrawingAreaCoordinatedGraphics final : public DrawingArea {
     bool m_transientZoom { false };
     WebCore::FloatPoint m_transientZoomInitialOrigin;
 #endif
+
+    bool m_usingPageLifecycle { false };
 };
 
 } // namespace WebKit

Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/LayerTreeHost.cpp

@@ -257,10 +257,13 @@ void LayerTreeHost::targetRefreshRateDidChange(uint32_t rate)
     m_compositor->targetRefreshRateDidChange(rate);
 }
 
-void LayerTreeHost::pauseRendering()
+void LayerTreeHost::pauseRendering(bool toTransparent)
 {
     m_isSuspended = true;
-    m_compositor->suspendToTransparent();
+    if (toTransparent)
+        m_compositor->suspendToTransparent();
+    else
+        m_compositor->suspend();
 }
 
 void LayerTreeHost::resumeRendering()

Source/WebKit/WebProcess/WebPage/CoordinatedGraphics/LayerTreeHost.h

@@ -83,7 +83,7 @@ class LayerTreeHost
     void sizeDidChange(const WebCore::IntSize& newSize);
     void targetRefreshRateDidChange(unsigned);
 
-    void pauseRendering();
+    void pauseRendering(bool toTransparent = false);
     void resumeRendering();
 
     WebCore::GraphicsLayerFactory* graphicsLayerFactory();