Disable prerenders if we aren't focused

 Bug: 6448418

Change-Id: I624d78a2b674cbd91ebe70008c70967101fbb12a

3 files changed, 41 insertions, 2 deletions

diff --git a/Source/WebKit/android/jni/WebViewCore.cpp b/Source/WebKit/android/jni/WebViewCore.cpp
index dddae43..5c7012f 100644
--- a/Source/WebKit/android/jni/WebViewCore.cpp
+++ b/Source/WebKit/android/jni/WebViewCore.cpp
@@ -444,6 +444,7 @@ WebViewCore::WebViewCore(JNIEnv* env, jobject javaWebViewCore, WebCore::Frame* m
     , m_forwardingTouchEvents(false)
 #endif
     , m_webRequestContext(0)
+    , m_prerenderEnabled(false)
 {
     ALOG_ASSERT(m_mainFrame, "Uh oh, somehow a frameview was made without an initial frame!");
 
@@ -739,10 +740,30 @@ void WebViewCore::paintContents(WebCore::GraphicsContext* gc, WebCore::IntRect&
     view->platformWidget()->draw(gc, drawArea);
 }
 
+void WebViewCore::setPrerenderingEnabled(bool enable)
+{
+    MutexLocker locker(m_prerenderLock);
+    m_prerenderEnabled = enable;
+}
+
+bool WebViewCore::prerenderingEnabled()
+{
+    MutexLocker locker(m_prerenderLock);
+    return m_prerenderEnabled;
+}
+
 SkCanvas* WebViewCore::createPrerenderCanvas(PrerenderedInval* prerendered)
 {
+    // Has WebView disabled prerenders (not attached, etc...)?
+    if (!prerenderingEnabled())
+        return 0;
+    // Does this WebView have focus?
+    if (!m_mainFrame->page()->focusController()->isActive())
+        return 0;
+    // Are we scrolling?
     if (currentTimeMS() - m_scrollSetTime < PRERENDER_AFTER_SCROLL_DELAY)
         return 0;
+    // Do we have anything to render?
     if (prerendered->area.isEmpty())
         return 0;
     FloatRect scaleTemp(m_scrollOffsetX, m_scrollOffsetY, m_screenWidth, m_screenHeight);
diff --git a/Source/WebKit/android/jni/WebViewCore.h b/Source/WebKit/android/jni/WebViewCore.h
index 4603cb8..c8b10d8 100644
--- a/Source/WebKit/android/jni/WebViewCore.h
+++ b/Source/WebKit/android/jni/WebViewCore.h
@@ -50,6 +50,7 @@
 #include <androidfw/KeycodeLabels.h>
 #include <ui/PixelFormat.h>
 #include <utils/threads.h>
+#include <wtf/Threading.h>
 
 namespace WebCore {
     class Color;
@@ -605,6 +606,8 @@ namespace android {
         int m_lastGeneration; // last action using up to date cache
         // end of shared members
 
+        void setPrerenderingEnabled(bool enable);
+
         // internal functions
     private:
         enum InputType {
@@ -740,6 +743,8 @@ namespace android {
         // called from destructor, to remove this from a global list
         static void removeInstance(WebViewCore*);
 
+        bool prerenderingEnabled();
+
         friend class ListBoxReply;
         struct JavaGlue;
         struct JavaGlue*       m_javaGlue;
@@ -792,6 +797,9 @@ namespace android {
 #endif
 
         scoped_refptr<WebRequestContext> m_webRequestContext;
+
+        WTF::Mutex m_prerenderLock;
+        bool m_prerenderEnabled;
     };
 
 }   // namespace android
diff --git a/Source/WebKit/android/nav/WebView.cpp b/Source/WebKit/android/nav/WebView.cpp
index 3822239..1e84a12 100644
--- a/Source/WebKit/android/nav/WebView.cpp
+++ b/Source/WebKit/android/nav/WebView.cpp
@@ -259,6 +259,9 @@ int drawGL(WebCore::IntRect& invScreenRect, WebCore::IntRect* invalRect,
     if (!m_baseLayer)
         return 0;
 
+    if (m_viewImpl)
+        m_viewImpl->setPrerenderingEnabled(!m_isDrawingPaused);
+
     if (!m_glWebViewState) {
         TilesManager::instance()->setHighEndGfx(m_isHighEndGfx);
         m_glWebViewState = new GLWebViewState();
@@ -648,8 +651,15 @@ int setHwAccelerated(bool hwAccelerated) {
     return 0;
 }
 
-    bool m_isDrawingPaused;
+void setDrawingPaused(bool isPaused)
+{
+    m_isDrawingPaused = isPaused;
+    if (m_viewImpl)
+        m_viewImpl->setPrerenderingEnabled(!isPaused);
+}
+
 private: // local state for WebView
+    bool m_isDrawingPaused;
     // private to getFrameCache(); other functions operate in a different thread
     WebViewCore* m_viewImpl;
     int m_generation; // associate unique ID with sent kit focus to match with ui
@@ -1167,7 +1177,7 @@ static int nativeGetBackgroundColor(JNIEnv* env, jobject obj, jint nativeView)
 static void nativeSetPauseDrawing(JNIEnv *env, jobject obj, jint nativeView,
                                       jboolean pause)
 {
-    reinterpret_cast<WebView*>(nativeView)->m_isDrawingPaused = pause;
+    reinterpret_cast<WebView*>(nativeView)->setDrawingPaused(pause);
 }
 
 static void nativeSetTextSelection(JNIEnv *env, jobject obj, jint nativeView,