bug 573669 - Suspend Gecko's event loop when onPause() is called by Android r=vlad

embedding/android/GeckoApp.java

@@ -161,6 +161,8 @@ abstract public class GeckoApp
     @Override
     public void onPause()
     {
+
+        Log.i("GeckoApp", "pause");
         GeckoAppShell.sendEventToGecko(new GeckoEvent(GeckoEvent.ACTIVITY_PAUSING));
         // The user is navigating away from this activity, but nothing
         // has come to the foreground yet; for Gecko, we may want to
@@ -176,6 +178,10 @@ abstract public class GeckoApp
     @Override
     public void onResume()
     {
+        Log.i("GeckoApp", "resume");
+        GeckoAppShell.onResume();
+        if (surfaceView != null)
+            surfaceView.mSurfaceNeedsRedraw = true;
         // After an onPause, the activity is back in the foreground.
         // Undo whatever we did in onPause.
         super.onResume();

embedding/android/GeckoAppShell.java

@@ -82,6 +82,7 @@ class GeckoAppShell
     public static native void setInitialSize(int width, int height);
     public static native void setSurfaceView(GeckoSurfaceView sv);
     public static native void putenv(String map);
+    public static native void onResume();
 
     // java-side stuff
     public static void loadGeckoLibs() {

widget/src/android/AndroidJNI.cpp

@@ -57,6 +57,7 @@ extern "C" {
     NS_EXPORT void JNICALL Java_org_mozilla_gecko_GeckoAppShell_setSurfaceView(JNIEnv *jenv, jclass, jobject sv);
     NS_EXPORT void JNICALL Java_org_mozilla_gecko_GeckoAppShell_setInitialSize(JNIEnv *jenv, jclass, int width, int height);
     NS_EXPORT void JNICALL Java_org_mozilla_gecko_GeckoAppShell_putenv(JNIEnv *jenv, jclass, jstring map);
+    NS_EXPORT void JNICALL Java_org_mozilla_gecko_GeckoAppShell_onResume(JNIEnv *, jclass);
 }
 
 
@@ -106,3 +107,10 @@ Java_org_mozilla_gecko_GeckoAppShell_putenv(JNIEnv *jenv, jclass, jstring map)
     jenv->ReleaseStringUTFChars(map, str);
     
 }
+
+NS_EXPORT void JNICALL
+Java_org_mozilla_gecko_GeckoAppShell_onResume(JNIEnv *jenv, jclass jc)
+{
+    if (nsAppShell::gAppShell)
+        nsAppShell::gAppShell->OnResume();
+}

widget/src/android/nsAppShell.cpp

@@ -79,6 +79,8 @@ nsAppShell::nsAppShell()
     : mQueueLock(nsnull),
       mCondLock(nsnull),
       mQueueCond(nsnull),
+      mPausedLock(nsnull),
+      mPaused(nsnull),
       mNumDraws(0)
 {
     gAppShell = this;
@@ -111,7 +113,9 @@ nsAppShell::Init()
 
     mQueueLock = PR_NewLock();
     mCondLock = PR_NewLock();
+    mPausedLock = PR_NewLock();
     mQueueCond = PR_NewCondVar(mCondLock);
+    mPaused = PR_NewCondVar(mPausedLock);
 
     return nsBaseAppShell::Init();
 }
@@ -252,6 +256,10 @@ nsAppShell::ProcessNextNativeEvent(PRBool mayWait)
         nsCOMPtr<nsIObserverService> obsServ =
           mozilla::services::GetObserverService();
         obsServ->NotifyObservers(nsnull, "profile-before-change", nsnull);
+
+        // The OS is sending us to the background, block this thread until 
+        // onResume is called to signal that we're back in the foreground
+        PR_WaitCondVar(mPaused, PR_INTERVAL_NO_TIMEOUT);
         break;
     }
 
@@ -346,6 +354,15 @@ nsAppShell::RemoveNextEvent()
     PR_Unlock(mQueueLock);
 }
 
+void
+nsAppShell::OnResume()
+{
+    PR_Lock(mPausedLock);
+    PR_NotifyCondVar(mPaused);
+    PR_Unlock(mPausedLock);
+
+}
+
 // Used by IPC code
 namespace mozilla {
 

widget/src/android/nsAppShell.h

@@ -68,6 +68,8 @@ public:
 
     void PostEvent(mozilla::AndroidGeckoEvent *event);
     void RemoveNextEvent();
+    void OnResume();
+
 protected:
     virtual void ScheduleNativeEventCallback();
     virtual ~nsAppShell();
@@ -75,7 +77,9 @@ protected:
     int mNumDraws;
     PRLock *mQueueLock;
     PRLock *mCondLock;
+    PRLock *mPausedLock;
     PRCondVar *mQueueCond;
+    PRCondVar *mPaused;
     nsTArray<mozilla::AndroidGeckoEvent *> mEventQueue;
 
     mozilla::AndroidGeckoEvent *GetNextEvent();