Bug 879717: Part 3: Fix camera preview stream and wake locks from lock screen. r=roc

dom/camera/CameraPreviewMediaStream.cpp

@@ -17,6 +17,8 @@
 using namespace mozilla::layers;
 using namespace mozilla::dom;
 
+static const TrackID TRACK_VIDEO = 2;
+
 namespace mozilla {
 
 void
@@ -32,6 +34,7 @@ CameraPreviewMediaStream::CameraPreviewMediaStream(DOMMediaStream* aWrapper)
   , mInvalidatePending(0)
   , mDiscardedFrames(0)
   , mRateLimit(false)
+  , mTrackCreated(false)
 {
   SetGraphImpl(MediaStreamGraph::GetInstance());
   mFakeMediaStreamGraph = new FakeMediaStreamGraph();
@@ -111,6 +114,22 @@ CameraPreviewMediaStream::RemoveListener(MediaStreamListener* aListener)
   listener->NotifyEvent(mFakeMediaStreamGraph, MediaStreamListener::EVENT_REMOVED);
 }
 
+void
+CameraPreviewMediaStream::OnPreviewStateChange(bool aActive)
+{
+  MutexAutoLock lock(mMutex);
+  if (!mTrackCreated && aActive) {
+    mTrackCreated = true;
+    VideoSegment tmpSegment;
+    uint32_t trackEvent = aActive ? MediaStreamListener::TRACK_EVENT_CREATED
+                                  : MediaStreamListener::TRACK_EVENT_ENDED;
+    for (uint32_t j = 0; j < mListeners.Length(); ++j) {
+      MediaStreamListener* l = mListeners[j];
+      l->NotifyQueuedTrackChanges(mFakeMediaStreamGraph, TRACK_VIDEO, 0, 0, trackEvent, tmpSegment);
+    }
+  }
+}
+
 void
 CameraPreviewMediaStream::Destroy()
 {

dom/camera/CameraPreviewMediaStream.h

@@ -51,6 +51,7 @@ public:
   virtual void AddListener(MediaStreamListener* aListener) MOZ_OVERRIDE;
   virtual void RemoveListener(MediaStreamListener* aListener) MOZ_OVERRIDE;
   virtual void Destroy();
+  void OnPreviewStateChange(bool aActive);
 
   void Invalidate();
 
@@ -67,6 +68,7 @@ protected:
   int32_t mInvalidatePending;
   uint32_t mDiscardedFrames;
   bool mRateLimit;
+  bool mTrackCreated;
   nsRefPtr<FakeMediaStreamGraph> mFakeMediaStreamGraph;
 };
 

dom/camera/DOMCameraControl.cpp

@@ -218,7 +218,8 @@ nsDOMCameraControl::nsDOMCameraControl(uint32_t aCameraId,
   mCurrentConfiguration = initialConfig.forget();
 
   // Attach our DOM-facing media stream to our viewfinder stream.
-  mStream = mInput;
+  SetHintContents(HINT_CONTENTS_VIDEO);
+  InitStreamCommon(mInput);
   MOZ_ASSERT(mWindow, "Shouldn't be created with a null window!");
   if (mWindow->GetExtantDoc()) {
     CombineWithPrincipal(mWindow->GetExtantDoc()->NodePrincipal());

dom/camera/DOMCameraControlListener.cpp

@@ -137,6 +137,7 @@ DOMCameraControlListener::OnPreviewStateChange(PreviewState aState)
       MOZ_ASSERT_UNREACHABLE("Invalid preview state");
       return;
   }
+  mStream->OnPreviewStateChange(aState == kPreviewStarted);
   NS_DispatchToMainThread(new Callback(mDOMCameraControl, aState));
 }
 

dom/camera/test/test_camera.html

@@ -109,18 +109,26 @@ var Camera = {
     var blob = e.data;
     var img = new Image();
     var test = this._currentTest;
+    var onPreviewStateChange = function(e) {
+      if (e.newState === 'started') {
+        ok(true, "viewfinder is ready and playing after resume");
+        Camera.cameraObj.removeEventListener('previewstatechange', onPreviewStateChange);
+        Camera._testsCompleted++;
+        if(Camera._testsCompleted == Camera._tests.length) {
+          ok(true, "test finishing");
+          SimpleTest.finish();
+        } else {
+          Camera.runTests();
+        }
+      }
+    }
+    Camera.cameraObj.addEventListener('previewstatechange', onPreviewStateChange);
     img.onload = function Imgsize() {
       ok(this.width == test.pictureSize.width, "The image taken has the width " +
                                               this.width + " pictureSize width = " + test.pictureSize.width);
       ok(this.height == test.pictureSize.height, "The image taken has the height " +
                                               this.height + " picturesize height = " + test.pictureSize.height);
-      Camera._testsCompleted++;
-      if(Camera._testsCompleted == Camera._tests.length) {
-        ok(true, "test finishing");
-        SimpleTest.finish();
-      } else {
-        Camera.runTests();
-      }
+      Camera.cameraObj.resumePreview();
     }
     ok(blob.size > 100 , "Blob Size Gathered = " + blob.size);
     ok("image/" + test.fileFormat ==  blob.type, "Blob Type = " + blob.type);