Bug 1276272 - part 3 - implement promise-based HTMLMediaElement::seekToNextFrame(); r=jwwang

MozReview-Commit-ID: JaUQe5GK6bF

dom/html/HTMLMediaElement.cpp

@@ -1466,19 +1466,19 @@ HTMLMediaElement::FastSeek(double aTime, ErrorResult& aRv)
 {
   LOG(LogLevel::Debug, ("Reporting telemetry VIDEO_FASTSEEK_USED"));
   Telemetry::Accumulate(Telemetry::VIDEO_FASTSEEK_USED, 1);
-  Seek(aTime, SeekTarget::PrevSyncPoint, aRv);
+  RefPtr<Promise> tobeDropped = Seek(aTime, SeekTarget::PrevSyncPoint, aRv);
 }
 
-void
+already_AddRefed<Promise>
 HTMLMediaElement::SeekToNextFrame(ErrorResult& aRv)
 {
-  Seek(CurrentTime(), SeekTarget::NextFrame, aRv);
+  return Seek(CurrentTime(), SeekTarget::NextFrame, aRv);
 }
 
 void
 HTMLMediaElement::SetCurrentTime(double aCurrentTime, ErrorResult& aRv)
 {
-  Seek(aCurrentTime, SeekTarget::Accurate, aRv);
+  RefPtr<Promise> tobeDropped = Seek(aCurrentTime, SeekTarget::Accurate, aRv);
 }
 
 /**
@@ -1519,7 +1519,7 @@ IsInRanges(dom::TimeRanges& aRanges,
   return NS_OK;
 }
 
-void
+already_AddRefed<Promise>
 HTMLMediaElement::Seek(double aTime,
                        SeekTarget::Type aSeekType,
                        ErrorResult& aRv)
@@ -1527,6 +1527,19 @@ HTMLMediaElement::Seek(double aTime,
   // aTime should be non-NaN.
   MOZ_ASSERT(!mozilla::IsNaN(aTime));
 
+  nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(OwnerDoc()->GetInnerWindow());
+
+  if (!global) {
+    aRv.Throw(NS_ERROR_UNEXPECTED);
+    return nullptr;
+  }
+
+  RefPtr<Promise> promise = Promise::Create(global, aRv);
+
+  if (NS_WARN_IF(aRv.Failed())) {
+    return nullptr;
+  }
+
   // Detect if user has interacted with element by seeking so that
   // play will not be blocked when initiated by a script.
   if (EventStateManager::IsHandlingUserInput() || nsContentUtils::LegacyIsCallerChromeOrNativeCode()) {
@@ -1537,7 +1550,8 @@ HTMLMediaElement::Seek(double aTime,
 
   if (mSrcStream) {
     // do nothing since media streams have an empty Seekable range.
-    return;
+    promise->MaybeRejectWithUndefined();
+    return promise.forget();
   }
 
   if (mPlayed && mCurrentPlayRangeStart != -1.0) {
@@ -1554,27 +1568,30 @@ HTMLMediaElement::Seek(double aTime,
 
   if (mReadyState == nsIDOMHTMLMediaElement::HAVE_NOTHING) {
     mDefaultPlaybackStartPosition = aTime;
-    return;
+    promise->MaybeRejectWithUndefined();
+    return promise.forget();
   }
 
   if (!mDecoder) {
     // mDecoder must always be set in order to reach this point.
     NS_ASSERTION(mDecoder, "SetCurrentTime failed: no decoder");
-    return;
+    promise->MaybeRejectWithUndefined();
+    return promise.forget();
   }
 
   // Clamp the seek target to inside the seekable ranges.
   RefPtr<dom::TimeRanges> seekable = new dom::TimeRanges(ToSupports(OwnerDoc()));
   media::TimeIntervals seekableIntervals = mDecoder->GetSeekable();
   if (seekableIntervals.IsInvalid()) {
-    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
-    return;
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR); // This will reject the promise.
+    return promise.forget();
   }
   seekableIntervals.ToTimeRanges(seekable);
   uint32_t length = 0;
   seekable->GetLength(&length);
   if (!length) {
-    return;
+    promise->MaybeRejectWithUndefined();
+    return promise.forget();
   }
 
   // If the position we want to seek to is not in a seekable range, we seek
@@ -1585,8 +1602,8 @@ HTMLMediaElement::Seek(double aTime,
   int32_t range = 0;
   bool isInRange = false;
   if (NS_FAILED(IsInRanges(*seekable, aTime, isInRange, range))) {
-    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
-    return;
+    aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR); // This will reject the promise.
+    return promise.forget();
   }
   if (!isInRange) {
     if (range != -1) {
@@ -1596,11 +1613,11 @@ HTMLMediaElement::Seek(double aTime,
         double leftBound, rightBound;
         if (NS_FAILED(seekable->End(range, &leftBound))) {
           aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
-          return;
+          return promise.forget();
         }
         if (NS_FAILED(seekable->Start(range + 1, &rightBound))) {
           aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
-          return;
+          return promise.forget();
         }
         double distanceLeft = Abs(leftBound - aTime);
         double distanceRight = Abs(rightBound - aTime);
@@ -1615,7 +1632,7 @@ HTMLMediaElement::Seek(double aTime,
         // Clamp the seek target to the end of the last seekable range.
         if (NS_FAILED(seekable->End(length - 1, &aTime))) {
           aRv.Throw(NS_ERROR_DOM_INVALID_STATE_ERR);
-          return;
+          return promise.forget();
         }
       }
     } else {
@@ -1641,13 +1658,15 @@ HTMLMediaElement::Seek(double aTime,
   // The media backend is responsible for dispatching the timeupdate
   // event if it changes the playback position as a result of the seek.
   LOG(LogLevel::Debug, ("%p SetCurrentTime(%f) starting seek", this, aTime));
-  nsresult rv = mDecoder->Seek(aTime, aSeekType);
+  nsresult rv = mDecoder->Seek(aTime, aSeekType, promise);
   if (NS_FAILED(rv)) {
     aRv.Throw(rv);
   }
 
   // We changed whether we're seeking so we need to AddRemoveSelfReference.
   AddRemoveSelfReference();
+
+  return promise.forget();
 }
 
 NS_IMETHODIMP HTMLMediaElement::SetCurrentTime(double aCurrentTime)