Bug 867823 - Implement TextTrack Add/RemoveCue. r=rillian

- Updated RemoveCue to throw NotFoundError if the cue being removed is
not in the cue list.
- Updated AddCue to not add cues that are already in the list. This is
done by reference comparing.

content/media/TextTrack.cpp

@@ -73,15 +73,13 @@ TextTrack::SetMode(TextTrackMode aValue)
 void
 TextTrack::AddCue(TextTrackCue& aCue)
 {
-  //XXX: If cue exists, remove. Bug 867823.
   mCueList->AddCue(aCue);
 }
 
 void
-TextTrack::RemoveCue(TextTrackCue& aCue)
+TextTrack::RemoveCue(TextTrackCue& aCue, ErrorResult& aRv)
 {
-  //XXX: If cue does not exists throw NotFoundError. Bug 867823.
-  mCueList->RemoveCue(aCue);
+  mCueList->RemoveCue(aCue, aRv);
 }
 
 void

content/media/TextTrack.h

@@ -99,7 +99,7 @@ public:
   void Update(double aTime);
 
   void AddCue(TextTrackCue& aCue);
-  void RemoveCue(TextTrackCue& aCue);
+  void RemoveCue(TextTrackCue& aCue, ErrorResult& aRv);
   void CueChanged(TextTrackCue& aCue);
 
   IMPL_EVENT_HANDLER(cuechange)

content/media/TextTrackCueList.cpp

@@ -66,12 +66,19 @@ TextTrackCueList::GetCueById(const nsAString& aId)
 void
 TextTrackCueList::AddCue(TextTrackCue& cue)
 {
+  if (mList.Contains(&cue)) {
+    return;
+  }
   mList.AppendElement(&cue);
 }
 
 void
-TextTrackCueList::RemoveCue(TextTrackCue& cue)
+TextTrackCueList::RemoveCue(TextTrackCue& cue, ErrorResult& aRv)
 {
+  if (!mList.Contains(&cue)) {
+    aRv.Throw(NS_ERROR_DOM_NOT_FOUND_ERR);
+    return;
+  }
   mList.RemoveElement(&cue);
 }
 

content/media/TextTrackCueList.h

@@ -11,6 +11,7 @@
 #include "nsCOMPtr.h"
 #include "nsCycleCollectionParticipant.h"
 #include "nsWrapperCache.h"
+#include "mozilla/ErrorResult.h"
 
 namespace mozilla {
 namespace dom {
@@ -47,7 +48,7 @@ public:
   TextTrackCue* GetCueById(const nsAString& aId);
 
   void AddCue(TextTrackCue& cue);
-  void RemoveCue(TextTrackCue& cue);
+  void RemoveCue(TextTrackCue& cue, ErrorResult& aRv);
 
 private:
   nsCOMPtr<nsISupports> mParent;

content/media/test/test_texttrackcue.html

@@ -84,40 +84,29 @@ SpecialPowers.pushPrefEnv({"set": [["media.webvtt.enabled", true]]},
       is(cue.text, "foo", "Cue's text should be foo.");
 
       // Adding the same cue again should not increase the cue count.
-      // TODO: https://bugzilla.mozilla.org/show_bug.cgi?id=867823
-      //       http://www.whatwg.org/specs/web-apps/current-work/multipage/the-video-element.html#dom-texttrack-addcue
       trackElement.track.addCue(vttCue);
-      todo_is(cueList.length, 5, "Cue list length should be 5.");
+      is(cueList.length, 5, "Cue list length should be 5.");
 
       // Check that we are able to remove cues.
       trackElement.track.removeCue(cue);
-      // TODO: Marked as todo as incorrect addition up top increases cue count
-      // to 4 -- https://bugzilla.mozilla.org/show_bug.cgi?id=867823
-      todo_is(cueList.length, 4, "Cue list length should be 4.");
+      is(cueList.length, 4, "Cue list length should be 4.");
 
       var exceptionHappened = false;
       try {
         // We should not be able to remove a cue that is not in the list.
         cue = new VTTCue(1, 2, "foo");
-        trackElement.removeCue(cue);
+        trackElement.track.removeCue(cue);
       } catch (e) {
         // "NotFoundError" should be thrown when trying to remove a cue that is
         // not in the list.
-        // TODO: https://bugzilla.mozilla.org/show_bug.cgi?id=867823
-        //       http://www.whatwg.org/specs/web-apps/current-work/multipage/the-video-element.html#dom-texttrack-removecue
-        todo_is(e.name, "NotFoundError", "We should have caught an error.");
+        is(e.name, "NotFoundError", "Should have thrown NotFoundError.");
         exceptionHappened = true;
       }
       // If this is false then we did not throw an error and probably removed a cue
       // when we shouln't have.
       ok(exceptionHappened, "Exception should have happened.");
 
-      // We should not have removed a cue so the cue list length should not
-      // have changed.
-      // TODO: Marked as todo as incorrect addition of cue up top increases
-      // count erroneously.
-      // https://bugzilla.mozilla.org/show_bug.cgi?id=867823
-      todo_is(cueList.length, 4, "Cue list length should be 4.");
+      is(cueList.length, 4, "Cue list length should be 4.");
 
       SimpleTest.finish();
     });

dom/webidl/TextTrack.webidl

@@ -37,6 +37,7 @@ interface TextTrack : EventTarget {
   readonly attribute TextTrackRegionList? regions;
 
   void addCue(VTTCue cue);
+  [Throws]
   void removeCue(VTTCue cue);
 
            attribute EventHandler oncuechange;