Bug 949642 - Implement VTTCue::LineAlign. r=rillian

content/media/TextTrackCue.cpp

@@ -41,6 +41,7 @@ TextTrackCue::SetDefaultCueSettings()
   mSnapToLines = true;
   mLine = WEBVTT_AUTO;
   mAlign = AlignSetting::Middle;
+  mLineAlign = AlignSetting::Start;
   mVertical = DirectionSetting::_empty;
 }
 

content/media/TextTrackCue.h

@@ -174,6 +174,26 @@ public:
     mLine = aLine;
   }
 
+  AlignSetting LineAlign() const
+  {
+    return mLineAlign;
+  }
+
+  void SetLineAlign(AlignSetting& aLineAlign, ErrorResult& aRv)
+  {
+    if (mLineAlign == aLineAlign)
+      return;
+
+    if (aLineAlign == AlignSetting::Left ||
+        aLineAlign == AlignSetting::Right) {
+      return aRv.Throw(NS_ERROR_DOM_SYNTAX_ERR);
+    }
+
+    mReset = true;
+    mLineAlign = aLineAlign;
+    CueChanged();
+  }
+
   int32_t Position() const
   {
     return mPosition;
@@ -324,6 +344,7 @@ private:
   DirectionSetting mVertical;
   int mLine;
   AlignSetting mAlign;
+  AlignSetting mLineAlign;
 
   // Holds the computed DOM elements that represent the parsed cue text.
   // http://www.whatwg.org/specs/web-apps/current-work/#text-track-cue-display-state

content/media/test/test_texttrackcue.html

@@ -76,6 +76,34 @@ SpecialPowers.pushPrefEnv({"set": [["media.webvtt.enabled", true]]},
       cue.pauseOnExit = true;
       is(cue.pauseOnExit, true, "Cue's pause on exit flag should be true.");
 
+      // Check that cue line align works properly
+      is(cue.lineAlign, "start", "Cue's default line alignment should be start.");
+
+      var exceptionHappened = false;
+      try {
+        cue.lineAlign = "left";
+      } catch(e) {
+        exceptionHappened = true;
+        is(e.name, "SyntaxError", "Should have thrown SyntaxError.");
+      }
+      ok(exceptionHappened, "Exception should have happened.");
+
+      exceptionHappened = false;
+      try {
+        cue.lineAlign = "right";
+      } catch(e) {
+        exceptionHappened = true;
+        is(e.name, "SyntaxError", "Should have thrown SyntaxError.");
+      }
+      ok(exceptionHappened, "Exception should have happened.");
+
+      cue.lineAlign = "middle";
+      is(cue.lineAlign, "middle", "Cue's line align should be middle.");
+      cue.lineAlign = "START";
+      is(cue.lineAlign, "middle", "Cue's line align should be middle.");
+      cue.lineAlign = "end";
+      is(cue.lineAlign, "end", "Cue's line align should be end.");
+
       // Check that we can create and add new VTTCues
       var vttCue = new VTTCue(3.999, 4, "foo");
       trackElement.track.addCue(vttCue);
@@ -95,7 +123,7 @@ SpecialPowers.pushPrefEnv({"set": [["media.webvtt.enabled", true]]},
       trackElement.track.removeCue(cue);
       is(cueList.length, 6, "Cue list length should be 6.");
 
-      var exceptionHappened = false;
+      exceptionHappened = false;
       try {
         // We should not be able to remove a cue that is not in the list.
         cue = new VTTCue(1, 2, "foo");

dom/webidl/VTTCue.webidl

@@ -38,6 +38,8 @@ interface VTTCue : EventTarget {
   // XXXhumph: https://www.w3.org/Bugs/Public/show_bug.cgi?id=20651
   // attribute (long or AutoKeyword) line;
   [SetterThrows]
+  attribute AlignSetting lineAlign;
+  [SetterThrows]
   attribute long position;
   [SetterThrows]
   attribute long size;