Bug 1276832 - part1 : modify VTTCue's line to double. r=rillian,smaug

MozReview-Commit-ID: 7P79SO5TI0K

--HG--
extra : rebase_source : 2f05ccdfccaabf02474f087cf6561c132d412a2b

dom/media/TextTrackCue.cpp

@@ -5,6 +5,7 @@
 
 #include "mozilla/dom/HTMLTrackElement.h"
 #include "mozilla/dom/TextTrackCue.h"
+#include "mozilla/dom/TextTrackList.h"
 #include "mozilla/dom/TextTrackRegion.h"
 #include "nsComponentManagerUtils.h"
 #include "mozilla/ClearOnShutdown.h"
@@ -169,6 +170,40 @@ TextTrackCue::SetRegion(TextTrackRegion* aRegion)
   mReset = true;
 }
 
+double
+TextTrackCue::ComputedLine()
+{
+  // See spec https://w3c.github.io/webvtt/#cue-computed-line
+  if (!mLineIsAutoKeyword && !mSnapToLines &&
+      (mLine < 0.0 || mLine > 100.0)) {
+    return 100.0;
+  } else if (!mLineIsAutoKeyword) {
+    return mLine;
+  } else if (mLineIsAutoKeyword && !mSnapToLines) {
+    return 100.0;
+  } else if (!mTrack ||
+             !mTrack->GetTextTrackList() ||
+             !mTrack->GetTextTrackList()->GetMediaElement()) {
+    return -1.0;
+  }
+
+  RefPtr<TextTrackList> trackList = mTrack->GetTextTrackList();
+  bool dummy;
+  uint32_t showingTracksNum = 0;
+  for (uint32_t idx = 0; idx < trackList->Length(); idx++) {
+    RefPtr<TextTrack> track = trackList->IndexedGetter(idx, dummy);
+    if (track->Mode() == TextTrackMode::Showing) {
+      showingTracksNum++;
+    }
+
+    if (mTrack == track) {
+      break;
+    }
+  }
+
+  return (-1.0) * showingTracksNum;
+}
+
 PositionAlignSetting
 TextTrackCue::ComputedPositionAlign()
 {

dom/media/TextTrackCue.h

@@ -151,21 +151,21 @@ public:
     mSnapToLines = aSnapToLines;
   }
 
-  void GetLine(OwningLongOrAutoKeyword& aLine) const
+  void GetLine(OwningDoubleOrAutoKeyword& aLine) const
   {
     if (mLineIsAutoKeyword) {
       aLine.SetAsAutoKeyword() = AutoKeyword::Auto;
       return;
     }
-    aLine.SetAsLong() = mLineLong;
+    aLine.SetAsDouble() = mLine;
   }
 
-  void SetLine(const LongOrAutoKeyword& aLine)
+  void SetLine(const DoubleOrAutoKeyword& aLine)
   {
-    if (aLine.IsLong() &&
-        (mLineIsAutoKeyword || (aLine.GetAsLong() != mLineLong))) {
+    if (aLine.IsDouble() &&
+        (mLineIsAutoKeyword || (aLine.GetAsDouble() != mLine))) {
       mLineIsAutoKeyword = false;
-      mLineLong = aLine.GetAsLong();
+      mLine = aLine.GetAsDouble();
       mReset = true;
       return;
     }
@@ -299,6 +299,7 @@ public:
     return mReset;
   }
 
+  double ComputedLine();
   PositionAlignSetting ComputedPositionAlign();
 
   // Helper functions for implementation.
@@ -367,7 +368,7 @@ private:
   RefPtr<TextTrackRegion> mRegion;
   DirectionSetting mVertical;
   bool mLineIsAutoKeyword;
-  long mLineLong;
+  double mLine;
   AlignSetting mAlign;
   LineAlignSetting mLineAlign;
 

dom/webidl/VTTCue.webidl

@@ -43,7 +43,7 @@ interface VTTCue : TextTrackCue {
   attribute VTTRegion? region;
   attribute DirectionSetting vertical;
   attribute boolean snapToLines;
-  attribute (long or AutoKeyword) line;
+  attribute (double or AutoKeyword) line;
   [SetterThrows]
   attribute LineAlignSetting lineAlign;
   [SetterThrows]
@@ -64,5 +64,7 @@ partial interface VTTCue {
   [ChromeOnly]
   readonly attribute boolean hasBeenReset;
   [ChromeOnly]
+  readonly attribute double computedLine;
+  [ChromeOnly]
   readonly attribute PositionAlignSetting computedPositionAlign;
 };