Check element type in TTML inheritance

Also adds support for style attributes on the cue element itself. Closes #473 Change-Id: I886ec2d0c07c9192f7599b565422692a165b43e5
shaka-project · Aug 12, 2016 · 2ee7eec · 2ee7eec
1 parent 0a9cae8
commit 2ee7eec
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Showing 2 changed files with 48 additions and 17 deletions.
diff --git a/lib/media/ttml_text_parser.js b/lib/media/ttml_text_parser.js
@@ -228,7 +228,7 @@ shaka.media.TtmlTextParser.parseCue_ = function(
     // Get other properties if available
     var region = shaka.media.TtmlTextParser.getElementFromCollection_(
         cueElement, 'region', regions);
-    shaka.media.TtmlTextParser.addStyle_(cue, region, styles);
+    shaka.media.TtmlTextParser.addStyle_(cue, cueElement, region, styles);
   } else {
     cue = new TextTrackCue(start, end, payload);
   }
@@ -241,20 +241,23 @@ shaka.media.TtmlTextParser.parseCue_ = function(
  * Adds applicable style properties to a cue.
  *
  * @param {!VTTCue} cue
+ * @param {!Element} cueElement
  * @param {Element} region
  * @param {!Array.<!Element>} styles
  * @private
  */
-shaka.media.TtmlTextParser.addStyle_ = function(cue, region, styles) {
+shaka.media.TtmlTextParser.addStyle_ = function(
+    cue, cueElement, region, styles) {
   var TtmlTextParser = shaka.media.TtmlTextParser;
   var results = null;
 
   var align = TtmlTextParser.getStyleAttribute_(
-      region, styles, 'tts:textAlign');
+      cueElement, region, styles, 'tts:textAlign');
   if (align)
     cue.lineAlign = align;
 
-  var extent = TtmlTextParser.getStyleAttribute_(region, styles, 'tts:extent');
+  var extent = TtmlTextParser.getStyleAttribute_(
+      cueElement, region, styles, 'tts:extent');
   if (extent) {
     results = TtmlTextParser.percentValues_.exec(extent);
     if (results != null) {
@@ -265,7 +268,7 @@ shaka.media.TtmlTextParser.addStyle_ = function(cue, region, styles) {
   }
 
   var writingMode = TtmlTextParser.getStyleAttribute_(
-      region, styles, 'tts:writingMode');
+      cueElement, region, styles, 'tts:writingMode');
   var isVerticalText = true;
   if (writingMode == 'tb' || writingMode == 'tblr')
     cue.vertical = 'lr';
@@ -274,7 +277,8 @@ shaka.media.TtmlTextParser.addStyle_ = function(cue, region, styles) {
   else
     isVerticalText = false;
 
-  var origin = TtmlTextParser.getStyleAttribute_(region, styles, 'tts:origin');
+  var origin = TtmlTextParser.getStyleAttribute_(
+      cueElement, region, styles, 'tts:origin');
   if (origin) {
     results = TtmlTextParser.percentValues_.exec(origin);
     if (results != null) {
@@ -294,29 +298,32 @@ shaka.media.TtmlTextParser.addStyle_ = function(cue, region, styles) {
 
 
 /**
- * Finds a specified attribute in ttml and returns its value if the
- * attribute was found.
+ * Finds a specified attribute on either the original cue element or its
+ * associated region and returns the value if the attribute was found.
  *
+ * @param {!Element} cueElement
  * @param {Element} region
  * @param {!Array.<!Element>} styles
  * @param {string} attribute
  * @return {?string}
  * @private
  */
 shaka.media.TtmlTextParser.getStyleAttribute_ = function(
-    region, styles, attribute) {
+    cueElement, region, styles, attribute) {
 
-  // an attribute can be specified on region level or in a styling block
-  // associated with the region
+  // An attribute can be specified on region level or in a styling block
+  // associated with the region or original element.
   var regionChildren = shaka.media.TtmlTextParser.getLeafNodes_(region);
   for (var i = 0; i < regionChildren.length; i++) {
     var attr = regionChildren[i].getAttribute(attribute);
     if (attr)
       return attr;
   }
 
-  var style = shaka.media.TtmlTextParser.getElementFromCollection_(
-      region, 'style', styles);
+  var getElementFromCollection_ =
+      shaka.media.TtmlTextParser.getElementFromCollection_;
+  var style = getElementFromCollection_(region, 'style', styles) ||
+              getElementFromCollection_(cueElement, 'style', styles);
   if (style)
     return style.getAttribute(attribute);
   return null;
@@ -370,10 +377,16 @@ shaka.media.TtmlTextParser.getInheritedAttribute_ = function(
     if (ret) {
       break;
     }
-    // TODO: Temporary cast, Node must be handled explicitly.
-    element = /** @type {!Element} */(element.parentNode);
-  }
 
+    // Element.parentNode can lead to XMLDocument, which is not an Element and
+    // has no getAttribute().
+    var parentNode = element.parentNode;
+    if (parentNode instanceof Element) {
+      element = parentNode;
+    } else {
+      break;
+    }
+  }
   return ret;
 };
 

diff --git a/test/media/ttml_text_parser_unit.js b/test/media/ttml_text_parser_unit.js
@@ -165,7 +165,7 @@ describe('TtmlTextParser', function() {
         '</tt>');
   });
 
-  it('parses alignment from <style> block', function() {
+  it('parses alignment from <style> block with id on region', function() {
     verifyHelper(
         [
           {start: 62.05, end: 3723.2, text: 'Test', lineAlign: 'end'}
@@ -183,6 +183,24 @@ describe('TtmlTextParser', function() {
         '</tt>');
   });
 
+  it('parses alignment from <style> block with id on p', function() {
+    verifyHelper(
+        [
+          {start: 62.05, end: 3723.2, text: 'Test', lineAlign: 'end'}
+        ],
+        '<tt xmlns:tts="ttml#styling">' +
+        '<styling>' +
+        '<style xml:id="s1" tts:textAlign="end"/>' +
+        '</styling>' +
+        '<layout xmlns:tts="ttml#styling">' +
+        '<region xml:id="subtitleArea" />' +
+        '</layout>' +
+        '<body region="subtitleArea">' +
+        '<p begin="01:02.05" end="01:02:03.200" style="s1">Test</p>' +
+        '</body>' +
+        '</tt>');
+  });
+
   it('supports size setting', function() {
     verifyHelper(
         [