Sync snap-to-lines VTT cue layout steps with spec

Source/core/html/track/vtt/VTTCue.cpp

Index: Source/core/html/track/vtt/VTTCue.cpp
diff --git a/Source/core/html/track/vtt/VTTCue.cpp b/Source/core/html/track/vtt/VTTCue.cpp
index d991b9fa58d812853182acbf8315a50acb34643e..990ec66e2768ae06bbc63c32d159ff0399ed0c09 100644
--- a/Source/core/html/track/vtt/VTTCue.cpp
+++ b/Source/core/html/track/vtt/VTTCue.cpp
@@ -189,8 +189,8 @@ void VTTCueBox::applyCSSProperties(const VTTDisplayParameters& displayParameters
 
     // The 'text-align' property on the (root) List of WebVTT Node Objects must
     // be set to the value in the second cell of the row of the table below
-    // whose first cell is the value of the corresponding cue's text track cue
-    // alignment:
+    // whose first cell is the value of the corresponding cue's WebVTT cue
+    // text alignment:
     setInlineStyleProperty(CSSPropertyTextAlign, displayParameters.textAlign);
 
     // TODO(philipj): The position adjustment for non-snap-to-lines cues has
@@ -324,10 +324,9 @@ void VTTCue::line(DoubleOrAutoKeyword& result) const
 void VTTCue::setLine(const DoubleOrAutoKeyword& position)
 {
     // http://dev.w3.org/html5/webvtt/#dfn-vttcue-line
-    // On setting, the text track cue line position must be set to the new
-    // value; if the new value is the string "auto", then it must be
-    // interpreted as the special value auto.
-    // ("auto" is translated to NaN.)
+    // On setting, the WebVTT cue line must be set to the new value; if the new
+    // value is the string "auto", then it must be interpreted as the special
+    // value auto.  ("auto" is translated to NaN.)
     float floatPosition;
     if (position.isAutoKeyword()) {
         if (lineIsAuto())
@@ -362,9 +361,9 @@ void VTTCue::setPosition(const DoubleOrAutoKeyword& position, ExceptionState& ex
 {
     // http://dev.w3.org/html5/webvtt/#dfn-vttcue-position
     // On setting, if the new value is negative or greater than 100, then an
-    // IndexSizeError exception must be thrown. Otherwise, the text track cue
-    // text position must be set to the new value; if the new value is the
-    // string "auto", then it must be interpreted as the special value auto.
+    // IndexSizeError exception must be thrown. Otherwise, the WebVTT cue
+    // position must be set to the new value; if the new value is the string
+    // "auto", then it must be interpreted as the special value auto.
     float floatPosition;
     if (position.isAutoKeyword()) {
         if (textPositionIsAuto())
@@ -386,13 +385,13 @@ void VTTCue::setPosition(const DoubleOrAutoKeyword& position, ExceptionState& ex
 
 void VTTCue::setSize(double size, ExceptionState& exceptionState)
 {
-    // http://www.whatwg.org/specs/web-apps/current-work/multipage/the-video-element.html#dom-texttrackcue-size
-    // On setting, if the new value is negative or greater than 100, then throw an IndexSizeError
-    // exception. Otherwise, set the text track cue size to the new value.
+    // http://dev.w3.org/html5/webvtt/#dfn-vttcue-size
+    // On setting, if the new value is negative or greater than 100, then throw
+    // an IndexSizeError exception.
     if (isInvalidPercentage(size, exceptionState))
         return;
 
-    // Otherwise, set the text track cue line position to the new value.
+    // Otherwise, set the WebVTT cue size to the new value.
     float floatSize = narrowPrecisionToFloat(size);
     if (m_cueSize == floatSize)
         return;
@@ -498,33 +497,32 @@ void VTTCue::setRegionId(const String& regionId)
 
 float VTTCue::calculateComputedLinePosition() const
 {
-    // http://dev.w3.org/html5/webvtt/#dfn-text-track-cue-computed-line-position
-    // A text track cue has a text track cue computed line position whose value
-    // is that returned by the following algorithm, which is defined in terms
-    // of the other aspects of the cue:
-
-    // 1. If the text track cue line position is numeric, the text track cue
-    //    snap-to-lines flag of the text track cue is not set, and the text
-    //    track cue line position is negative or greater than 100, then return
-    //    100 and abort these steps.
+    // http://dev.w3.org/html5/webvtt/#dfn-cue-computed-line
+    // A WebVTT cue has a computed line whose value is that returned by the
+    // following algorithm, which is defined in terms of the other aspects of
+    // the cue:
+
+    // 1. If the line is numeric, the WebVTT cue snap-to-lines flag of the
+    //    WebVTT cue is not set, and the line is negative or greater than 100,
+    //    then return 100 and abort these steps.
     if (!lineIsAuto() && !m_snapToLines && isInvalidPercentage(m_linePosition))
         return 100;
 
-    // 2. If the text track cue line position is numeric, return the value of
-    //    the text track cue line position and abort these steps. (Either the
-    //    text track cue snap-to-lines flag is set, so any value, not just
-    //    those in the range 0..100, is valid, or the value is in the range
-    //    0..100 and is thus valid regardless of the value of that flag.)
+    // 2. If the line is numeric, return the value of the WebVTT cue line and
+    //    abort these steps. (Either the WebVTT cue snap-to-lines flag is set,
+    //    so any value, not just those in the range 0..100, is valid, or the
+    //    value is in the range 0..100 and is thus valid regardless of the
+    //    value of that flag.)
     if (!lineIsAuto())
         return m_linePosition;
 
-    // 3. If the text track cue snap-to-lines flag of the text track cue is not
-    //    set, return the value 100 and abort these steps. (The text track cue
-    //    line position is the special value auto.)
+    // 3. If the WebVTT cue snap-to-lines flag of the WebVTT cue is not set,
+    //    return the value 100 and abort these steps. (The WebVTT cue line is
+    //    the special value auto.)
     if (!m_snapToLines)
         return 100;
 
-    // 4. Let cue be the text track cue.
+    // 4. Let cue be the WebVTT cue.
     // 5. If cue is not in a list of cues of a text track, or if that text
     //    track is not in the list of text tracks of a media element, return -1
     //    and abort these steps.
@@ -598,24 +596,23 @@ static CSSValueID determineTextDirection(DocumentFragment* vttRoot)
 
 float VTTCue::calculateComputedTextPosition() const
 {
-    // http://dev.w3.org/html5/webvtt/#dfn-text-track-cue-computed-text-position
+    // http://dev.w3.org/html5/webvtt/#dfn-cue-computed-position
 
-    // 1. If the text track cue text position is numeric, then return the value
-    // of the text track cue text position and abort these steps. (Otherwise,
-    // the text track cue text position is the special value auto.)
+    // 1. If the position is numeric, then return the value of the position and
+    // abort these steps. (Otherwise, the position is the special value auto.)
     if (!textPositionIsAuto())
         return m_textPosition;
 
     switch (m_cueAlignment) {
-    // 2. If the text track cue text alignment is start or left, return 0 and abort these steps.
+    // 2. If the cue text alignment is start or left, return 0 and abort these steps.
     case Start:
     case Left:
         return 0;
-    // 3. If the text track cue text alignment is end or right, return 100 and abort these steps.
+    // 3. If the cue text alignment is end or right, return 100 and abort these steps.
     case End:
     case Right:
         return 100;
-    // 4. If the text track cue text alignment is middle, return 50 and abort these steps.
+    // 4. If the cue text alignment is middle, return 50 and abort these steps.
     case Middle:
         return 50;
     default:
@@ -659,11 +656,10 @@ VTTDisplayParameters VTTCue::calculateDisplayParameters() const
     // VTTCueBox::applyCSSProperties need not have access to a VTTCue.
     displayParameters.textAlign = displayAlignmentMap[cueAlignment()];
 
-    // 3. If the text track cue writing direction is horizontal, then let
-    // block-flow be 'tb'. Otherwise, if the text track cue writing direction is
-    // vertical growing left, then let block-flow be 'lr'. Otherwise, the text
-    // track cue writing direction is vertical growing right; let block-flow be
-    // 'rl'.
+    // 3. If the cue writing direction is horizontal, then let block-flow be
+    // 'tb'. Otherwise, if the cue writing direction is vertical growing left,
+    // then let block-flow be 'lr'. Otherwise, the cue writing direction is
+    // vertical growing right; let block-flow be 'rl'.
     displayParameters.writingMode = displayWritingModeMap[m_writingDirection];
 
     // Resolve the cue alignment to one of the values {start, end, middle}.
@@ -684,11 +680,11 @@ VTTDisplayParameters VTTCue::calculateDisplayParameters() const
         ASSERT_NOT_REACHED();
     }
 
-    // 5. If the text track cue size is less than maximum size, then let size
-    // be text track cue size. Otherwise, let size be maximum size.
+    // 5. If the cue size is less than maximum size, then let size
+    // be cue size. Otherwise, let size be maximum size.
     displayParameters.size = std::min(m_cueSize, maximumSize);
 
-    // 6. If the text track cue writing direction is horizontal, then let width
+    // 6. If the cue writing direction is horizontal, then let width
     // be 'size vw' and height be 'auto'. Otherwise, let width be 'auto' and
     // height be 'size vh'. (These are CSS values used by the next section to
     // set CSS properties for the rendering; 'vw' and 'vh' are CSS units.)
@@ -727,8 +723,8 @@ VTTDisplayParameters VTTCue::calculateDisplayParameters() const
         }
     }
 
-    // A text track cue has a text track cue computed line position whose value
-    // is defined in terms of the other aspects of the cue.
+    // A cue has a computed line whose value is defined in terms of
+    // the other aspects of the cue.
     float computedLinePosition = calculateComputedLinePosition();
 
     // 8. Determine the value of whichever of x-position or y-position is not
@@ -886,16 +882,16 @@ void VTTCue::updateDisplay(HTMLDivElement& container)
         region = track()->regions()->getRegionById(regionId());
 
     if (!region) {
-        // If cue has an empty text track cue region identifier or there is no
-        // WebVTT region whose region identifier is identical to cue's text
-        // track cue region identifier, run the following substeps:
+        // If cue has an empty region identifier or there is no WebVTT region
+        // whose region identifier is identical to cue's region identifier, run
+        // the following substeps:
         if (displayBox->hasChildren() && !container.contains(displayBox.get())) {
             // Note: the display tree of a cue is removed when the active flag of the cue is unset.
             container.appendChild(displayBox);
         }
     } else {
-        // Let region be the WebVTT region whose region identifier
-        // matches the text track cue region identifier of cue.
+        // Let region be the WebVTT region whose region identifier matches the
+        // region identifier of cue.
         RefPtrWillBeRawPtr<HTMLDivElement> regionNode = region->getDisplayTree(document());
 
         // Append the region to the viewport, if it was not already.
@@ -978,13 +974,13 @@ void VTTCue::parseSettings(const String& inputString)
         case Vertical: {
             // If name is a case-sensitive match for "vertical"
             // 1. If value is a case-sensitive match for the string "rl", then
-            //    let cue's text track cue writing direction be vertical
+            //    let cue's WebVTT cue writing direction be vertical
             //    growing left.
             if (input.scanRun(valueRun, verticalGrowingLeftKeyword()))
                 m_writingDirection = VerticalGrowingLeft;
 
             // 2. Otherwise, if value is a case-sensitive match for the string
-            //    "lr", then let cue's text track cue writing direction be
+            //    "lr", then let cue's WebVTT cue writing direction be
             //    vertical growing right.
             else if (input.scanRun(valueRun, verticalGrowingRightKeyword()))
                 m_writingDirection = VerticalGrowingRight;
@@ -1021,10 +1017,10 @@ void VTTCue::parseSettings(const String& inputString)
             }
             if (!input.isAt(valueRun.end()))
                 break;
-            // 5. Let cue's text track cue line position be number.
+            // 5. Let cue's WebVTT cue line be number.
             m_linePosition = number;
             // 6. If the last character in linepos is a U+0025 PERCENT SIGN
-            //    character (%), then let cue's text track cue snap-to-lines
+            //    character (%), then let cue's WebVTT cue snap-to-lines
             //    flag be false. Otherwise, let it be true.
             m_snapToLines = !isPercentage;
             // Steps 7 - 9 skipped.
@@ -1042,7 +1038,7 @@ void VTTCue::parseSettings(const String& inputString)
                 break;
             if (!input.isAt(valueRun.end()))
                 break;
-            // 4. Let cue's text track cue text position be number.
+            // 4. Let cue's cue position be number.
             m_textPosition = number;
             // Steps 5 - 7 skipped.
             break;
@@ -1057,34 +1053,34 @@ void VTTCue::parseSettings(const String& inputString)
                 break;
             if (!input.isAt(valueRun.end()))
                 break;
-            // 2. Let cue's text track cue size be number.
+            // 2. Let cue's WebVTT cue size be number.
             m_cueSize = number;
             break;
         }
         case Align: {
             // If name is a case-sensitive match for "align"
             // 1. If value is a case-sensitive match for the string "start",
-            //    then let cue's text track cue alignment be start alignment.
+            //    then let cue's WebVTT cue text alignment be start alignment.
             if (input.scanRun(valueRun, startKeyword()))
                 m_cueAlignment = Start;
 
             // 2. If value is a case-sensitive match for the string "middle",
-            //    then let cue's text track cue alignment be middle alignment.
+            //    then let cue's WebVTT cue text alignment be middle alignment.
             else if (input.scanRun(valueRun, middleKeyword()))
                 m_cueAlignment = Middle;
 
             // 3. If value is a case-sensitive match for the string "end", then
-            //    let cue's text track cue alignment be end alignment.
+            //    let cue's WebVTT cue text alignment be end alignment.
             else if (input.scanRun(valueRun, endKeyword()))
                 m_cueAlignment = End;
 
             // 4. If value is a case-sensitive match for the string "left",
-            //    then let cue's text track cue alignment be left alignment.
+            //    then let cue's WebVTT cue text alignment be left alignment.
             else if (input.scanRun(valueRun, leftKeyword()))
                 m_cueAlignment = Left;
 
             // 5. If value is a case-sensitive match for the string "right",
-            //    then let cue's text track cue alignment be right alignment.
+            //    then let cue's WebVTT cue text alignment be right alignment.
             else if (input.scanRun(valueRun, rightKeyword()))
                 m_cueAlignment = Right;
             break;