Separate VTTCue from VTTCueBox and LayoutVTTCue

Source/core/layout/LayoutVTTCue.cpp

 /*
  * Copyright (C) 2012 Victor Carbune (victor@rosedu.org)
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "core/layout/LayoutVTTCue.h"
 
 #include "core/html/shadow/MediaControls.h"
-#include "core/html/track/vtt/VTTCue.h"
 #include "core/layout/LayoutInline.h"
 #include "core/layout/LayoutState.h"
 
 namespace blink {
 
-LayoutVTTCue::LayoutVTTCue(VTTCueBox* element)
-    : LayoutBlockFlow(element)
-    , m_cue(element->getCue())
+LayoutVTTCue::LayoutVTTCue(ContainerNode* node, float snapToLinesPosition)
+    : LayoutBlockFlow(node)
+    , m_snapToLinesPosition(snapToLinesPosition)
 {
 }
 
 class SnapToLinesLayouter {
     STACK_ALLOCATED();
 public:
-    SnapToLinesLayouter(LayoutVTTCue& cueBox, const IntRect& controlsRect, float linePosition)
+    SnapToLinesLayouter(LayoutVTTCue& cueBox, const IntRect& controlsRect)
         : m_cueBox(cueBox)
         , m_controlsRect(controlsRect)
-        , m_linePosition(linePosition)
     {
     }
 
     void layout();
 
 private:
     bool isOutside() const;
     bool isOverlapping() const;
     LayoutUnit computeInitialPositionAdjustment(LayoutUnit&) const;
     bool shouldSwitchDirection(InlineFlowBox*, LayoutUnit) const;
 
     void moveBoxesBy(LayoutUnit distance)
     {
         m_cueBox.setLogicalTop(m_cueBox.logicalTop() + distance);
     }
 
     InlineFlowBox* findFirstLineBox() const;
 
     LayoutPoint m_specifiedPosition;
     LayoutVTTCue& m_cueBox;
     IntRect m_controlsRect;
-    float m_linePosition;
 };
 
 InlineFlowBox* SnapToLinesLayouter::findFirstLineBox() const
 {
     if (!m_cueBox.firstChild()->isLayoutInline())
         return nullptr;
     return toLayoutInline(m_cueBox.firstChild())->firstLineBox();
 }
 
 LayoutUnit SnapToLinesLayouter::computeInitialPositionAdjustment(LayoutUnit& step) const
 {
+    ASSERT(std::isfinite(m_cueBox.snapToLinesPosition()));
+
     // 6. Let line position be the text track cue computed line position.
     // 7. Round line position to an integer by adding 0.5 and then flooring it.
-    LayoutUnit linePosition = floorf(m_linePosition + 0.5f);
+    LayoutUnit linePosition = floorf(m_cueBox.snapToLinesPosition() + 0.5f);
 
     WritingMode writingMode = m_cueBox.style()->writingMode();
     // 8. Vertical Growing Left: Add one to line position then negate it.
     if (writingMode == RightToLeftWritingMode)
         linePosition = -(linePosition + 1);
 
     // 9. Let position be the result of multiplying step and line position.
     LayoutUnit position = step * linePosition;
 
     // 10. Vertical Growing Left: Decrease position by the width of the
@@ skipping 211 matching lines @@
     if (!adjustment)
         return;
 
     setY(location().y() + adjustment);
 }
 
 void LayoutVTTCue::layout()
 {
     LayoutBlockFlow::layout();
 
-    // If WebVTT Regions are used, the regular WebVTT layout algorithm is no
-    // longer necessary, since cues having the region parameter set do not have
-    // any positioning parameters. Also, in this case, the regions themselves
-    // have positioning information.
-    if (!m_cue->regionId().isEmpty())
-        return;
-
     ASSERT(firstChild());
 
     LayoutState state(*this, locationOffset());
 
     // Determine the area covered by the media controls, if any. If the controls
     // are present, they are the next sibling of the text track container, which
     // is our parent. (LayoutMedia ensures that the media controls are laid out
     // before text tracks, so that the layout is up-to-date here.)
     ASSERT(parent()->node()->isTextTrackContainer());
     IntRect controlsRect;
     if (LayoutObject* parentSibling = parent()->nextSibling()) {
         // Only a part of the media controls is used for overlap avoidance.
         MediaControls* controls = toMediaControls(parentSibling->node());
         if (LayoutObject* controlsLayout = controls->layoutObjectForTextTrackLayout())
             controlsRect = controlsLayout->absoluteBoundingBoxRect();
     }
 
     // http://dev.w3.org/html5/webvtt/#dfn-apply-webvtt-cue-settings - step 13.
-    if (m_cue->snapToLines()) {
-        SnapToLinesLayouter(*this, controlsRect, m_cue->calculateComputedLinePosition()).layout();
+    if (!std::isnan(m_snapToLinesPosition)) {
+        SnapToLinesLayouter(*this, controlsRect).layout();
 
         adjustForTopAndBottomMarginBorderAndPadding();
     } else {
         repositionCueSnapToLinesNotSet();
     }
 }
 
 } // namespace blink