TextBlob: Start caching a text blob per InlineTextBox.

Source/core/rendering/InlineTextBox.h

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef InlineTextBox_h
 #define InlineTextBox_h
 
 #include "core/rendering/InlineBox.h"
 #include "core/rendering/RenderText.h" // so textRenderer() can be inline
+#include "platform/fonts/TextBlob.h"
 #include "platform/text/TextRun.h"
 #include "wtf/Forward.h"
 
 namespace blink {
 
 struct CompositionUnderline;
 class DocumentMarker;
 class GraphicsContext;
 
 const unsigned short cNoTruncation = USHRT_MAX;
@@ skipping 116 matching lines @@
     virtual float positionForOffset(int offset) const;
 
     bool containsCaretOffset(int offset) const; // false for offset after line break
 
     // Fills a vector with the pixel width of each character.
     void characterWidths(Vector<float>&) const;
 
 private:
     InlineTextBox* m_prevTextBox; // The previous box that also uses our RenderObject
     InlineTextBox* m_nextTextBox; // The next box that also uses our RenderObject
+    TextBlobPtr m_textBlobCache;

[f(malita), 2014/09/12 13:21:23]

naming nit: this sounds a bit like a general/multiple entry cache, maybe
m_cachedBlob or m_cachedTextBlob would be clearer?

[jbroman, 2014/09/13 00:06:42]

m_cachedTextBlob was previously the name, and I bikeshedded away. Will change it
back in the next patch set.

[jbroman, 2014/09/17 22:25:37]

Actually, using a hash map on the side makes this moot.

 
     int m_start;
     unsigned short m_len;
 
     unsigned short m_truncation; // Where to truncate when text overflow is applied.  We use special constants to
                       // denote no truncation (the whole run paints) and full truncation (nothing paints at all).
 
     unsigned underlinePaintStart(const CompositionUnderline&);
     unsigned underlinePaintEnd(const CompositionUnderline&);
 
@@ skipping 24 matching lines @@
 
 inline AffineTransform InlineTextBox::rotation(const FloatRect& boxRect, RotationDirection rotationDirection)
 {
     return rotationDirection == Clockwise ? AffineTransform(0, 1, -1, 0, boxRect.x() + boxRect.maxY(), boxRect.maxY() - boxRect.x())
         : AffineTransform(0, -1, 1, 0, boxRect.x() - boxRect.maxY(), boxRect.x() + boxRect.maxY());
 }
 
 } // namespace blink
 
 #endif // InlineTextBox_h