Expose InlineTextBoxes in the accessibility tree.

Source/core/rendering/RenderText.h

 /*
  * (C) 1999 Lars Knoll (knoll@kde.org)
  * (C) 2000 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 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.
  *
@@ skipping 123 matching lines @@
 
     void checkConsistency() const;
 
     bool isAllCollapsibleWhitespace() const;
 
     bool canUseSimpleFontCodePath() const { return m_canUseSimpleFontCodePath; }
     bool knownToHaveNoOverflowAndNoFallbackFonts() const { return m_knownToHaveNoOverflowAndNoFallbackFonts; }
 
     void removeAndDestroyTextBoxes();
 
+    // High-level abstraction of InlineTextBox to allow the accessibility module to
+    // get information about InlineTextBoxes without tight coupling.
+    typedef InlineTextBox AbstractInlineTextBox;

[eseidel, 2013/10/03 20:36:55]

So this actually isn't going to do anything. :)  The compiler won't stop you
from calling any method you like on these, despite the fact that in the source
they're called AbstractInlineTextBox.  We'd have to actually static_cast these
pointers to ints or something before the compiler would stop you from using
them.

+    struct WordBoundaries {
+        WordBoundaries(int startIndex, int endIndex) : startIndex(startIndex), endIndex(endIndex) { }
+        int startIndex;
+        int endIndex;
+    };
+    enum AbstractInlineTextBoxDirection {
+        AbstractInlineTextBoxDirectionLR,
+        AbstractInlineTextBoxDirectionRL,
+        AbstractInlineTextBoxDirectionTB,
+        AbstractInlineTextBoxDirectionBT
+    };
+    AbstractInlineTextBox* firstInlineTextBox() const;

[eseidel, 2013/10/03 20:36:55]

I might have moved this all out of RenderText into a separate object and make
that object a friend class of RenderText if necessary.

[leviw_travelin_and_unemployed, 2013/10/03 20:42:07]

This description is what I was expecting after the conversation we'd had.

[dmazzoni, 2013/10/04 07:56:09]

Got it. That way we can really decouple it.

+    AbstractInlineTextBox* nextInlineTextBox(AbstractInlineTextBox*) const;
+    LayoutRect inlineTextBoxBounds(AbstractInlineTextBox*) const;
+    unsigned inlineTextBoxStart(AbstractInlineTextBox*) const;
+    unsigned inlineTextBoxLen(AbstractInlineTextBox*) const;
+    AbstractInlineTextBoxDirection inlineTextBoxDirection(AbstractInlineTextBox*) const;
+    void inlineTextBoxCharacterWidths(AbstractInlineTextBox*, Vector<float>&) const;
+    void inlineTextBoxWordBoundaries(AbstractInlineTextBox*, Vector<WordBoundaries>&) const;
+    String inlineTextBoxText(AbstractInlineTextBox*) const;
+
 protected:
     virtual void computePreferredLogicalWidths(float leadWidth);
     virtual void willBeDestroyed();
 
     virtual void styleWillChange(StyleDifference, const RenderStyle*) OVERRIDE FINAL { }
     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle);
 
     virtual void setTextInternal(PassRefPtr<StringImpl>);
     virtual UChar previousCharacter() const;
 
@@ skipping 84 matching lines @@
 inline void RenderText::checkConsistency() const
 {
 }
 #endif
 
 void applyTextTransform(const RenderStyle*, String&, UChar);
 
 } // namespace WebCore
 
 #endif // RenderText_h