Expose InlineTextBoxes in the accessibility tree.

Source/core/rendering/RenderText.h

Index: Source/core/rendering/RenderText.h
diff --git a/Source/core/rendering/RenderText.h b/Source/core/rendering/RenderText.h
index 1a49794cf22450e687aded43e5773126fcb995d2..15ffbaa9c20a3435116d97c8c7d046775c112eef 100644
--- a/Source/core/rendering/RenderText.h
+++ b/Source/core/rendering/RenderText.h
@@ -141,6 +141,30 @@ public:
 
     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();