Expose InlineTextBoxes in the accessibility tree.

Source/core/accessibility/AccessibilityInlineTextBox.h

+/*
+ * Copyright (C) 2013, Google Inc. All rights reserved.
+ *
+ * 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.
+ * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
+ *     its contributors may be used to endorse or promote products derived
+ *     from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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.
+ */
+
+#ifndef AccessibilityInlineTextBox_h
+#define AccessibilityInlineTextBox_h
+
+#include "core/accessibility/AccessibilityObject.h"
+#include "core/rendering/RenderText.h"
+
+namespace WebCore {
+
+class AccessibilityInlineTextBox : public AccessibilityObject {
+
+private:
+    AccessibilityInlineTextBox(RenderText*, RenderText::AbstractInlineTextBox*);
+
+public:
+    static PassRefPtr<AccessibilityInlineTextBox> create(RenderText*, RenderText::AbstractInlineTextBox*);
+    virtual ~AccessibilityInlineTextBox();
+
+    virtual void init() OVERRIDE;
+    virtual void detach() OVERRIDE;
+
+    void setInlineTextBox(InlineTextBox* inlineTextBox) { m_inlineTextBox = inlineTextBox; }
+
+    virtual AccessibilityRole roleValue() const OVERRIDE { return InlineTextBoxRole; }
+    virtual String stringValue() const OVERRIDE;
+    virtual void textCharacterOffsets(Vector<int>&) const OVERRIDE;
+    virtual void wordBoundaries(Vector<PlainTextRange>& words) const OVERRIDE;
+    virtual LayoutRect elementRect() const OVERRIDE;
+    virtual AccessibilityObject* parentObject() const OVERRIDE;
+    virtual AccessibilityTextDirection textDirection() const OVERRIDE;
+
+private:
+    RenderText* m_renderText;
+    RenderText::AbstractInlineTextBox* m_inlineTextBox;

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

So this is still holding a raw pointer into InlineTextBox.  I see that you've
added a callback from ~InlineTextBox(), but this is still rather scary. :)

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

Well, we're doing that with RenderObject already. Scary. A WeakPtr would be a
bit better, but wouldn't totally solve the problem, and the cost would be a
WeakPtrFactory for every RenderObject and Node, which seems too expensive. Any
ideas?

What I can do in this case to make it a lot less scary is to make this a RefPtr
to a ref-counted AbstractInlineTextBox. Then we just need an InlineTextBox to
detach its associated AbstractInlineTextBox when it's deleted, which we can do
with a HashMap. That way there's no added cost when AbstractInlineTextBox isn't
used.

+
+    virtual bool computeAccessibilityIsIgnored() const;
+};
+
+} // namespace WebCore
+
+#endif // AccessibilityInlineTextBox_h