Expose InlineTextBoxes in the accessibility tree.

Source/core/accessibility/AccessibilityInlineTextBox.cpp

+/*
+ * 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.
+ */
+
+#include "config.h"
+#include "core/accessibility/AccessibilityInlineTextBox.h"
+
+#include "core/accessibility/AXObjectCache.h"
+#include "core/dom/Range.h"
+#include "core/editing/TextIterator.h"
+#include "core/platform/LayoutUnit.h"
+#include "core/platform/text/TextBreakIterator.h"
+#include "core/rendering/InlineTextBox.h"
+
+using namespace std;
+
+namespace WebCore {
+
+using namespace HTMLNames;
+
+AccessibilityInlineTextBox::AccessibilityInlineTextBox(InlineTextBox* inlineTextBox)
+    : m_inlineTextBox(inlineTextBox)
+{
+}
+
+AccessibilityInlineTextBox::~AccessibilityInlineTextBox()
+{
+}
+
+PassRefPtr<AccessibilityInlineTextBox> AccessibilityInlineTextBox::create(InlineTextBox* inlineTextBox)
+{
+    return adoptRef(new AccessibilityInlineTextBox(inlineTextBox));
+}
+
+void AccessibilityInlineTextBox::init()
+{
+    RenderObject* renderer = m_inlineTextBox->renderer();
+    AccessibilityObject* parent = renderer->document().axObjectCache()->getOrCreate(renderer);
+}
+
+void AccessibilityInlineTextBox::detach()
+{
+    m_inlineTextBox = 0;
+    AccessibilityObject::detach();
+}
+
+LayoutRect AccessibilityInlineTextBox::elementRect() const
+{
+    if (!m_inlineTextBox)
+        return LayoutRect();
+
+    AccessibilityObject* parent = parentObject();
+    if (!parent)
+        return LayoutRect();
+
+    LayoutRect rect(m_inlineTextBox->topLeft(), m_inlineTextBox->size());
+    rect.moveBy(parent->elementRect().location());
+    return rect;
+}
+
+bool AccessibilityInlineTextBox::computeAccessibilityIsIgnored() const
+{
+    if (AccessibilityObject* parent = parentObject())
+        return parent->accessibilityIsIgnored();
+
+    return false;
+}
+
+void AccessibilityInlineTextBox::textCharacterOffsets(Vector<int>& offsets) const
+{
+    if (!m_inlineTextBox)
+        return;
+
+    int len = m_inlineTextBox->len();
+    float* widths = new float[len];
+    m_inlineTextBox->characterWidths(widths);
+    offsets.resize(len);
+
+    float widthSoFar = 0;
+    for (int i = 0; i < len; i++) {
+        widthSoFar += widths[i];
+        offsets[i] = LayoutUnit::fromFloatRound(widthSoFar);
+    }
+    delete[] widths;
+}
+
+void AccessibilityInlineTextBox::wordBoundaries(Vector<int>& starts, Vector<int>& ends) const
+{
+    if (!m_inlineTextBox)
+        return;
+
+    RenderText* renderText = toRenderText(m_inlineTextBox->renderer());
+    ASSERT(renderText);
+
+    unsigned start = m_inlineTextBox->start();
+    unsigned len = m_inlineTextBox->len();
+    TextBreakIterator* iterator = wordBreakIterator(renderText->text(), start, len);
+    int pos = textBreakFirst(iterator);
+    while (pos >= 0 && pos < len) {
+        pos = textBreakNext(iterator);

[aboxhall, 2013/09/06 17:19:21]

Out of curiosity, how does this deal with spaces? Does textBreakPrevious return
the start of the previous word, while textBreakNext returns the end of the
current word?

[dmazzoni, 2013/09/06 20:25:27]

That's what it seems to do, yes. It's a bit confusing to me, we need someone
who knows the text iterators to review this and make sure this is the right
way to do it.

+        if (isWordTextBreak(iterator)) {
+            starts.append(textBreakPrevious(iterator));
+            ends.append(textBreakNext(iterator));
+        }
+    }
+}
+
+String AccessibilityInlineTextBox::stringValue() const
+{
+    if (!m_inlineTextBox)
+        return String();
+
+    RenderText* renderText = toRenderText(m_inlineTextBox->renderer());
+    ASSERT(renderText);
+
+    unsigned start = m_inlineTextBox->start();
+    unsigned len = m_inlineTextBox->len();
+    if (Node* node = renderText->node()) {

[aboxhall, 2013/09/06 17:19:21]

Why is this a special case?

[dmazzoni, 2013/09/06 20:25:27]

This is the common case. What we want is the "plain text" rendering of the text,
for example if the DOM contains literally <span>    Hello,   world  </span> then
we want just "Hello, world" as the string value, since that's what's actually
rendered. This does the right thing with regards to implicit spaces too.

+        RefPtr<Range> range = Range::create(node->document());
+        range->setStart(node, start, IGNORE_EXCEPTION);
+        range->setEnd(node, start + len, IGNORE_EXCEPTION);
+        return plainText(range.get(), textIteratorBehaviorForTextRange());
+    }
+
+    return renderText->text().substring(start, len);

[dmazzoni, 2013/09/06 20:25:27]

This is the uncommon case. We only reach this for cases like CSS-inserted text.

+}
+
+AccessibilityObject* AccessibilityInlineTextBox::parentObject() const
+{
+    if (!m_inlineTextBox)
+        return 0;
+
+    RenderObject* renderer = m_inlineTextBox->renderer();
+    return renderer->document().axObjectCache()->getOrCreate(renderer);
+}
+
+} // namespace WebCore