Implement basic parts of hit regions on canvas2d.

Source/core/html/canvas/HitRegion.cpp

Index: Source/core/html/canvas/HitRegion.cpp
diff --git a/Source/core/html/canvas/HitRegion.cpp b/Source/core/html/canvas/HitRegion.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..ba25dd998385f56c65fb577f303701a9a2716d9d
--- /dev/null
+++ b/Source/core/html/canvas/HitRegion.cpp
@@ -0,0 +1,158 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "config.h"
+#include "core/html/canvas/HitRegion.h"
+
+#include "core/accessibility/AXObjectCache.h"
+#include "core/rendering/RenderBoxModelObject.h"
+
+namespace WebCore {
+
+HitRegion::HitRegion(const HitRegionOptions& options)
+    : m_id(options.id)
+    , m_control(options.control)
+    , m_path(options.path)
+{
+}
+
+void HitRegion::updateAccessibility(Element* canvas)
+{
+    if (!m_control || !canvas || !canvas->renderer() || !m_control->isDescendantOf(canvas))
+        return;
+
+    AXObjectCache* axObjectCache = m_control->document().existingAXObjectCache();
+    if (!axObjectCache)
+        return;
+
+    FloatRect boundingRect = m_path.boundingRect();
+
+    // Offset by the canvas rect, taking border and padding into account.
+    RenderBoxModelObject* rbmo = canvas->renderBoxModelObject();
+    IntRect canvasRect = canvas->renderer()->absoluteBoundingBoxRect();
+    canvasRect.move(rbmo->borderLeft() + rbmo->paddingLeft(),
+        rbmo->borderTop() + rbmo->paddingTop());
+    LayoutRect elementRect = enclosingLayoutRect(boundingRect);
+    elementRect.moveBy(canvasRect.location());
+
+    axObjectCache->setCanvasObjectBounds(m_control.get(), elementRect);
+}
+
+bool HitRegion::contains(const LayoutPoint& point) const
+{
+    if (!m_path.boundingRect().contains(point))
+        return false;
+
+    return m_path.contains(point, RULE_NONZERO);
+}
+
+void HitRegion::removePixels(const Path& clearArea)
+{
+    m_path.subtractPath(clearArea);
+}
+
+void HitRegion::trace(Visitor* visitor)
+{
+    visitor->trace(m_control);
+}
+
+void HitRegionManager::addHitRegion(PassRefPtrWillBeRawPtr<HitRegion> passHitRegion)
+{
+    RefPtrWillBeRawPtr<HitRegion> hitRegion = passHitRegion;
+
+    m_hitRegionList.add(hitRegion);
+
+    if (!hitRegion->id().isEmpty())
+        m_hitRegionIdMap.set(hitRegion->id(), hitRegion);
+
+    if (hitRegion->control())
+        m_hitRegionControlMap.set(hitRegion->control(), hitRegion);
+}
+
+void HitRegionManager::removeHitRegion(HitRegion* hitRegion)
+{
+    if (!hitRegion)
+        return;
+
+    if (!hitRegion->id().isEmpty())
+        m_hitRegionIdMap.remove(hitRegion->id());
+
+    if (hitRegion->control())
+        m_hitRegionControlMap.remove(hitRegion->control());
+
+    m_hitRegionList.remove(hitRegion);
+}
+
+void HitRegionManager::removeHitRegionById(const String& id)
+{
+    if (!id.isEmpty())
+        removeHitRegion(getHitRegionById(id));
+}
+
+void HitRegionManager::removeHitRegionByControl(Element* control)
+{
+    removeHitRegion(getHitRegionByControl(control));
+}
+
+void HitRegionManager::removeHitRegionsInRect(const FloatRect& rect, const AffineTransform& ctm)
+{
+    Path clearArea;
+    clearArea.addRect(rect);
+    clearArea.transform(ctm);
+
+    HitRegionIterator itEnd = m_hitRegionList.rend();
+
+    for (HitRegionIterator it = m_hitRegionList.rbegin(); it != itEnd; ++it) {
+        RefPtrWillBeRawPtr<HitRegion> hitRegion = *it;
+        hitRegion->removePixels(clearArea);
+        if (hitRegion->path().isEmpty())
+            removeHitRegion(hitRegion.get());
+    }
+}
+
+void HitRegionManager::removeAllHitRegions()
+{
+    m_hitRegionList.clear();
+    m_hitRegionIdMap.clear();
+}
+
+HitRegion* HitRegionManager::getHitRegionById(const String& id) const
+{
+    return m_hitRegionIdMap.get(id);
+}
+
+HitRegion* HitRegionManager::getHitRegionByControl(Element* control) const
+{
+    if (control)
+        return m_hitRegionControlMap.get(control);
+
+    return 0;
+}
+
+HitRegion* HitRegionManager::getHitRegionAtPoint(const LayoutPoint& point) const
+{
+    HitRegionIterator itEnd = m_hitRegionList.rend();
+
+    for (HitRegionIterator it = m_hitRegionList.rbegin(); it != itEnd; ++it) {
+        RefPtrWillBeRawPtr<HitRegion> hitRegion = *it;
+        if (hitRegion->contains(point))
+            return hitRegion.get();
+    }
+
+    return 0;
+}
+
+unsigned HitRegionManager::getHitRegionsCount() const
+{
+    return m_hitRegionList.size();
+}
+
+void HitRegionManager::trace(Visitor* visitor)
+{
+    visitor->trace(m_hitRegionList);
+    visitor->trace(m_hitRegionIdMap);
+    visitor->trace(m_hitRegionControlMap);
+}
+
+} // namespace WebCore