Implement basic parts of hit regions on canvas2d.

Source/core/html/canvas/HitRegion.cpp

+// 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;
+
+    FloatRect boundingRect = m_path.boundingRect();
+
+    // Offset by the canvas rect (We should take border and padding into account).

[dmazzoni, 2014/06/09 07:27:26]

What do you mean by "we should take border and padding into account"?

1. Offset by the canvas rect, taking border and padding into account
2. Offset by the canvas rect. FIXME: we should take border and padding into
account

[zino, 2014/06/10 10:09:34]

Done.

+    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* axObjectCache = m_control->document().existingAXObjectCache();
+    if (!axObjectCache)

[dmazzoni, 2014/06/09 07:27:26]

Move this test up to the top; there's no reason to do the rest of the
calculation if there's no AXObjectCache.

[zino, 2014/06/10 10:09:34]

Done.

+        return;
+
+    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)
+{
+#if ENABLE(OILPAN)
+    visitor->trace(m_control);
+#endif
+}
+
+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)
+{
+#if ENABLE(OILPAN)
+    visitor->trace(m_hitRegionList);
+    visitor->trace(m_hitRegionIdMap);
+    visitor->trace(m_hitRegionControlMap);
+#endif
+}
+
+} // namespace WebCore