Send node transition events for touch events

third_party/WebKit/Source/core/events/PointerEventFactory.h

+// Copyright 2016 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.
+
+#ifndef PointerEventFactory_h
+#define PointerEventFactory_h
+
+#include "core/CoreExport.h"
+#include "core/events/PointerEvent.h"
+#include "public/platform/WebPointerProperties.h"
+#include "wtf/Allocator.h"
+#include "wtf/HashMap.h"
+
+namespace blink {
+
+// Helper class for tracking the pointer ids for each type of PointerEvents.
+// Using id re-mapping at this layer, this class makes sure that regardless of
+// the domain of the id (i.e. in touch or pen) the corresponding pointer event
+// will have a unique id amongst all pointer events as per pointer events'
+// specification. This class intended to behave the same as existing browsers as
+// much as possible for compatibility reasons. Particularly it behaves very
+// similar to MS Edge to have pointer event ids generated by mouse always equal
+// 1 and those that are generated by touch and pen will have increasing ids from
+// 2.
+class CORE_EXPORT PointerEventFactory {
+    DISALLOW_NEW();
+public:
+
+    PointerEventFactory();
+    ~PointerEventFactory();
+
+    PassRefPtrWillBeRawPtr<PointerEvent> create(const AtomicString& type,
+        const PlatformMouseEvent&, PassRefPtrWillBeRawPtr<Node> relatedTarget,
+        PassRefPtrWillBeRawPtr<AbstractView>);
+
+    PassRefPtrWillBeRawPtr<PointerEvent> create(const AtomicString& type,
+        const PlatformTouchPoint&, PlatformEvent::Modifiers,
+        const double width, const double height,
+        const double clientX, const double clientY);
+
+    PassRefPtrWillBeRawPtr<PointerEvent> createPointerCancel(
+        const PlatformTouchPoint&);
+
+    PassRefPtrWillBeRawPtr<PointerEvent> create(
+        PassRefPtrWillBeRawPtr<PointerEvent>,
+        const AtomicString& type,
+        PassRefPtrWillBeRawPtr<EventTarget>);
+
+    // Clear all the existing ids.
+    void clear();
+
+    // When a pointerEvent with a particular id is removed that id is considered
+    // free even though there might have been other PointerEvents that were
+    // generated with the same id before.
+    void remove(const PassRefPtrWillBeRawPtr<PointerEvent>);
+
+private:
+    typedef std::pair<int, int> IncomingId;
+    typedef WTF::UnsignedWithZeroKeyHashTraits<int> UnsignedHash;
+
+    int add(const IncomingId);
+    bool isPrimary(const int) const;
+    void setIdAndType(PointerEventInit &, const WebPointerProperties &);
+
+    static const int s_invalidId;
+    static const int s_mouseId;
+
+    int m_currentId;
+    HashMap<IncomingId, int, WTF::PairHash<int, int>, WTF::PairHashTraits<UnsignedHash, UnsignedHash>> m_idMapping;
+    HashMap<int, IncomingId, WTF::IntHash<int>, UnsignedHash> m_idReverseMapping;
+    int m_primaryId[static_cast<int>(WebPointerProperties::PointerType::LastEntry) + 1];
+    int m_idCount[static_cast<int>(WebPointerProperties::PointerType::LastEntry) + 1];
+};
+
+} // namespace blink
+
+#endif // PointerEventFactory_h