Extract touch handling logic from EventHandler

third_party/WebKit/Source/core/input/TouchEventManager.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 TouchEventManager_h
+#define TouchEventManager_h
+
+#include "core/CoreExport.h"
+#include "core/events/PointerEventFactory.h"
+#include "platform/UserGestureIndicator.h"
+#include "public/platform/WebInputEventResult.h"
+#include "wtf/Allocator.h"
+#include "wtf/HashMap.h"
+
+
+namespace blink {
+
+class LocalFrame;
+class Document;
+class PlatformTouchEvent;
+class PointerEventWithTarget;
+
+// This class takes care of dispatching all touch events and
+// maintaining related states.
+class CORE_EXPORT TouchEventManager {
+    DISALLOW_NEW();
+public:
+    class TouchInfo {
+        DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
+    public:
+        DEFINE_INLINE_TRACE()
+        {
+            visitor->trace(touchNode);
+            visitor->trace(targetFrame);
+        }
+
+        PlatformTouchPoint point;
+        Member<Node> touchNode;
+        Member<LocalFrame> targetFrame;
+        FloatPoint adjustedPagePoint;
+        FloatSize adjustedRadius;
+        bool knownTarget;
+        bool consumed;
+        String region;
+    };
+
+    explicit TouchEventManager(LocalFrame*);
+    ~TouchEventManager();
+    DECLARE_TRACE();
+
+    // Returns true if it succesfully generates touchInfos.
+    bool generateTouchInfosAfterHittest(
+        const PlatformTouchEvent&,
+        HeapVector<TouchInfo>&);
+
+    WebInputEventResult handleTouchEvent(
+        const PlatformTouchEvent&,
+        const HeapVector<TouchInfo>&);
+
+    // Resets the internal state of this object.
+    void clear();
+
+    // Returns whether there is any touch on the screen.
+    bool isAnyTouchActive() const;
+
+private:
+
+    void updateTargetAndRegionMapsForTouchStarts(HeapVector<TouchInfo>&);
+    void setAllPropertiesOfTouchInfos(HeapVector<TouchInfo>&);
+
+    WebInputEventResult dispatchTouchEvents(
+        const PlatformTouchEvent&,
+        const HeapVector<TouchInfo>&,
+        bool allTouchesReleased);
+
+
+    // NOTE: If adding a new field to this class please ensure that it is
+    // cleared in |TouchEventManager::clear()|.
+
+    const Member<LocalFrame> m_frame;
+
+    // The target of each active touch point indexed by the touch ID.
+    using TouchTargetMap = HeapHashMap<unsigned, Member<Node>, DefaultHash<unsigned>::Hash, WTF::UnsignedWithZeroKeyHashTraits<unsigned>>;
+    TouchTargetMap m_targetForTouchID;
+    using TouchRegionMap = HashMap<unsigned, String, DefaultHash<unsigned>::Hash, WTF::UnsignedWithZeroKeyHashTraits<unsigned>>;
+    TouchRegionMap m_regionForTouchID;
+
+    // If set, the document of the active touch sequence. Unset if no touch sequence active.
+    Member<Document> m_touchSequenceDocument;
+
+    RefPtr<UserGestureToken> m_touchSequenceUserGestureToken;
+    bool m_touchPressed;
+    // True if waiting on first touch move after a touch start.
+    bool m_waitingForFirstTouchMove;
+
+};
+
+} // namespace blink
+
+WTF_ALLOW_INIT_WITH_MEM_FUNCTIONS(blink::TouchEventManager::TouchInfo);
+
+#endif // TouchEventManager_h