Extract more of the mouse logic from EventHandler

third_party/WebKit/Source/core/input/MouseEventManager.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 MouseEventManager_h
 #define MouseEventManager_h
 
 #include "core/CoreExport.h"
-#include "core/frame/LocalFrame.h"
 #include "core/input/BoundaryEventDispatcher.h"
+#include "core/page/DragActions.h"
+#include "core/page/EventWithHitTestResults.h"
 #include "platform/PlatformMouseEvent.h"
+#include "platform/Timer.h"
 #include "public/platform/WebInputEventResult.h"
 #include "wtf/Allocator.h"
 
 namespace blink {
 
+class DragState;
+class DataTransfer;
+class Element;
+class FloatQuad;
+class HitTestResult;
+class InputDeviceCapabilities;
 class LocalFrame;
+class ScrollManager;
+
+enum class DragInitiator;
 
 // This class takes care of dispatching all mouse events and keeps track of
 // positions and states of mouse.
 class CORE_EXPORT MouseEventManager : public GarbageCollectedFinalized<MouseEventManager> {
     WTF_MAKE_NONCOPYABLE(MouseEventManager);
 
 public:
-    explicit MouseEventManager(LocalFrame*);
+    explicit MouseEventManager(LocalFrame*, ScrollManager*);
+    ~MouseEventManager();
     DECLARE_TRACE();
 
     WebInputEventResult dispatchMouseEvent(
         EventTarget*, const AtomicString&, const PlatformMouseEvent&,
-        EventTarget* relatedTarget, int detail = 0,
-        bool checkForListener = false);
+        EventTarget* relatedTarget, bool checkForListener = false);
+
+    WebInputEventResult dispatchMouseEvent(
+        Node* targetNode, const AtomicString& eventType,
+        const PlatformMouseEvent&);
+
+    WebInputEventResult dispatchMouseClickIfNeeded(
+        const MouseEventWithHitTestResults&);
+
+    WebInputEventResult dispatchDragSrcEvent(const AtomicString& eventType, const PlatformMouseEvent&);
+    WebInputEventResult dispatchDragEvent(const AtomicString& eventType, Node* target, const PlatformMouseEvent&, DataTransfer*);
 
     // Resets the internal state of this object.
     void clear();
 
     void sendBoundaryEvents(
         EventTarget* exitedTarget,
         EventTarget* enteredTarget,
         const PlatformMouseEvent& mousePlatformEvent);
 
+    void setNodeUnderMouse(Node*, const PlatformMouseEvent&);
+
+    WebInputEventResult handleMouseFocus(const HitTestResult&, InputDeviceCapabilities* sourceCapabilities);
+
+    void fakeMouseMoveEventTimerFired(TimerBase*);
+
+    void cancelFakeMouseMoveEvent();
+    void dispatchFakeMouseMoveEventSoon();
+    void dispatchFakeMouseMoveEventSoonInQuad(const FloatQuad&);
+
+    void setLastKnownMousePosition(const PlatformMouseEvent&);
+
+    bool handleDragDropIfPossible(const GestureEventWithHitTestResults&);
+
+    WebInputEventResult handleMouseDraggedEvent(const MouseEventWithHitTestResults&);
+    WebInputEventResult handleMousePressEvent(const MouseEventWithHitTestResults&);
+    WebInputEventResult handleMouseReleaseEvent(const MouseEventWithHitTestResults&);
+
+    void nodeWillBeRemoved(Node& nodeToBeRemoved);
+
+    static DragState& dragState();

[dtapuska, 2016/09/21 17:07:44]

Is the intended DragState supposed to be one per top level frame? I just
wondered if this is one of the top level frame data structures.

[Navid Zolghadr, 2016/09/21 17:17:30]

Since the variable is defined in this way as static inside a function then I
would believe this is a page level.  So I need to investigate how we can move it
to the page EventHandler when we create that class.

+
+    void focusDocumentView();
+
+    // Resets the state that indicates the next events could cause a drag. It is called when
+    // we realize the next events should not cause drag based on the drag heuristics.
+    void clearDragHeuristicState();
+
+    void dragSourceEndedAt(const PlatformMouseEvent&, DragOperation);
+
+    void updateSelectionForMouseDrag();
+
+    void handleMousePressEventUpdateStates(const PlatformMouseEvent&);
+
+    // Returns whether pan is handled.

[mustaq, 2016/09/21 17:28:14]

also say: resets the state on release.

[Navid Zolghadr, 2016/09/23 11:11:16]

Done.

+    bool handleSvgPanIfNeeded(bool isReleaseEvent);
+
+    void invalidateClick();
+
+
+    // TODO: These functions ideally should be private but the code needs more
+    // refactoring to be able to remove the dependency from EventHandler.
+    Node* getNodeUnderMouse();
+    bool isMousePositionUnknown();
+    IntPoint lastKnownMousePosition();
+
+    bool mousePressed();
+    void setMousePressed(bool);
+
+    bool capturesDragging() const;
+    void setCapturesDragging(bool);
+
+    void setMouseDownMayStartAutoscroll() { m_mouseDownMayStartAutoscroll = true; }
+
+    Node* mousePressNode();
+    void setMousePressNode(Node*);
+
+    void setClickNode(Node*);
+    void setClickCount(int);
+
+    bool mouseDownMayStartDrag();
+
 private:
     class MouseEventBoundaryEventDispatcher : public BoundaryEventDispatcher {
         WTF_MAKE_NONCOPYABLE(MouseEventBoundaryEventDispatcher);
 
     public:
         MouseEventBoundaryEventDispatcher(MouseEventManager*,
             const PlatformMouseEvent*, EventTarget* exitedTarget);
 
     protected:
         void dispatchOut(EventTarget*, EventTarget* relatedTarget) override;
         void dispatchOver(EventTarget*, EventTarget* relatedTarget) override;
         void dispatchLeave(EventTarget*, EventTarget* relatedTarget, bool checkForListener) override;
         void dispatchEnter(EventTarget*, EventTarget* relatedTarget, bool checkForListener) override;
         AtomicString getLeaveEvent() override;
         AtomicString getEnterEvent() override;
 
     private:
         void dispatch(EventTarget*, EventTarget* relatedTarget,
             const AtomicString&, const PlatformMouseEvent&,
             bool checkForListener);
         Member<MouseEventManager> m_mouseEventManager;
         const PlatformMouseEvent* m_platformMouseEvent;
         Member<EventTarget> m_exitedTarget;
     };
 
+    // If the given element is a shadow host and its root has delegatesFocus=false flag,
+    // slide focus to its inner element. Returns true if the resulting focus is different from
+    // the given element.
+    bool slideFocusOnShadowHostIfNecessary(const Element&);
+
+    bool dragHysteresisExceeded(const IntPoint&) const;
+    bool handleDrag(const MouseEventWithHitTestResults&, DragInitiator);
+    bool tryStartDrag(const MouseEventWithHitTestResults&);
+    void clearDragDataTransfer();
+    DataTransfer* createDraggingDataTransfer() const;
+
     // NOTE: If adding a new field to this class please ensure that it is
     // cleared in |MouseEventManager::clear()|.
 
     const Member<LocalFrame> m_frame;
+    Member<ScrollManager> m_scrollManager;
 
     // The effective position of the mouse pointer.
     // See https://w3c.github.io/pointerevents/#dfn-tracking-the-effective-position-of-the-legacy-mouse-pointer.
     Member<Node> m_nodeUnderMouse;
+
+    bool m_isMousePositionUnknown;

[dtapuska, 2016/09/21 17:07:44]

We should probably use unsigned m_ : 1 for all these booleans and put them
beside each other for the packing of this object.

[Navid Zolghadr, 2016/09/21 17:17:30]

Sure. I'll do that.

+    // The last mouse movement position this frame has seen in root frame coordinates.
+    IntPoint m_lastKnownMousePosition;
+    IntPoint m_lastKnownMouseGlobalPosition;
+
+    // Current button-press state for mouse/mouse-like-stylus.
+    // TODO(crbug.com/563676): Buggy for chorded buttons.
+    bool m_mousePressed;
+
+    bool m_mouseDownMayStartAutoscroll;
+
+    bool m_capturesDragging;
+    Member<Node> m_mousePressNode;
+
+    bool m_mouseDownMayStartDrag;
+
+    int m_clickCount;
+    Member<Node> m_clickNode;
+
+    IntPoint m_mouseDownPos; // In our view's coords.
+    double m_mouseDownTimestamp;
+    PlatformMouseEvent m_mouseDown;
+
+    bool m_svgPan;
+
+    LayoutPoint m_dragStartPos;
+
+    Timer<MouseEventManager> m_fakeMouseMoveEventTimer;
+
 };
 
 } // namespace blink
 
 #endif // MouseEventManager_h