Hook ScrollElasticityController to InputHandlerProxy

content/renderer/input/input_scroll_elasticity_controller.h

 // 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.
 
 #ifndef CONTENT_RENDERER_INPUT_INPUT_SCROLL_ELASTICITY_CONTROLLER_H_
 #define CONTENT_RENDERER_INPUT_INPUT_SCROLL_ELASTICITY_CONTROLLER_H_
 
 #include "base/macros.h"
-#include "base/time/time.h"
+#include "base/memory/weak_ptr.h"
+#include "cc/input/scroll_elasticity_helper.h"
 #include "third_party/WebKit/public/web/WebInputEvent.h"
-#include "ui/gfx/geometry/vector2d_f.h"
 
-// ScrollElasticityController and ScrollElasticityControllerClient are based on
+// InputScrollElasticityController is based on
 // WebKit/Source/platform/mac/ScrollElasticityController.h
 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
  * THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+namespace cc {
+struct InputHandlerScrollResult;
+}  // namespace cc
+
 namespace content {
 
-class ScrollElasticityControllerClient {
- protected:
-  virtual ~ScrollElasticityControllerClient() {}
+class InputScrollElasticityController {
+ public:
+  explicit InputScrollElasticityController(cc::ScrollElasticityHelper* helper);
+  virtual ~InputScrollElasticityController();
 
- public:
-  virtual bool AllowsHorizontalStretching() = 0;
-  virtual bool AllowsVerticalStretching() = 0;
-  // The amount that the view is stretched past the normal allowable bounds.
-  // The "overhang" amount.
-  virtual gfx::Vector2dF StretchAmount() = 0;
-  virtual bool PinnedInDirection(const gfx::Vector2dF& direction) = 0;
-  virtual bool CanScrollHorizontally() = 0;
-  virtual bool CanScrollVertically() = 0;
+  base::WeakPtr<InputScrollElasticityController> GetWeakPtr();
+  void ObserveWheelEventAndResult(
+      const blink::WebMouseWheelEvent& wheel_event,
+      const cc::InputHandlerScrollResult& scroll_result);
 
-  // Return the absolute scroll position, not relative to the scroll origin.
-  virtual gfx::Vector2dF AbsoluteScrollPosition() = 0;
+  void WillShutdown();
+  void Animate(base::TimeTicks time);
 
-  virtual void ImmediateScrollBy(const gfx::Vector2dF& scroll) = 0;
-  virtual void ImmediateScrollByWithoutContentEdgeConstraints(
-      const gfx::Vector2dF& scroll) = 0;
-  virtual void StartSnapRubberbandTimer() = 0;
-  virtual void StopSnapRubberbandTimer() = 0;
-
-  // If the current scroll position is within the overhang area, this function
-  // will cause
-  // the page to scroll to the nearest boundary point.
-  virtual void AdjustScrollPositionToBoundsIfNecessary() = 0;
-};
-
-class ScrollElasticityController {
- public:
-  explicit ScrollElasticityController(ScrollElasticityControllerClient*);
-
+ private:
   // This method is responsible for both scrolling and rubber-banding.
   //
   // Events are passed by IPC from the embedder. Events on Mac are grouped
   // into "gestures". If this method returns 'true', then this object has
   // handled the event. It expects the embedder to continue to forward events
   // from the gesture.
   //
   // This method makes the assumption that there is only 1 input device being
   // used at a time. If the user simultaneously uses multiple input devices,
   // Cocoa does not correctly pass all the gestureBegin/End events. The state
   // of this class is guaranteed to become eventually consistent, once the
   // user stops using multiple input devices.
   bool HandleWheelEvent(const blink::WebMouseWheelEvent& wheel_event);
   void SnapRubberbandTimerFired();
 
   bool IsRubberbandInProgress() const;
 
- private:
   void StopSnapRubberbandTimer();
   void SnapRubberband();
 
   // This method determines whether a given event should be handled. The
   // logic for control events of gestures (PhaseBegan, PhaseEnded) is handled
   // elsewhere.
   //
   // This class handles almost all wheel events. All of the following
   // conditions must be met for this class to ignore an event:
   // + No previous events in this gesture have caused any scrolling or rubber
   // banding.
   // + The event contains a horizontal component.
-  // + The client's view is pinned in the horizontal direction of the event.
+  // + The helper's view is pinned in the horizontal direction of the event.
   // + The wheel event disallows rubber banding in the horizontal direction
   // of the event.
   bool ShouldHandleEvent(const blink::WebMouseWheelEvent& wheel_event);
 
-  ScrollElasticityControllerClient* client_;
+  cc::ScrollElasticityHelper* helper_;
 
   // There is an active scroll gesture event. This parameter only gets set to
   // false after the rubber band has been snapped, and before a new gesture
   // has begun. A careful audit of the code may deprecate the need for this
   // parameter.
   bool in_scroll_gesture_;
   // At least one event in the current gesture has been consumed and has
   // caused the view to scroll or rubber band. All future events in this
   // gesture will be consumed and overscrolls will cause rubberbanding.
   bool has_scrolled_;
   bool momentum_scroll_in_progress_;
   bool ignore_momentum_scrolls_;
 
   // Used with blink::WebInputEvent::timeStampSeconds, in seconds since epoch.
   double last_momentum_scroll_timestamp_;
   gfx::Vector2dF overflow_scroll_delta_;
   gfx::Vector2dF stretch_scroll_force_;
   gfx::Vector2dF momentum_velocity_;
 
   // Rubber band state.
   base::Time start_time_;
   gfx::Vector2dF start_stretch_;
   gfx::Vector2dF orig_origin_;
   gfx::Vector2dF orig_velocity_;
 
   bool snap_rubberband_timer_is_active_;
 
-  DISALLOW_COPY_AND_ASSIGN(ScrollElasticityController);
+  base::WeakPtrFactory<InputScrollElasticityController> weak_factory_;
+  DISALLOW_COPY_AND_ASSIGN(InputScrollElasticityController);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_INPUT_INPUT_SCROLL_ELASTICITY_CONTROLLER_H_