content/renderer/input/input_handler_proxy.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef CONTENT_RENDERER_INPUT_INPUT_HANDLER_PROXY_H_
   6 #define CONTENT_RENDERER_INPUT_INPUT_HANDLER_PROXY_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/containers/hash_tables.h"
  10 #include "base/gtest_prod_util.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "cc/input/input_handler.h"
  13 #include "content/common/content_export.h"
  14 #include "content/renderer/input/synchronous_input_handler_proxy.h"
  15 #include "third_party/WebKit/public/platform/WebGestureCurve.h"
  16 #include "third_party/WebKit/public/platform/WebGestureCurveTarget.h"
  17 #include "third_party/WebKit/public/web/WebActiveWheelFlingParameters.h"
  18 #include "third_party/WebKit/public/web/WebInputEvent.h"
  19
  20 namespace content {
  21
  22 class InputHandlerProxyClient;
  23 class InputScrollElasticityController;
  24
  25 // This class is a proxy between the content input event filtering and the
  26 // compositor's input handling logic. InputHandlerProxy instances live entirely
  27 // on the compositor thread. Each InputHandler instance handles input events
  28 // intended for a specific WebWidget.
  29 class CONTENT_EXPORT InputHandlerProxy
  30     : public cc::InputHandlerClient,
  31       public SynchronousInputHandlerProxy,
  32       public NON_EXPORTED_BASE(blink::WebGestureCurveTarget) {
  33  public:
  34   InputHandlerProxy(cc::InputHandler* input_handler,
  35                     InputHandlerProxyClient* client);
  36   virtual ~InputHandlerProxy();
  37
  38   InputScrollElasticityController* scroll_elasticity_controller() {
  39     return scroll_elasticity_controller_.get();
  40   }
  41
  42   enum EventDisposition {
  43     DID_HANDLE,
  44     DID_NOT_HANDLE,
  45     DROP_EVENT
  46   };
  47   EventDisposition HandleInputEventWithLatencyInfo(
  48       const blink::WebInputEvent& event,
  49       ui::LatencyInfo* latency_info);
  50   EventDisposition HandleInputEvent(const blink::WebInputEvent& event);
  51
  52   // cc::InputHandlerClient implementation.
  53   void WillShutdown() override;
  54   void Animate(base::TimeTicks time) override;
  55   void MainThreadHasStoppedFlinging() override;
  56   void ReconcileElasticOverscrollAndRootScroll() override;
  57   void UpdateRootLayerStateForSynchronousInputHandler(
  58       const gfx::ScrollOffset& total_scroll_offset,
  59       const gfx::ScrollOffset& max_scroll_offset,
  60       const gfx::SizeF& scrollable_size,
  61       float page_scale_factor,
  62       float min_page_scale_factor,
  63       float max_page_scale_factor) override;
  64
  65   // SynchronousInputHandlerProxy implementation.
  66   void SetOnlySynchronouslyAnimateRootFlings(
  67       SynchronousInputHandler* synchronous_input_handler) override;
  68   void SynchronouslyAnimate(base::TimeTicks time) override;
  69   void SynchronouslySetRootScrollOffset(
  70       const gfx::ScrollOffset& root_offset) override;
  71
  72   // blink::WebGestureCurveTarget implementation.
  73   virtual bool scrollBy(const blink::WebFloatSize& offset,
  74                         const blink::WebFloatSize& velocity);
  75
  76   bool gesture_scroll_on_impl_thread_for_testing() const {
  77     return gesture_scroll_on_impl_thread_;
  78   }
  79
  80  private:
  81   // Helper functions for handling more complicated input events.
  82   EventDisposition HandleMouseWheel(
  83       const blink::WebMouseWheelEvent& event);
  84   EventDisposition HandleGestureScrollBegin(
  85       const blink::WebGestureEvent& event);
  86   EventDisposition HandleGestureScrollUpdate(
  87       const blink::WebGestureEvent& event);
  88   EventDisposition HandleGestureScrollEnd(
  89       const blink::WebGestureEvent& event);
  90   EventDisposition HandleGestureFlingStart(
  91       const blink::WebGestureEvent& event);
  92   EventDisposition HandleTouchStart(
  93       const blink::WebTouchEvent& event);
  94
  95   // Returns true if the event should be suppressed due to to an active,
  96   // boost-enabled fling, in which case further processing should cease.
  97   bool FilterInputEventForFlingBoosting(const blink::WebInputEvent& event);
  98
  99   // Schedule a time in the future after which a boost-enabled fling will
 100   // terminate without further momentum from the user (see |Animate()|).
 101   void ExtendBoostedFlingTimeout(const blink::WebGestureEvent& event);
 102
 103   // Returns true if we scrolled by the increment.
 104   bool TouchpadFlingScroll(const blink::WebFloatSize& increment);
 105
 106   // Returns true if we actually had an active fling to cancel, also notifying
 107   // the client that the fling has ended. Note that if a boosted fling is active
 108   // and suppressing an active scroll sequence, a synthetic GestureScrollBegin
 109   // will be injected to resume scrolling.
 110   bool CancelCurrentFling();
 111
 112   // Returns true if we actually had an active fling to cancel.
 113   bool CancelCurrentFlingWithoutNotifyingClient();
 114
 115   // Request a frame of animation from the InputHandler or
 116   // SynchronousInputHandler. They can provide that by calling Animate().
 117   void RequestAnimation();
 118
 119   // Used to send overscroll messages to the browser.
 120   void HandleOverscroll(
 121       const gfx::Point& causal_event_viewport_point,
 122       const cc::InputHandlerScrollResult& scroll_result);
 123
 124   scoped_ptr<blink::WebGestureCurve> fling_curve_;
 125   // Parameters for the active fling animation, stored in case we need to
 126   // transfer it out later.
 127   blink::WebActiveWheelFlingParameters fling_parameters_;
 128
 129   InputHandlerProxyClient* client_;
 130   cc::InputHandler* input_handler_;
 131
 132   // Time at which an active fling should expire due to a deferred cancellation
 133   // event. A call to |Animate()| after this time will end the fling.
 134   double deferred_fling_cancel_time_seconds_;
 135
 136   // The last event that extended the lifetime of the boosted fling. If the
 137   // event was a scroll gesture, a GestureScrollBegin will be inserted if the
 138   // fling terminates (via |CancelCurrentFling()|).
 139   blink::WebGestureEvent last_fling_boost_event_;
 140
 141   // When present, Animates are not requested to the InputHandler, but to this
 142   // SynchronousInputHandler instead. And all Animate() calls are expected to
 143   // happen via the SynchronouslyAnimate() call instead of coming directly from
 144   // the InputHandler.
 145   SynchronousInputHandler* synchronous_input_handler_;
 146   bool allow_root_animate_;
 147
 148 #ifndef NDEBUG
 149   bool expect_scroll_update_end_;
 150 #endif
 151   bool gesture_scroll_on_impl_thread_;
 152   bool gesture_pinch_on_impl_thread_;
 153   // This is always false when there are no flings on the main thread, but
 154   // conservative in the sense that we might not be actually flinging when it is
 155   // true.
 156   bool fling_may_be_active_on_main_thread_;
 157   // The axes on which the current fling is allowed to scroll.  If a given fling
 158   // has overscrolled on a particular axis, further fling scrolls on that axis
 159   // will be disabled.
 160   bool disallow_horizontal_fling_scroll_;
 161   bool disallow_vertical_fling_scroll_;
 162
 163   // Whether an active fling has seen an |Animate()| call. This is useful for
 164   // determining if the fling start time should be re-initialized.
 165   bool has_fling_animation_started_;
 166
 167   // Non-zero only within the scope of |scrollBy|.
 168   gfx::Vector2dF current_fling_velocity_;
 169
 170   // Used to animate rubber-band over-scroll effect on Mac.
 171   scoped_ptr<InputScrollElasticityController> scroll_elasticity_controller_;
 172
 173   bool smooth_scroll_enabled_;
 174
 175   bool uma_latency_reporting_enabled_;
 176
 177   base::TimeTicks last_fling_animate_time_;
 178
 179   DISALLOW_COPY_AND_ASSIGN(InputHandlerProxy);
 180 };
 181
 182 }  // namespace content
 183
 184 #endif  // CONTENT_RENDERER_INPUT_INPUT_HANDLER_PROXY_H_