content/browser/renderer_host/input/synthetic_smooth_scroll_gesture.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_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_SMOOTH_SCROLL_GESTURE_H_
   6 #define CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_SMOOTH_SCROLL_GESTURE_H_
   7
   8 #include "base/time/time.h"
   9 #include "content/browser/renderer_host/input/synthetic_gesture.h"
  10 #include "content/browser/renderer_host/input/synthetic_gesture_target.h"
  11 #include "content/common/content_export.h"
  12 #include "content/common/input/synthetic_smooth_scroll_gesture_params.h"
  13 #include "content/common/input/synthetic_web_input_event_builders.h"
  14 #include "third_party/WebKit/public/web/WebInputEvent.h"
  15 #include "ui/gfx/vector2d.h"
  16 #include "ui/gfx/vector2d_f.h"
  17
  18 namespace content {
  19
  20 // Simulates scrolling given a sequence of scroll distances as a continuous
  21 // gestures (i.e. when synthesizing touch events, the touch pointer is not
  22 // lifted when changing scroll direction).
  23 // If no distance is provided or the first one is 0, no touch events are
  24 // generated.
  25 // When synthesizing touch events, the first distance is extended to compensate
  26 // for the touch slop.
  27 class CONTENT_EXPORT SyntheticSmoothScrollGesture : public SyntheticGesture {
  28  public:
  29   explicit SyntheticSmoothScrollGesture(
  30       const SyntheticSmoothScrollGestureParams& params);
  31   virtual ~SyntheticSmoothScrollGesture();
  32
  33   virtual SyntheticGesture::Result ForwardInputEvents(
  34       const base::TimeTicks& timestamp,
  35       SyntheticGestureTarget* target) OVERRIDE;
  36
  37  private:
  38   enum GestureState {
  39     SETUP,
  40     STARTED,
  41     MOVING,
  42     STOPPING,
  43     DONE
  44   };
  45
  46   void ForwardTouchInputEvents(
  47       const base::TimeTicks& timestamp, SyntheticGestureTarget* target);
  48   void ForwardMouseInputEvents(
  49       const base::TimeTicks& timestamp, SyntheticGestureTarget* target);
  50
  51   void ForwardTouchEvent(SyntheticGestureTarget* target,
  52                          const base::TimeTicks& timestamp);
  53   void ForwardMouseWheelEvent(SyntheticGestureTarget* target,
  54                               const gfx::Vector2dF& delta,
  55                               const base::TimeTicks& timestamp) const;
  56
  57   void PressTouchPoint(SyntheticGestureTarget* target,
  58                        const base::TimeTicks& timestamp);
  59   void MoveTouchPoint(SyntheticGestureTarget* target,
  60                       const gfx::Vector2dF& delta,
  61                       const base::TimeTicks& timestamp);
  62   void ReleaseTouchPoint(SyntheticGestureTarget* target,
  63                          const base::TimeTicks& timestamp);
  64
  65   void AddTouchSlopToFirstDistance(SyntheticGestureTarget* target);
  66   gfx::Vector2dF GetPositionDeltaAtTime(const base::TimeTicks& timestamp)
  67       const;
  68   void ComputeNextScrollSegment();
  69   base::TimeTicks ClampTimestamp(const base::TimeTicks& timestamp) const;
  70   bool FinishedCurrentScrollSegment(const base::TimeTicks& timestamp) const;
  71   bool IsLastScrollSegment() const;
  72   bool ScrollIsNoOp() const;
  73
  74   SyntheticSmoothScrollGestureParams params_;
  75   // Used for mouse input.
  76   gfx::Vector2d current_scroll_segment_total_delta_discrete_;
  77   // Used for touch input.
  78   gfx::Point current_scroll_segment_start_position_;
  79   SyntheticWebTouchEvent touch_event_;
  80   SyntheticGestureParams::GestureSourceType gesture_source_type_;
  81   GestureState state_;
  82   int current_scroll_segment_;
  83   base::TimeTicks current_scroll_segment_start_time_;
  84   base::TimeTicks current_scroll_segment_stop_time_;
  85
  86   DISALLOW_COPY_AND_ASSIGN(SyntheticSmoothScrollGesture);
  87 };
  88
  89 }  // namespace content
  90
  91 #endif  // CONTENT_BROWSER_RENDERER_HOST_INPUT_SYNTHETIC_SMOOTH_SCROLL_GESTURE_H_