webkit/glue/touch_fling_platform_gesture_curve.h

   1 // Copyright (c) 2012 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 WEBKIT_GLUE_TOUCH_FLING_PLATFORM_GESTURE_CURVE_H_
   6 #define WEBKIT_GLUE_TOUCH_FLING_PLATFORM_GESTURE_CURVE_H_
   7
   8 #include "third_party/WebKit/Source/Platform/chromium/public/WebFloatPoint.h"
   9 #include "third_party/WebKit/Source/Platform/chromium/public/WebGestureCurve.h"
  10 #include "third_party/WebKit/Source/Platform/chromium/public/WebSize.h"
  11 #include "webkit/glue/webkit_glue_export.h"
  12
  13 namespace WebKit {
  14 class WebGestureCurveTarget;
  15 }
  16
  17 namespace webkit_glue {
  18
  19 // Implementation of WebGestureCurve suitable for touch pad/screen-based
  20 // fling scroll. Starts with a flat velocity profile based on 'velocity', which
  21 // tails off to zero. Time is scaled to that duration of the fling is
  22 // proportional to the initial velocity.
  23 class TouchFlingGestureCurve : public WebKit::WebGestureCurve {
  24  public:
  25   static WebGestureCurve* CreateForTouchPad(
  26       const WebKit::WebFloatPoint& velocity,
  27       const WebKit::WebSize& cumulativeScroll);
  28   static WebGestureCurve* CreateForTouchScreen(
  29       const WebKit::WebFloatPoint& velocity,
  30       const WebKit::WebSize& cumulativeScroll);
  31   WEBKIT_GLUE_EXPORT static WebGestureCurve* Create(
  32       const WebKit::WebFloatPoint& initial_velocity,
  33       float p0, float p1, float p2,
  34       float curveDuration,
  35       const WebKit::WebSize& cumulativeScroll);
  36
  37  virtual bool apply(double monotonicTime,
  38                     WebKit::WebGestureCurveTarget*) OVERRIDE;
  39
  40  private:
  41   TouchFlingGestureCurve(const WebKit::WebFloatPoint& initial_velocity,
  42                          float p0,
  43                          float p1,
  44                          float p2,
  45                          float curve_duration,
  46                          const WebKit::WebSize& cumulativeScroll);
  47   virtual ~TouchFlingGestureCurve();
  48
  49   WebKit::WebFloatPoint displacement_ratio_;
  50   WebKit::WebSize cumulative_scroll_;
  51   float coefficients_[3];
  52   float time_offset_;
  53   float curve_duration_;
  54   float position_offset_;
  55
  56   DISALLOW_COPY_AND_ASSIGN(TouchFlingGestureCurve);
  57 };
  58
  59 } // namespace webkit_glue
  60
  61 #endif // WEBKIT_GLUE_TOUCH_FLING_PLATFORM_GESTURE_CURVE_H_