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.
5 #ifndef UI_EVENTS_GESTURES_GESTURE_POINT_H_
6 #define UI_EVENTS_GESTURES_GESTURE_POINT_H_
8 #include "base/basictypes.h"
9 #include "ui/events/gestures/velocity_calculator.h"
10 #include "ui/gfx/point.h"
11 #include "ui/gfx/rect.h"
16 // A GesturePoint represents a single touch-point/finger during a gesture
17 // recognition process.
23 // Resets various states.
28 // Updates some states when a Tap gesture has been recognized for this point.
31 // Updates some states when a Scroll gesture has been recognized for this
33 void UpdateForScroll();
35 // Updates states depending on the event and the gesture-state.
36 void UpdateValues(const TouchEvent& event);
38 // Responds according to the state of the gesture point (i.e. the point can
39 // represent a click or scroll etc.)
40 bool IsInClickWindow(const TouchEvent& event) const;
41 bool IsInDoubleClickWindow(const TouchEvent& event) const;
42 bool IsInTripleClickWindow(const TouchEvent& event) const;
43 bool IsInFlickWindow(const TouchEvent& event);
44 bool IsInHorizontalRailWindow() const;
45 bool IsInVerticalRailWindow() const;
46 bool IsInsideTouchSlopRegion(const TouchEvent& event) const;
47 bool IsInScrollWindow(const TouchEvent& event) const;
48 bool BreaksHorizontalRail();
49 bool BreaksVerticalRail();
50 bool DidScroll(const TouchEvent& event, int distance) const;
52 const gfx::PointF& first_touch_position() const {
53 return first_touch_position_;
56 double last_touch_time() const { return last_touch_time_; }
57 const gfx::PointF& last_touch_position() const {
58 return last_touch_position_;
60 float x() const { return last_touch_position_.x(); }
61 float y() const { return last_touch_position_.y(); }
63 // point_id_ is used to drive GestureSequence::ProcessTouchEventForGesture.
64 // point_ids are maintained such that the set of point_ids is always
65 // contiguous, from 0 to the number of current touches.
66 // A lower point_id indicates that a touch occurred first.
67 // A negative point_id indicates that the GesturePoint is not currently
68 // associated with a touch.
69 void set_point_id(int point_id) { point_id_ = point_id; }
70 int point_id() const { return point_id_; }
72 void set_touch_id(int touch_id) { touch_id_ = touch_id; }
73 int touch_id() const { return touch_id_; }
75 bool in_use() const { return point_id_ >= 0; }
77 gfx::Vector2dF ScrollDelta() const;
79 float XVelocity() { return velocity_calculator_.XVelocity(); }
80 float YVelocity() { return velocity_calculator_.YVelocity(); }
82 const gfx::RectF& enclosing_rectangle() const { return enclosing_rect_; }
84 void set_source_device_id(int source_device_id) {
85 source_device_id_ = source_device_id;
87 int source_device_id() const { return source_device_id_; }
90 // Various statistical functions to manipulate gestures.
92 bool IsInClickTimeWindow() const;
93 bool IsInClickAggregateTimeWindow(double before, double after) const;
94 bool IsPointInsideDoubleTapTouchSlopRegion(
95 gfx::PointF p1, gfx::PointF p2) const;
96 bool IsOverMinFlickSpeed();
98 // Returns -1, 0, 1 for |v| below the negative velocity threshold,
99 // in [-threshold, threshold] or above respectively.
100 int ScrollVelocityDirection(float v);
102 // The enclosing rectangle represents a rectangular touch region generated
103 // by a sequence of ET_TOUCH_PRESSED, ET_TOUCH_MOVED, and ET_TOUCH_RELEASED
104 // events forming a GESTURE_TAP event. The enclosing rectangle is updated
105 // to be the union of the touch data from each of these events. It is
106 // cleared on a ET_TOUCH_PRESSED event (i.e., at the beginning of a possible
107 // GESTURE_TAP event) or when Reset is called.
108 void UpdateEnclosingRectangle(const TouchEvent& event);
109 void clear_enclosing_rectangle() { enclosing_rect_ = gfx::RectF(); }
111 // The position of the first touchdown event.
112 gfx::PointF first_touch_position_;
113 double first_touch_time_;
115 gfx::PointF second_last_touch_position_;
116 double second_last_touch_time_;
118 gfx::PointF last_touch_position_;
119 double last_touch_time_;
121 double second_last_tap_time_;
122 gfx::PointF second_last_tap_position_;
124 double last_tap_time_;
125 gfx::PointF last_tap_position_;
127 VelocityCalculator velocity_calculator_;
132 // Represents the rectangle that encloses the circles/ellipses
133 // generated by a sequence of touch events
134 gfx::RectF enclosing_rect_;
136 int source_device_id_;
138 float max_touch_move_in_pixels_for_click_squared_;
139 float max_distance_between_taps_for_double_tap_squared_;
141 DISALLOW_COPY_AND_ASSIGN(GesturePoint);
146 #endif // UI_EVENTS_GESTURES_GESTURE_POINT_H_