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 IsInsideManhattanSquare(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::Point& first_touch_position() const {
53 return first_touch_position_;
56 double last_touch_time() const { return last_touch_time_; }
57 const gfx::Point& last_touch_position() const { return last_touch_position_; }
58 int x() const { return last_touch_position_.x(); }
59 int y() const { return last_touch_position_.y(); }
61 // point_id_ is used to drive GestureSequence::ProcessTouchEventForGesture.
62 // point_ids are maintained such that the set of point_ids is always
63 // contiguous, from 0 to the number of current touches.
64 // A lower point_id indicates that a touch occurred first.
65 // A negative point_id indicates that the GesturePoint is not currently
66 // associated with a touch.
67 void set_point_id(int point_id) { point_id_ = point_id; }
68 int point_id() const { return point_id_; }
70 void set_touch_id(int touch_id) { touch_id_ = touch_id; }
71 int touch_id() const { return touch_id_; }
73 bool in_use() const { return point_id_ >= 0; }
75 gfx::Vector2d ScrollDelta();
77 float XVelocity() { return velocity_calculator_.XVelocity(); }
78 float YVelocity() { return velocity_calculator_.YVelocity(); }
80 const gfx::Rect& enclosing_rectangle() const { return enclosing_rect_; }
83 // Various statistical functions to manipulate gestures.
85 // Tests if the point has a consistent scroll vector across a window of touch
87 bool IsConsistentScrollingActionUnderway() const;
88 bool IsInClickTimeWindow() const;
89 bool IsInClickAggregateTimeWindow(double before, double after) const;
90 bool IsPointInsideManhattanSquare(gfx::Point p1, gfx::Point p2) const;
91 bool IsOverMinFlickSpeed();
93 // Returns -1, 0, 1 for |v| below the negative velocity threshold,
94 // in [-threshold, threshold] or above respectively.
95 int ScrollVelocityDirection(float v);
97 // The enclosing rectangle represents a rectangular touch region generated
98 // by a sequence of ET_TOUCH_PRESSED, ET_TOUCH_MOVED, and ET_TOUCH_RELEASED
99 // events forming a GESTURE_TAP event. The enclosing rectangle is updated
100 // to be the union of the touch data from each of these events. It is
101 // cleared on a ET_TOUCH_PRESSED event (i.e., at the beginning of a possible
102 // GESTURE_TAP event) or when Reset is called.
103 void UpdateEnclosingRectangle(const TouchEvent& event);
104 void clear_enclosing_rectangle() { enclosing_rect_ = gfx::Rect(); }
106 // The position of the first touchdown event.
107 gfx::Point first_touch_position_;
108 double first_touch_time_;
110 gfx::Point second_last_touch_position_;
111 double second_last_touch_time_;
113 gfx::Point last_touch_position_;
114 double last_touch_time_;
116 double second_last_tap_time_;
117 gfx::Point second_last_tap_position_;
119 double last_tap_time_;
120 gfx::Point last_tap_position_;
122 VelocityCalculator velocity_calculator_;
127 // Represents the rectangle that encloses the circles/ellipses
128 // generated by a sequence of touch events
129 gfx::Rect enclosing_rect_;
131 // Count of the number of events with same direction.
132 gfx::Vector2d same_direction_count_;
134 DISALLOW_COPY_AND_ASSIGN(GesturePoint);
139 #endif // UI_EVENTS_GESTURES_GESTURE_POINT_H_