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 UI_EVENTS_GESTURES_GESTURE_POINT_H_ 6 #define UI_EVENTS_GESTURES_GESTURE_POINT_H_ 7 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" 12 13 namespace ui { 14 class TouchEvent; 15 16 // A GesturePoint represents a single touch-point/finger during a gesture 17 // recognition process. 18 class GesturePoint { 19 public: 20 GesturePoint(); 21 ~GesturePoint(); 22 23 // Resets various states. 24 void Reset(); 25 26 void ResetVelocity(); 27 28 // Updates some states when a Tap gesture has been recognized for this point. 29 void UpdateForTap(); 30 31 // Updates some states when a Scroll gesture has been recognized for this 32 // point. 33 void UpdateForScroll(); 34 35 // Updates states depending on the event and the gesture-state. 36 void UpdateValues(const TouchEvent& event); 37 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; 51 first_touch_position()52 const gfx::Point& first_touch_position() const { 53 return first_touch_position_; 54 } 55 last_touch_time()56 double last_touch_time() const { return last_touch_time_; } last_touch_position()57 const gfx::Point& last_touch_position() const { return last_touch_position_; } x()58 int x() const { return last_touch_position_.x(); } y()59 int y() const { return last_touch_position_.y(); } 60 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. set_point_id(int point_id)67 void set_point_id(int point_id) { point_id_ = point_id; } point_id()68 int point_id() const { return point_id_; } 69 set_touch_id(int touch_id)70 void set_touch_id(int touch_id) { touch_id_ = touch_id; } touch_id()71 int touch_id() const { return touch_id_; } 72 in_use()73 bool in_use() const { return point_id_ >= 0; } 74 75 gfx::Vector2d ScrollDelta(); 76 XVelocity()77 float XVelocity() { return velocity_calculator_.XVelocity(); } YVelocity()78 float YVelocity() { return velocity_calculator_.YVelocity(); } 79 enclosing_rectangle()80 const gfx::Rect& enclosing_rectangle() const { return enclosing_rect_; } 81 82 private: 83 // Various statistical functions to manipulate gestures. 84 85 // Tests if the point has a consistent scroll vector across a window of touch 86 // move events. 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(); 92 93 // Returns -1, 0, 1 for |v| below the negative velocity threshold, 94 // in [-threshold, threshold] or above respectively. 95 int ScrollVelocityDirection(float v); 96 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); clear_enclosing_rectangle()104 void clear_enclosing_rectangle() { enclosing_rect_ = gfx::Rect(); } 105 106 // The position of the first touchdown event. 107 gfx::Point first_touch_position_; 108 double first_touch_time_; 109 110 gfx::Point second_last_touch_position_; 111 double second_last_touch_time_; 112 113 gfx::Point last_touch_position_; 114 double last_touch_time_; 115 116 double second_last_tap_time_; 117 gfx::Point second_last_tap_position_; 118 119 double last_tap_time_; 120 gfx::Point last_tap_position_; 121 122 VelocityCalculator velocity_calculator_; 123 124 int point_id_; 125 int touch_id_; 126 127 // Represents the rectangle that encloses the circles/ellipses 128 // generated by a sequence of touch events 129 gfx::Rect enclosing_rect_; 130 131 // Count of the number of events with same direction. 132 gfx::Vector2d same_direction_count_; 133 134 DISALLOW_COPY_AND_ASSIGN(GesturePoint); 135 }; 136 137 } // namespace ui 138 139 #endif // UI_EVENTS_GESTURES_GESTURE_POINT_H_ 140