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// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef UI_BASE_GESTURES_GESTURE_SEQUENCE_H_
#define UI_BASE_GESTURES_GESTURE_SEQUENCE_H_
#include "base/timer.h"
#include "ui/base/events.h"
#include "ui/base/gestures/gesture_point.h"
#include "ui/base/gestures/gesture_recognizer.h"
#include "ui/gfx/rect.h"
namespace ui {
class TouchEvent;
class GestureEvent;
// Gesture state.
enum GestureState {
GS_NO_GESTURE,
GS_PENDING_SYNTHETIC_CLICK,
GS_SCROLL,
GS_PINCH,
GS_PENDING_TWO_FINGER_TAP,
};
enum ScrollType {
ST_FREE,
ST_HORIZONTAL,
ST_VERTICAL,
};
// A GestureSequence recognizes gestures from touch sequences.
class UI_EXPORT GestureSequence {
public:
// Maximum number of points in a single gesture.
static const int kMaxGesturePoints = 12;
explicit GestureSequence(GestureEventHelper* consumer);
virtual ~GestureSequence();
typedef GestureRecognizer::Gestures Gestures;
// Invoked for each touch event that could contribute to the current gesture.
// Returns list of zero or more GestureEvents identified after processing
// TouchEvent.
// Caller would be responsible for freeing up Gestures.
virtual Gestures* ProcessTouchEventForGesture(const TouchEvent& event,
ui::TouchStatus status);
const GesturePoint* points() const { return points_; }
int point_count() const { return point_count_; }
const gfx::Point& last_touch_location() const { return last_touch_location_; }
protected:
virtual base::OneShotTimer<GestureSequence>* CreateTimer();
base::OneShotTimer<GestureSequence>* long_press_timer() {
return long_press_timer_.get();
}
private:
// Recreates the axis-aligned bounding box that contains all the touch-points
// at their most recent position.
void RecreateBoundingBox();
void ResetVelocities();
GesturePoint& GesturePointForEvent(const TouchEvent& event);
// Do a linear scan through points_ to find the GesturePoint
// with id |point_id|.
GesturePoint* GetPointByPointId(int point_id);
bool IsSecondTouchDownCloseEnoughForTwoFingerTap();
// Creates a gesture event with the specified parameters. The function
// includes some common information (e.g. number of touch-points in the
// gesture etc.) in the gesture event as well.
GestureEvent* CreateGestureEvent(const GestureEventDetails& details,
const gfx::Point& location,
int flags,
base::Time timestamp,
unsigned int touch_id_bitmask);
// Functions to be called to add GestureEvents, after successful recognition.
// Tap gestures.
void AppendTapDownGestureEvent(const GesturePoint& point, Gestures* gestures);
void AppendBeginGestureEvent(const GesturePoint& point, Gestures* gestures);
void AppendEndGestureEvent(const GesturePoint& point, Gestures* gestures);
void AppendClickGestureEvent(const GesturePoint& point,
int tap_count,
Gestures* gestures);
void AppendDoubleClickGestureEvent(const GesturePoint& point,
Gestures* gestures);
void AppendLongPressGestureEvent();
// Scroll gestures.
void AppendScrollGestureBegin(const GesturePoint& point,
const gfx::Point& location,
Gestures* gestures);
void AppendScrollGestureEnd(const GesturePoint& point,
const gfx::Point& location,
Gestures* gestures,
float x_velocity,
float y_velocity);
void AppendScrollGestureUpdate(GesturePoint& point,
const gfx::Point& location,
Gestures* gestures);
// Pinch gestures.
void AppendPinchGestureBegin(const GesturePoint& p1,
const GesturePoint& p2,
Gestures* gestures);
void AppendPinchGestureEnd(const GesturePoint& p1,
const GesturePoint& p2,
float scale,
Gestures* gestures);
void AppendPinchGestureUpdate(const GesturePoint& point,
float scale,
Gestures* gestures);
void AppendSwipeGesture(const GesturePoint& point,
int swipe_x,
int swipe_y,
Gestures* gestures);
void AppendTwoFingerTapGestureEvent(Gestures* gestures);
void set_state(const GestureState state) { state_ = state; }
// Various GestureTransitionFunctions for a signature.
// There is, 1:many mapping from GestureTransitionFunction to Signature
// But a Signature have only one GestureTransitionFunction.
bool Click(const TouchEvent& event,
const GesturePoint& point,
Gestures* gestures);
bool ScrollStart(const TouchEvent& event,
GesturePoint& point,
Gestures* gestures);
void BreakRailScroll(const TouchEvent& event,
GesturePoint& point,
Gestures* gestures);
bool ScrollUpdate(const TouchEvent& event,
GesturePoint& point,
Gestures* gestures);
bool TouchDown(const TouchEvent& event,
const GesturePoint& point,
Gestures* gestures);
bool TwoFingerTouchDown(const TouchEvent& event,
const GesturePoint& point,
Gestures* gestures);
bool TwoFingerTouchMove(const TouchEvent& event,
const GesturePoint& point,
Gestures* gestures);
bool TwoFingerTouchReleased(const TouchEvent& event,
const GesturePoint& point,
Gestures* gestures);
bool ScrollEnd(const TouchEvent& event,
GesturePoint& point,
Gestures* gestures);
bool PinchStart(const TouchEvent& event,
const GesturePoint& point,
Gestures* gestures);
bool PinchUpdate(const TouchEvent& event,
GesturePoint& point,
Gestures* gestures);
bool PinchEnd(const TouchEvent& event,
const GesturePoint& point,
Gestures* gestures);
bool MaybeSwipe(const TouchEvent& event,
const GesturePoint& point,
Gestures* gestures);
void StopLongPressTimerIfRequired(const TouchEvent& event);
// Current state of gesture recognizer.
GestureState state_;
// ui::EventFlags.
int flags_;
// We maintain the smallest axis-aligned rectangle that contains all the
// current touch-points. The 'distance' represents the diagonal distance.
// This box is updated after every touch-event.
gfx::Rect bounding_box_;
gfx::Point bounding_box_last_center_;
// For pinch, the 'distance' represents the diagonal distance of
// |bounding_box_|.
// The distance between the two points at PINCH_START.
float pinch_distance_start_;
// This distance is updated after each PINCH_UPDATE.
float pinch_distance_current_;
// This is the time when second touch down was received. Used for determining
// if a two finger double tap has happened.
base::TimeDelta second_touch_time_;
ScrollType scroll_type_;
scoped_ptr<base::OneShotTimer<GestureSequence> > long_press_timer_;
GesturePoint points_[kMaxGesturePoints];
int point_count_;
// Location of the last touch event.
gfx::Point last_touch_location_;
GestureEventHelper* helper_;
DISALLOW_COPY_AND_ASSIGN(GestureSequence);
};
} // namespace ui
#endif // UI_BASE_GESTURES_GESTURE_SEQUENCE_H_
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