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// Copyright 2014 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_EVENTS_GESTURE_DETECTION_GESTURE_DETECTOR_H_
#define UI_EVENTS_GESTURE_DETECTION_GESTURE_DETECTOR_H_
#include <memory>
#include "base/logging.h"
#include "base/macros.h"
#include "ui/events/gesture_detection/gesture_detection_export.h"
#include "ui/events/gesture_detection/velocity_tracker_state.h"
namespace ui {
class DoubleTapListener;
class GestureListener;
class MotionEvent;
// Port of GestureDetector.java from Android
// * platform/frameworks/base/core/java/android/view/GestureDetector.java
// * Change-Id: Ib470735ec929b0b358fca4597e92dc81084e675f
// * Please update the Change-Id as upstream Android changes are pulled.
class GESTURE_DETECTION_EXPORT GestureDetector {
public:
struct GESTURE_DETECTION_EXPORT Config {
Config();
Config(const Config& other);
~Config();
base::TimeDelta longpress_timeout;
base::TimeDelta showpress_timeout;
base::TimeDelta double_tap_timeout;
// The minimum duration between the first tap's up event and the second
// tap's down event for an interaction to be considered a double-tap.
base::TimeDelta double_tap_min_time;
// Distance a touch can wander before a scroll will occur (in dips).
float touch_slop;
// Distance the first touch can wander before it is no longer considered a
// double tap (in dips).
float double_tap_slop;
// Minimum velocity to initiate a fling (in dips/second).
float minimum_fling_velocity;
// Maximum velocity of an initiated fling (in dips/second).
float maximum_fling_velocity;
// Whether |OnSwipe| should be called after a secondary touch is released
// while a logical swipe gesture is active. Defaults to false.
bool swipe_enabled;
// Minimum velocity to initiate a swipe (in dips/second).
float minimum_swipe_velocity;
// Maximum angle of the swipe from its dominant component axis, between
// (0, 45] degrees. The closer this is to 0, the closer the dominant
// direction of the swipe must be to up, down left or right.
float maximum_swipe_deviation_angle;
// Whether |OnTwoFingerTap| should be called for two finger tap
// gestures. Defaults to false.
bool two_finger_tap_enabled;
// Maximum distance between pointers for a two finger tap.
float two_finger_tap_max_separation;
// Maximum time the second pointer can be active for a two finger tap.
base::TimeDelta two_finger_tap_timeout;
// Single tap count repetition length. Defaults to 1 (no repetition count).
// Note that when double-tap detection is enabled, the single tap repeat
// count will always be 1.
int single_tap_repeat_interval;
VelocityTracker::Strategy velocity_tracker_strategy;
};
GestureDetector(const Config& config,
GestureListener* listener,
DoubleTapListener* optional_double_tap_listener);
~GestureDetector();
bool OnTouchEvent(const MotionEvent& ev);
// Setting a valid |double_tap_listener| will enable double-tap detection,
// wherein calls to |OnSimpleTapConfirmed| are delayed by the tap timeout.
// Note: The listener must never be changed while |is_double_tapping| is true.
void SetDoubleTapListener(DoubleTapListener* double_tap_listener);
bool has_doubletap_listener() const { return double_tap_listener_ != NULL; }
bool is_double_tapping() const { return is_double_tapping_; }
void set_longpress_enabled(bool enabled) { longpress_enabled_ = enabled; }
void set_showpress_enabled(bool enabled) { showpress_enabled_ = enabled; }
// Returns the event storing the initial position of the pointer with given
// pointer ID. This returns nullptr if the source event isn't
// current_down_event_ or secondary_pointer_down_event_.
const MotionEvent* GetSourcePointerDownEvent(
const MotionEvent& current_down_event,
const MotionEvent& secondary_pointer_down_event,
const int pointer_id);
private:
void Init(const Config& config);
void OnShowPressTimeout();
void OnLongPressTimeout();
void OnTapTimeout();
void Cancel();
void CancelTaps();
bool IsRepeatedTap(const MotionEvent& first_down,
const MotionEvent& first_up,
const MotionEvent& second_down) const;
bool HandleSwipeIfNeeded(const MotionEvent& up, float vx, float vy);
bool IsWithinTouchSlop(const MotionEvent& ev);
class TimeoutGestureHandler;
std::unique_ptr<TimeoutGestureHandler> timeout_handler_;
GestureListener* const listener_;
DoubleTapListener* double_tap_listener_;
float touch_slop_square_;
float double_tap_touch_slop_square_;
float double_tap_slop_square_;
float two_finger_tap_distance_square_;
float min_fling_velocity_;
float max_fling_velocity_;
float min_swipe_velocity_;
float min_swipe_direction_component_ratio_;
base::TimeDelta double_tap_timeout_;
base::TimeDelta two_finger_tap_timeout_;
base::TimeDelta double_tap_min_time_;
bool still_down_;
bool defer_confirm_single_tap_;
bool all_pointers_within_slop_regions_;
bool always_in_bigger_tap_region_;
bool two_finger_tap_allowed_for_gesture_;
std::unique_ptr<MotionEvent> current_down_event_;
std::unique_ptr<MotionEvent> previous_up_event_;
std::unique_ptr<MotionEvent> secondary_pointer_down_event_;
// True when the user is still touching for the second tap (down, move, and
// up events). Can only be true if there is a double tap listener attached.
bool is_double_tapping_;
// Whether the current ACTION_DOWN event meets the criteria for being a
// repeated tap. Note that it will be considered a repeated tap only if the
// corresponding ACTION_UP yields a valid tap and double-tap detection is
// disabled.
bool is_down_candidate_for_repeated_single_tap_;
// Stores the maximum number of pointers that have been down simultaneously
// during the current touch sequence.
int maximum_pointer_count_;
// The number of repeated taps in the current sequence, i.e., for the initial
// tap this is 0, for the first *repeated* tap 1, etc...
int current_single_tap_repeat_count_;
int single_tap_repeat_interval_;
float last_focus_x_;
float last_focus_y_;
float down_focus_x_;
float down_focus_y_;
bool longpress_enabled_;
bool showpress_enabled_;
bool swipe_enabled_;
bool two_finger_tap_enabled_;
// Determines speed during touch scrolling.
VelocityTrackerState velocity_tracker_;
DISALLOW_COPY_AND_ASSIGN(GestureDetector);
};
} // namespace ui
#endif // UI_EVENTS_GESTURE_DETECTION_GESTURE_DETECTOR_H_