1 #ifndef DALI_INTERNAL_EVENT_PINCH_GESTURE_RECOGNIZER_H
2 #define DALI_INTERNAL_EVENT_PINCH_GESTURE_RECOGNIZER_H
5 * Copyright (c) 2021 Samsung Electronics Co., Ltd.
7 * Licensed under the Apache License, Version 2.0 (the "License");
8 * you may not use this file except in compliance with the License.
9 * You may obtain a copy of the License at
11 * http://www.apache.org/licenses/LICENSE-2.0
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
22 #include <dali/public-api/common/vector-wrapper.h>
25 #include <dali/internal/event/events/gesture-recognizer.h>
26 #include <dali/internal/event/events/pinch-gesture/pinch-gesture-event.h>
38 * When given a set of touch events, this detector attempts to determine if a pinch gesture has taken place.
40 class PinchGestureRecognizer : public GestureRecognizer
43 using Observer = RecognizerObserver<PinchGestureEvent>;
47 * @param[in] screenSize The size of the screen.
48 * @param[in] screenDpi The dpi value of the screen
49 * @param[in] minimumPinchDistance in pixels
50 * @param[in] minimumTouchEvents The number of touch events required
51 * @param[in] minimumTouchEventsAfterStart The number of touch events required after a gesture started
53 PinchGestureRecognizer(Observer& observer, Vector2 screenSize, Vector2 screenDpi, float minimumPinchDistance, uint32_t minimumTouchEvents, uint32_t minimumTouchEventsAfterStart);
58 ~PinchGestureRecognizer() override;
61 void SetMinimumPinchDistance(float value);
64 * Sets the minimum touch events required before a pinch can be started
65 * @param[in] value The number of touch events
67 void SetMinimumTouchEvents(uint32_t value);
70 * Sets the minimum touch events required after a pinch started
71 * @param[in] value The number of touch events
73 void SetMinimumTouchEventsAfterStart(uint32_t value);
76 * @copydoc Dali::Internal::GestureDetector::SendEvent(const Integration::TouchEvent&)
78 void SendEvent(const Integration::TouchEvent& event) override;
81 * @copydoc Dali::Internal::GestureDetector::Update(const Integration::GestureRequest&)
83 void Update(const GestureRequest& request) override;
87 * Emits the pinch gesture event to the core.
88 * @param[in] state The state of the pinch (whether it's starting, continuing or finished).
89 * @param[in] currentEvent The latest touch event.
91 void SendPinch(GestureState state, const Integration::TouchEvent& currentEvent);
94 // Reference to the gesture processor for this recognizer
98 * Internal state machine.
102 CLEAR, ///< No gesture detected.
103 POSSIBLE, ///< The current touch event data suggests that a gesture is possible.
104 STARTED, ///< A gesture has been detected.
107 State mState; ///< The current state of the detector.
108 std::vector<Integration::TouchEvent> mTouchEvents; ///< The touch events since initial touch down.
110 float mDefaultMinimumDistanceDelta; ///< The default value of the mMinimumDistanceDelta.
112 float mMinimumDistanceDelta; ///< The minimum distance before a pinch is applicable.
114 float mStartingDistance; ///< The distance between the two touch points when the pinch is first detected.
116 uint32_t mMinimumTouchEvents; ///< The minimum touch events required before a pinch can be started.
118 uint32_t mMinimumTouchEventsAfterStart; ///< The minimum touch events required after a pinch started.
121 } // namespace Internal
125 #endif // DALI_INTERNAL_EVENT_PINCH_GESTURE_RECOGNIZER_H