1 #ifndef DALI_INTERNAL_EVENT_PAN_GESTURE_RECOGNIZER_H
2 #define DALI_INTERNAL_EVENT_PAN_GESTURE_RECOGNIZER_H
5 * Copyright (c) 2019 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 <cstdint> // uint32_t
23 #include <dali/public-api/common/vector-wrapper.h>
24 #include <dali/public-api/math/vector2.h>
27 #include <dali/internal/event/events/gesture-recognizer.h>
28 #include <dali/internal/event/events/pan-gesture-event.h>
43 struct PanGestureRequest;
45 * When given a set of touch events, this detector attempts to determine if a pan gesture has taken place.
47 class PanGestureRecognizer : public GestureRecognizer
51 using Observer = RecognizerObserver<PanGestureEvent>;
55 * @param[in] screenSize The size of the screen.
56 * @param[in] request The details of the request.
58 PanGestureRecognizer( Observer& observer, Vector2 screenSize, const PanGestureRequest& request, int32_t minimumDistance, int32_t minimumPanEvents);
63 virtual ~PanGestureRecognizer();
68 * @copydoc Dali::Internal::GestureDetector::SendEvent(const Integration::TouchEvent&)
70 virtual void SendEvent(const Integration::TouchEvent& event);
73 * @copydoc Dali::Internal::GestureDetector::Update(const Integration::GestureRequest&)
75 virtual void Update(const GestureRequest& request);
80 * Emits the pan gesture event (performs some smoothing operation).
81 * @param[in] state The state of the pan.
82 * @param[in] currentEvent The latest touch event.
84 void SendPan(Gesture::State state, const Integration::TouchEvent& currentEvent);
88 // Reference to the gesture processor for this recognizer
92 * Internal state machine.
96 Clear, ///< No gesture detected.
97 Possible, ///< The current touch event data suggests that a gesture is possible.
98 Started, ///< A gesture has been detected.
99 Finished, ///< A previously started pan gesture has finished.
100 Failed, ///< Current touch event data suggests a pan gesture is not possible.
103 State mState; ///< The current state of the detector.
104 std::vector<Integration::TouchEvent> mTouchEvents; ///< A container of all touch events after an initial down event.
106 Vector2 mPrimaryTouchDownLocation; ///< The initial touch down point.
107 Vector2 mThresholdAdjustmentPerFrame; ///< The adjustment per frame at the start of a slow pan.
108 Vector2 mPreviousPosition; ///< The previous position.
110 unsigned int mThresholdAdjustmentsRemaining; ///< No. of threshold adjustments still to apply (for a slow-pan).
111 unsigned int mThresholdTotalAdjustments; ///< The total number of adjustments required.
113 uint32_t mPrimaryTouchDownTime; ///< The initial touch down time.
114 unsigned int mMinimumTouchesRequired; ///< The minimum touches required before a pan should be emitted.
115 unsigned int mMaximumTouchesRequired; ///< The maximum touches after which a pan should not be emitted.
117 unsigned int mMinimumDistanceSquared; ///< The minimum distance squared before pan should start.
118 unsigned int mMinimumMotionEvents; ///< The minimum motion events before pan should start.
119 unsigned int mMotionEvents; ///< The motion events received so far (before pan is emitted).
122 } // namespace Internal
126 #endif // DALI_INTERNAL_EVENT_PAN_GESTURE_RECOGNIZER_H