1 #ifndef DALI_TAP_GESTURE_DETECTOR_H
2 #define DALI_TAP_GESTURE_DETECTOR_H
5 * Copyright (c) 2022 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
25 #include <dali/public-api/events/gesture-detector.h>
26 #include <dali/public-api/signals/dali-signal.h>
31 * @addtogroup dali_core_events
35 namespace Internal DALI_INTERNAL
37 class TapGestureDetector;
43 * @brief This class emits a signal when a tap gesture occurs that meets the requirements set by the
46 * See @ref TapGestureDetector::SetMinimumTapsRequired
47 * See @ref TapGestureDetector::SetMaximumTapsRequired
49 * A TapGesture is a discrete gesture, which means it does not have any state information attached
50 * to it. Please see TapGesture for more information.
52 * The application programmer can use this gesture detector as follows:
54 * TapGestureDetector detector = TapGestureDetector::New();
55 * detector.Attach(myActor);
56 * detector.DetectedSignal().Connect(this, &MyApplication::OnTap);
60 * @note Multi-touch taps (two or more points of contact with the surface) are not currently
61 * supported. However, multiple taps (double & triple tap etc.) are supported.
64 * | %Signal Name | Method |
65 * |--------------|-----------------------|
66 * | tapDetected | @ref DetectedSignal() |
70 class DALI_CORE_API TapGestureDetector : public GestureDetector
74 * @brief Signal type for detected signal.
77 using DetectedSignalType = Signal<void(Actor, const TapGesture&)>;
79 public: // Creation & Destruction
81 * @brief Creates an uninitialized TapGestureDetector; this can be initialized with TapGestureDetector::New().
83 * Calling member functions with an uninitialized TapGestureDetector handle is not allowed.
89 * @brief Creates an initialized TapGestureDetector.
91 * By default, this would create a gesture detector which requires one tap with one touch.
93 * @return A handle to a newly allocated Dali resource
95 static TapGestureDetector New();
98 * @brief Creates an initialized TapGestureDetector with the specified parameters.
101 * @param[in] tapsRequired The minimum & maximum number of taps required
102 * @return A handle to a newly allocated Dali resource
104 static TapGestureDetector New(uint32_t tapsRequired);
107 * @brief Downcasts a handle to TapGestureDetector handle.
109 * If handle points to a TapGestureDetector object, the
110 * downcast produces valid handle. If not, the returned handle is left uninitialized.
112 * @param[in] handle Handle to an object
113 * @return Handle to a TapGestureDetector object or an uninitialized handle
115 static TapGestureDetector DownCast(BaseHandle handle);
120 * This is non-virtual since derived Handle types must not contain data or virtual methods.
123 ~TapGestureDetector();
126 * @brief This copy constructor is required for (smart) pointer semantics.
129 * @param[in] handle A reference to the copied handle
131 TapGestureDetector(const TapGestureDetector& handle);
134 * @brief This assignment operator is required for (smart) pointer semantics.
137 * @param[in] rhs A reference to the copied handle
138 * @return A reference to this
140 TapGestureDetector& operator=(const TapGestureDetector& rhs);
143 * @brief This move constructor is required for (smart) pointer semantics.
146 * @param[in] handle A reference to the moved handle
148 TapGestureDetector(TapGestureDetector&& handle) noexcept;
151 * @brief This move assignment operator is required for (smart) pointer semantics.
154 * @param[in] rhs A reference to the moved handle
155 * @return A reference to this
157 TapGestureDetector& operator=(TapGestureDetector&& rhs) noexcept;
161 * @brief Sets the minimum number of taps required.
163 * The tap count is the number of times a user should "tap" the screen.
165 * @param[in] minimumTaps The minimum taps required
166 * @pre The gesture detector has been initialized.
167 * @note The default is '1', the maximum is 2.
168 * @see ReceiveAllTapEvents
170 void SetMinimumTapsRequired(uint32_t minimumTaps);
173 * @brief Sets the maximum number of taps required.
175 * The tap count is the number of times a user should "tap" the screen.
177 * @param[in] maximumTaps The maximum taps required
178 * @pre The gesture detector has been initialized.
179 * @note The default is '1', the maximum is 2.
180 * @see ReceiveAllTapEvents
182 void SetMaximumTapsRequired(uint32_t maximumTaps);
185 * @brief When set to true, all tap gestures will be received when multiple taps are supported by the gesture detector.
187 * @param[in] receive The receiving all tap events flag
188 * @pre The gesture detector has been initialized.
189 * @note The default is false.
191 void ReceiveAllTapEvents(bool receive);
195 * @brief Retrieves the minimum number of taps required.
198 * @return The minimum taps required
199 * @pre The gesture detector has been initialized.
201 uint32_t GetMinimumTapsRequired() const;
204 * @brief Retrieves the maximum number of taps required.
207 * @return The maximum taps required
208 * @pre The gesture detector has been initialized.
210 uint32_t GetMaximumTapsRequired() const;
214 * @brief This signal is emitted when the specified tap is detected on the attached actor.
216 * A callback of the following type may be connected:
218 * void YourCallbackName( Actor actor, const TapGesture& gesture );
221 * @return The signal to connect to
222 * @pre The gesture detector has been initialized.
224 DetectedSignalType& DetectedSignal();
226 public: // Not intended for Application developers
229 * @brief This constructor is used by TapGestureDetector::New() methods.
232 * @param[in] internal A pointer to a newly allocated Dali resource
234 explicit DALI_INTERNAL TapGestureDetector(Internal::TapGestureDetector* internal);
244 #endif // DALI_TAP_GESTURE_DETECTOR_H