1 #ifndef DALI_GESTURE_DETECTOR_H
2 #define DALI_GESTURE_DETECTOR_H
5 * Copyright (c) 2020 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/object/handle.h>
27 * @addtogroup dali_core_events
31 namespace Internal DALI_INTERNAL
33 class GestureDetector;
39 * @brief GestureDetectors analyse a stream of touch events and attempt to determine the intention of the user.
41 * An actor is attached to a gesture detector and if the detector recognises a pattern in its analysis, it will
42 * emit a detected signal to the application.
44 * This is the base class for different gesture detectors available and provides functionality that is common
45 * to all the gesture detectors.
50 class DALI_CORE_API GestureDetector : public Handle
52 public: // Creation & Destruction
54 * @brief Creates an uninitialized GestureDetector.
56 * This can be initialized with one of the derived gesture detectors' New() methods. For example, PanGestureDetector::New().
58 * Calling member functions with an uninitialized Dali::GestureDetector handle is not allowed.
64 * @brief Downcasts a handle to GestureDetector handle.
66 * If handle points to a GestureDetector object, the downcast produces valid handle.
67 * If not, the returned handle is left uninitialized.
69 * @param[in] handle Handle to an object
70 * @return Handle to a GestureDetector object or an uninitialized handle
72 static GestureDetector DownCast(BaseHandle handle);
75 * @brief Dali::GestureDetector is intended as a base class.
77 * This is non-virtual since derived Handle types must not contain data or virtual methods.
83 * @brief This copy constructor is required for (smart) pointer semantics.
86 * @param[in] handle A reference to the copied handle
88 GestureDetector(const GestureDetector& handle);
91 * @brief This assignment operator is required for (smart) pointer semantics.
94 * @param[in] rhs A reference to the copied handle
95 * @return A reference to this
97 GestureDetector& operator=(const GestureDetector& rhs);
99 public: // Actor related
101 * @brief Attaches an actor to the gesture.
103 * The detected signal will be dispatched when the gesture occurs on
104 * the attached actor.
106 * @param[in] actor The actor to attach to the gesture detector
107 * @pre The gesture detector has been initialized.
108 * @note You can attach several actors to a gesture detector.
110 void Attach(Actor actor);
113 * @brief Detaches the attached actor from the gesture detector.
116 * @param[in] actor The actor to detach from the gesture detector
117 * @pre The gesture detector has been initialized.
118 * @pre The specified actor has been attached to the gesture detector.
120 void Detach(Actor actor);
123 * @brief Detaches all the actors that have been attached to the gesture detector.
126 * @pre The gesture detector has been initialized.
127 * @pre At least one actor has been attached to the gesture detector.
132 * @brief Returns the number of actors attached to the gesture detector.
136 * @pre The gesture detector has been initialized.
138 size_t GetAttachedActorCount() const;
141 * @brief Returns an actor by index. An empty handle if the index is not valid.
144 * @param[in] index The attached actor's index
145 * @return The attached actor or an empty handle
146 * @pre The gesture detector has been initialized.
148 Actor GetAttachedActor(size_t index) const;
153 * @brief This constructor is used by New() methods of derived classes (For example, PanGestureDetector::New()).
156 * @param[in] internal A pointer to a newly allocated Dali resource
158 explicit DALI_INTERNAL GestureDetector(Internal::GestureDetector* internal);
167 #endif // DALI_GESTURE_DETECTOR_H