1 #ifndef DALI_PINCH_GESTURE_DETECTOR_H
2 #define DALI_PINCH_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/events/gesture-detector.h>
23 #include <dali/public-api/signals/dali-signal.h>
28 * @addtogroup dali_core_events
32 namespace Internal DALI_INTERNAL
34 class PinchGestureDetector;
40 * @brief This class looks for pinching gestures involving two touches.
42 * It tries to detect when the user moves two touch points towards or
43 * away from each other. Please see PinchGesture for more
46 * The application programmer can use this gesture detector as follows:
48 * PinchGestureDetector detector = PinchGestureDetector::New();
49 * detector.Attach(myActor);
50 * detector.DetectedSignal().Connect(this, &MyApplication::OnPinch);
57 * | %Signal Name | Method |
58 * |----------------|-----------------------|
59 * | pinchDetected | @ref DetectedSignal() |
61 class DALI_CORE_API PinchGestureDetector : public GestureDetector
69 using DetectedSignalType = Signal<void( Actor, const PinchGesture& )>;
71 public: // Creation & Destruction
74 * @brief Creates an uninitialized PinchGestureDetector; this can be initialized with PinchGestureDetector::New().
76 * Calling member functions with an uninitialized PinchGestureDetector handle is not allowed.
79 PinchGestureDetector();
82 * @brief Creates an initialized PinchGestureDetector.
85 * @return A handle to a newly allocated Dali resource
87 static PinchGestureDetector New();
90 * @brief Downcasts a handle to PinchGestureDetector handle.
92 * If handle points to a PinchGestureDetector object, the
93 * downcast produces valid handle. If not, the returned handle is left uninitialized.
95 * @param[in] handle Handle to an object
96 * @return Handle to a PinchGestureDetector object or an uninitialized handle
98 static PinchGestureDetector DownCast( BaseHandle handle );
103 * This is non-virtual since derived Handle types must not contain data or virtual methods.
106 ~PinchGestureDetector();
109 * @brief This copy constructor is required for (smart) pointer semantics.
112 * @param[in] handle A reference to the copied handle
114 PinchGestureDetector(const PinchGestureDetector& handle);
117 * @brief This assignment operator is required for (smart) pointer semantics.
120 * @param[in] rhs A reference to the copied handle
121 * @return A reference to this
123 PinchGestureDetector& operator=(const PinchGestureDetector& rhs);
128 * @brief This signal is emitted when the pinch gesture is detected on the attached actor.
130 * A callback of the following type may be connected:
132 * void YourCallbackName( Actor actor, const PinchGesture& gesture );
135 * @return The signal to connect to
136 * @pre The gesture detector has been initialized.
138 DetectedSignalType& DetectedSignal();
140 public: // Not intended for Application developers
144 * @brief This constructor is used by PinchGestureDetector::New() methods.
147 * @param[in] internal A pointer to a newly allocated Dali resource
149 explicit DALI_INTERNAL PinchGestureDetector(Internal::PinchGestureDetector* internal);
159 #endif // DALI_PINCH_GESTURE_DETECTOR_H