1 #ifndef __DALI_PAN_GESTURE_H__
2 #define __DALI_PAN_GESTURE_H__
5 * Copyright (c) 2015 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.h>
23 #include <dali/public-api/math/vector2.h>
28 * @addtogroup dali_core_events
33 * @brief A PanGesture is emitted when the user moves one or more fingers in a particular direction.
35 * This gesture can be in one of three states, when the pan gesture is first detected: Gesture::Started
36 * when the pan gesture is continuing: Gesture::Continuing and finally, when the pan gesture ends:
39 * A pan gesture will end in the following ways:
40 * - User releases the primary finger (the first touch).
41 * - User has more fingers on the screen than the maximum specified.
42 * - User has less fingers on the screen than the minimum specified.
43 * - Cancelled by the system.
45 * A pan gesture will continue to be sent to the actor under than initial pan until it ends.
48 struct DALI_IMPORT_API PanGesture: public Gesture
50 // Construction & Destruction
53 * @brief Default Constructor.
62 * @param[in] state The state of the gesture
64 PanGesture(Gesture::State state);
67 * @brief Copy constructor.
69 * @param[in] rhs A reference to the copied handle
71 PanGesture( const PanGesture& rhs );
74 * @brief Assignment operator.
76 * @param[in] rhs A reference to the copied handle
77 * @return A reference to this
79 PanGesture& operator=( const PanGesture& rhs );
82 * @brief Virtual destructor.
85 virtual ~PanGesture();
90 * @brief The velocity at which the user is moving their fingers.
92 * This is represented as a Vector2 and is the pixel movement per millisecond.
93 * A positive x value shows that the user is panning to the right, a negative x value means the opposite.
94 * A positive y value shows that the user is panning downwards, a negative y values means upwards.
95 * This value represents the local coordinates of the actor attached to the PanGestureDetector.
100 * @brief This is a Vector2 showing how much the user has panned (dragged) since the last pan gesture or,
101 * if the gesture has just started, then the amount panned since the user touched the screen.
103 * A positive x value shows that the user is panning to the right, a negative x value means the opposite.
104 * A positive y value shows that the user is panning downwards, a negative y value means upwards.
105 * This value is in local actor coordinates, the actor being the one attached to the
106 * PanGestureDetector.
108 Vector2 displacement;
111 * @brief This current touch position of the primary touch point in local actor coordinates.
116 * @brief The velocity at which the user is moving their fingers.
118 * This is represented as a Vector2 and is the pixel movement per millisecond.
119 * A positive x value shows that the user is panning to the right, a negative x value means the opposite.
120 * A positive y value shows that the user is panning downwards, a negative y values means upwards.
121 * This value represents the screen coordinates.
123 Vector2 screenVelocity;
126 * @brief This is a Vector2 showing how much the user has panned (dragged) since the last pan gesture or,
127 * if the gesture has just started, then the amount panned since the user touched the screen.
129 * A positive x value shows that the user is panning to the right, a negative x value means the opposite.
130 * A positive y value shows that the user is panning downwards, a negative y value means upwards.
131 * This value is in screen coordinates.
133 Vector2 screenDisplacement;
136 * @brief This current touch position of the primary touch point in screen coordinates.
138 Vector2 screenPosition;
141 * @brief The total number of fingers touching the screen in a pan gesture.
143 unsigned int numberOfTouches;
145 // Convenience Methods
148 * @brief Returns the speed at which the user is moving their fingers.
150 * This is the pixel movement per millisecond.
152 * @return The speed of the pan (in pixels per millisecond).
154 float GetSpeed() const;
157 * @brief This returns the distance the user has panned (dragged) since the last pan gesture or,
158 * if the gesture has just started, then the distance moved since the user touched the screen.
160 * This is always a positive value.
162 * @return The distance, as a float, a user's finger has panned.
164 float GetDistance() const;
167 * @brief Returns the speed at which the user is moving their fingers relative to screen coordinates.
169 * This is the pixel movement per millisecond.
171 * @return The speed of the pan (in pixels per millisecond).
173 float GetScreenSpeed() const;
176 * @brief This returns the distance the user has panned (dragged) since the last pan gesture in screen
177 * coordinates or, if the gesture has just started, then the distance in screen coordinates moved
178 * since the user touched the screen.
180 * This is always a positive value.
182 * @return The distance, as a float, a user's finger has panned.
184 float GetScreenDistance() const;
192 #endif // __DALI_PAN_GESTURE_H__