1 #ifndef __DALI_PAN_GESTURE_DETECTOR_H__
2 #define __DALI_PAN_GESTURE_DETECTOR_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-detector.h>
23 #include <dali/public-api/object/property-index-ranges.h>
24 #include <dali/public-api/signals/dali-signal.h>
31 namespace Internal DALI_INTERNAL
33 class PanGestureDetector;
39 * @addtogroup dali-core-events
44 * @brief This class looks for panning (or dragging) gestures.
46 * The user will be pressing one or more fingers on an actor while they pan it.
48 * The application programmer can use this gesture detector as follows:
50 * PanGestureDetector detector = PanGestureDetector::New();
51 * detector.Attach(myActor);
52 * detector.DetectedSignal().Connect(this, &MyApplication::OnPan);
54 * // Detect pan gesture for single and double touch.
55 * detector.SetMaximumTouchesRequired(2);
61 * | %Signal Name | Method |
62 * |--------------|-----------------------|
63 * | pan-detected | @ref DetectedSignal() |
65 class DALI_IMPORT_API PanGestureDetector : public GestureDetector
70 * @brief An enumeration of properties belonging to the PanGestureDetector class.
76 SCREEN_POSITION = DEFAULT_GESTURE_DETECTOR_PROPERTY_START_INDEX, ///< name "screen-position", type Vector2
77 SCREEN_DISPLACEMENT, ///< name "screen-displacement", type Vector2
78 SCREEN_VELOCITY, ///< name "screen-velocity", type Vector2
79 LOCAL_POSITION, ///< name "local-position", type Vector2
80 LOCAL_DISPLACEMENT, ///< name "local-displacement", type Vector2
81 LOCAL_VELOCITY, ///< name "local-velocity", type Vector2
82 PANNING, ///< name "panning", type bool
87 typedef Signal< void ( Actor, const PanGesture& ) > DetectedSignalType; ///< Pan gesture detected signal type
90 typedef std::pair< Radian, Radian > AngleThresholdPair; ///< Range of angles for a direction
92 static const Radian DIRECTION_LEFT; ///< For a left pan (-PI Radians).
93 static const Radian DIRECTION_RIGHT; ///< For a right pan (0 Radians).
94 static const Radian DIRECTION_UP; ///< For an up pan (-0.5 * PI Radians).
95 static const Radian DIRECTION_DOWN; ///< For a down pan (0.5 * PI Radians).
96 static const Radian DIRECTION_HORIZONTAL; ///< For a left and right pan (PI Radians). Useful for AddDirection().
97 static const Radian DIRECTION_VERTICAL; ///< For an up and down pan (-0.5 * PI Radians). Useful for AddDirection().
99 static const Radian DEFAULT_THRESHOLD; ///< The default threshold is PI * 0.25 radians (or 45 degrees).
101 public: // Creation & Destruction
104 * @brief Create an uninitialized PanGestureDetector; this can be initialized with PanGestureDetector::New().
106 * Calling member functions with an uninitialized Dali::Object is not allowed.
108 PanGestureDetector();
111 * @brief Create an initialized PanGestureDetector.
113 * @return A handle to a newly allocated Dali resource.
115 static PanGestureDetector New();
118 * @brief Downcast an Object handle to PanGestureDetector handle.
120 * If handle points to a PanGestureDetector object the
121 * downcast produces valid handle. If not the returned handle is left uninitialized.
122 * @param[in] handle to An object
123 * @return handle to a PanGestureDetector object or an uninitialized handle
125 static PanGestureDetector DownCast( BaseHandle handle );
130 * This is non-virtual since derived Handle types must not contain data or virtual methods.
132 ~PanGestureDetector();
135 * @brief This copy constructor is required for (smart) pointer semantics.
137 * @param [in] handle A reference to the copied handle
139 PanGestureDetector(const PanGestureDetector& handle);
142 * @brief This assignment operator is required for (smart) pointer semantics.
144 * @param [in] rhs A reference to the copied handle
145 * @return A reference to this
147 PanGestureDetector& operator=(const PanGestureDetector& rhs);
152 * @brief This is the minimum number of touches required for the pan gesture to be detected.
154 * @param[in] minimum Minimum touches required.
155 * @pre The gesture detector has been initialized.
156 * @note The default minimum is '1'.
158 void SetMinimumTouchesRequired(unsigned int minimum);
161 * @brief This is the maximum number of touches required for the pan gesture to be detected.
163 * @param[in] maximum Maximum touches required.
164 * @pre The gesture detector has been initialized.
165 * @note The default maximum is '1'.
167 void SetMaximumTouchesRequired(unsigned int maximum);
172 * @brief Retrieves the minimum number of touches required for the pan gesture to be detected.
174 * @return The minimum touches required.
175 * @pre The gesture detector has been initialized.
177 unsigned int GetMinimumTouchesRequired() const;
180 * @brief Retrieves the maximum number of touches required for the pan gesture to be detected.
182 * @return The maximum touches required.
183 * @pre The gesture detector has been initialized.
185 unsigned int GetMaximumTouchesRequired() const;
187 public: // Directional Panning
190 * @brief The pan gesture is only emitted if the pan occurs in the direction specified by this method with a +/- threshold allowance.
192 * The angle is from -180 -> 0 -> 180 degrees (or -M_PI -> 0 -> M_PI in radians) i.e:
195 * -90.0f ( -0.5f * PI )
198 * 180.0f ( PI ) ------------- 0.0f ( 0.0f )
201 * 90.0f ( 0.5f * PI )
204 * If an angle of 0.0 degrees is specified and the threshold is 45 degrees then the acceptable
205 * direction range is from -45 to 45 degrees.
207 * @param[in] angle The angle that pan should be allowed.
208 * @param[in] threshold The threshold around that angle.
210 * @note The angle added using this API is only checked when the gesture first starts, after that,
211 * this detector will emit the gesture regardless of what angle the pan is moving.
212 * @note The user can add as many angles as they require.
213 * @note If an angle outside the range above is given, then it is wrapped within the range, i.e.
214 * 190 degrees becomes -170 degrees and 370 degrees becomes 10 degrees.
215 * @note As long as you specify the type, you can also pass in a Dali::Degree to this method.
216 * @note If no threshold is provided, then the default threshold (PI * 0.25) is used.
217 * @note If the threshold is greater than PI, then PI will be used as the threshold.
219 * @pre The gesture detector has been initialized.
221 void AddAngle( Radian angle, Radian threshold = DEFAULT_THRESHOLD );
224 * @brief A helper method for adding bi-directional angles where the pan should take place.
226 * In other words, if 0 is requested, then PI will also be added so that we have both left and
229 * @param[in] direction The direction of panning required.
230 * @param[in] threshold The threshold.
232 * @note If a direction outside the range above is given, then it is wrapped within the range, i.e.
233 * 190 degrees becomes -170 degrees and 370 degrees becomes 10 degrees.
234 * @note If no threshold is provided, then the default threshold (PI * 0.25) is used.
235 * @note If the threshold is greater than PI, then PI will be used as the threshold.
236 * @note As long as you specify the type, you can also pass in a Dali::Degree to this method.
238 * @pre The gesture detector has been initialized.
242 void AddDirection( Radian direction, Radian threshold = DEFAULT_THRESHOLD );
245 * @brief Returns the count of angles that this pan gesture detector emits a signal.
248 * @pre The gesture detector has been initialized.
250 size_t GetAngleCount() const;
253 * @brief Returns the angle by index that this pan gesture detector emits a signal.
255 * @return an angle threshold pair, or a zero valued angle pair when index is invalid.
256 * @pre The gesture detector has been initialized.
257 * @pre The index is less than GetAngleCount()
259 AngleThresholdPair GetAngle(size_t index) const;
262 * @brief Clears any directional angles that are used by the gesture detector.
264 * After this, the pan gesture
265 * will be emitted for a pan in ANY direction.
266 * @pre The gesture detector has been initialized.
271 * @brief Removes the angle specified from the container.
273 * @param[in] angle The angle to remove.
274 * @pre The gesture detector has been initialized.
275 * @note This will only remove the first instance of the angle found from the container.
276 * @note If an angle outside the range in AddAngle() is given, then the value is wrapped within
277 * the range and that is removed.
279 void RemoveAngle( Radian angle );
282 * @brief Removes the two angles that make up the direction from the container.
284 * @param[in] direction The direction to remove.
285 * @pre The gesture detector has been initialized.
286 * @note If a direction outside the range in AddAngle() is given, then the value is wrapped within
287 * the range and that is removed.
289 void RemoveDirection( Radian direction );
294 * @brief This signal is emitted when the pan gesture is detected on the attached actor.
296 * A callback of the following type may be connected:
298 * void YourCallbackName( Actor actor, const PanGesture& gesture );
300 * @pre The gesture detector has been initialized.
301 * @return The signal to connect to.
303 DetectedSignalType& DetectedSignal();
305 public: // Pan Properties Setters
308 * @brief Allows setting of the pan properties that are returned in constraints.
310 * @param[in] pan The pan gesture to set.
311 *@note If a normal pan is taking place, then any value set is ignored.
313 static void SetPanGestureProperties( const PanGesture& pan );
315 public: // Not intended for Application developers
318 * @brief This constructor is used by Dali New() methods.
320 * @param [in] internal A pointer to a newly allocated Dali resource.
322 explicit DALI_INTERNAL PanGestureDetector(Internal::PanGestureDetector* internal);
332 #endif // __DALI_PAN_GESTURE_DETECTOR_H__