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);
62 * | %Signal Name | Method |
63 * |--------------|-----------------------|
64 * | panDetected | @ref DetectedSignal() |
66 class DALI_IMPORT_API PanGestureDetector : public GestureDetector
71 * @brief An enumeration of properties belonging to the PanGestureDetector class.
78 SCREEN_POSITION = DEFAULT_GESTURE_DETECTOR_PROPERTY_START_INDEX, ///< name "screenPosition", type Vector2 @SINCE_1_0.0
79 SCREEN_DISPLACEMENT, ///< name "screenDisplacement", type Vector2 @SINCE_1_0.0
80 SCREEN_VELOCITY, ///< name "screenVelocity", type Vector2 @SINCE_1_0.0
81 LOCAL_POSITION, ///< name "localPosition", type Vector2 @SINCE_1_0.0
82 LOCAL_DISPLACEMENT, ///< name "localDisplacement", type Vector2 @SINCE_1_0.0
83 LOCAL_VELOCITY, ///< name "localVelocity", type Vector2 @SINCE_1_0.0
84 PANNING, ///< name "panning", type bool @SINCE_1_0.0
89 typedef Signal< void ( Actor, const PanGesture& ) > DetectedSignalType; ///< Pan gesture detected signal type @SINCE_1_0.0
92 typedef std::pair< Radian, Radian > AngleThresholdPair; ///< Range of angles for a direction @SINCE_1_0.0
94 static const Radian DIRECTION_LEFT; ///< For a left pan (-PI Radians).
95 static const Radian DIRECTION_RIGHT; ///< For a right pan (0 Radians).
96 static const Radian DIRECTION_UP; ///< For an up pan (-0.5 * PI Radians).
97 static const Radian DIRECTION_DOWN; ///< For a down pan (0.5 * PI Radians).
98 static const Radian DIRECTION_HORIZONTAL; ///< For a left and right pan (PI Radians). Useful for AddDirection().
99 static const Radian DIRECTION_VERTICAL; ///< For an up and down pan (-0.5 * PI Radians). Useful for AddDirection().
101 static const Radian DEFAULT_THRESHOLD; ///< The default threshold is PI * 0.25 radians (or 45 degrees).
103 public: // Creation & Destruction
106 * @brief Create an uninitialized PanGestureDetector; this can be initialized with PanGestureDetector::New().
108 * Calling member functions with an uninitialized PanGestureDetector handle is not allowed.
111 PanGestureDetector();
114 * @brief Create an initialized PanGestureDetector.
117 * @return A handle to a newly allocated Dali resource.
119 static PanGestureDetector New();
122 * @brief Downcast a handle to PanGestureDetector handle.
124 * If handle points to a PanGestureDetector object the
125 * downcast produces valid handle. If not the returned handle is left uninitialized.
127 * @param[in] handle Handle to an object
128 * @return Handle to a PanGestureDetector object or an uninitialized handle
130 static PanGestureDetector DownCast( BaseHandle handle );
135 * This is non-virtual since derived Handle types must not contain data or virtual methods.
138 ~PanGestureDetector();
141 * @brief This copy constructor is required for (smart) pointer semantics.
144 * @param [in] handle A reference to the copied handle
146 PanGestureDetector(const PanGestureDetector& handle);
149 * @brief This assignment operator is required for (smart) pointer semantics.
152 * @param [in] rhs A reference to the copied handle
153 * @return A reference to this
155 PanGestureDetector& operator=(const PanGestureDetector& rhs);
160 * @brief This is the minimum number of touches required for the pan gesture to be detected.
163 * @param[in] minimum Minimum touches required.
164 * @pre The gesture detector has been initialized.
165 * @note The default minimum is '1'.
167 void SetMinimumTouchesRequired(unsigned int minimum);
170 * @brief This is the maximum number of touches required for the pan gesture to be detected.
173 * @param[in] maximum Maximum touches required.
174 * @pre The gesture detector has been initialized.
175 * @note The default maximum is '1'.
177 void SetMaximumTouchesRequired(unsigned int maximum);
182 * @brief Retrieves the minimum number of touches required for the pan gesture to be detected.
185 * @return The minimum touches required.
186 * @pre The gesture detector has been initialized.
188 unsigned int GetMinimumTouchesRequired() const;
191 * @brief Retrieves the maximum number of touches required for the pan gesture to be detected.
194 * @return The maximum touches required.
195 * @pre The gesture detector has been initialized.
197 unsigned int GetMaximumTouchesRequired() const;
199 public: // Directional Panning
202 * @brief The pan gesture is only emitted if the pan occurs in the direction specified by this method with a +/- threshold allowance.
204 * The angle is from -180 -> 0 -> 180 degrees (or -M_PI -> 0 -> M_PI in radians) i.e:
207 * -90.0f ( -0.5f * PI )
210 * 180.0f ( PI ) ------------- 0.0f ( 0.0f )
213 * 90.0f ( 0.5f * PI )
216 * If an angle of 0.0 degrees is specified and the threshold is 45 degrees then the acceptable
217 * direction range is from -45 to 45 degrees.
220 * @param[in] angle The angle that pan should be allowed.
221 * @param[in] threshold The threshold around that angle.
223 * @pre The gesture detector has been initialized.
224 * @note The angle added using this API is only checked when the gesture first starts, after that,
225 * this detector will emit the gesture regardless of what angle the pan is moving.
226 * @note The user can add as many angles as they require.
227 * @note If an angle outside the range above is given, then it is wrapped within the range, i.e.
228 * 190 degrees becomes -170 degrees and 370 degrees becomes 10 degrees.
229 * @note As long as you specify the type, you can also pass in a Dali::Degree to this method.
230 * @note If no threshold is provided, then the default threshold (PI * 0.25) is used.
231 * @note If the threshold is greater than PI, then PI will be used as the threshold.
234 void AddAngle( Radian angle, Radian threshold = DEFAULT_THRESHOLD );
237 * @brief A helper method for adding bi-directional angles where the pan should take place.
239 * In other words, if 0 is requested, then PI will also be added so that we have both left and
243 * @param[in] direction The direction of panning required.
244 * @param[in] threshold The threshold.
246 * @pre The gesture detector has been initialized.
248 * @note If a direction outside the range above is given, then it is wrapped within the range, i.e.
249 * 190 degrees becomes -170 degrees and 370 degrees becomes 10 degrees.
250 * @note If no threshold is provided, then the default threshold (PI * 0.25) is used.
251 * @note If the threshold is greater than PI, then PI will be used as the threshold.
252 * @note As long as you specify the type, you can also pass in a Dali::Degree to this method.
256 void AddDirection( Radian direction, Radian threshold = DEFAULT_THRESHOLD );
259 * @brief Returns the count of angles that this pan gesture detector emits a signal.
263 * @pre The gesture detector has been initialized.
265 size_t GetAngleCount() const;
268 * @brief Returns the angle by index that this pan gesture detector emits a signal.
271 * @return An angle threshold pair, or a zero valued angle pair when index is invalid.
272 * @pre The gesture detector has been initialized.
273 * @pre The index is less than GetAngleCount()
275 AngleThresholdPair GetAngle(size_t index) const;
278 * @brief Clears any directional angles that are used by the gesture detector.
280 * After this, the pan gesture
281 * will be emitted for a pan in ANY direction.
283 * @pre The gesture detector has been initialized.
288 * @brief Removes the angle specified from the container.
291 * @param[in] angle The angle to remove.
292 * @pre The gesture detector has been initialized.
293 * @note This will only remove the first instance of the angle found from the container.
294 * @note If an angle outside the range in AddAngle() is given, then the value is wrapped within
295 * the range and that is removed.
297 void RemoveAngle( Radian angle );
300 * @brief Removes the two angles that make up the direction from the container.
303 * @param[in] direction The direction to remove.
304 * @pre The gesture detector has been initialized.
305 * @note If a direction outside the range in AddAngle() is given, then the value is wrapped within
306 * the range and that is removed.
308 void RemoveDirection( Radian direction );
313 * @brief This signal is emitted when the pan gesture is detected on the attached actor.
315 * A callback of the following type may be connected:
317 * void YourCallbackName( Actor actor, const PanGesture& gesture );
320 * @return The signal to connect to.
321 * @pre The gesture detector has been initialized.
323 DetectedSignalType& DetectedSignal();
325 public: // Pan Properties Setters
328 * @brief Allows setting of the pan properties that are returned in constraints.
331 * @param[in] pan The pan gesture to set.
332 * @note If a normal pan is taking place, then any value set is ignored.
334 static void SetPanGestureProperties( const PanGesture& pan );
336 public: // Not intended for Application developers
339 * @brief This constructor is used by PanGestureDetector::New() methods.
342 * @param [in] internal A pointer to a newly allocated Dali resource.
344 explicit DALI_INTERNAL PanGestureDetector(Internal::PanGestureDetector* internal);
354 #endif // __DALI_PAN_GESTURE_DETECTOR_H__