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 * @brief This class looks for panning (or dragging) gestures.
41 * The user will be pressing one or more fingers on an actor while they pan it.
43 * The application programmer can use this gesture detector as follows:
45 * PanGestureDetector detector = PanGestureDetector::New();
46 * detector.Attach(myActor);
47 * detector.DetectedSignal().Connect(this, &MyApplication::OnPan);
49 * // Detect pan gesture for single and double touch.
50 * detector.SetMaximumTouchesRequired(2);
56 * | %Signal Name | Method |
57 * |--------------|-----------------------|
58 * | pan-detected | @ref DetectedSignal() |
60 class DALI_IMPORT_API PanGestureDetector : public GestureDetector
65 * @brief An enumeration of properties belonging to the PanGestureDetector class.
71 SCREEN_POSITION = DEFAULT_GESTURE_DETECTOR_PROPERTY_START_INDEX, ///< name "screen-position", type Vector2
72 SCREEN_DISPLACEMENT, ///< name "screen-displacement", type Vector2
73 SCREEN_VELOCITY, ///< name "screen-velocity", type Vector2
74 LOCAL_POSITION, ///< name "local-position", type Vector2
75 LOCAL_DISPLACEMENT, ///< name "local-displacement", type Vector2
76 LOCAL_VELOCITY, ///< name "local-velocity", type Vector2
77 PANNING, ///< name "panning", type bool
82 typedef Signal< void ( Actor, const PanGesture& ) > DetectedSignalType; ///< Pan gesture detected signal type
85 typedef std::pair< Radian, Radian > AngleThresholdPair; ///< Range of angles for a direction
87 static const Radian DIRECTION_LEFT; ///< For a left pan (-PI Radians).
88 static const Radian DIRECTION_RIGHT; ///< For a right pan (0 Radians).
89 static const Radian DIRECTION_UP; ///< For an up pan (-0.5 * PI Radians).
90 static const Radian DIRECTION_DOWN; ///< For a down pan (0.5 * PI Radians).
91 static const Radian DIRECTION_HORIZONTAL; ///< For a left and right pan (PI Radians). Useful for AddDirection().
92 static const Radian DIRECTION_VERTICAL; ///< For an up and down pan (-0.5 * PI Radians). Useful for AddDirection().
94 static const Radian DEFAULT_THRESHOLD; ///< The default threshold is PI * 0.25 radians (or 45 degrees).
96 public: // Creation & Destruction
99 * @brief Create an uninitialized PanGestureDetector; this can be initialized with PanGestureDetector::New().
101 * Calling member functions with an uninitialized Dali::Object is not allowed.
103 PanGestureDetector();
106 * @brief Create an initialized PanGestureDetector.
108 * @return A handle to a newly allocated Dali resource.
110 static PanGestureDetector New();
113 * @brief Downcast an Object handle to PanGestureDetector handle.
115 * If handle points to a PanGestureDetector object the
116 * downcast produces valid handle. If not the returned handle is left uninitialized.
117 * @param[in] handle to An object
118 * @return handle to a PanGestureDetector object or an uninitialized handle
120 static PanGestureDetector DownCast( BaseHandle handle );
125 * This is non-virtual since derived Handle types must not contain data or virtual methods.
127 ~PanGestureDetector();
130 * @brief This copy constructor is required for (smart) pointer semantics.
132 * @param [in] handle A reference to the copied handle
134 PanGestureDetector(const PanGestureDetector& handle);
137 * @brief This assignment operator is required for (smart) pointer semantics.
139 * @param [in] rhs A reference to the copied handle
140 * @return A reference to this
142 PanGestureDetector& operator=(const PanGestureDetector& rhs);
147 * @brief This is the minimum number of touches required for the pan gesture to be detected.
149 * @param[in] minimum Minimum touches required.
150 * @pre The gesture detector has been initialized.
151 * @note The default minimum is '1'.
153 void SetMinimumTouchesRequired(unsigned int minimum);
156 * @brief This is the maximum number of touches required for the pan gesture to be detected.
158 * @param[in] maximum Maximum touches required.
159 * @pre The gesture detector has been initialized.
160 * @note The default maximum is '1'.
162 void SetMaximumTouchesRequired(unsigned int maximum);
167 * @brief Retrieves the minimum number of touches required for the pan gesture to be detected.
169 * @return The minimum touches required.
170 * @pre The gesture detector has been initialized.
172 unsigned int GetMinimumTouchesRequired() const;
175 * @brief Retrieves the maximum number of touches required for the pan gesture to be detected.
177 * @return The maximum touches required.
178 * @pre The gesture detector has been initialized.
180 unsigned int GetMaximumTouchesRequired() const;
182 public: // Directional Panning
185 * @brief The pan gesture is only emitted if the pan occurs in the direction specified by this method with a +/- threshold allowance.
187 * The angle is from -180 -> 0 -> 180 degrees (or -M_PI -> 0 -> M_PI in radians) i.e:
190 * -90.0f ( -0.5f * PI )
193 * 180.0f ( PI ) ------------- 0.0f ( 0.0f )
196 * 90.0f ( 0.5f * PI )
199 * If an angle of 0.0 degrees is specified and the threshold is 45 degrees then the acceptable
200 * direction range is from -45 to 45 degrees.
202 * @param[in] angle The angle that pan should be allowed.
203 * @param[in] threshold The threshold around that angle.
205 * @note The angle added using this API is only checked when the gesture first starts, after that,
206 * this detector will emit the gesture regardless of what angle the pan is moving.
207 * @note The user can add as many angles as they require.
208 * @note If an angle outside the range above is given, then it is wrapped within the range, i.e.
209 * 190 degrees becomes -170 degrees and 370 degrees becomes 10 degrees.
210 * @note As long as you specify the type, you can also pass in a Dali::Degree to this method.
211 * @note If no threshold is provided, then the default threshold (PI * 0.25) is used.
212 * @note If the threshold is greater than PI, then PI will be used as the threshold.
214 * @pre The gesture detector has been initialized.
216 void AddAngle( Radian angle, Radian threshold = DEFAULT_THRESHOLD );
219 * @brief A helper method for adding bi-directional angles where the pan should take place.
221 * In other words, if 0 is requested, then PI will also be added so that we have both left and
224 * @param[in] direction The direction of panning required.
225 * @param[in] threshold The threshold.
227 * @note If a direction 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 If no threshold is provided, then the default threshold (PI * 0.25) is used.
230 * @note If the threshold is greater than PI, then PI will be used as the threshold.
231 * @note As long as you specify the type, you can also pass in a Dali::Degree to this method.
233 * @pre The gesture detector has been initialized.
237 void AddDirection( Radian direction, Radian threshold = DEFAULT_THRESHOLD );
240 * @brief Returns the count of angles that this pan gesture detector emits a signal.
243 * @pre The gesture detector has been initialized.
245 size_t GetAngleCount() const;
248 * @brief Returns the angle by index that this pan gesture detector emits a signal.
250 * @return an angle threshold pair, or a zero valued angle pair when index is invalid.
251 * @pre The gesture detector has been initialized.
252 * @pre The index is less than GetAngleCount()
254 AngleThresholdPair GetAngle(size_t index) const;
257 * @brief Clears any directional angles that are used by the gesture detector.
259 * After this, the pan gesture
260 * will be emitted for a pan in ANY direction.
261 * @pre The gesture detector has been initialized.
266 * @brief Removes the angle specified from the container.
268 * @param[in] angle The angle to remove.
269 * @pre The gesture detector has been initialized.
270 * @note This will only remove the first instance of the angle found from the container.
271 * @note If an angle outside the range in AddAngle() is given, then the value is wrapped within
272 * the range and that is removed.
274 void RemoveAngle( Radian angle );
277 * @brief Removes the two angles that make up the direction from the container.
279 * @param[in] direction The direction to remove.
280 * @pre The gesture detector has been initialized.
281 * @note If a direction outside the range in AddAngle() is given, then the value is wrapped within
282 * the range and that is removed.
284 void RemoveDirection( Radian direction );
289 * @brief This signal is emitted when the pan gesture is detected on the attached actor.
291 * A callback of the following type may be connected:
293 * void YourCallbackName( Actor actor, const PanGesture& gesture );
295 * @pre The gesture detector has been initialized.
296 * @return The signal to connect to.
298 DetectedSignalType& DetectedSignal();
300 public: // Pan Properties Setters
303 * @brief Allows setting of the pan properties that are returned in constraints.
305 * @param[in] pan The pan gesture to set.
306 *@note If a normal pan is taking place, then any value set is ignored.
308 static void SetPanGestureProperties( const PanGesture& pan );
310 public: // Not intended for Application developers
313 * @brief This constructor is used by Dali New() methods.
315 * @param [in] internal A pointer to a newly allocated Dali resource.
317 explicit DALI_INTERNAL PanGestureDetector(Internal::PanGestureDetector* internal);
323 #endif // __DALI_PAN_GESTURE_DETECTOR_H__