1 #ifndef __DALI_PAN_GESTURE_DETECTOR_H__
2 #define __DALI_PAN_GESTURE_DETECTOR_H__
5 * Copyright (c) 2014 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 * @addtogroup CAPI_DALI_EVENTS_MODULE
27 #include <dali/public-api/events/gesture-detector.h>
28 #include <dali/public-api/signals/dali-signal-v2.h>
30 namespace Dali DALI_IMPORT_API
35 namespace Internal DALI_INTERNAL
37 class PanGestureDetector;
43 * @brief This class looks for panning (or dragging) gestures.
45 * The user will be pressing one or more fingers on an actor while they pan it.
47 * The application programmer can use this gesture detector as follows:
49 * PanGestureDetector detector = PanGestureDetector::New();
50 * detector.Attach(myActor);
51 * detector.SignalDetected().Connect(this, &MyApplication::OnPan);
53 * // Detect pan gesture for single and double touch.
54 * detector.SetMaximumTouchesRequired(2);
59 class PanGestureDetector : public GestureDetector
64 typedef SignalV2< void (Actor, PanGesture) > DetectedSignalV2; ///< Pan gesture detected signal type
67 static const char* const SIGNAL_PAN_DETECTED; ///< name "pan-detected"
70 typedef std::pair< Radian, Radian > AngleThresholdPair; ///< Range of angles for a direction
71 typedef std::vector< AngleThresholdPair > AngleContainer; ///< Group of angular thresholds for all directions
73 static const Radian DIRECTION_LEFT; ///< For a left pan (-PI Radians).
74 static const Radian DIRECTION_RIGHT; ///< For a right pan (0 Radians).
75 static const Radian DIRECTION_UP; ///< For an up pan (-0.5 * PI Radians).
76 static const Radian DIRECTION_DOWN; ///< For a down pan (0.5 * PI Radians).
77 static const Radian DIRECTION_HORIZONTAL; ///< For a left and right pan (PI Radians). Useful for AddDirection().
78 static const Radian DIRECTION_VERTICAL; ///< For an up and down pan (-0.5 * PI Radians). Useful for AddDirection().
80 static const Radian DEFAULT_THRESHOLD; ///< The default threshold is PI * 0.25 radians (or 45 degrees).
83 static const Property::Index SCREEN_POSITION; ///< name "screen-position", type VECTOR2
84 static const Property::Index SCREEN_DISPLACEMENT; ///< name "screen-displacement", type VECTOR2
85 static const Property::Index LOCAL_POSITION; ///< name "local-position", type VECTOR2
86 static const Property::Index LOCAL_DISPLACEMENT; ///< name "local-displacement", type VECTOR2
88 public: // Creation & Destruction
91 * @brief Create an uninitialized PanGestureDetector; this can be initialized with PanGestureDetector::New().
93 * Calling member functions with an uninitialized Dali::Object is not allowed.
98 * @brief Create an initialized PanGestureDetector.
100 * @return A handle to a newly allocated Dali resource.
102 static PanGestureDetector New();
105 * @brief Downcast an Object handle to PanGestureDetector handle.
107 * If handle points to a PanGestureDetector object the
108 * downcast produces valid handle. If not the returned handle is left uninitialized.
109 * @param[in] handle to An object
110 * @return handle to a PanGestureDetector object or an uninitialized handle
112 static PanGestureDetector DownCast( BaseHandle handle );
115 * @brief Virtual destructor.
117 * Dali::Object derived classes typically do not contain member data.
119 virtual ~PanGestureDetector();
122 * @copydoc Dali::BaseHandle::operator=
124 using BaseHandle::operator=;
129 * @brief This is the minimum number of touches required for the pan gesture to be detected.
131 * @param[in] minimum Minimum touches required.
132 * @pre The gesture detector has been initialized.
133 * @note The default minimum is '1'.
135 void SetMinimumTouchesRequired(unsigned int minimum);
138 * @brief This is the maximum number of touches required for the pan gesture to be detected.
140 * @param[in] maximum Maximum touches required.
141 * @pre The gesture detector has been initialized.
142 * @note The default maximum is '1'.
144 void SetMaximumTouchesRequired(unsigned int maximum);
149 * @brief Retrieves the minimum number of touches required for the pan gesture to be detected.
151 * @return The minimum touches required.
152 * @pre The gesture detector has been initialized.
154 unsigned int GetMinimumTouchesRequired() const;
157 * @brief Retrieves the maximum number of touches required for the pan gesture to be detected.
159 * @return The maximum touches required.
160 * @pre The gesture detector has been initialized.
162 unsigned int GetMaximumTouchesRequired() const;
164 public: // Directional Panning
167 * @brief The pan gesture is only emitted if the pan occurs in the direction specified by this method with a +/- threshold allowance.
169 * The angle is from -180 -> 0 -> 180 degrees (or -M_PI -> 0 -> M_PI in radians) i.e:
172 * -90.0f ( -0.5f * PI )
175 * 180.0f ( PI ) ------------- 0.0f ( 0.0f )
178 * 90.0f ( 0.5f * PI )
181 * If an angle of 0.0 degrees is specified and the threshold is 45 degrees then the acceptable
182 * direction range is from -45 to 45 degrees.
184 * @param[in] angle The angle that pan should be allowed.
185 * @param[in] threshold The threshold around that angle.
187 * @note The angle added using this API is only checked when the gesture first starts, after that,
188 * this detector will emit the gesture regardless of what angle the pan is moving.
189 * @note The user can add as many angles as they require.
190 * @note If an angle outside the range above is given, then it is wrapped within the range, i.e.
191 * 190 degrees becomes -170 degrees and 370 degrees becomes 10 degrees.
192 * @note As long as you specify the type, you can also pass in a Dali::Degree to this method.
193 * @note If no threshold is provided, then the default threshold (PI * 0.25) is used.
194 * @note If the threshold is greater than PI, then PI will be used as the threshold.
196 * @pre The gesture detector has been initialized.
198 void AddAngle( Radian angle, Radian threshold = DEFAULT_THRESHOLD );
201 * @brief A helper method for adding bi-directional angles where the pan should take place.
203 * In other words, if 0 is requested, then PI will also be added so that we have both left and
206 * @param[in] direction The direction of panning required.
207 * @param[in] threshold The threshold.
209 * @note If a direction outside the range above is given, then it is wrapped within the range, i.e.
210 * 190 degrees becomes -170 degrees and 370 degrees becomes 10 degrees.
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.
213 * @note As long as you specify the type, you can also pass in a Dali::Degree to this method.
215 * @pre The gesture detector has been initialized.
219 void AddDirection( Radian direction, Radian threshold = DEFAULT_THRESHOLD );
222 * @brief Returns the container of all the angles this pan gesture detector emits a signal.
224 * @return a const reference to the container of all the angles.
225 * @pre The gesture detector has been initialized.
227 const AngleContainer& GetAngles() const;
230 * @brief Clears any directional angles that are used by the gesture detector.
232 * After this, the pan gesture
233 * will be emitted for a pan in ANY direction.
234 * @pre The gesture detector has been initialized.
239 * @brief Removes the angle specified from the container.
241 * @param[in] angle The angle to remove.
242 * @pre The gesture detector has been initialized.
243 * @note This will only remove the first instance of the angle found from the container.
244 * @note If an angle outside the range in AddAngle() is given, then the value is wrapped within
245 * the range and that is removed.
247 void RemoveAngle( Radian angle );
250 * @brief Removes the two angles that make up the direction from the container.
252 * @param[in] direction The direction to remove.
253 * @pre The gesture detector has been initialized.
254 * @note If a direction outside the range in AddAngle() is given, then the value is wrapped within
255 * the range and that is removed.
257 void RemoveDirection( Radian direction );
262 * @brief This signal is emitted when the pan gesture is detected on the attached actor.
264 * A callback of the following type may be connected:
266 * void YourCallbackName(Actor actor, PanGesture gesture);
268 * @pre The gesture detector has been initialized.
269 * @return The signal to connect to.
271 DetectedSignalV2& DetectedSignal();
273 public: // Pan Properties Setters
276 * @brief Allows setting of the pan properties that are returned in constraints.
278 * @param[in] pan The pan gesture to set.
279 *@note If a normal pan is taking place, then any value set is ignored.
281 static void SetPanGestureProperties( const PanGesture& pan );
283 public: // Not intended for Application developers
286 * @brief This constructor is used by Dali New() methods.
288 * @param [in] internal A pointer to a newly allocated Dali resource.
290 explicit DALI_INTERNAL PanGestureDetector(Internal::PanGestureDetector* internal);
299 #endif // __DALI_PAN_GESTURE_DETECTOR_H__