5 * Copyright (c) 2020 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 <cstdint> // uint32_t
25 #include <dali/public-api/object/base-handle.h>
26 #include <dali/public-api/signals/dali-signal.h>
31 * @addtogroup dali_core_common
35 namespace Internal DALI_INTERNAL
52 * @brief The Stage is a top-level object used for displaying a tree of Actors.
54 * Stage is a top-level object that represents the entire screen.
55 * It is used for displaying a hierarchy of actors managed by the scene graph structure,
56 * which means an actor inherits a position relative to its parent,
57 * and can be moved in relation to this point.
59 * The stage instance is a singleton object (the only instance of its class during the
60 * lifetime of the program). You can get it using a static function.
62 * To display the contents of an actor, it must be added to a stage.
63 * The following example shows how to connect a new actor to the stage:
65 * Actor actor = Actor::New();
66 * Stage::GetCurrent().Add( actor );
69 * The stage has a 2D size that matches the size of the application window.
70 * The default unit 1 is 1 pixel with the default camera.
72 * Multiple stage/window support is not currently provided.
75 * | %Signal Name | Method |
76 * |-------------------------|--------------------------------------|
77 * | keyEvent | @ref KeyEventSignal() |
78 * | eventProcessingFinished | @ref EventProcessingFinishedSignal() |
79 * | touch | @ref TouchSignal() |
80 * | wheelEvent | @ref WheelEventSignal() |
81 * | contextLost | @ref ContextLostSignal() |
82 * | contextRegained | @ref ContextRegainedSignal() |
83 * | sceneCreated | @ref SceneCreatedSignal() |
86 class DALI_CORE_API Stage : public BaseHandle
90 typedef Signal< void (const KeyEvent&) > KeyEventSignalType; ///< Key event signal type @SINCE_1_0.0
91 typedef Signal< void () > EventProcessingFinishedSignalType; ///< Event Processing finished signal type @SINCE_1_0.0
92 typedef Signal< void (const TouchEvent&) > TouchSignalType; ///< Touch signal type @SINCE_1_1.37
93 typedef Signal< void (const WheelEvent&) > WheelEventSignalType; ///< Wheel signal type @SINCE_1_0.0
94 typedef Signal< void () > ContextStatusSignal; ///< Context status signal type @SINCE_1_0.0
95 typedef Signal< void () > SceneCreatedSignalType; ///< Scene created signal type @SINCE_1_0.0
98 * @brief Allows the creation of an empty stage handle.
100 * To retrieve the current stage, this handle can be set using Stage::GetCurrent().
105 * @brief Gets the current Stage.
107 * @return The current stage or an empty handle if the internal core has not been created or has been already destroyed
109 static Stage GetCurrent();
112 * @brief Queries whether the Stage exists; this should only return false during or after destruction of Dali core.
114 * @return True when it's safe to call Stage::GetCurrent()
116 static bool IsInstalled();
121 * This is non-virtual since derived Handle types must not contain data or virtual methods.
126 * @brief This copy constructor is required for (smart) pointer semantics.
128 * @param[in] handle A reference to the copied handle
130 Stage(const Stage& handle);
133 * @brief This assignment operator is required for (smart) pointer semantics.
135 * @param[in] rhs A reference to the copied handle
136 * @return A reference to this
138 Stage& operator=(const Stage& rhs);
143 * @brief Adds a child Actor to the Stage.
145 * The child will be referenced.
146 * @param[in] actor The child
147 * @pre The actor has been initialized.
148 * @pre The actor does not have a parent.
150 void Add(Actor& actor);
153 * @brief Removes a child Actor from the Stage.
155 * The child will be unreferenced.
156 * @param[in] actor The child
157 * @pre The actor has been added to the stage.
159 void Remove(Actor& actor);
162 * @brief Returns the size of the Stage in pixels as a Vector.
164 * The x component will be the width of the Stage in pixels.
165 * The y component will be the height of the Stage in pixels.
166 * The z component will be the distance between far and near planes.
168 * @return The size of the Stage as a Vector
170 Vector2 GetSize() const;
175 * @brief Retrieves the list of render-tasks.
177 * @return A valid handle to a RenderTaskList
179 RenderTaskList GetRenderTaskList() const;
184 * @brief Queries the number of on-stage layers.
186 * Note that a default layer is always provided (count >= 1).
187 * @return The number of layers
189 uint32_t GetLayerCount() const;
192 * @brief Retrieves the layer at a specified depth.
194 * @param[in] depth The depth
195 * @return The layer found at the given depth
196 * @pre Depth is less than layer count; see GetLayerCount().
198 Layer GetLayer(uint32_t depth) const;
201 * @brief Returns the Stage's Root Layer.
203 * @return The root layer
205 Layer GetRootLayer() const;
210 * @brief Sets the background color of the stage.
212 * @param[in] color The new background color
214 void SetBackgroundColor(Vector4 color);
217 * @brief Retrieves the background color of the stage.
219 * @return The background color
221 Vector4 GetBackgroundColor() const;
224 * @brief Retrieves the DPI of the display device to which the stage is connected.
226 * @return The horizontal and vertical DPI
228 Vector2 GetDpi() const;
231 * @brief Gets the Object registry.
233 * @return The object registry
235 ObjectRegistry GetObjectRegistry() const;
240 * @brief Keep rendering for at least the given amount of time.
242 * By default, Dali will stop rendering when no Actor positions are being set, and when no animations are running etc.
243 * This method is useful to force screen refreshes e.g. when updating a NativeImage.
244 * @param[in] durationSeconds Time to keep rendering, 0 means render at least one more frame
246 void KeepRendering( float durationSeconds );
251 * @brief This signal is emitted when key event is received.
253 * A callback of the following type may be connected:
255 * void YourCallbackName(const KeyEvent& event);
258 * @return The signal to connect to
260 KeyEventSignalType& KeyEventSignal();
263 * @brief This signal is emitted just after the event processing is finished.
265 * @return The signal to connect to
267 EventProcessingFinishedSignalType& EventProcessingFinishedSignal();
270 * @brief This signal is emitted when the screen is touched and when the touch ends
271 * (i.e. the down & up touch events only).
273 * If there are multiple touch points, then this will be emitted when the first touch occurs and
274 * then when the last finger is lifted.
275 * An interrupted event will also be emitted (if it occurs).
276 * A callback of the following type may be connected:
278 * void YourCallbackName( TouchEvent event );
281 * @return The touch signal to connect to
282 * @note Motion events are not emitted.
284 TouchSignalType& TouchSignal();
287 * @brief This signal is emitted when wheel event is received.
289 * A callback of the following type may be connected:
291 * void YourCallbackName(const WheelEvent& event);
293 * @return The signal to connect to
295 WheelEventSignalType& WheelEventSignal();
298 * @brief This signal is emitted when the GL context is lost (Platform specific behaviour).
300 * If the application is responsible for handling context loss, it should listen to
301 * this signal and tear down UI components when received.
302 * @return The context lost signal to connect to
304 ContextStatusSignal& ContextLostSignal();
307 * @brief This signal is emitted when the GL context is regained (Platform specific
310 * If the application is responsible for handling context loss, it should listen to
311 * this signal and rebuild UI components on receipt.
312 * @return The context regained signal to connect to
314 ContextStatusSignal& ContextRegainedSignal();
317 * @brief This signal is emitted after the initial scene is created.
319 * It will be triggered after the
320 * application init signal.
322 * A callback of the following type may be connected:
324 * void YourCallbackName();
326 * @return The signal to connect to
328 SceneCreatedSignalType& SceneCreatedSignal();
330 public: // Not intended for application developers
334 * @brief This constructor is used by Stage::GetCurrent() methods.
336 * @param[in] stage A pointer to a Dali resource
338 explicit DALI_INTERNAL Stage(Internal::Stage* stage);
348 #endif // DALI_STAGE_H