1 #ifndef __DALI_LAYER_H__
2 #define __DALI_LAYER_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/object/ref-object.h>
23 #include <dali/public-api/actors/actor.h>
24 #include <dali/public-api/math/rect.h>
25 #include <dali/public-api/math/vector3.h>
26 #include <dali/public-api/images/frame-buffer-image.h>
31 * @addtogroup dali_core_actors
35 namespace Internal DALI_INTERNAL
41 * @brief Rectangle describing area on screen that a layer can draw to.
44 * @see Dali::Layer::SetClippingBox()
46 typedef Rect<int> ClippingBox;
49 * @brief Layers provide a mechanism for overlaying groups of actors on top of each other.
51 * When added to the stage, a layer can be ordered relative to other layers. The bottom
52 * layer is at depth zero. The stage provides a default layer for it's children.
54 * Layered actors inherit position etc. as normal, but are drawn in an order determined
55 * by the layers. The depth buffer is cleared before each layer is rendered unless depth
56 * test is disabled or there's no need for it based on the layers contents;
57 * actors in lower layers cannot obscure actors in higher layers.
59 * If depth test is disabled, there is no performance overhead from clearing the depth buffer.
62 * | %Action Name | %Layer method called |
63 * |-----------------|----------------------|
64 * | raise | @ref Raise() |
65 * | lower | @ref Lower() |
66 * | raiseToTop | @ref RaiseToTop() |
67 * | lowerToBottom | @ref LowerToBottom() |
70 class DALI_IMPORT_API Layer : public Actor
75 * @brief An enumeration of properties belonging to the Layer class.
76 * Properties additional to Actor.
83 CLIPPING_ENABLE = DEFAULT_DERIVED_ACTOR_PROPERTY_START_INDEX, ///< name "clippingEnable", type bool @SINCE_1_0.0
84 CLIPPING_BOX, ///< name "clippingBox", type Rect<int> @SINCE_1_0.0
85 BEHAVIOR, ///< name "behavior", type String @SINCE_1_0.0
90 * @brief Enumeration for the behavior of the layer.
92 * Check each value to see how it affects the layer.
98 * @brief Layer doesn't make use of the depth test.
100 * This mode is expected to have better performance than the 3D mode.
101 * When using this mode any ordering would be with respect to depthIndex property of Renderers.
107 * @brief Layer will use depth test.
109 * When using this mode depth depth test will be used. Opaque renderers are drawn first
110 * and write to the depth buffer. Then transparent renderers are drawn with depth test
111 * enabled but depth write switched off.
112 * Transparent renderers are drawn based on their distance from the camera (painter's algorithm).
113 * A renderers DEPTH_INDEX property is used to offset the distance to the camera when ordering transparent renderers.
114 * This is useful if you want to define the draw order of two or more transparent renderers that are
115 * equal distance from the camera.
123 * TREE_DEPTH_MULTIPLIER is used by the rendering sorting algorithm to decide which actors to render first.
124 * For 2D layers, this value will be multiplied to the actor depth in the tree and added to the depth index
125 * to obtain the value which will be used for ordering
127 enum TreeDepthMultiplier
129 TREE_DEPTH_MULTIPLIER = 10000,
132 * @brief The sort function type.
135 * @param[in] position this is the actor translation from camera.
137 typedef float (*SortFunctionType)( const Vector3& position );
140 * @brief Create an empty Layer handle.
142 * This can be initialised with Layer::New(...)
148 * @brief Create a Layer object.
151 * @return A handle to a newly allocated Layer
156 * @brief Downcast an Object handle to Layer.
158 * If handle points to a Layer the downcast produces valid
159 * handle. If not the returned handle is left uninitialized.
161 * @param[in] handle to An object
162 * @return handle to a Layer or an uninitialized handle
164 static Layer DownCast( BaseHandle handle );
169 * This is non-virtual since derived Handle types must not contain data or virtual methods.
175 * @brief Copy constructor
178 * @param [in] copy The actor to copy.
180 Layer(const Layer& copy);
183 * @brief Assignment operator
186 * @param [in] rhs The actor to copy.
188 Layer& operator=(const Layer& rhs);
191 * @brief Query the depth of the layer
193 * 0 is bottom most layer, higher number is on top
195 * @return the current depth of the layer.
196 * @pre layer is on the stage
197 * If layer is not added to the stage, returns 0.
199 unsigned int GetDepth() const;
202 * @brief Increment the depth of the layer.
205 * @pre layer is on the stage
210 * @brief Decrement the depth of the layer.
213 * @pre layer is on the stage
218 * @brief Ensures the layers depth is greater than the target layer.
220 * If the layer already is above target layer its depth is not changed
221 * If the layer was below target, its new depth will be immediately above target
222 * Note! All layers between this layer and target get new depth values
224 * @param target layer to get above of
225 * @pre layer is on the stage
226 * @pre target layer is on the stage
228 void RaiseAbove( Layer target );
231 * @brief Ensures the layers depth is less than the target layer.
233 * If the layer already is below the layer its depth is not changed
234 * If the layer was above target, its new depth will be immediately below target
235 * Note! All layers between this layer and target get new depth values
237 * @param target layer to get below of
238 * @pre layer is on the stage
239 * @pre target layer is on the stage
241 void LowerBelow( Layer target );
244 * @brief Raises the layer to the top.
246 * @pre layer is on the stage
251 * @brief Lowers the layer to the bottom.
253 * @pre layer is on the stage
255 void LowerToBottom();
258 * @brief Moves the layer directly above the given layer.
260 * After the call this layers depth will be immediately above target
261 * Note! All layers between this layer and target get new depth values
263 * @param target layer to get on top of
264 * @pre layer is on the stage
265 * @pre target layer is on the stage
267 void MoveAbove( Layer target );
270 * @brief Moves the layer directly below the given layer.
272 * After the call this layers depth will be immediately below target
273 * Note! All layers between this layer and target get new depth values
275 * @param target layer to get below of
276 * @pre layer is on the stage
277 * @pre target layer is on the stage
279 void MoveBelow( Layer target );
282 * @brief Set the behavior of the layer
285 * @param[in] behavior The desired behavior
287 void SetBehavior( Behavior behavior );
290 * @brief Get the behavior of the layer
293 * @return The behavior of the layer
295 Behavior GetBehavior() const;
298 * @brief Sets whether clipping is enabled for a layer.
300 * Clipping is initially disabled; see also SetClippingBox().
302 * @param [in] enabled True if clipping is enabled.
304 * @note When clipping is enabled, the default clipping box is empty (0,0,0,0) which means everything is clipped.
306 void SetClipping(bool enabled);
309 * @brief Query whether clipping is enabled for a layer.
311 * @return True if clipping is enabled.
313 bool IsClipping() const;
316 * @brief Sets the clipping box of a layer, in window coordinates.
318 * The contents of the layer will not be visible outside this box, when clipping is
319 * enabled. The default clipping box is empty (0,0,0,0) which means everything is clipped.
320 * You can only do rectangular clipping using this API in window coordinates.
321 * For other kinds of clipping, @see Dali::Actor::SetDrawMode().
323 * @param [in] x The X-coordinate of the top-left corner of the box.
324 * @param [in] y The Y-coordinate of the top-left corner of the box.
325 * @param [in] width The width of the box.
326 * @param [in] height The height of the box.
328 void SetClippingBox(int x, int y, int width, int height);
331 * @brief Sets the clipping box of a layer, in window coordinates.
333 * The contents of the layer will not be visible outside this box, when clipping is
334 * enabled. The default clipping box is empty (0,0,0,0).
336 * @param [in] box The clipping box
338 void SetClippingBox(ClippingBox box);
341 * @brief Retrieves the clipping box of a layer, in window coordinates.
344 * @return The clipping box
346 ClippingBox GetClippingBox() const;
351 * @brief Whether to disable the depth test.
353 * By default a layer enables depth test if there is more than one opaque actor or if there is one opaque actor and one, or more, transparent actors.
354 * However, it's possible to disable the depth test by calling this method.
357 * @param[in] disable \e true disables depth test. \e false sets the default behavior.
359 void SetDepthTestDisabled( bool disable );
362 * @brief Retrieves whether depth test is disabled.
365 * @return \e true if depth test is disabled.
367 bool IsDepthTestDisabled() const;
372 * @brief This allows the user to specify the sort function that the layer should use.
374 * The sort function is used to determine the order in which the actors are drawn
375 * and input is processed on the actors in the layer.
377 * A function of the following type should be used:
379 * float YourSortFunction(const Vector3& position);
383 * @param[in] function The sort function pointer
384 * @note If the sort function returns a low number, the actor the data applies to will be
385 * drawn in front of an actor whose data yields a high value from the sort function.
387 * @note All child layers use the same sort function. If a child layer is added to this
388 * layer then the sort function used by the child layer will also be the same.
391 void SetSortFunction( SortFunctionType function );
394 * @brief This allows the user to specify whether this layer should consume touch (including gestures).
396 * If set, any layers behind this layer will not be hit-test.
399 * @param[in] consume Whether the layer should consume touch (including gestures).
401 void SetTouchConsumed( bool consume );
404 * @brief Retrieves whether the layer consumes touch (including gestures).
407 * @return true if consuming touch, false otherwise.
409 bool IsTouchConsumed() const;
412 * @brief This allows the user to specify whether this layer should consume hover.
414 * If set, any layers behind this layer will not be hit-test.
417 * @param[in] consume Whether the layer should consume hover.
419 void SetHoverConsumed( bool consume );
422 * @brief Retrieves whether the layer consumes hover.
425 * @return true if consuming hover, false otherwise.
427 bool IsHoverConsumed() const;
429 public: // Not intended for application developers
432 * @brief This constructor is used by Dali New() methods.
435 * @param [in] Layer A pointer to a newly allocated Dali resource
437 explicit DALI_INTERNAL Layer(Internal::Layer* Layer);
445 #endif //__DALI_LAYER_H__