1 #ifndef __DALI_LAYER_H__
2 #define __DALI_LAYER_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_ACTORS_MODULE
27 #include <dali/public-api/object/ref-object.h>
28 #include <dali/public-api/actors/actor.h>
29 #include <dali/public-api/math/rect.h>
30 #include <dali/public-api/math/vector3.h>
31 #include <dali/public-api/images/frame-buffer-image.h>
33 namespace Dali DALI_IMPORT_API
36 namespace Internal DALI_INTERNAL
42 * @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.
61 class DALI_IMPORT_API Layer : public Actor
65 // Default Properties additional to Actor
66 static const Property::Index CLIPPING_ENABLE; ///< name "clipping-enable", type BOOLEAN
67 static const Property::Index CLIPPING_BOX; ///< name "clipping-box", type RECTANGLE
70 static const char* const ACTION_RAISE; ///< name "raise"
71 static const char* const ACTION_LOWER; ///< name "lower"
72 static const char* const ACTION_RAISE_TO_TOP; ///< name "raise-to-top"
73 static const char* const ACTION_LOWER_TO_BOTTOM; ///< name "lower-to-bottom"
76 * @brief The sort function type.
78 * The position value is the actor translation from camera.
79 * The sortModifier is the user value that can be used to sort coplanar actors/nodes. This value is
80 * the one set by calling RenderableActor::SetSortModifier().
82 * A high return value means that the actor will be positioned further away by the sort algorithm.
83 * @see RenderableActor::SetSortModifier
85 typedef float (*SortFunctionType)(const Vector3& position, float sortModifier);
88 * @brief Create an empty Layer handle.
90 * This can be initialised with Layer::New(...)
95 * @brief Create a Layer object.
97 * @return A handle to a newly allocated Layer
102 * @brief Downcast an Object handle to Layer.
104 * If handle points to a Layer the downcast produces valid
105 * handle. If not the returned handle is left uninitialized.
106 * @param[in] handle to An object
107 * @return handle to a Layer or an uninitialized handle
109 static Layer DownCast( BaseHandle handle );
112 * @brief Virtual destructor.
114 * Dali::Object derived classes typically do not contain member data.
119 * @copydoc Dali::BaseHandle::operator=
121 using BaseHandle::operator=;
124 * @brief Query the depth of the layer
126 * 0 is bottom most layer, higher number is on top
127 * @pre layer is on the stage
128 * If layer is not added to the stage, returns 0.
129 * @return the current depth of the layer.
131 unsigned int GetDepth() const;
134 * @brief Increment the depth of the layer.
136 * @pre layer is on the stage
141 * @brief Decrement the depth of the layer.
143 * @pre layer is on the stage
148 * @brief Ensures the layers depth is greater than the target layer.
150 * If the layer already is above target layer its depth is not changed
151 * If the layer was below target, its new depth will be immediately above target
152 * Note! All layers between this layer and target get new depth values
153 * @pre layer is on the stage
154 * @pre target layer is on the stage
155 * @param target layer to get above of
157 void RaiseAbove( Layer target );
160 * @brief Ensures the layers depth is less than the target layer.
162 * If the layer already is below the layer its depth is not changed
163 * If the layer was above target, its new depth will be immediately below target
164 * Note! All layers between this layer and target get new depth values
165 * @pre layer is on the stage
166 * @pre target layer is on the stage
167 * @param target layer to get below of
169 void LowerBelow( Layer target );
172 * @brief Raises the layer to the top.
173 * @pre layer is on the stage
178 * @brief Lowers the layer to the bottom.
179 * @pre layer is on the stage
181 void LowerToBottom();
184 * @brief Moves the layer directly above the given layer.
186 * After the call this layers depth will be immediately above target
187 * Note! All layers between this layer and target get new depth values
188 * @pre layer is on the stage
189 * @pre target layer is on the stage
190 * @param target layer to get on top of
192 void MoveAbove( Layer target );
195 * @brief Moves the layer directly below the given layer.
197 * After the call this layers depth will be immediately below target
198 * Note! All layers between this layer and target get new depth values
199 * @pre layer is on the stage
200 * @pre target layer is on the stage
201 * @param target layer to get below of
203 void MoveBelow( Layer target );
206 * @brief Sets whether clipping is enabled for a layer.
208 * Clipping is initially disabled; see also SetClippingBox().
209 * @param [in] enabled True if clipping is enabled.
211 void SetClipping(bool enabled);
214 * @brief Query whether clipping is enabled for a layer.
215 * @return True if clipping is enabled.
217 bool IsClipping() const;
220 * @brief Sets the clipping box of a layer, in window coordinates.
222 * The contents of the layer will not be visible outside this box, when clipping is
223 * enabled. The default clipping box is empty (0,0,0,0).
224 * This has the limitation that it only applies to rectangles on a window.
225 * For other kinds of clipping, @see Dali::Actor::SetDrawMode().
226 * @param [in] x The X-coordinate of the lower-left corner.
227 * @param [in] y The Y-coordinate of the lower-left corner.
228 * @param [in] width The width of the box.
229 * @param [in] height The height of the box.
231 void SetClippingBox(int x, int y, int width, int height);
234 * @brief Sets the clipping box of a layer, in window coordinates.
236 * The contents of the layer will not be visible outside this box, when clipping is
237 * enabled. The default clipping box is empty (0,0,0,0).
238 * @param [in] box The clipping box
240 void SetClippingBox(ClippingBox box);
243 * @brief Retrieves the clipping box of a layer, in window coordinates.
245 * @return The clipping box
247 ClippingBox GetClippingBox() const;
252 * @brief Whether to disable the depth test.
254 * 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.
255 * However, it's possible to disable the depth test by calling this method.
257 * @param[in] disable \e true disables depth test. \e false sets the default behaviour.
259 void SetDepthTestDisabled( bool disable );
262 * @brief Retrieves whether depth test is disabled.
264 * @return \e true if depth test is disabled.
266 bool IsDepthTestDisabled() const;
271 * @brief This sort function sorts translucent actors according to the Z-value in view space.
273 * This is useful for 2D user interfaces.
275 * This is the default sorting function.
277 * We return a negative z value as in our translation, a low z means that it should
278 * be sorted further away and a high z means that it should be closer.
279 * @param[in] position position of actor in view space
280 * @param[in] sortModifier additional sort modifer
283 static float ZValue(const Vector3& position, float sortModifier);
286 * @brief This allows the user to specify the sort function that the layer should use.
288 * The sort function is used to determine the order in which the actors are drawn
289 * and input is processed on the actors in the layer.
291 * A function of the following type should be used:
293 * float YourSortFunction(const Vector3& position, float sortModifier);
296 * @note If the sort function returns a low number, the actor the data applies to will be
297 * drawn in front of an actor whose data yields a high value from the sort function.
299 * @note All child layers use the same sort function. If a child layer is added to this
300 * layer then the sort function used by the child layer will also be the same.
302 * @param[in] function The sort function pointer
304 void SetSortFunction( SortFunctionType function );
307 * @brief This allows the user to specify whether this layer should consume touch (including gestures).
309 * If set, any layers behind this layer will not be hit-test.
311 * @param[in] consume Whether the layer should consume touch (including gestures).
313 void SetTouchConsumed( bool consume );
316 * @brief Retrieves whether the layer consumes touch (including gestures).
318 * @return true if consuming touch, false otherwise.
320 bool IsTouchConsumed() const;
322 public: // Not intended for application developers
325 * @brief This constructor is used by Dali New() methods.
327 * @param [in] Layer A pointer to a newly allocated Dali resource
329 explicit DALI_INTERNAL Layer(Internal::Layer* Layer);
337 #endif //__DALI_LAYER_H__