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 namespace Internal DALI_INTERNAL
37 * @brief Rectangle describing area on screen that a layer can draw to.
39 * @see Dali::Layer::SetClippingBox()
41 typedef Rect<int> ClippingBox;
44 * @brief Layers provide a mechanism for overlaying groups of actors on top of each other.
46 * When added to the stage, a layer can be ordered relative to other layers. The bottom
47 * layer is at depth zero. The stage provides a default layer for it's children.
49 * Layered actors inherit position etc. as normal, but are drawn in an order determined
50 * by the layers. The depth buffer is cleared before each layer is rendered unless depth
51 * test is disabled or there's no need for it based on the layers contents;
52 * actors in lower layers cannot obscure actors in higher layers.
54 * If depth test is disabled, there is no performance overhead from clearing the depth buffer.
57 * | %Action Name | %Layer method called |
58 * |-----------------|----------------------|
59 * | raise | @ref Raise() |
60 * | lower | @ref Lower() |
61 * | raise-to-top | @ref RaiseToTop() |
62 * | lower-to-bottom | @ref LowerToBottom() |
64 class DALI_IMPORT_API Layer : public Actor
69 * @brief An enumeration of properties belonging to the Layer class.
70 * Properties additional to Actor.
76 CLIPPING_ENABLE = DEFAULT_DERIVED_ACTOR_PROPERTY_START_INDEX, ///< name "clipping-enable", type bool
77 CLIPPING_BOX, ///< name "clipping-box", type Rect<int>
78 BEHAVIOR, ///< name "behavior", type String
83 * @brief Enumeration for the behavior of the layer.
85 * Check each value to see how it affects the layer.
90 * @brief Layer doesn't make use of the depth test.
92 * This mode is expected to have better performance than the 3D mode.
93 * When using this mode any ordering would be with respect to depth-index property of Renderers.
98 * @brief Layer will use depth test and do several clears.
100 * When using this mode depth depth test will be used. A depth clear will happen for each distinct
101 * depth-index value in the layer, opaque renderers are drawn first and write to the depth buffer.
102 * Then transparent renderers are drawn with depth test enabled but depth write switched off.
108 * @brief The sort function type.
110 * @param[in] position this is the actor translation from camera.
112 typedef float (*SortFunctionType)( const Vector3& position );
115 * @brief Create an empty Layer handle.
117 * This can be initialised with Layer::New(...)
122 * @brief Create a Layer object.
124 * @return A handle to a newly allocated Layer
129 * @brief Downcast an Object handle to Layer.
131 * If handle points to a Layer the downcast produces valid
132 * handle. If not the returned handle is left uninitialized.
133 * @param[in] handle to An object
134 * @return handle to a Layer or an uninitialized handle
136 static Layer DownCast( BaseHandle handle );
141 * This is non-virtual since derived Handle types must not contain data or virtual methods.
146 * @brief Copy constructor
148 * @param [in] copy The actor to copy.
150 Layer(const Layer& copy);
153 * @brief Assignment operator
155 * @param [in] rhs The actor to copy.
157 Layer& operator=(const Layer& rhs);
160 * @brief Query the depth of the layer
162 * 0 is bottom most layer, higher number is on top
163 * @pre layer is on the stage
164 * If layer is not added to the stage, returns 0.
165 * @return the current depth of the layer.
167 unsigned int GetDepth() const;
170 * @brief Increment the depth of the layer.
172 * @pre layer is on the stage
177 * @brief Decrement the depth of the layer.
179 * @pre layer is on the stage
184 * @brief Ensures the layers depth is greater than the target layer.
186 * If the layer already is above target layer its depth is not changed
187 * If the layer was below target, its new depth will be immediately above target
188 * Note! All layers between this layer and target get new depth values
189 * @pre layer is on the stage
190 * @pre target layer is on the stage
191 * @param target layer to get above of
193 void RaiseAbove( Layer target );
196 * @brief Ensures the layers depth is less than the target layer.
198 * If the layer already is below the layer its depth is not changed
199 * If the layer was above target, its new depth will be immediately below target
200 * Note! All layers between this layer and target get new depth values
201 * @pre layer is on the stage
202 * @pre target layer is on the stage
203 * @param target layer to get below of
205 void LowerBelow( Layer target );
208 * @brief Raises the layer to the top.
209 * @pre layer is on the stage
214 * @brief Lowers the layer to the bottom.
215 * @pre layer is on the stage
217 void LowerToBottom();
220 * @brief Moves the layer directly above the given layer.
222 * After the call this layers depth will be immediately above target
223 * Note! All layers between this layer and target get new depth values
224 * @pre layer is on the stage
225 * @pre target layer is on the stage
226 * @param target layer to get on top of
228 void MoveAbove( Layer target );
231 * @brief Moves the layer directly below the given layer.
233 * After the call this layers depth will be immediately below target
234 * Note! All layers between this layer and target get new depth values
235 * @pre layer is on the stage
236 * @pre target layer is on the stage
237 * @param target layer to get below of
239 void MoveBelow( Layer target );
242 * @brief Set the behavior of the layer
244 * @param[in] behavior The desired behavior
246 void SetBehavior( Behavior behavior );
249 * @brief Get the behavior of the layer
251 * @return The behavior of the layer
253 Behavior GetBehavior() const;
256 * @brief Sets whether clipping is enabled for a layer.
258 * Clipping is initially disabled; see also SetClippingBox().
259 * @param [in] enabled True if clipping is enabled.
261 * @note When clipping is enabled, the default clipping box is empty (0,0,0,0) which means everything is clipped.
263 void SetClipping(bool enabled);
266 * @brief Query whether clipping is enabled for a layer.
267 * @return True if clipping is enabled.
269 bool IsClipping() const;
272 * @brief Sets the clipping box of a layer, in window coordinates.
274 * The contents of the layer will not be visible outside this box, when clipping is
275 * enabled. The default clipping box is empty (0,0,0,0) which means everything is clipped.
276 * You can only do rectangular clipping using this API in window coordinates.
277 * For other kinds of clipping, @see Dali::Actor::SetDrawMode().
278 * @param [in] x The X-coordinate of the top-left corner of the box.
279 * @param [in] y The Y-coordinate of the top-left corner of the box.
280 * @param [in] width The width of the box.
281 * @param [in] height The height of the box.
283 void SetClippingBox(int x, int y, int width, int height);
286 * @brief Sets the clipping box of a layer, in window coordinates.
288 * The contents of the layer will not be visible outside this box, when clipping is
289 * enabled. The default clipping box is empty (0,0,0,0).
290 * @param [in] box The clipping box
292 void SetClippingBox(ClippingBox box);
295 * @brief Retrieves the clipping box of a layer, in window coordinates.
297 * @return The clipping box
299 ClippingBox GetClippingBox() const;
304 * @brief Whether to disable the depth test.
306 * 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.
307 * However, it's possible to disable the depth test by calling this method.
309 * @param[in] disable \e true disables depth test. \e false sets the default behavior.
311 void SetDepthTestDisabled( bool disable );
314 * @brief Retrieves whether depth test is disabled.
316 * @return \e true if depth test is disabled.
318 bool IsDepthTestDisabled() const;
323 * @brief This allows the user to specify the sort function that the layer should use.
325 * The sort function is used to determine the order in which the actors are drawn
326 * and input is processed on the actors in the layer.
328 * A function of the following type should be used:
330 * float YourSortFunction(const Vector3& position);
333 * @note If the sort function returns a low number, the actor the data applies to will be
334 * drawn in front of an actor whose data yields a high value from the sort function.
336 * @note All child layers use the same sort function. If a child layer is added to this
337 * layer then the sort function used by the child layer will also be the same.
339 * @param[in] function The sort function pointer
341 void SetSortFunction( SortFunctionType function );
344 * @brief This allows the user to specify whether this layer should consume touch (including gestures).
346 * If set, any layers behind this layer will not be hit-test.
348 * @param[in] consume Whether the layer should consume touch (including gestures).
350 void SetTouchConsumed( bool consume );
353 * @brief Retrieves whether the layer consumes touch (including gestures).
355 * @return true if consuming touch, false otherwise.
357 bool IsTouchConsumed() const;
360 * @brief This allows the user to specify whether this layer should consume hover.
362 * If set, any layers behind this layer will not be hit-test.
364 * @param[in] consume Whether the layer should consume hover.
366 void SetHoverConsumed( bool consume );
369 * @brief Retrieves whether the layer consumes hover.
371 * @return true if consuming hover, false otherwise.
373 bool IsHoverConsumed() const;
375 public: // Not intended for application developers
378 * @brief This constructor is used by Dali New() methods.
380 * @param [in] Layer A pointer to a newly allocated Dali resource
382 explicit DALI_INTERNAL Layer(Internal::Layer* Layer);
387 #endif //__DALI_LAYER_H__