1 #ifndef __DALI_IMAGE_H__
2 #define __DALI_IMAGE_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.
25 #include <dali/public-api/object/base-handle.h>
26 #include <dali/public-api/signals/dali-signal.h>
31 namespace Internal DALI_INTERNAL
37 * @brief An Image object represents an image resource that can be added to ImageActors.
39 * Image objects can be shared between ImageActors. This is practical if you have a visual element on screen
40 * which is repeatedly used. An example would be a button background image.
41 * The image resource is discarded when all ImageActors using the Image object are discarded or in case they
42 * were created with ReleasePolicy::Unused, taken off stage.
43 * Note: if a resource was shared between Image objects it exists until its last reference is gone.
45 * Image objects are responsible for the underlying resource's lifetime.
47 * <i>ReleasePolicies</i>
48 * - Unused: release resource once ImageActor using it is taken off stage.
49 * - Never: keep resource alive until Image object is thrown away.
51 * <i>Resolution of conflicting policies</i>
52 * If the same image is created more than once with conflicting policies, ReleasePolicy "Never" overrides "Unused".
55 * | %Signal Name | Method |
56 * |------------------------|------------------------------|
57 * | uploaded | @ref UploadedSignal() |
59 class DALI_IMPORT_API Image : public BaseHandle
63 * @brief Resource management options.
67 * @brief ReleasePolicy controls the way images are deleted from memory.
71 UNUSED, ///< release resource once image is not in use anymore (eg. all actors using it become offstage). Reload when resource is required again.
72 NEVER ///< keep image data for the lifetime of the object. (default)
76 * @brief Type of signal for Image Uploaded.
78 typedef Signal< void (Image) > ImageSignalType;
83 * @brief Constructor which creates an empty Image handle.
85 * Use Image::New(...) to create an initialised handle.
92 * This is non-virtual since derived Handle types must not contain data or virtual methods.
97 * @brief This copy constructor is required for (smart) pointer semantics.
99 * @param [in] handle A reference to the copied handle
101 Image(const Image& handle);
104 * @brief This assignment operator is required for (smart) pointer semantics.
106 * @param [in] rhs A reference to the copied handle
107 * @return A reference to this
109 Image& operator=(const Image& rhs);
112 * @brief Downcast an Object handle to Image handle.
114 * If handle points to a Image object the
115 * downcast produces valid handle. If not the returned handle is left uninitialized.
116 * @param[in] handle to An object
117 * @return handle to a Image object or an uninitialized handle
119 static Image DownCast( BaseHandle handle );
122 * @brief Return resource release policy.
124 * @return resource release policy
126 ReleasePolicy GetReleasePolicy() const;
129 * @brief Returns the width of the image.
131 * Returns either the requested width or the actual loaded width if no specific size was requested.
133 * @return width of the image in pixels.
135 unsigned int GetWidth() const;
138 * @brief Returns the height of the image.
140 * Returns either the requested height or the actual loaded height if no specific size was requested.
142 * @return height of the image in pixels.
144 unsigned int GetHeight() const;
149 * @brief This signal is emitted when the image data gets uploaded to GL.
151 * It Will be sent after an actor using the image is added to
152 * the stage, when such a staged image is reloaded, or when a staged
153 * BufferImage calls Update().
154 * @return A signal object to Connect() with.
156 ImageSignalType& UploadedSignal();
158 public: // Not intended for application developers
160 explicit DALI_INTERNAL Image(Internal::Image*);
165 #endif // __DALI_IMAGE_H__