#include <string>
// INTERNAL INCLUDES
-#include <dali/public-api/common/loading-state.h>
-#include <dali/public-api/images/pixel.h>
#include <dali/public-api/object/base-handle.h>
#include <dali/public-api/signals/dali-signal.h>
namespace Dali
{
-struct Vector2;
namespace Internal DALI_INTERNAL
{
}
class NativeImage;
-class ImageAttributes;
-
/**
* @brief An Image object represents an image resource that can be added to ImageActors.
*
- * Image objects can also handle custom requests for image loading and are responsible for
- * the underlying resource's lifetime.
- *
- * <h3>Image Loading</h3>
- *
- * When the Image object is created, resource loading will be attempted unless
- * the Image object is created with OnDemand loading policy or a compatible resource is found in cache.
- * In case of loading images on demand, resource loading will only be attempted if the associated ImageActor
- * is put on Stage.
- * Custom loading requests can be made by providing an ImageAttributes object to Image::New().
+ * Image objects can be shared between ImageActors. This is practical if you have a visual element on screen
+ * which is repeatedly used. An example would be a button background image.
+ * The image resource is discarded when all ImageActors using the Image object are discarded or in case they
+ * were created with ReleasePolicy::Unused, taken off stage.
+ * Note: if a resource was shared between Image objects it exists until its last reference is gone.
*
- * <i>LoadPolicies</i>
- * - Immediate: acquire image resource when creating Image object.
- * - OnDemand: only load in case the associated ImageActor is put on Stage
+ * Image objects are responsible for the underlying resource's lifetime.
*
* <i>ReleasePolicies</i>
* - Unused: release resource once ImageActor using it is taken off stage.
* - Never: keep resource alive until Image object is thrown away.
*
* <i>Resolution of conflicting policies</i>
- * If the same image is created more than once with conflicting policies, LoadPolicy "Immediate" overrides "OnDemand"
- * and ReleasePolicy "Never" overrides "Unused".
- *
- * <i>Custom load requests</i>
- * Size, scaling mode, orientation compensation can be set when requesting an image resource.
- * See ImageAttributes for more details.
- *
- * <i>Compatible resources</i>
- *
- * Before loading a new image the internal image resource cache is checked by dali.
- * If there is an Image already loaded in memory and is deemed "compatible" with the requested Image,
- * that resource is reused.
- * This happens for example if a loaded image exists with the same filename, and the difference between both
- * of the dimensions is less than 50%.
- *
- * <i>Reloading Images</i>
- *
- * The same request used on creating the Image is re-issued when reloading Images.
- * If the file changed since the last load operation, this might result in a different resource.
- * Reload only takes effect if both of these conditions apply:
- * - The Image has already finished loading
- * - The Image is either on Stage or using Immediate load policy
- *
- * <h3>Image resource lifetime</h3>
- *
- * Image objects can be shared between ImageActors. This is practical if you have a visual element on screen
- * which is repeatedly used. An example would be a button background image.
- * The image resource is discarded when all ImageActors using the Image object are discarded or in case they
- * were created with ReleasePolicy::Unused, taken off stage.
- * Note: if a resource was shared between Image objects it exists until its last reference is gone.
+ * If the same image is created more than once with conflicting policies, ReleasePolicy "Never" overrides "Unused".
*
*/
class DALI_IMPORT_API Image : public BaseHandle
*/
/**
- * @brief LoadPolicy controls the way images are loaded into memory.
- */
- enum LoadPolicy
- {
- Immediate, ///< load image once it is created (default)
- OnDemand ///< delay loading until the image is being used (a related actor is added to Stage)
- };
-
- /**
* @brief ReleasePolicy controls the way images are deleted from memory.
*/
enum ReleasePolicy
{
- Unused, ///< release resource once image is not in use anymore (eg. all actors using it become offstage). Reload when resource is required again.
- Never ///< keep image data for the lifetime of the object. (default)
+ UNUSED, ///< release resource once image is not in use anymore (eg. all actors using it become offstage). Reload when resource is required again.
+ NEVER ///< keep image data for the lifetime of the object. (default)
};
/**
typedef Signal< void (Image) > ImageSignalType;
// Signal Names
- static const char* const SIGNAL_IMAGE_LOADING_FINISHED; ///< Name of LoadingFinished signal
static const char* const SIGNAL_IMAGE_UPLOADED; ///< Name of Uploaded signal
public:
/**
- * @brief Get the size of an image from disk.
- *
- * This function will read the header info from file on disk and is
- * synchronous, so it should not be used repeatedly or in tight
- * loops.
- *
- * @param [in] filename of the image file to use.
- * @return The width and height in pixels of the image.
- */
- static Vector2 GetImageSize(const std::string filename);
-
- /**
- * @brief Constructor which creates an empty Image object.
+ * @brief Constructor which creates an empty Image handle.
*
- * Use Image::New(...) to create an initialised object.
+ * Use Image::New(...) to create an initialised handle.
*/
Image();
Image& operator=(const Image& rhs);
/**
- * @brief Create an initialised image object.
- *
- * @param [in] filename The filename of the image file to use.
- * @return A handle to a newly allocated object
- */
- static Image New(const std::string& filename);
-
- /**
- * @brief Create an initialised image object.
- *
- * @param [in] filename The filename of the image file to use.
- * @param [in] loadPol The LoadPolicy to apply when loading the image resource.
- * @param [in] releasePol The ReleasePolicy to apply to Image.
- * @return A handle to a newly allocated object
- */
- static Image New(const std::string& filename, LoadPolicy loadPol, ReleasePolicy releasePol);
-
- /**
- * @brief Create an initialised image object.
- *
- * @param [in] filename The filename of the image file to use.
- * @param [in] attributes Requested parameters for loading (size, scaling etc.).
- * @return A handle to a newly allocated object
- */
- static Image New(const std::string& filename, const ImageAttributes& attributes);
-
- /**
- * @brief Create an initialised image object.
- *
- * @param [in] filename The filename of the image file to use.
- * @param [in] attributes Requested parameters for loading (size, scaling etc.).
- * @param [in] loadPol The LoadPolicy to apply when loading the image resource.
- * @param [in] releasePol The ReleasePolicy to apply to Image.
- * @return A handle to a newly allocated object
- */
- static Image New(const std::string& filename, const ImageAttributes& attributes, LoadPolicy loadPol, ReleasePolicy releasePol);
-
- /**
- * @brief Create an initialised image object.
- *
- * @param [in] filename The filename of the image file to use.
- * @return A handle to a newly allocated object
- */
- static Image NewDistanceField(const std::string& filename);
-
- /**
- * @brief Create an initialised image object.
- *
- * @param [in] filename The filename of the image file to use.
- * @param [in] loadPol The LoadPolicy to apply when loading the image resource.
- * @param [in] releasePol The ReleasePolicy to apply to Image.
- * @return A handle to a newly allocated object
- */
- static Image NewDistanceField(const std::string& filename, LoadPolicy loadPol, ReleasePolicy releasePol);
-
- /**
- * @brief Create an initialised image object.
- *
- * @param [in] filename The filename of the image file to use.
- * @param [in] attributes The minimum search radius to check for differing pixels
- * @return A handle to a newly allocated object
- */
- static Image NewDistanceField(const std::string& filename, const ImageAttributes& attributes );
-
- /**
- * @brief Create an initialised image object.
- *
- * @param [in] filename The filename of the image file to use.
- * @param [in] attributes The minimum search radius to check for differing pixels
- * @param [in] loadPol The LoadPolicy to apply when loading the image resource.
- * @param [in] releasePol The ReleasePolicy to apply to Image.
- * @return A handle to a newly allocated object
- */
- static Image NewDistanceField(const std::string& filename, const ImageAttributes& attributes, LoadPolicy loadPol, ReleasePolicy releasePol);
-
- /**
* @brief Creates object with already loaded NativeImage.
*
* The maximum size of the image is limited by GL_MAX_TEXTURE_SIZE
static Image DownCast( BaseHandle handle );
/**
- * @brief Query whether the image data has loaded.
- *
- * The asynchronous loading begins when the Image object is created.
- * After the Image object is discarded, the image data will be released from memory.
- * @return The loading state, either Loading, Success or Failed.
- */
- LoadingState GetLoadingState() const;
-
- /**
- * @brief Returns the filename of the image if the image is created from a file.
- *
- * @return the image filename or empty string
- */
- std::string GetFilename() const;
-
- /**
- * @brief Return load policy.
- *
- * @return resource load policy
- */
- LoadPolicy GetLoadPolicy () const;
-
- /**
* @brief Return resource release policy.
*
* @return resource release policy
*/
- ReleasePolicy GetReleasePolicy () const;
-
- /**
- * @brief Reload image from filesystem.
- *
- * The set ImageAttributes are used when requesting the image again.
- * @note if Image is offstage and OnDemand policy is set, reload request is ignored.
- */
- void Reload();
+ ReleasePolicy GetReleasePolicy() const;
/**
* @brief Returns the width of the image.
*/
unsigned int GetHeight() const;
- /**
- * @brief Get the attributes of an image.
- *
- * Only to be used after the image has finished loading.
- * (Ticket's LoadingSucceeded callback was called)
- * The returned value will reflect the true image dimensions once the asynchronous loading has finished.
- * Connect to SignalLoadingFinished or use GetLoadingState to make sure this value is actual.
- * @pre image should be loaded
- * @return a copy of the attributes
- */
- ImageAttributes GetAttributes() const;
-
public: // Signals
/**
- * @brief Emitted when the image data loads successfully, or when the loading fails.
- *
- * @return A signal object to Connect() with.
- */
- ImageSignalType& LoadingFinishedSignal();
-
- /**
* @brief This signal is emitted when the image data gets uploaded to GL.
*
* It Will be sent after an actor using the image is added to
projects / platform / core / uifw / dali-core.git / blobdiff