org.apache.xmlgraphics.image.loader.spi
Interface ImagePreloader

All Known Implementing Classes:

AbstractImagePreloader, PreloaderBMP, PreloaderEMF, PreloaderEPS, PreloaderGIF, PreloaderImageIO, PreloaderJPEG, PreloaderRawPNG, PreloaderTIFF

public interface ImagePreloader

This interface provides two functions: determining whether an image format is supported and if that's the case, some minimal information (mostly the image's intrinsic size) is extracted and returned.

Field Summary

static int

DEFAULT_PRIORITY Default priority for preloaders

Method Summary

int	getPriority() Returns the priority of the preloader.
ImageInfo	preloadImage(String originalURI, Source src, ImageContext context) "Preloads" an image, i.e.

Field Detail

DEFAULT_PRIORITY

static final int DEFAULT_PRIORITY

Default priority for preloaders

See Also:

Constant Field Values

Method Detail

preloadImage

ImageInfo preloadImage(String originalURI,
                       Source src,
                       ImageContext context)
                       throws ImageException,
                              IOException

"Preloads" an image, i.e. indentifies whether the source image is supported by this implementation and determines the image's intrinsic size and possibly some additional information. The image is usually not fully loaded at this time to conserve memory. The method returns null if the image was not identified. An ImageException is only thrown if the image is identified but some error has happened while working on the file.

Parameters:

originalURI - the original (unresolved) URI of the image

src - a image source the image is loaded from

context - the context object that provides configuration information

Returns:

an image info object with the basic information about an image or null if the image is not supported by this implementation

Throws:

ImageException - if an error occurs while preloading the image

IOException - if an I/O error occurs while preloading the image

getPriority

int getPriority()

Returns the priority of the preloader. The lower the value, the higher the preloader's priority.

Returns:

an integer (default is 1000)