ImagePreloader
Date: 2016-04-28

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

    Fields
    Modifier and Type | Field and Description
    --- | ---
    `static int` | `DEFAULT_PRIORITY` Default priority for preloaders

  - ### Method Summary

    Methods
    Modifier and Type | Method and Description
    --- | ---
    `int` | `getPriority()` Returns the priority of the preloader.
    `ImageInfo` | `preloadImage(java.lang.String originalURI, javax.xml.transform.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(java.lang.String originalURI,
                               javax.xml.transform.Source src,
                               ImageContext context)
                                 throws ImageException,
                                        java.io.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
        `java.io.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)