Class PreloaderImageIO

java.lang.Object
org.apache.xmlgraphics.image.loader.impl.AbstractImagePreloader
org.apache.xmlgraphics.image.loader.impl.imageio.PreloaderImageIO
All Implemented Interfaces:
ImagePreloader

public class PreloaderImageIO extends AbstractImagePreloader
Image preloader for images supported by ImageIO.

Note: The implementation relies on the presence of a working ImageIO implementation which provides accurate image metadata. This is particularly important for PNG image because the PNG loader relies on that.

  • Constructor Details

    • PreloaderImageIO

      public PreloaderImageIO()
  • Method Details

    • preloadImage

      public ImageInfo preloadImage(String uri, Source src, ImageContext context) throws IOException, ImageException
      "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:
      uri - 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
      IOException - if an I/O error occurs while preloading the image
    • getPriority

      public int getPriority()
      Returns the priority of the preloader. The lower the value, the higher the preloader's priority.
      Specified by:
      getPriority in interface ImagePreloader
      Overrides:
      getPriority in class AbstractImagePreloader
      Returns:
      an integer (default is 1000)