Class ImageManager


  • public class ImageManager
    extends java.lang.Object
    ImageManager is the central starting point for image access.
    • Field Detail

      • log

        protected static final org.apache.commons.logging.Log log
        logger
    • Constructor Detail

      • ImageManager

        public ImageManager​(ImageContext context)
        Main constructor.
        Parameters:
        context - the session-independent context information
      • ImageManager

        public ImageManager​(ImageImplRegistry registry,
                            ImageContext context)
        Constructor for testing purposes.
        Parameters:
        registry - the implementation registry with all plug-ins
        context - the session-independent context information
    • Method Detail

      • getRegistry

        public ImageImplRegistry getRegistry()
        Returns the ImageImplRegistry in use by the ImageManager.
        Returns:
        the ImageImplRegistry
      • getImageContext

        public ImageContext getImageContext()
        Returns the ImageContext in use by the ImageManager.
        Returns:
        the ImageContext
      • getCache

        public ImageCache getCache()
        Returns the ImageCache in use by the ImageManager.
        Returns:
        the ImageCache
      • getPipelineFactory

        public PipelineFactory getPipelineFactory()
        Returns the PipelineFactory in use by the ImageManager.
        Returns:
        the PipelineFactory
      • getImageInfo

        public ImageInfo getImageInfo​(java.lang.String uri,
                                      ImageSessionContext session)
                               throws ImageException,
                                      java.io.IOException
        Returns an ImageInfo object containing its intrinsic size for a given URI. The ImageInfo is retrieved from an image cache if it has been requested before.
        Parameters:
        uri - the URI of the image
        session - the session context through which to resolve the URI if the image is not in the cache
        Returns:
        the ImageInfo object created from the image
        Throws:
        ImageException - If no suitable ImagePreloader can be found to load the image or if an error occurred while preloading the image.
        java.io.IOException - If an I/O error occurs while preloading the image
      • preloadImage

        public ImageInfo preloadImage​(java.lang.String uri,
                                      ImageSessionContext session)
                               throws ImageException,
                                      java.io.IOException
        Preloads an image, i.e. the format of the image is identified and some basic information (MIME type, intrinsic size and possibly other values) are loaded and returned as an ImageInfo object. Note that the image is not fully loaded normally. Only with certain formats the image is already fully loaded and references added to the ImageInfo's custom objects (see ImageInfo.getOriginalImage()).

        The reason for the preloading: Apache FOP, for example, only needs the image's intrinsic size during layout. Only when the document is rendered to the final format does FOP need to load the full image. Like this a lot of memory can be saved.

        Parameters:
        uri - the original URI of the image
        session - the session context through which to resolve the URI
        Returns:
        the ImageInfo object created from the image
        Throws:
        ImageException - If no suitable ImagePreloader can be found to load the image or if an error occurred while preloading the image.
        java.io.IOException - If an I/O error occurs while preloading the image
      • preloadImage

        public ImageInfo preloadImage​(java.lang.String uri,
                                      javax.xml.transform.Source src)
                               throws ImageException,
                                      java.io.IOException
        Preloads an image, i.e. the format of the image is identified and some basic information (MIME type, intrinsic size and possibly other values) are loaded and returned as an ImageInfo object. Note that the image is not fully loaded normally. Only with certain formats the image is already fully loaded and references added to the ImageInfo's custom objects (see ImageInfo.getOriginalImage()).

        The reason for the preloading: Apache FOP, for example, only needs the image's intrinsic size during layout. Only when the document is rendered to the final format does FOP need to load the full image. Like this a lot of memory can be saved.

        Parameters:
        uri - the original URI of the image
        src - the Source object to load the image from
        Returns:
        the ImageInfo object created from the image
        Throws:
        ImageException - If no suitable ImagePreloader can be found to load the image or if an error occurred while preloading the image.
        java.io.IOException - If an I/O error occurs while preloading the image
      • getImage

        public Image getImage​(ImageInfo info,
                              ImageFlavor flavor,
                              java.util.Map hints,
                              ImageSessionContext session)
                       throws ImageException,
                              java.io.IOException
        Loads an image. The caller can indicate what kind of image flavor is requested. When this method is called the code looks for a suitable ImageLoader and, if necessary, builds a conversion pipeline so it can return the image in exactly the form the caller needs.

        Optionally, it is possible to pass in Map of hints. These hints may be used by ImageLoaders and ImageConverters to act on the image. See ImageProcessingHints for common hints used by the bundled implementations. You can, of course, define your own hints.

        Parameters:
        info - the ImageInfo instance for the image (obtained by getImageInfo(String, ImageSessionContext))
        flavor - the requested image flavor.
        hints - a Map of hints to any of the background components or null
        session - the session context
        Returns:
        the fully loaded image
        Throws:
        ImageException - If no suitable loader/converter combination is available to fulfill the request or if an error occurred while loading the image.
        java.io.IOException - If an I/O error occurs
      • getImage

        public Image getImage​(ImageInfo info,
                              ImageFlavor[] flavors,
                              java.util.Map hints,
                              ImageSessionContext session)
                       throws ImageException,
                              java.io.IOException
        Loads an image. The caller can indicate what kind of image flavors are requested. When this method is called the code looks for a suitable ImageLoader and, if necessary, builds a conversion pipeline so it can return the image in exactly the form the caller needs. The array of image flavors is ordered, so the first image flavor is given highest priority.

        Optionally, it is possible to pass in Map of hints. These hints may be used by ImageLoaders and ImageConverters to act on the image. See ImageProcessingHints for common hints used by the bundled implementations. You can, of course, define your own hints.

        Parameters:
        info - the ImageInfo instance for the image (obtained by getImageInfo(String, ImageSessionContext))
        flavors - the requested image flavors (in preferred order).
        hints - a Map of hints to any of the background components or null
        session - the session context
        Returns:
        the fully loaded image
        Throws:
        ImageException - If no suitable loader/converter combination is available to fulfill the request or if an error occurred while loading the image.
        java.io.IOException - If an I/O error occurs
      • closeImage

        public void closeImage​(java.lang.String uri,
                               ImageSessionContext session)
        Closes the resources associated to the given image. This method should be used only when none of the getImage methods is called by the client application.
        Parameters:
        uri - the URI of the image
        session - the session context that was used to resolve the URI
      • convertImage

        public Image convertImage​(Image image,
                                  ImageFlavor[] flavors,
                                  java.util.Map hints)
                           throws ImageException,
                                  java.io.IOException
        Converts an image. The caller can indicate what kind of image flavors are requested. When this method is called the code looks for a suitable combination of ImageConverters so it can return the image in exactly the form the caller needs. The array of image flavors is ordered, so the first image flavor is given highest priority.

        Optionally, it is possible to pass in Map of hints. These hints may be used by ImageConverters to act on the image. See ImageProcessingHints for common hints used by the bundled implementations. You can, of course, define your own hints.

        Parameters:
        image - the image to convert
        flavors - the requested image flavors (in preferred order).
        hints - a Map of hints to any of the background components or null
        Returns:
        the fully loaded image
        Throws:
        ImageException - If no suitable loader/converter combination is available to fulfill the request or if an error occurred while loading the image.
        java.io.IOException - If an I/O error occurs
      • convertImage

        public Image convertImage​(Image image,
                                  ImageFlavor[] flavors)
                           throws ImageException,
                                  java.io.IOException
        Converts an image with no hints. See convertImage(Image, ImageFlavor[], Map) for more information.
        Parameters:
        image - the image to convert
        flavors - the requested image flavors (in preferred order).
        Returns:
        the fully loaded image
        Throws:
        ImageException - If no suitable loader/converter combination is available to fulfill the request or if an error occurred while loading the image.
        java.io.IOException - If an I/O error occurs