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package javax.imageio.event;

import java.util.EventListener;
import javax.imageio.ImageReader;


An interface used by ImageReader implementations to notify callers of their image and thumbnail reading methods of progress. 
 This interface receives general indications of decoding progress (via the imageProgress and thumbnailProgress methods), and events indicating when an entire image has been updated (via the imageStarted, imageComplete, thumbnailStarted and thumbnailComplete methods). Applications that wish to be informed of pixel updates as they happen (for example, during progressive decoding), should provide an IIOReadUpdateListener. 
See Also:
/**
 * An interface used by {@code ImageReader} implementations to
 * notify callers of their image and thumbnail reading methods of
 * progress.
 *
 * <p> This interface receives general indications of decoding
 * progress (via the {@code imageProgress} and
 * {@code thumbnailProgress} methods), and events indicating when
 * an entire image has been updated (via the
 * {@code imageStarted}, {@code imageComplete},
 * {@code thumbnailStarted} and {@code thumbnailComplete}
 * methods).  Applications that wish to be informed of pixel updates
 * as they happen (for example, during progressive decoding), should
 * provide an {@code IIOReadUpdateListener}.
 *
 * @see IIOReadUpdateListener
 * @see javax.imageio.ImageReader#addIIOReadProgressListener
 * @see javax.imageio.ImageReader#removeIIOReadProgressListener
 *
 */
public interface IIOReadProgressListener extends EventListener {

    
Reports that a sequence of read operations is beginning. ImageReader implementations are required to call this method exactly once from their readAll(Iterator) method. 
Params:
  • source – the ImageReader object calling this method.
  • minIndex – the index of the first image to be read.
/**
     * Reports that a sequence of read operations is beginning.
     * {@code ImageReader} implementations are required to call
     * this method exactly once from their
     * {@code readAll(Iterator)} method.
     *
     * @param source the {@code ImageReader} object calling this method.
     * @param minIndex the index of the first image to be read.
     */
    void sequenceStarted(ImageReader source, int minIndex);

    
Reports that a sequence of read operations has completed. ImageReader implementations are required to call this method exactly once from their readAll(Iterator) method. 
Params:
  • source – the ImageReader object calling this method.
/**
     * Reports that a sequence of read operations has completed.
     * {@code ImageReader} implementations are required to call
     * this method exactly once from their
     * {@code readAll(Iterator)} method.
     *
     * @param source the {@code ImageReader} object calling this method.
     */
    void sequenceComplete(ImageReader source);

    
Reports that an image read operation is beginning. All ImageReader implementations are required to call this method exactly once when beginning an image read operation. 
Params:
  • source – the ImageReader object calling this method.
  • imageIndex – the index of the image being read within its
containing input file or stream.
/**
     * Reports that an image read operation is beginning.  All
     * {@code ImageReader} implementations are required to call
     * this method exactly once when beginning an image read
     * operation.
     *
     * @param source the {@code ImageReader} object calling this method.
     * @param imageIndex the index of the image being read within its
     * containing input file or stream.
     */
    void imageStarted(ImageReader source, int imageIndex);

    
Reports the approximate degree of completion of the current read call of the associated ImageReader. 
 The degree of completion is expressed as a percentage varying from 0.0F to 100.0F. The percentage should ideally be calculated in terms of the remaining time to completion, but it is usually more practical to use a more well-defined metric such as pixels decoded or portion of input stream consumed. In any case, a sequence of calls to this method during a given read operation should supply a monotonically increasing sequence of percentage values. It is not necessary to supply the exact values 0 and 100, as these may be inferred by the callee from other methods. 
 Each particular ImageReader implementation may call this method at whatever frequency it desires. A rule of thumb is to call it around each 5 percent mark. 
Params:
  • source – the ImageReader object calling this method.
  • percentageDone – the approximate percentage of decoding that
has been completed.
/**
     * Reports the approximate degree of completion of the current
     * {@code read} call of the associated
     * {@code ImageReader}.
     *
     * <p> The degree of completion is expressed as a percentage
     * varying from {@code 0.0F} to {@code 100.0F}.  The
     * percentage should ideally be calculated in terms of the
     * remaining time to completion, but it is usually more practical
     * to use a more well-defined metric such as pixels decoded or
     * portion of input stream consumed.  In any case, a sequence of
     * calls to this method during a given read operation should
     * supply a monotonically increasing sequence of percentage
     * values.  It is not necessary to supply the exact values
     * {@code 0} and {@code 100}, as these may be inferred
     * by the callee from other methods.
     *
     * <p> Each particular {@code ImageReader} implementation may
     * call this method at whatever frequency it desires.  A rule of
     * thumb is to call it around each 5 percent mark.
     *
     * @param source the {@code ImageReader} object calling this method.
     * @param percentageDone the approximate percentage of decoding that
     * has been completed.
     */
    void imageProgress(ImageReader source, float percentageDone);

    
Reports that the current image read operation has completed. All ImageReader implementations are required to call this method exactly once upon completion of each image read operation. 
Params:
  • source – the ImageReader object calling this method.
/**
     * Reports that the current image read operation has completed.
     * All {@code ImageReader} implementations are required to
     * call this method exactly once upon completion of each image
     * read operation.
     *
     * @param source the {@code ImageReader} object calling this
     * method.
     */
    void imageComplete(ImageReader source);

    
Reports that a thumbnail read operation is beginning. All ImageReader implementations are required to call this method exactly once when beginning a thumbnail read operation. 
Params:
  • source – the ImageReader object calling this method.
  • imageIndex – the index of the image being read within its
containing input file or stream.
  • thumbnailIndex – the index of the thumbnail being read.
/**
     * Reports that a thumbnail read operation is beginning.  All
     * {@code ImageReader} implementations are required to call
     * this method exactly once when beginning a thumbnail read
     * operation.
     *
     * @param source the {@code ImageReader} object calling this method.
     * @param imageIndex the index of the image being read within its
     * containing input file or stream.
     * @param thumbnailIndex the index of the thumbnail being read.
     */
    void thumbnailStarted(ImageReader source,
                          int imageIndex, int thumbnailIndex);

    
Reports the approximate degree of completion of the current getThumbnail call within the associated ImageReader. The semantics are identical to those of imageProgress. 
Params:
  • source – the ImageReader object calling this method.
  • percentageDone – the approximate percentage of decoding that
has been completed.
/**
     * Reports the approximate degree of completion of the current
     * {@code getThumbnail} call within the associated
     * {@code ImageReader}.  The semantics are identical to those
     * of {@code imageProgress}.
     *
     * @param source the {@code ImageReader} object calling this method.
     * @param percentageDone the approximate percentage of decoding that
     * has been completed.
     */
    void thumbnailProgress(ImageReader source, float percentageDone);

    
Reports that a thumbnail read operation has completed. All ImageReader implementations are required to call this method exactly once upon completion of each thumbnail read operation. 
Params:
  • source – the ImageReader object calling this method.
/**
     * Reports that a thumbnail read operation has completed.  All
     * {@code ImageReader} implementations are required to call
     * this method exactly once upon completion of each thumbnail read
     * operation.
     *
     * @param source the {@code ImageReader} object calling this
     * method.
     */
    void thumbnailComplete(ImageReader source);

    
Reports that a read has been aborted via the reader's abort method. No further notifications will be given. 
Params:
  • source – the ImageReader object calling this method.
/**
     * Reports that a read has been aborted via the reader's
     * {@code abort} method.  No further notifications will be
     * given.
     *
     * @param source the {@code ImageReader} object calling this
     * method.
     */
    void readAborted(ImageReader source);
}