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* ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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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 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.
*
* @param source the 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 operationshas completed.
* ImageReader
implementations are required to call
* this method exactly once from their
* readAll(Iterator)
method.
*
* @param source the 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.
*
* @param source the 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.
*
* @param source the 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.
*
* @param source the 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.
*
* @param source the 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
.
*
* @param source the 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.
*
* @param source the 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.
*
* @param source the ImageReader
object calling this
* method.
*/
void readAborted(ImageReader source);
}