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An interface used by ImageReader
implementations to
notify callers of their image reading methods of progress.
This interface receives general indications of decoding
progress (via the imageProgress
,
and events indicating when
an entire image has been updated (via the
imageStarted
, imageComplete
methods). Applications that wish to be informed of pixel updates
as they happen (for example, during progressive decoding), should
provide an IIOReadUpdateListener
.
IIOReadUpdateListener
,
ImageReader.addIIOReadProgressListener(javax.imageio.event.IIOReadProgressListener)
,
ImageReader.removeIIOReadProgressListener(javax.imageio.event.IIOReadProgressListener)
Method Summary | |
void |
imageComplete(ImageReader source)
Reports that the current image read operation has completed. |
void |
imageProgress(ImageReader source,
float percentageDone)
Reports the approximate degree of completion of the current read call of the associated
ImageReader . |
void |
imageStarted(ImageReader source,
int imageIndex)
Reports that an image read operation is beginning. |
void |
readAborted(ImageReader source)
Reports that a read has been aborted via the reader's abort method. |
void |
sequenceComplete(ImageReader source)
Reports that a sequence of read operationshas completed. |
void |
sequenceStarted(ImageReader source,
int minIndex)
Reports that a sequence of read operations is beginning. |
Method Detail |
public void sequenceStarted(ImageReader source, int minIndex)
ImageReader
implementations are required to call
this method exactly once from their
readAll(Iterator)
method.
source
- the ImageReader
object calling this method.minIndex
- the index of the first image to be read.public void sequenceComplete(ImageReader source)
ImageReader
implementations are required to call
this method exactly once from their
readAll(Iterator)
method.
source
- the ImageReader
object calling this method.public void imageStarted(ImageReader source, int imageIndex)
ImageReader
implementations are required to call
this method exactly once when beginning an image read
operation.
source
- the ImageReader
object calling this method.imageIndex
- the index of the image being read within its
containing input file or stream.public void imageProgress(ImageReader source, float percentageDone)
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.
source
- the ImageReader
object calling this method.percentageDone
- the approximate percentage of decoding that
has been completed.public void imageComplete(ImageReader source)
ImageReader
implementations are required to
call this method exactly once upon completion of each image
read operation.
source
- the ImageReader
object calling this
method.public void readAborted(ImageReader source)
abort
method. No further notifications will be
given.
source
- the ImageReader
object calling this
method.
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