Interface IIOReadProgressListener
- All Superinterfaces:
EventListener
public interface IIOReadProgressListener extends EventListener
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:
-
IIOReadUpdateListener
,ImageReader.addIIOReadProgressListener(javax.imageio.event.IIOReadProgressListener)
,ImageReader.removeIIOReadProgressListener(javax.imageio.event.IIOReadProgressListener)
Method Summary
Modifier and Type | Method | Description |
---|---|---|
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 |
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 |
void | sequenceComplete(ImageReader source) | Reports that a sequence of read operations has completed. |
void | sequenceStarted(ImageReader source,
int minIndex) | Reports that a sequence of read operations is beginning. |
void | thumbnailComplete(ImageReader source) | Reports that a thumbnail read operation has completed. |
void | thumbnailProgress(ImageReader source,
float percentageDone) | Reports the approximate degree of completion of the current |
void | thumbnailStarted(ImageReader source,
int imageIndex,
int thumbnailIndex) | Reports that a thumbnail read operation is beginning. |
Method Detail
sequenceStarted
void sequenceStarted(ImageReader source, int minIndex)
Reports that a sequence of read operations is beginning. ImageReader
implementations are required to call this method exactly once from their readAll(Iterator)
method.
- Parameters:
-
source
- theImageReader
object calling this method. -
minIndex
- the index of the first image to be read.
sequenceComplete
void sequenceComplete(ImageReader source)
Reports that a sequence of read operations has completed. ImageReader
implementations are required to call this method exactly once from their readAll(Iterator)
method.
- Parameters:
-
source
- theImageReader
object calling this method.
imageStarted
void imageStarted(ImageReader source, int imageIndex)
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.
- Parameters:
-
source
- theImageReader
object calling this method. -
imageIndex
- the index of the image being read within its containing input file or stream.
imageProgress
void imageProgress(ImageReader source, float percentageDone)
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.
- Parameters:
-
source
- theImageReader
object calling this method. -
percentageDone
- the approximate percentage of decoding that has been completed.
imageComplete
void imageComplete(ImageReader source)
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.
- Parameters:
-
source
- theImageReader
object calling this method.
thumbnailStarted
void thumbnailStarted(ImageReader source, int imageIndex, int thumbnailIndex)
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.
- Parameters:
-
source
- theImageReader
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.
thumbnailProgress
void thumbnailProgress(ImageReader source, float percentageDone)
Reports the approximate degree of completion of the current getThumbnail
call within the associated ImageReader
. The semantics are identical to those of imageProgress
.
- Parameters:
-
source
- theImageReader
object calling this method. -
percentageDone
- the approximate percentage of decoding that has been completed.
thumbnailComplete
void thumbnailComplete(ImageReader source)
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.
- Parameters:
-
source
- theImageReader
object calling this method.
readAborted
void readAborted(ImageReader source)
Reports that a read has been aborted via the reader's abort
method. No further notifications will be given.
- Parameters:
-
source
- theImageReader
object calling this method.