javax.imageio.event.IIOReadUpdateListener |
An interface used by ImageReader
implementations to
notify callers of their image and thumbnail reading methods of
pixel updates.
Public Methods | |||||||||||
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Reports that a given region of the image has been updated.
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Reports that the current read operation has completed a
progressive pass.
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Reports that the current read operation is about to begin a
progressive pass.
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Reports that the current thumbnail read operation has completed
a progressive pass.
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Reports that the current thumbnail read operation is about to
begin a progressive pass.
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Reports that a given region of a thumbnail image has been updated.
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Reports that a given region of the image has been updated. The application might choose to redisplay the specified area, for example, in order to provide a progressive display effect, or perform other incremental processing.
Note that different image format readers may produce decoded pixels in a variety of different orders. Many readers will produce pixels in a simple top-to-bottom, left-to-right-order, but others may use multiple passes of interlacing, tiling, etc. The sequence of updates may even differ from call to call depending on network speeds, for example. A call to this method does not guarantee that all the specified pixels have actually been updated, only that some activity has taken place within some subregion of the one specified.
The particular ImageReader
implementation may
choose how often to provide updates. Each update specifies
that a given region of the image has been updated since the
last update. A region is described by its spatial bounding box
(minX
, minY
, width
, and
height
); X and Y subsampling factors
(periodX
and periodY
); and a set of
updated bands (bands
). For example, the update:
minX = 10 minY = 20 width = 3 height = 4 periodX = 2 periodY = 3 bands = { 1, 3 }would indicate that bands 1 and 3 of the following pixels were updated:
(10, 20) (12, 20) (14, 20) (10, 23) (12, 23) (14, 23) (10, 26) (12, 26) (14, 26) (10, 29) (12, 29) (14, 29)
source | the ImageReader object calling this method. |
---|---|
theImage | the BufferedImage being updated. |
minX | the X coordinate of the leftmost updated column of pixels. |
minY | the Y coordinate of the uppermost updated row of pixels. |
width | the number of updated pixels horizontally. |
height | the number of updated pixels vertically. |
periodX | the horizontal spacing between updated pixels; a value of 1 means no gaps. |
periodY | the vertical spacing between updated pixels; a value of 1 means no gaps. |
bands | an array of int s indicating which
bands are being updated.
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Reports that the current read operation has completed a progressive pass. Readers of formats that support progressive encoding should use this to notify clients when each pass is completed when reading a progressively encoded image.
source | the ImageReader object calling this
method. |
---|---|
theImage | the BufferedImage being updated. |
Reports that the current read operation is about to begin a progressive pass. Readers of formats that support progressive encoding should use this to notify clients when each pass is completed when reading a progressively encoded image.
An estimate of the area that will be updated by the pass is
indicated by the minX
, minY
,
width
, and height
parameters. If the
pass is interlaced, that is, it only updates selected rows or
columns, the periodX
and periodY
parameters will indicate the degree of subsampling. The set of
bands that may be affected is indicated by the value of
bands
.
source | the ImageReader object calling this
method. |
---|---|
theImage | the BufferedImage being updated. |
pass | the numer of the pass that is about to begin, starting with 0. |
minPass | the index of the first pass that will be decoded. |
maxPass | the index of the last pass that will be decoded. |
minX | the X coordinate of the leftmost updated column of pixels. |
minY | the Y coordinate of the uppermost updated row of pixels. |
periodX | the horizontal spacing between updated pixels; a value of 1 means no gaps. |
periodY | the vertical spacing between updated pixels; a value of 1 means no gaps. |
bands | an array of int s indicating the the
set bands that may be updated.
|
Reports that the current thumbnail read operation has completed a progressive pass. Readers of formats that support progressive encoding should use this to notify clients when each pass is completed when reading a progressively encoded thumbnail image.
source | the ImageReader object calling this
method. |
---|---|
theThumbnail | the BufferedImage thumbnail
being updated. |
Reports that the current thumbnail read operation is about to begin a progressive pass. Readers of formats that support progressive encoding should use this to notify clients when each pass is completed when reading a progressively encoded thumbnail image.
source | the ImageReader object calling this
method. |
---|---|
theThumbnail | the BufferedImage thumbnail
being updated. |
pass | the numer of the pass that is about to begin, starting with 0. |
minPass | the index of the first pass that will be decoded. |
maxPass | the index of the last pass that will be decoded. |
minX | the X coordinate of the leftmost updated column of pixels. |
minY | the Y coordinate of the uppermost updated row of pixels. |
periodX | the horizontal spacing between updated pixels; a value of 1 means no gaps. |
periodY | the vertical spacing between updated pixels; a value of 1 means no gaps. |
bands | an array of int s indicating the the
set bands that may be updated. |
Reports that a given region of a thumbnail image has been updated. The application might choose to redisplay the specified area, for example, in order to provide a progressive display effect, or perform other incremental processing.
source | the ImageReader object calling this method. |
---|---|
theThumbnail | the BufferedImage thumbnail
being updated. |
minX | the X coordinate of the leftmost updated column of pixels. |
minY | the Y coordinate of the uppermost updated row of pixels. |
width | the number of updated pixels horizontally. |
height | the number of updated pixels vertically. |
periodX | the horizontal spacing between updated pixels; a value of 1 means no gaps. |
periodY | the vertical spacing between updated pixels; a value of 1 means no gaps. |
bands | an array of int s indicating which
bands are being updated. |