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package javax.imageio.event;

import java.awt.image.BufferedImage;
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
pixel updates.

See Also:
/**
 * An interface used by <code>ImageReader</code> implementations to
 * notify callers of their image and thumbnail reading methods of
 * pixel updates.
 *
 * @see javax.imageio.ImageReader#addIIOReadUpdateListener
 * @see javax.imageio.ImageReader#removeIIOReadUpdateListener
 *
 */
public interface IIOReadUpdateListener extends EventListener {

    
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.

Params:
  • source – the ImageReader object calling this
method.
  • theImage – the BufferedImage being updated.
  • pass – the number 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 ints indicating the the
set bands that may be 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.
     *
     * <p> An estimate of the area that will be updated by the pass is
     * indicated by the <code>minX</code>, <code>minY</code>,
     * <code>width</code>, and <code>height</code> parameters.  If the
     * pass is interlaced, that is, it only updates selected rows or
     * columns, the <code>periodX</code> and <code>periodY</code>
     * parameters will indicate the degree of subsampling.  The set of
     * bands that may be affected is indicated by the value of
     * <code>bands</code>.
     *
     * @param source the <code>ImageReader</code> object calling this
     * method.
     * @param theImage the <code>BufferedImage</code> being updated.
     * @param pass the number of the pass that is about to begin,
     * starting with 0.
     * @param minPass the index of the first pass that will be decoded.
     * @param maxPass the index of the last pass that will be decoded.
     * @param minX the X coordinate of the leftmost updated column
     * of pixels.
     * @param minY the Y coordinate of the uppermost updated row
     * of pixels.
     * @param periodX the horizontal spacing between updated pixels;
     * a value of 1 means no gaps.
     * @param periodY the vertical spacing between updated pixels;
     * a value of 1 means no gaps.
     * @param bands an array of <code>int</code>s indicating the the
     * set bands that may be updated.
     */
    void passStarted(ImageReader source,
                     BufferedImage theImage,
                     int pass,
                     int minPass, int maxPass,
                     int minX, int minY,
                     int periodX, int periodY,
                     int[] bands);

    
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)



Params:
  • 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 ints indicating which
bands are being updated.
/**
     * 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.
     *
     * <p> 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.
     *
     * <p> The particular <code>ImageReader</code> 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
     * (<code>minX</code>, <code>minY</code>, <code>width</code>, and
     * <code>height</code>); X and Y subsampling factors
     * (<code>periodX</code> and <code>periodY</code>); and a set of
     * updated bands (<code>bands</code>).  For example, the update:
     *
     * <pre>
     * minX = 10
     * minY = 20
     * width = 3
     * height = 4
     * periodX = 2
     * periodY = 3
     * bands = { 1, 3 }
     * </pre>
     *
     * would indicate that bands 1 and 3 of the following pixels were
     * updated:
     *
     * <pre>
     * (10, 20) (12, 20) (14, 20)
     * (10, 23) (12, 23) (14, 23)
     * (10, 26) (12, 26) (14, 26)
     * (10, 29) (12, 29) (14, 29)
     * </pre>
     *
     * @param source the <code>ImageReader</code> object calling this method.
     * @param theImage the <code>BufferedImage</code> being updated.
     * @param minX the X coordinate of the leftmost updated column
     * of pixels.
     * @param minY the Y coordinate of the uppermost updated row
     * of pixels.
     * @param width the number of updated pixels horizontally.
     * @param height the number of updated pixels vertically.
     * @param periodX the horizontal spacing between updated pixels;
     * a value of 1 means no gaps.
     * @param periodY the vertical spacing between updated pixels;
     * a value of 1 means no gaps.
     * @param bands an array of <code>int</code>s indicating which
     * bands are being updated.
     */
    void imageUpdate(ImageReader source,
                     BufferedImage theImage,
                     int minX, int minY,
                     int width, int height,
                     int periodX, int periodY,
                     int[] bands);

    
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.

Params:
  • source – the ImageReader object calling this
method.
  • theImage – the BufferedImage being updated.
See Also:
/**
     * 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.
     *
     * @param source the <code>ImageReader</code> object calling this
     * method.
     * @param theImage the <code>BufferedImage</code> being updated.
     *
     * @see javax.imageio.ImageReadParam#setSourceProgressivePasses(int, int)
     */
    void passComplete(ImageReader source, BufferedImage theImage);

    
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.

Params:
  • source – the ImageReader object calling this
method.
  • theThumbnail – the BufferedImage thumbnail
being updated.
  • pass – the number 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 ints indicating the the
set bands that may be updated.
See Also:
/**
     * 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.
     *
     * @param source the <code>ImageReader</code> object calling this
     * method.
     * @param theThumbnail the <code>BufferedImage</code> thumbnail
     * being updated.
     * @param pass the number of the pass that is about to begin,
     * starting with 0.
     * @param minPass the index of the first pass that will be decoded.
     * @param maxPass the index of the last pass that will be decoded.
     * @param minX the X coordinate of the leftmost updated column
     * of pixels.
     * @param minY the Y coordinate of the uppermost updated row
     * of pixels.
     * @param periodX the horizontal spacing between updated pixels;
     * a value of 1 means no gaps.
     * @param periodY the vertical spacing between updated pixels;
     * a value of 1 means no gaps.
     * @param bands an array of <code>int</code>s indicating the the
     * set bands that may be updated.
     *
     * @see #passStarted
     */
    void thumbnailPassStarted(ImageReader source,
                              BufferedImage theThumbnail,
                              int pass,
                              int minPass, int maxPass,
                              int minX, int minY,
                              int periodX, int periodY,
                              int[] bands);

    
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.

Params:
  • 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 ints indicating which
bands are being updated.
See Also:
/**
     * 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.
     *
     * @param source the <code>ImageReader</code> object calling this method.
     * @param theThumbnail the <code>BufferedImage</code> thumbnail
     * being updated.
     * @param minX the X coordinate of the leftmost updated column
     * of pixels.
     * @param minY the Y coordinate of the uppermost updated row
     * of pixels.
     * @param width the number of updated pixels horizontally.
     * @param height the number of updated pixels vertically.
     * @param periodX the horizontal spacing between updated pixels;
     * a value of 1 means no gaps.
     * @param periodY the vertical spacing between updated pixels;
     * a value of 1 means no gaps.
     * @param bands an array of <code>int</code>s indicating which
     * bands are being updated.
     *
     * @see #imageUpdate
     */
    void thumbnailUpdate(ImageReader source,
                         BufferedImage theThumbnail,
                         int minX, int minY,
                         int width, int height,
                         int periodX, int periodY,
                         int[] bands);

    
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.

Params:
  • source – the ImageReader object calling this
method.
  • theThumbnail – the BufferedImage thumbnail
being updated.
See Also:
/**
     * 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.
     *
     * @param source the <code>ImageReader</code> object calling this
     * method.
     * @param theThumbnail the <code>BufferedImage</code> thumbnail
     * being updated.
     *
     * @see #passComplete
     */
    void thumbnailPassComplete(ImageReader source, BufferedImage theThumbnail);
}