ImageReader implementations to
* notify callers of their image and thumbnail reading methods of
* pixel updates.
*
* @see javax.imageio.ImageReader#addIIOReadUpdateListener
* @see javax.imageio.ImageReader#removeIIOReadUpdateListener
*
* @version 0.5
*/
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.
*
* @param source the ImageReader object calling this
* method.
* @param theImage the BufferedImage being updated.
* @param pass the numer 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 ints 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)
*
*
* @param source the ImageReader object calling this method.
* @param theImage the BufferedImage 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 ints 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.
*
* @param source the ImageReader object calling this
* method.
* @param theImage the BufferedImage 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.
*
* @param source the ImageReader object calling this
* method.
* @param theThumbnail the BufferedImage thumbnail
* being updated.
* @param pass the numer 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 ints 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.
*
* @param source the ImageReader object calling this method.
* @param theThumbnail the BufferedImage 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 ints 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.
*
* @param source the ImageReader object calling this
* method.
* @param theThumbnail the BufferedImage thumbnail
* being updated.
*
* @see #passComplete
*/
void thumbnailPassComplete(ImageReader source, BufferedImage theThumbnail);
}