javax.media.jai
Class SourcelessOpImage

java.lang.Object
  javax.media.jai.PlanarImage
      javax.media.jai.OpImage
          javax.media.jai.SourcelessOpImage

All Implemented Interfaces:

ImageJAI, PropertyChangeEmitter, PropertySource, RenderedImage, WritablePropertySource

public abstract class SourcelessOpImage

extends OpImage

An abstract base class for image operators that have no image sources.

SourcelessOpImage is intended as a convenient superclass for OpImages that have no source image. Some examples are constant color images, file readers, protocol-based network readers, and mathematically-defined imagery such as fractals.

The computeTile method of this class will call the computeRect(PlanarImage[], WritableRaster, Rectangle) method of the subclass to perform the computation. The first argument will be null as there are no source images.

See Also:

OpImage

Field Summary

Fields inherited from class javax.media.jai.OpImage

cache, cobbleSources, OP_COMPUTE_BOUND, OP_IO_BOUND, OP_NETWORK_BOUND, tileCacheMetric, tileRecycler

Fields inherited from class javax.media.jai.PlanarImage

colorModel, eventManager, height, minX, minY, properties, sampleModel, tileFactory, tileGridXOffset, tileGridYOffset, tileHeight, tileWidth, width

Constructor Summary

SourcelessOpImage(ImageLayout layout, Map configuration, SampleModel sampleModel, int minX, int minY, int width, int height)
Constructs a SourcelessOpImage.

Method Summary

boolean	computesUniqueTiles() Returns false as SourcelessOpImages often return Rasters via computeTile() tile that are internally cached.
Raster	computeTile(int tileX, int tileY) Computes a tile.
Rectangle	mapDestRect(Rectangle destRect, int sourceIndex) Throws an IllegalArgumentException since the image has no image sources.
Rectangle	mapSourceRect(Rectangle sourceRect, int sourceIndex) Throws an IllegalArgumentException since the image has no image sources.

Methods inherited from class javax.media.jai.OpImage

addTileToCache, cancelTiles, computeRect, computeRect, createTile, dispose, getExpandedNumBands, getFormatTags, getOperationComputeType, getTile, getTileCache, getTileCacheMetric, getTileDependencies, getTileFromCache, getTileRecycler, getTiles, hasExtender, mapDestPoint, mapSourcePoint, prefetchTiles, queueTiles, recycleTile, setTileCache, vectorize, vectorize, vectorize

Methods inherited from class javax.media.jai.PlanarImage

addPropertyChangeListener, addPropertyChangeListener, addSink, addSink, addSource, addTileComputationListener, copyData, copyData, copyExtendedData, createColorModel, createSnapshot, createWritableRaster, finalize, getAsBufferedImage, getAsBufferedImage, getBounds, getColorModel, getData, getData, getDefaultColorModel, getExtendedData, getGraphics, getHeight, getImageID, getMaxTileX, getMaxTileY, getMaxX, getMaxY, getMinTileX, getMinTileY, getMinX, getMinY, getNumBands, getNumSources, getNumXTiles, getNumYTiles, getProperties, getProperty, getPropertyClass, getPropertyNames, getPropertyNames, getSampleModel, getSinks, getSource, getSourceImage, getSourceObject, getSources, getSplits, getTileComputationListeners, getTileFactory, getTileGridXOffset, getTileGridYOffset, getTileHeight, getTileIndices, getTileRect, getTiles, getTileWidth, getWidth, overlapsMultipleTiles, removeProperty, removePropertyChangeListener, removePropertyChangeListener, removeSink, removeSink, removeSinks, removeSource, removeSources, removeTileComputationListener, setImageLayout, setProperties, setProperty, setSource, setSources, tileXToX, tileXToX, tileYToY, tileYToY, toString, wrapRenderedImage, XToTileX, XToTileX, YToTileY, YToTileY

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

SourcelessOpImage

public SourcelessOpImage(ImageLayout layout,
                         Map configuration,
                         SampleModel sampleModel,
                         int minX,
                         int minY,
                         int width,
                         int height)

Constructs a SourcelessOpImage. The image bounds and SampleModel are set explicitly; other layout parameters may be set using the layout parameter. The min X, min Y, width, height, and SampleModel fields of the layout parameter are ignored.

If sampleModel is null, no exceptions will be thrown. However, the caller must be sure to set the sampleModel instance variable before construction terminates. This feature allows subclasses that require external computation such as file loading to defer the determination of their SampleModel until after the call to super.

Similarly, minX, minY, width, and height may be dummy values if care is taken to manually set all values that depend on them, namely the tile grid offset, tile size, and SampleModel width and height.

The tile dimensions, tile grid X and Y offsets, and ColorModel of the output will be set in the standard way by the OpImage constructor.

Parameters:

configuration - Configurable attributes of the image including configuration variables indexed by RenderingHints.Keys and image properties indexed by Strings or CaselessStringKeys. This is simply forwarded to the superclass constructor.

layout - an ImageLayout describing the layout.

Since:

JAI 1.1

Method Detail

computesUniqueTiles

public boolean computesUniqueTiles()

Returns false as SourcelessOpImages often return Rasters via computeTile() tile that are internally cached. Some subclasses may want to override this method and return true.

Overrides:

computesUniqueTiles in class OpImage

computeTile

public Raster computeTile(int tileX,
                          int tileY)

Computes a tile. Since the operation has no sources, there is no need to worry about cobbling.

Subclasses should implement the computeRect(PlanarImage[], WritableRaster, Rectangle) method to perform the actual computation.

Overrides:

computeTile in class OpImage

Parameters:

tileX - The X index of the tile.

tileY - The Y index of the tile.

mapSourceRect

public Rectangle mapSourceRect(Rectangle sourceRect,
                               int sourceIndex)

Throws an IllegalArgumentException since the image has no image sources.

Specified by:

mapSourceRect in class OpImage

Parameters:

sourceRect - ignored.

sourceIndex - ignored.

Returns:

A Rectangle indicating the potentially affected destination region, or null if the region is unknown.

Throws:

IllegalArgumentException - since the image has no sources.

mapDestRect

public Rectangle mapDestRect(Rectangle destRect,
                             int sourceIndex)

Throws an IllegalArgumentException since the image has no image sources.

Specified by:

mapDestRect in class OpImage

Parameters:

destRect - ignored.

sourceIndex - ignored.

Returns:

A non-null Rectangle indicating the required source region.

Throws:

IllegalArgumentException - since the image has no sources.