java.awt.image

Class ImageFilter

Implemented Interfaces:
Cloneable, ImageConsumer
Known Direct Subclasses:
BufferedImageFilter, CropImageFilter, ReplicateScaleFilter, RGBImageFilter

public class ImageFilter
extends Object
implements ImageConsumer, Cloneable

This class implements a filter for the set of interface methods that are used to deliver data from an ImageProducer to an ImageConsumer. It is meant to be used in conjunction with a FilteredImageSource object to produce filtered versions of existing images. It is a base class that provides the calls needed to implement a "Null filter" which has no effect on the data being passed through. Filters should subclass this class and override the methods which deal with the data that needs to be filtered and modify it as necessary.
See Also:
FilteredImageSource, ImageConsumer

Field Summary

protected ImageConsumer
consumer
The consumer of the particular image data stream for which this instance of the ImageFilter is filtering data.

Fields inherited from interface java.awt.image.ImageConsumer

COMPLETESCANLINES, IMAGEABORTED, IMAGEERROR, RANDOMPIXELORDER, SINGLEFRAME, SINGLEFRAMEDONE, SINGLEPASS, STATICIMAGEDONE, TOPDOWNLEFTRIGHT

Method Summary

Object
clone()
Clones this object.
ImageFilter
getFilterInstance(ImageConsumer ic)
Returns a unique instance of an ImageFilter object which will actually perform the filtering for the specified ImageConsumer.
void
imageComplete(int status)
Filters the information provided in the imageComplete method of the ImageConsumer interface.
void
resendTopDownLeftRight(ImageProducer ip)
Responds to a request for a TopDownLeftRight (TDLR) ordered resend of the pixel data from an ImageConsumer.
void
setColorModel(ColorModel model)
Filter the information provided in the setColorModel method of the ImageConsumer interface.
void
setDimensions(int width, int height)
Filters the information provided in the setDimensions method of the ImageConsumer interface.
void
setHints(int hints)
Filters the information provided in the setHints method of the ImageConsumer interface.
void
setPixels(int x, int y, int w, int h, ColorModel model, pixels[] , int off, int scansize)
Filters the information provided in the setPixels method of the ImageConsumer interface which takes an array of bytes.
void
setPixels(int x, int y, int w, int h, ColorModel model, pixels[] , int off, int scansize)
Filters the information provided in the setPixels method of the ImageConsumer interface which takes an array of integers.
void
setProperties(Hashtable props)
Passes the properties from the source object along after adding a property indicating the stream of filters it has been run through.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

consumer

protected ImageConsumer consumer
The consumer of the particular image data stream for which this instance of the ImageFilter is filtering data. It is not initialized during the constructor, but rather during the getFilterInstance() method call when the FilteredImageSource is creating a unique instance of this object for a particular image data stream.

Method Details

clone

public Object clone()
Clones this object.
Overrides:
clone in interface Object

getFilterInstance

public ImageFilter getFilterInstance(ImageConsumer ic)
Returns a unique instance of an ImageFilter object which will actually perform the filtering for the specified ImageConsumer. The default implementation just clones this object.

Note: This method is intended to be called by the ImageProducer of the Image whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

Parameters:
ic - the specified ImageConsumer
Returns:
an ImageFilter used to perform the filtering for the specified ImageConsumer.

imageComplete

public void imageComplete(int status)
Filters the information provided in the imageComplete method of the ImageConsumer interface.

Note: This method is intended to be called by the ImageProducer of the Image whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

Specified by:
imageComplete in interface ImageConsumer

resendTopDownLeftRight

public void resendTopDownLeftRight(ImageProducer ip)
Responds to a request for a TopDownLeftRight (TDLR) ordered resend of the pixel data from an ImageConsumer. When an ImageConsumer being fed by an instance of this ImageFilter requests a resend of the data in TDLR order, the FilteredImageSource invokes this method of the ImageFilter.

An ImageFilter subclass might override this method or not, depending on if and how it can send data in TDLR order. Three possibilities exist:

  • Do not override this method. This makes the subclass use the default implementation, which is to forward the request to the indicated ImageProducer using this filter as the requesting ImageConsumer. This behavior is appropriate if the filter can determine that it will forward the pixels in TDLR order if its upstream producer object sends them in TDLR order.
  • Override the method to simply send the data. This is appropriate if the filter can handle the request itself — for example, if the generated pixels have been saved in some sort of buffer.
  • Override the method to do nothing. This is appropriate if the filter cannot produce filtered data in TDLR order.
Parameters:
ip - the ImageProducer that is feeding this instance of the filter - also the ImageProducer that the request should be forwarded to if necessary
Throws:
NullPointerException - if ip is null

setColorModel

public void setColorModel(ColorModel model)
Filter the information provided in the setColorModel method of the ImageConsumer interface.

Note: This method is intended to be called by the ImageProducer of the Image whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

Specified by:
setColorModel in interface ImageConsumer

setDimensions

public void setDimensions(int width,
                          int height)
Filters the information provided in the setDimensions method of the ImageConsumer interface.

Note: This method is intended to be called by the ImageProducer of the Image whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

Specified by:
setDimensions in interface ImageConsumer

setHints

public void setHints(int hints)
Filters the information provided in the setHints method of the ImageConsumer interface.

Note: This method is intended to be called by the ImageProducer of the Image whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

Specified by:
setHints in interface ImageConsumer

setPixels

public void setPixels(int x,
                      int y,
                      int w,
                      int h,
                      ColorModel model,
                      pixels[] ,
                      int off,
                      int scansize)
Filters the information provided in the setPixels method of the ImageConsumer interface which takes an array of bytes.

Note: This method is intended to be called by the ImageProducer of the Image whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

Specified by:
setPixels in interface ImageConsumer
See Also:
ImageConsumer.setPixels

setPixels

public void setPixels(int x,
                      int y,
                      int w,
                      int h,
                      ColorModel model,
                      pixels[] ,
                      int off,
                      int scansize)
Filters the information provided in the setPixels method of the ImageConsumer interface which takes an array of integers.

Note: This method is intended to be called by the ImageProducer of the Image whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

Specified by:
setPixels in interface ImageConsumer
See Also:
ImageConsumer.setPixels

setProperties

public void setProperties(Hashtable props)
Passes the properties from the source object along after adding a property indicating the stream of filters it has been run through.

Note: This method is intended to be called by the ImageProducer of the Image whose pixels are being filtered. Developers using this class to filter pixels from an image should avoid calling this method directly since that operation could interfere with the filtering operation.

Specified by:
setProperties in interface ImageConsumer
Parameters:
props - the properties from the source object
Throws:
NullPointerException - if props is null