Module java.desktop

Package java.awt.image

Class ImageFilter

java.lang.Object

java.awt.image.ImageFilter

All Implemented Interfaces:

ImageConsumer, Cloneable

Direct Known 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

Fields

Modifier and Type	Field	Description
protected ImageConsumer	consumer	The consumer of the particular image data stream for which this instance of the ImageFilter is filtering data.

Fields declared in interface java.awt.image.ImageConsumer

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

Constructor Summary

Constructors

Constructor	Description
ImageFilter()	Constructs an ImageFilter.

Method Summary

Modifier and Type	Method	Description
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, byte[] 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, int[] 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 declared in class java.lang.Object

equals, finalize, getClass, 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.

See Also:

• getFilterInstance(java.awt.image.ImageConsumer)
• ImageConsumer

Constructor Details

ImageFilter

public ImageFilter()

Constructs an ImageFilter.

Method Details

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.

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

Parameters:

width - the width of the source image

height - the height of the source image

See Also:

• ImageConsumer.setDimensions(int, int)

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

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

Parameters:

model - the specified ColorModel

See Also:

• ImageConsumer.setColorModel(java.awt.image.ColorModel)

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

Parameters:

hints - a set of hints that the ImageConsumer uses to process the pixels

See Also:

• ImageConsumer.setHints(int)

setPixels

public void setPixels(int x,
 int y,
 int w,
 int h,
 ColorModel model,
 byte[] 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

Parameters:

x - the X coordinate of the upper-left corner of the area of pixels to be set

y - the Y coordinate of the upper-left corner of the area of pixels to be set

w - the width of the area of pixels

h - the height of the area of pixels

model - the specified ColorModel

pixels - the array of pixels

off - the offset into the pixels array

scansize - the distance from one row of pixels to the next in the pixels array

See Also:

• ImageConsumer.setPixels(int, int, int, int, java.awt.image.ColorModel, byte[], int, int)

setPixels

public void setPixels(int x,
 int y,
 int w,
 int h,
 ColorModel model,
 int[] 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

Parameters:

x - the X coordinate of the upper-left corner of the area of pixels to be set

y - the Y coordinate of the upper-left corner of the area of pixels to be set

w - the width of the area of pixels

h - the height of the area of pixels

model - the specified ColorModel

pixels - the array of pixels

off - the offset into the pixels array

scansize - the distance from one row of pixels to the next in the pixels array

See Also:

• ImageConsumer.setPixels(int, int, int, int, java.awt.image.ColorModel, byte[], int, int)

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

Parameters:

status - the status of image loading

See Also:

• ImageConsumer.imageComplete(int)

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

See Also:

• ImageProducer.requestTopDownLeftRightResend(java.awt.image.ImageConsumer)

clone

public Object clone()

Clones this object.

Overrides:

clone in class Object

Returns:

a clone of this instance.

See Also:

• Cloneable