java.awt.image
Interface ImageProducer

All Known Implementing Classes:

FilteredImageSource, MemoryImageSource, RenderableImageProducer, SyntheticImage

public interface ImageProducer

The interface for objects which can produce the image data for Images. Each image contains an ImageProducer which is used to reconstruct the image whenever it is needed, for example, when a new size of the Image is scaled, or when the width or height of the Image is being requested.

Author:

Jim Graham

See Also:

ImageConsumer

Method Summary

void	addConsumer(ImageConsumer ic) Registers an ImageConsumer with the ImageProducer for access to the image data during a later reconstruction of the Image.
boolean	isConsumer(ImageConsumer ic) Determines if a specified ImageConsumer object is currently registered with this ImageProducer as one of its consumers.
void	removeConsumer(ImageConsumer ic) Removes the specified ImageConsumer object from the list of consumers currently registered to receive image data.
void	requestTopDownLeftRightResend(ImageConsumer ic) Requests, on behalf of the ImageConsumer, that the ImageProducer attempt to resend the image data one more time in TOPDOWNLEFTRIGHT order so that higher quality conversion algorithms which depend on receiving pixels in order can be used to produce a better output version of the image.
void	startProduction(ImageConsumer ic) Registers the specified ImageConsumer object as a consumer and starts an immediate reconstruction of the image data which will then be delivered to this consumer and any other consumer which might have already been registered with the producer.

Method Detail

addConsumer

public void addConsumer(ImageConsumer ic)

Registers an ImageConsumer with the ImageProducer for access to the image data during a later reconstruction of the Image. The ImageProducer may, at its discretion, start delivering the image data to the consumer using the ImageConsumer interface immediately, or when the next available image reconstruction is triggered by a call to the startProduction method.

Parameters:

ic - the specified ImageConsumer

See Also:

startProduction(java.awt.image.ImageConsumer)

isConsumer

public boolean isConsumer(ImageConsumer ic)

Determines if a specified ImageConsumer object is currently registered with this ImageProducer as one of its consumers.

Parameters:

ic - the specified ImageConsumer

Returns:

true if the specified ImageConsumer is registered with this ImageProducer; false otherwise.

removeConsumer

public void removeConsumer(ImageConsumer ic)

Removes the specified ImageConsumer object from the list of consumers currently registered to receive image data. It is not considered an error to remove a consumer that is not currently registered. The ImageProducer should stop sending data to this consumer as soon as is feasible.

Parameters:

ic - the specified ImageConsumer

startProduction

public void startProduction(ImageConsumer ic)

Registers the specified ImageConsumer object as a consumer and starts an immediate reconstruction of the image data which will then be delivered to this consumer and any other consumer which might have already been registered with the producer. This method differs from the addConsumer method in that a reproduction of the image data should be triggered as soon as possible.

Parameters:

ic - the specified ImageConsumer

See Also:

addConsumer(java.awt.image.ImageConsumer)

requestTopDownLeftRightResend

public void requestTopDownLeftRightResend(ImageConsumer ic)

Requests, on behalf of the ImageConsumer, that the ImageProducer attempt to resend the image data one more time in TOPDOWNLEFTRIGHT order so that higher quality conversion algorithms which depend on receiving pixels in order can be used to produce a better output version of the image. The ImageProducer is free to ignore this call if it cannot resend the data in that order. If the data can be resent, the ImageProducer should respond by executing the following minimum set of ImageConsumer method calls:

	ic.setHints(TOPDOWNLEFTRIGHT | < otherhints >);
	ic.setPixels(...);	// As many times as needed
	ic.imageComplete();
 

Parameters:

ic - the specified ImageConsumer

See Also:

ImageConsumer.setHints(int)