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.
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.
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.
setDimensions
public void setDimensions(int width,
int height)
Filters the information provided in the setDimensions method
of the ImageConsumer interface.
Responds to a request for a TopDownLeftRight (TDLR) ordered resend
of the pixel data from an ImageConsumer.
The ImageFilter can respond to this request in one of three ways.
If the filter can determine that it will forward the pixels in
TDLR order if its upstream producer object sends them
in TDLR order, then the request is automatically forwarded by
default to the indicated ImageProducer using this filter as the
requesting ImageConsumer, so no override is necessary.
If the filter can resend the pixels in the right order on its
own (presumably because the generated pixels have been saved in
some sort of buffer), then it can override this method and
simply resend the pixels in TDLR order as specified in the
ImageProducer API.
If the filter simply returns from this
method then the request will be ignored and no resend will
occur.
Parameters:
ip - The ImageProducer that is feeding this instance of
the filter - also the ImageProducer that the request should be
forwarded to if necessary.