#  Copyright (c) 1994 The Regents of the University of California.
#  Copyright (c) 1994-1996 Sun Microsystems, Inc.
#  See the file "license.terms" for information on usage and redistribution
#  of this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
#

=head1 NAME

Tk_ImageChanged - notify widgets that image needs to be redrawn

=for category C Programming

=head1 SYNOPSIS

B<#include E<lt>tk.hE<gt>>

B<Tk_ImageChanged>(I<imageMaster, x, y, width, height, imageWidth, imageHeight>)

=head1 ARGUMENTS

=over 4

=item Tk_ImageMaster imageMaster (in)

Token for image, which was passed to image's I<createProc> when
the image was created.

=item int x (in)

X-coordinate of upper-left corner of region that needs redisplay (measured
from upper-left corner of image).

=item int y (in)

Y-coordinate of upper-left corner of region that needs redisplay (measured
from upper-left corner of image).

=item "int" width (in)

Width of region that needs to be redrawn, in pixels.

=item "int" height (in)

Height of region that needs to be redrawn, in pixels.

=item "int" imageWidth (in)

Current width of image, in pixels.

=item "int" imageHeight (in)

Current height of image, in pixels.

=back

=head1 DESCRIPTION

An image manager calls B<Tk_ImageChanged> for an image
whenever anything happens that requires the image to be redrawn.
As a result of calling B<Tk_ImageChanged>, any widgets using
the image are notified so that they can redisplay themselves
appropriately.
The I<imageMaster> argument identifies the image, and
I<x>, I<y>, I<width>, and I<height>
specify a rectangular region within the image that needs to
be redrawn.
I<imageWidth> and I<imageHeight> specify the image's (new) size.

An image manager should call B<Tk_ImageChanged> during
its I<createProc> to specify the image's initial size and to
force redisplay if there are existing instances for the image.
If any of the pixel values in the image should change later on,
B<Tk_ImageChanged> should be called again with I<x>, I<y>,
I<width>, and I<height> values that cover all the pixels
that changed.
If the size of the image should change, then B<Tk_ImageChanged>
must be called to indicate the new size, even if no pixels
need to be redisplayed.

=head1 SEE ALSO

L<Tk::CrtImgType>

=head1 KEYWORDS

images, redisplay, image size changes
