Tk_ImageChanged(3) Tk Library Procedures Tk_ImageChanged(3)
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NAME
Tk_ImageChanged - notify widgets that image needs to be redrawn
SYNOPSIS
#include <tk.h> Tk_ImageChanged(
model, x, y, width, height, imageWidth, imageHeight)
ARGUMENTS
Tk_ImageMaster
model (in) Token for image, which was
passed to image's
createProc when the image was created.
int
x (in) X-coordinate of upper-left
corner of region that needs
redisplay (measured from
upper-left corner of image).
int
y (in) Y-coordinate of upper-left
corner of region that needs
redisplay (measured from
upper-left corner of image).
int
width (in) Width of region that needs
to be redrawn, in pixels.
int
height (in) Height of region that needs
to be redrawn, in pixels.
int
imageWidth (in) Current width of image, in
pixels.
int
imageHeight (in) Current height of image, in
pixels.
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DESCRIPTION
An image manager calls
Tk_ImageChanged for an image whenever anything
happens that requires the image to be redrawn. As a result of
calling
Tk_ImageChanged, any widgets using the image are notified so
that they can redisplay themselves appropriately. The
model argument
identifies the image, and
x,
y,
width, and
height specify a
rectangular region within the image that needs to be redrawn.
imageWidth and
imageHeight specify the image's (new) size.
Tk_ImageModel is synonym for
Tk_ImageMaster |
An image manager should call
Tk_ImageChanged during its
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,
Tk_ImageChanged should be called again
with
x,
y,
width, and
height values that cover all the pixels that
changed. If the size of the image should change, then
Tk_ImageChanged must be called to indicate the new size, even if no
pixels need to be redisplayed.
SEE ALSO
Tk_CreateImageType
KEYWORDS
images, redisplay, image size changes
Tk 4.0 Tk_ImageChanged(3)
