NAME¶
Tk_ImageChanged - notify widgets that image needs to be redrawn
SYNOPSIS¶
#include <tk.h>
Tk_ImageChanged(imageMaster, x, y, width, height, imageWidth, imageHeight)
ARGUMENTS¶
- Tk_ImageMaster imageMaster (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.
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
imageMaster 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.
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