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ActiveTcl User Guide |
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Tk_ImageChanged - notify widgets that image needs to be redrawn
#include <tk.h>
Tk_ImageChanged(imageMaster, x, y, width, height,
imageWidth, imageHeight)
- 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.
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.
Tk_CreateImageType
images, redisplay, image size changes
Copyright © 1994 The Regents of the University of California.
Copyright © 1994-1996 Sun Microsystems, Inc.
Copyright © 1995-1997 Roger E. Critchlow Jr.