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  cre­
                                                ateProc  when the
                                                image  was   cre­
                                                ated.

       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 pix­
                                                els.

       int              height        (in)      Height of  region
                                                that  needs to be
                                                redrawn, in  pix­
                                                els.

       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 when­
       ever anything  happens  that  requires  the  image  to  be
       redrawn.  As a result of calling Tk_ImageChanged, any wid­
       gets using the image are notified so that they can  redis­
       play  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