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