1Tk_ImageChanged(3)           Tk Library Procedures          Tk_ImageChanged(3)
2
3
4
5______________________________________________________________________________
6

NAME

8       Tk_ImageChanged - notify widgets that image needs to be redrawn
9

SYNOPSIS

11       #include <tk.h>
12
13       Tk_ImageChanged(imageMaster, x, y, width, height, imageWidth, imageHeight)
14

ARGUMENTS

16       Tk_ImageMaster imageMaster (in)          Token  for  image,  which  was
17                                                passed to  image's  createProc
18                                                when the image was created.
19
20       int x (in)                               X-coordinate   of   upper-left
21                                                corner of  region  that  needs
22                                                redisplay    (measured    from
23                                                upper-left corner of image).
24
25       int y (in)                               Y-coordinate   of   upper-left
26                                                corner  of  region  that needs
27                                                redisplay    (measured    from
28                                                upper-left corner of image).
29
30       int width (in)                           Width  of region that needs to
31                                                be redrawn, in pixels.
32
33       int height (in)                          Height of region that needs to
34                                                be redrawn, in pixels.
35
36       int imageWidth (in)                      Current  width  of  image,  in
37                                                pixels.
38
39       int imageHeight (in)                     Current height  of  image,  in
40                                                pixels.
41______________________________________________________________________________
42

DESCRIPTION

44       An  image  manager calls Tk_ImageChanged for an image whenever anything
45       happens that requires the image to be redrawn.  As a result of  calling
46       Tk_ImageChanged,  any widgets using the image are notified so that they
47       can redisplay themselves appropriately.  The imageMaster argument iden‐
48       tifies  the  image,  and  x, y, width, and height specify a rectangular
49       region within the image that  needs  to  be  redrawn.   imageWidth  and
50       imageHeight specify the image's (new) size.
51
52       An  image  manager should call Tk_ImageChanged during its createProc to
53       specify the image's initial size and to force redisplay  if  there  are
54       existing  instances  for  the image.  If any of the pixel values in the
55       image should change later on, Tk_ImageChanged should  be  called  again
56       with  x,  y,  width,  and  height values that cover all the pixels that
57       changed.  If the size of the image should change, then  Tk_ImageChanged
58       must  be  called to indicate the new size, even if no pixels need to be
59       redisplayed.
60

SEE ALSO

62       Tk_CreateImageType
63

KEYWORDS

65       images, redisplay, image size changes
66
67
68
69Tk                                    4.0                   Tk_ImageChanged(3)