|AniGif:| '''animated GIF-Images'''|
|Where:| http://cardtable.go.to/tcltk/|
|Mirrored here:| http://cardtable.sourceforge.net/tcltk/|

|Description:| [Tk] [extension] allowing you to create, start, stop, restart and destroy animated [GIF]s.  Supports single play [image]s as well as images without full image data on each frame.  Use gifsicle to uncompress compressed/interlaced GIFs before subsequent processing.|

||        Currently at version 1.3.|
|Updated:| 03/2002|
|Contact:| mailto:scfiead_spammenot@hotmail.com|

----
Is "animated gif" somehow a [Windows]-specific notion?  Modern [Mac OS X] opens
animated gif-s with Preview, and Preview does ''not'' appear to animate.
<<br>>
''[Lars H]: I don't think it's Windows-specific, but I recall seeing the animation feature descibed as a bit of an oddity. Try opening in a web browser instead; I see the test animation on this page fine in Safari. It's possible that Preview lets you view each frame of the gif as a still image instead.''

The [Tk] code which follows, of course, executes and displays quite nicely on all platforms.

Note that it does not read the delay time out of the gif — it appears that [Img] does not provide such metadata.  Fortunately here on the wiki is [gifblock] which can be used.

[SeS] Aug. 17th, 2015
Looking into the https://en.wikipedia.org/wiki/GIF%|%format description of a .gif%|%, I can tell that I need to search for the first 21 F9 data pattern in the file. The next two bytes we can ignore, the 2 bytes following is the frame rate. Based on my assumption, that this is the correct way to extract the frame rate, here the tcl solution:

======
proc getGifFrameRate {file} {
  set d 0
  set i 0
  set f [open $file r]
  fconfigure $f -translation binary
  while {$i<1000} {
    binary scan [read $f 2] s B1
    if {$B1=="-1759"} {
      binary scan [read $f 2] s B1
      binary scan [read $f 2] s d
      break
    }
    incr i
  }
  close $f
  return $d
}
======
Not sayin this is the best way or fastest or whatever, just a quick and dirty method which works for me and the majority of .gif files I used to test it on. The returned value * 10ms is the frame rate in the file. Returns 0 if .gif is not an animated one.

----
[RS] 2004-07-27: Also, in plain [Tk] (but documented only for [Img]), 
you have access to the partial images of an animated [GIF]. 
This code was enough for me:

======
package require Img

proc anigif file {
    #-- returns a list of images from the given GIF file
    set index 0
    set results {}
    while 1 {
        if [catch {
            image create photo -file $file -format "gif -index $index"
        } res] {
            return $results
        }
        lappend results $res
        incr index
    }    
}

#-- Testing (dumping the animation phases, one next to the other, into a text widget):
======
[WikiDbImage anigif.jpg] Test image: [WikiDbImage underconstruction.gif]
======
#-- Testing (dumping the animation phases into a text widget, and an animation):
proc lcycle listName {
    upvar 1 $listName list
    set res [lindex $list 0]
    set list [concat [lrange $list 1 end] [list $res]]
    set res
}
proc every {ms body} {eval $body; after $ms [info level 0]}
set file [lindex $argv 0]

pack [text .t]
set images [anigif $file]
foreach img $images {
    .t image create end -image $img
}
.t insert end animated:
set id [.t image create end -image [lindex $images 0]]
every 100 ".t image config $id -image \[lcycle ::images\]"
======


----
Here's a slightly more minimal-but-generalizable form, applied to a canvas:
======
  proc animate_in_canvas {canvas gif} {
    global id_list

        # As written, there's only room for a single animation at a time.
    set id_list {}
    foreach img [anigif $gif] {
       lappend id_list [.c create image 0 0 -anchor nw -image $img]
    }
    every 150 ".c raise \[lcycle ::id_list\]"
  }

  pack [canvas .c -height 300 -width 300]
  animate_in_canvas .c [lindex $argv 0]
======

----
[mzgcoco]
======
  #apply to a label
  proc play {ms lbl img_list} {
    set img [lindex [$lbl config -image] end]
    set idx [lsearch $img_list $img]
    incr idx
    if {$idx > [llength $img_list] - 1} {
       set idx 0
    }
    $lbl config -image [lindex $img_list $idx]
    after $ms "play $ms $lbl \"$img_list\""
  }

  set img_list [anigif d:/dummy/ss.gif]
  label .l -image [lindex $img_list 0]
  pack .l 

  play 100 .l "$img_list"
======

----
[rahulj]
what about destroying animated gif canvas or label?

[SeS] hey [rahulj], not 100% sure if I understood your question, but if it is what I think, then I propose the following mod in proc play:
======
   if {[catch {set img [lindex [$lbl config -image] end]}]} {return}
======
This will effectively stop the play procedure in case the label is destoyed.




<<categories>> Package | Animation | Graphics