File: anigif.tcl

package info (click to toggle)
coccinella 0.96.20-9
  • links: PTS, VCS
  • area: main
  • in suites: bookworm, bullseye, buster, sid, trixie
  • size: 13,184 kB
  • sloc: tcl: 124,744; xml: 206; makefile: 66; sh: 62
file content (323 lines) | stat: -rw-r--r-- 7,464 bytes parent folder | download | duplicates (4)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
# AniGif Package written in pure Tcl/Tk
#
# anigif.tcl v1.3 2002-09-09 (c) 2001-2002 Ryan Casey
#
# AniGif is distributed under the same license as Tcl/Tk.  As of
# AniGif 1.3, this license is applicable to all previous versions.
#
# Modified by Alexey Shchepin <alexey@sevcom.net>
# 
# Modified by Mats Bengtsson <matben@users.sf.net>
#
# ###############################  USAGE  #################################
#
#  ::anigif::anigif FILENAME NAME INDEX
#    FILENAME: appropriate path and file to use for the animated gif
#    INDEX:    what image to begin on (first image is 0) (Default: 0)
#
#  ::anigif::stop IMAGE
#  ::anigif::restart IMAGE INDEX
#    INDEX:    defaults to next index in loop
#  ::anigif::destroy IMAGE
#  ::anigif::delete IMAGE
#
#  NOTES:
#    There is currently a -zoom and -subsample hack to keep transparency.
#    Anigif does not handle interlaced gifs properly.  The image will look
#      distorted.
#    A delay of 0 renders as fast as possible, per the GIF specification.
#      This is currently set to 40 ms to approximate the IE default.
#    If you experience a problem with a compressed gif, try uncompressing
#      it. Search the web for gifsicle.    
#
# ############################## HISTORY #################################
#
#  1.4: Major rewrite by Mats
#  1.3: Fixed error in disposal flag handling.
#       Added handling for non-valid comment/graphic blocks.
#       Searches for actual loop control block.  If it extists, loops.
#       Added more comments.
#  1.2: Now handles single playthrough gifs or gifs with partial images
#       Fixed bug in delay time (unsigned int was being treated as signed)
#  1.1: Reads default timing instead of 100 ms or user-defined.
#       You can no longer set the delay manually.
#  1.0: Moved all anigif variables to the anigif namespace
#  0.9: Initial release
# 

package provide anigif 1.4


namespace eval ::anigif {
    variable allNames {}
    variable heartbeat
    array set heartbeat {
	ms          2000
    }

    proc anigif {fileName name {idx 0}} {
	variable allNames
	variable heartbeat

	set n 0
	set images {}
	set delay {}

	# Read image file.
	set fd [open $fileName r]
	fconfigure $fd -translation binary
	set data [read $fd [file size $fileName]]
	close $fd

	if {$name == ""} {
	    set img [image create photo -file $fileName]
	} else {
	    set img [image create photo $name -file $fileName]
	}
	lappend allNames $img
	
	set token [GetToken $img]
	upvar 0 $token state
	variable $token

	# Find Loop Record
	set start [string first "\x21\xFF\x0B" $data]

	if {$start < 0} {
	    set repeat 0
	} else {
	    set repeat 1
	}

	# Find Control Records
	set start [string first "\x21\xF9\x04" $data]
	
	set cmd [list image create photo -file $fileName \
	  -format [list gif89 -index $n]]

	while {![catch $cmd tmpname]} {
	    set stop [string first "\x00" $data [expr {$start + 1}]]
	    if {$stop < $start} {
		break
	    }
	    set record [string range $data $start $stop]
	    
	    if {[binary scan $record @4c1 thisdelay]} {

		# Change to unsigned integer
		set thisdelay [expr {$thisdelay & 0xFF}]

		# Convert hundreths to thousandths for after
		set thisdelay [expr {$thisdelay * 10}]

		# If 0, set to fastest (25 ms min to seem to match browser default)
		if {$thisdelay == 0} {
		    set thisdelay 40
		}
		lappend delay $thisdelay

		binary scan $record @2b3b3b1b1 -> disposalval userinput transflag

		lappend images $tmpname
		lappend disposal $disposalval
		incr n
	    }
	    set cmd [list image create photo -file $fileName \
	      -format [list gif89 -index $n]]

	    if {($start >= 0) && ($stop >= 0)} {
		set start [string first "\x21\xF9\x04" $data [expr {$stop + 1}]]
	    } else {
		break
	    }
	}
	
	set state(repeat)   $repeat
	set state(delay)    $delay
	set state(disposal) $disposal
	set state(current)  $img
	set state(images)   $images
	set state(idx)      $idx
	set state(runs)     1
	
	$state(current) blank
	$state(current) copy [lindex $images 0]
	
	if {![info exists heartbeat(after)]} {
	    Beat
	}
	return $img
    }
    
    proc GetToken {img} {
	
	# Protect from the case when the image name contains any ::
	# Not 100% foolproof!
	#set img [string map {- --} $img]
	return ::anigif::[string map {:: -} $img]
    }

    proc Step {token {idx 0}} {
	upvar 0 $token state
	variable $token
	
	# Need a way to detect if original image was deleted.
	# Internal error handling in tk seems inconsistent!
	if {![array exists state]} {
	    return
	}
	set img $state(current)
	if {[catch {image inuse $img}]} {
	    delete $img
	    return
	}
	if {$idx >= [llength $state(images)]} {
	    set idx 0
	    if {$state(repeat) == 0} {
		# Non-repeating GIF
		stop $img
		return
	    }
	} 
	set dispflag [lindex $state(disposal) $idx]
	
	switch -- $dispflag {
	    "000" {
		# Do nothing
	    }
	    "001" {
		# Do not dispose
	    }
	    "100" {
		# Restore to background
		if {[catch {$state(current) blank}]} {
		    delete $img
		    return
		}
	    }
	    "101" {
		# Restore to previous - not supported
		# As recommended, since this is not supported, it is set to blank
		if {[catch {$state(current) blank}]} {
		    delete $img
		    return
		}
	    }
	    default { 
		puts "no match: $dispflag" 
	    }
	}
	if {[catch {$state(current) copy [lindex $state(images) $idx]}]} {
	    delete $img
	    return
	}
	if {[lindex $state(delay) $idx] == 0} {
	    stop $img
	    return
	}
	
	# Reschedule.
	set delay [lindex $state(delay) $idx]
	set state(after) [after $delay [list ::anigif::Step $token [incr idx]]]
	set state(idx) [incr idx]
    }

    proc stop {img} {
	set token [GetToken $img]
	upvar 0 $token state
	variable $token

	catch {
	    after cancel $state(after)
	}
	set state(runs) 0
	unset -nocomplain state(after)
    }

    # TODO
    proc restart {img {idx -1}} {
	set token [GetToken $img]
	upvar 0 $token state
	variable $token

	if {$idx == -1} {
	    if {[lindex $state(delay) $idx] < 0} {
		set idx 0
	    } else {
		set idx $state(idx)
	    }
	}
	catch {
	    stop $img
	    Step $token $idx
	}
    }

    proc destroy {img} {
	delete $img
    }
    
    proc delete {img} {
	set token [GetToken $img]
	upvar 0 $token state
	variable $token
	variable allNames

	set allNames [lsearch -all -not -inline $allNames $img]
	
	catch {
	    stop $img
	    eval {image delete $state(current)} $state(images)
	    unset state
	}
    }
    
    proc isanigif {img} {
	set token [GetToken $img]
	upvar 0 $token state

	return [array exists state]
    }
    
    proc Pause {token} {
	upvar 0 $token state
	variable $token

	catch {
	    after cancel $state(after)
	}
	unset -nocomplain state(after)
    }	
    
    # Static procedure to schedule timers only when needed.
    proc Beat { } {
	variable allNames
	variable heartbeat
    
	if {$allNames == {}} {
	    catch {after cancel $heartbeat(after)}
	    unset -nocomplain heartbeat(after)
	    return
	}
	
	# This shall start and stop timers for each image when needed.
	foreach name $allNames {
	    set token [GetToken $name]
	    upvar 0 $token state
	    variable $token

	    # Need a way to detect if original image was deleted.
	    if {[catch {image inuse $name} inuse]} {
		delete $name
		continue
	    }
	    if {$inuse && ![info exists state(after)]} {
		Step $token
	    } elseif {!$inuse && [info exists state(after)]} {
		Pause [GetToken $name]
	    }
	}	
	set heartbeat(after) [after $heartbeat(ms) [namespace current]::Beat]
    }
}