mingw/lib/tk8.5/demos/anilabel.tcl

   1 # anilabel.tcl --
   2 #
   3 # This demonstration script creates a toplevel window containing
   4 # several animated label widgets.
   5
   6 if {![info exists widgetDemo]} {
   7     error "This script should be run from the \"widget\" demo."
   8 }
   9
  10 package require Tk
  11
  12 set w .anilabel
  13 catch {destroy $w}
  14 toplevel $w
  15 wm title $w "Animated Label Demonstration"
  16 wm iconname $w "anilabel"
  17 positionWindow $w
  18
  19 label $w.msg -font $font -wraplength 4i -justify left -text "Four animated labels are displayed below; each of the labels on the left is animated by making the text message inside it appear to scroll, and the label on the right is animated by animating the image that it displays."
  20 pack $w.msg -side top
  21
  22 ## See Code / Dismiss buttons
  23 set btns [addSeeDismiss $w.buttons $w]
  24 pack $btns -side bottom -fill x
  25
  26 # Ensure that this this is an array
  27 array set animationCallbacks {}
  28
  29 ## This callback is the core of how to do animation in Tcl/Tk; all
  30 ## animations work in basically the same way, with a procedure that
  31 ## uses the [after] command to reschedule itself at some point in the
  32 ## future. Of course, the details of how to update the state will vary
  33 ## according to what is being animated.
  34 proc RotateLabelText {w interval} {
  35     global animationCallbacks
  36
  37     # Schedule the calling of this procedure again in the future
  38     set animationCallbacks($w) [after $interval RotateLabelText $w $interval]
  39
  40     # We do marquee-like scrolling text by chopping characters off the
  41     # front of the text and sticking them on the end.
  42     set text [$w cget -text]
  43     set newText [string range $text 1 end][string index $text 0]
  44     $w configure -text $newText
  45 }
  46
  47 ## A helper procedure to start the animation happening.
  48 proc animateLabelText {w text interval} {
  49     global animationCallbacks
  50
  51     # Install the text into the widget
  52     $w configure -text $text
  53
  54     # Schedule the start of the animation loop
  55     set animationCallbacks($w) [after $interval RotateLabelText $w $interval]
  56
  57     # Make sure that the animation stops and is cleaned up after itself
  58     # when the animated label is destroyed.  Note that at this point we
  59     # cannot manipulate the widget itself, as that has already died.
  60     bind $w <Destroy> {
  61         after cancel $animationCallbacks(%W)
  62         unset animationCallbacks(%W)
  63     }
  64 }
  65
  66 ## Next, a similar pair of procedures to animate a GIF loaded into a
  67 ## photo image.
  68 proc SelectNextImageFrame {w interval} {
  69     global animationCallbacks
  70     set animationCallbacks($w) \
  71             [after $interval SelectNextImageFrame $w $interval]
  72     set image [$w cget -image]
  73
  74     # The easy way to animate a GIF!
  75     set idx -1
  76     scan [$image cget -format] "GIF -index %d" idx
  77     if {[catch {
  78         # Note that we get an error if the index is out of range
  79         $image configure -format "GIF -index [incr idx]"
  80     }]} then {
  81         $image configure -format "GIF -index 0"
  82     }
  83 }
  84 proc animateLabelImage {w imageData interval} {
  85     global animationCallbacks
  86
  87     # Create a multi-frame GIF from base-64-encoded data
  88     set image [image create photo -format GIF -data $imageData]
  89
  90     # Install the image into the widget
  91     $w configure -image $image
  92
  93     # Schedule the start of the animation loop
  94     set animationCallbacks($w) \
  95             [after $interval SelectNextImageFrame $w $interval]
  96
  97     # Make sure that the animation stops and is cleaned up after itself
  98     # when the animated label is destroyed.  Note that at this point we
  99     # cannot manipulate the widget itself, as that has already died.
 100     # Also note that this script is in double-quotes; this is always OK
 101     # because image names are chosen automatically to be simple words.
 102     bind $w <Destroy> "
 103         after cancel \$animationCallbacks(%W)
 104         unset animationCallbacks(%W)
 105         rename $image {}
 106     "
 107 }
 108
 109 # Make some widgets to contain the animations
 110 labelframe $w.left -text "Scrolling Texts"
 111 labelframe $w.right -text "GIF Image"
 112 pack $w.left $w.right -side left -padx 10 -pady 10 -expand yes
 113
 114 # This method of scrolling text looks far better with a fixed-width font
 115 label $w.left.l1 -bd 4 -relief ridge -font fixedFont
 116 label $w.left.l2 -bd 4 -relief groove -font fixedFont
 117 label $w.left.l3 -bd 4 -relief flat -font fixedFont -width 18
 118 pack $w.left.l1 $w.left.l2 $w.left.l3 -side top -expand yes -padx 10 -pady 10 -anchor w
 119 # Don't need to do very much with this label except turn off the border
 120 label $w.right.l -bd 0
 121 pack $w.right.l -side top -expand yes -padx 10 -pady 10
 122
 123 # This is a base-64-encoded animated GIF file.
 124 set tclPoweredData {
 125     R0lGODlhKgBAAPQAAP//////zP//AP/MzP/Mmf/MAP+Zmf+ZZv+ZAMz//8zM
 126     zMyZmcyZZsxmZsxmAMwzAJnMzJmZzJmZmZlmmZlmZplmM5kzM2aZzGZmzGZm
 127     mWZmZmYzZmYzMzNmzDMzZgAzmSH+IE1hZGUgd2l0aCBHSU1QIGJ5IExARGVt
 128     YWlsbHkuY29tACH5BAVkAAEALAAAAAAqAEAAAAX+YCCOZEkyTKM2jOm66yPP
 129     dF03bx7YcuHIDkGBR7SZeIyhTID4FZ+4Es8nQyCe2EeUNJ0peY2s9mi7PhAM
 130     ngEAMGRbUpvzSxskLh1J+Hkg134OdDIDEB+GHxtYMEQMTjMGEYeGFoomezaC
 131     DZGSHFmLXTQKkh8eNQVpZ2afmDQGHaOYSoEyhhcklzVmMpuHnaZmDqiGJbg0
 132     qFqvh6UNAwB7VA+OwydEjgujkgrPNhbTI8dFvNgEYcHcHx0lB1kX2IYeA2G6
 133     NN0YfkXJ2BsAMuAzHB9cZMk3qoEbRzUACsRCUBK5JxsC3iMiKd8GN088SIyT
 134     0RAFSROyeEg38caDiB/+JEgqxsODrZJ1BkT0oHKSmI0ceQxo94HDpg0qsuDk
 135     UmRAMgu8OgwQ+uIJgUMVeGXA+IQkzEeHGvD8cIGlDXsLiRjQ+EHroQhea7xY
 136     8IQBSgYYDi1IS+OFBCgaDMGVS3fGi5BPJpBaENdQ0EomKGD56IHwO39EXiSC
 137     Ysgxor5+Xfgq0qByYUpiXmwuoredB2aYH4gWWda0B7SeNENpEJHC1ghi+pS4
 138     AJpIAwWvKPBi+8YEht5EriEqpFfMlhEdkBNpx0HUhwypx5T4IB1MBg/Ws2sn
 139     wV3MSQOkzI8fUd48Aw3dOZto71x85hHtHijYv18Gf/3GqCdDCXHNoICBobSo
 140     IqBqJLyCoH8JPrLgdh88CKCFD0CGmAiGYPgffwceZh6FC2ohIIklnkhehTNY
 141     4CIHHGzgwYw01ujBBhvAqKOLLq5AAk9kuSPkkKO40NB+h1gnypJIIvkBf09a
 142     N5QIRz5p5ZJXJpmlIVhOGQA2TmIJZZhKKmmll2BqyWSXWUrZpQtpatlmk1c2
 143     KaWRHeTZEJF8SqLDn/hhsOeQgBbqAh6DGqronxeARUIIACH5BAUeAAAALAUA
 144     LgAFAAUAAAUM4CeKz/OV5YmqaRkCACH5BAUeAAEALAUALgAKAAUAAAUUICCK
 145     z/OdJVCaa7p+7aOWcDvTZwgAIfkEBR4AAQAsCwAuAAkABQAABRPgA4zP95zA
 146     eZqoWqqpyqLkZ38hACH5BAUKAAEALAcALgANAA4AAAU7ICA+jwiUJEqeKau+
 147     r+vGaTmac63v/GP9HM7GQyx+jsgkkoRUHJ3Qx0cK/VQVTKtWwbVKn9suNunc
 148     WkMAIfkEBQoAAAAsBwA3AAcABQAABRGgIHzk842j+Yjlt5KuO8JmCAAh+QQF
 149     CgAAACwLADcABwAFAAAFEeAnfN9TjqP5oOWziq05lmUIACH5BAUKAAAALA8A
 150     NwAHAAUAAAUPoPCJTymS3yiQj4qOcPmEACH5BAUKAAAALBMANwAHAAUAAAUR
 151     oCB+z/MJX2o+I2miKimiawgAIfkEBQoAAAAsFwA3AAcABQAABRGgIHzfY47j
 152     Q4qk+aHl+pZmCAAh+QQFCgAAACwbADcABwAFAAAFEaAgfs/zCV9qPiNJouo7
 153     ll8IACH5BAUKAAAALB8ANwADAAUAAAUIoCB8o0iWZggAOw==
 154 }
 155
 156 # Finally, set up the text scrolling animation
 157 animateLabelText $w.left.l1 "* Slow Animation *" 300
 158 animateLabelText $w.left.l2 "* Fast Animation *" 80
 159 animateLabelText $w.left.l3 "This is a longer scrolling text in a widget that will not show the whole message at once. " 150
 160 animateLabelImage $w.right.l $tclPoweredData 100