Ticker

JM 2 Apr 2014 - This code is heavily based on Rolling credits by RS

This is a canvas with a scrolling single line text message.

 console show
 package require Tk
 proc titleshow {w title} {
    set -fill black
    set -font {Helvetica 16}
    set x [winfo width $w]
    set y 20
    foreach line [split $title \n] {
        set line "[string trim $line] "
        if [string match -* $line] {
            eval [linsert $line 0 set]
        } else {
            $w create text $x $y -text $line -fill ${-fill} -font ${-font} -tag title -anchor w
            set index [lindex [.c bbox all] 2]
            set x $index
        }
    }
    every 10 "if !\[titleshow'roll $w title -2\] return"
 }
 proc titleshow'roll  {w tag dy} {
    $w move $tag $dy 0;# (1)
    foreach i [$w find withtag $tag] {
        set y1 [lindex [$w bbox $i] end]
        if {$y1<0} {$w delete $i}
    }
    llength [$w find withtag $tag]
 }
 proc every {ms body} {eval $body; after $ms [info level 0]}

 # That's all the code, here's a testing demo. Lines starting with - set parameters, the others are displayed:

 pack [canvas .c -bg gray -width 1000]
 tkwait visibility .c

 titleshow .c {
    -fill white
    -font {Helvetica 18 italic}
    The 12th European Tcl/Tk User Meeting (aka EuroTcl 2014) takes place July 12-13 2014 in Munich, Germany.
    -font {Helvetica 24 bold}
    -fill yellow
    The twenty-first Annual Tcl/Tk Conference (aka Tcl2014) takes place Nov 10-14 2014 in Portland, Oregon, USA.
    -font {Helvetica 18}
    -fill white
    Tcl/Tk 8.6.1 Released!
    -font {Helvetica 24}
    -fill yellow
    Please add your ideas to our GSoC Idea Page.

    -font {Helvetica 18}
     Our main page is the Tcl/Tk GSoC Page


    -font {Helvetica 10}
    Richard Suchenwirth
 }