[Richard Suchenwirth] 2007-09-28 - Installing Visual Studio 8, I found a [listbox] with some buttons to insert, delete, or move up or down items, and as I was waiting for a lengthy build, of course I had to try this in Tcl too :^) 

[WikiDbImage xlistbox.JPG]

For the "insert" function, a little overrideredirect toplevel with an entry is overlaid. This is however not very robust: pixel geometry needed to be tweaked (and is probably not right for other windowing themes), and it is only destroyed when the user hits <Return>. If he doesn't, multiple of those may be scattered over the screen... Improvement hints are very welcome.
[AEC] Couldn't you bind the entry widget to the <FocusOut> event and destroy the toplevel?  Also couldn't you simply use the place geometry manager and place an entry widget rather than using the overrideredirect toplevel? - [RS]: Oh yes, thanks! Fixed the ''insert'' and ''rewrite'' methods accordingly.

 proc xlb'delete w {
    set sel [$w curselection]
    $w delete $sel
    if {$sel==[$w size]} {incr sel -1}
    $w selection set $sel
 }
 proc xlb'insert w {
    set sel [$w curselection]
    if {$sel eq ""} {set sel 0}
    $w insert $sel ""
    $w selection clear 0 end
    $w selection set $sel
    foreach {x0 y0 x1 y1} [$w bbox $sel] break
    destroy $w.e
    place [entry $w.e -textvariable $w] -x [expr {$x0-4}] -y [expr {$y0-4}]
    focus $w.e
    set ::$w ""
    bind $w.e <Return> [list xlb'rewrite $w $sel]
 }
 proc xlb'rewrite {w sel} {
    global $w
    $w delete $sel
    $w insert $sel [set $w]
    $w selection set $sel
    destroy $w.e
 }
 proc xlb'move {w offset} {
    set sel [$w curselection]
    if {$sel ne "" && ($offset==-1 && $sel>0 || $offset==1 && $sel<[$w size]-1)} {
        set it [$w get $sel]
        $w delete $sel
        incr sel $offset
        $w insert $sel $it
        $w selection set $sel
    }
 }
#-- Test and demo:
 pack [frame .f] -anchor e
 button .f.+ -width 2 -text + -command {xlb'insert .l}
 button .f.x -width 2 -text x -command {xlb'delete .l}
 button .f.up -width 2 -text \u2191 -command {xlb'move .l -1} 
 button .f.dn -width 2 -text \u2193 -command {xlb'move .l 1}
 eval pack [winfo children .f] -side left

 pack [listbox .l]
 .l insert end foo bar grill baz wibble

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[AMG]: I think that's the first time I've ever seen [[[place]]] used for good, not evil. :^)

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