binding to a toplevel window

MGS [2003/09/20] - Sometimes it is necessary/desirable to bind to a toplevel window. For example, I might want to withdraw a toplevel window, instead of having it iconify, when clicking the minimize button. There are several ways to do this:

1. Bind directly to the window name. e.g.

  bind . <Unmap> [list wm withdraw .]

However, the binding will trigger if you decide to unmanage any of the window's child widgets, due to their default binding tags.

2. Bind to the toplevel window's class. e.g.

  bind [winfo class .] <Unmap> [list wm withdraw %W]

However, this binding will fire for all windows with the same class as . .

3. Create a new binding tag for the toplevel window and then create the binding to that tag. e.g.

  bindtags . [list . bind. [winfo class .] all]
  bind bind. <Unmap> [list wm withdraw %W]

or more generally:

  set W [toplevel .mywin]
  bindtags $W [linsert [bindtags $W] 1 bind$W]
  bind bind$W <Unmap> [list wm withdraw %W]

RUJ: Hi, I would like to know ... How to bind a "Leave" command to main toplevel but it should be work on its child widgets also. I want to make popupwindow which will have some entries and labels & this window should destroyed after cursor moved away from window.

MJ - Just destroy the toplevel and all its child widgets are destroyed as well. In the <Leave> event binding make sure you only call the destroy when the toplevel is closed. Leaving a child widget will also call the binding, because the toplevel is in every child widget's bindtags list.

  toplevel .l
  bind .l <Leave> {tlclose %W}
  proc tlclose {w} {if {$w == [winfo toplevel $w]} {destroy $w}}

RUJ: Thanking you it is working very well. Before that I was trying by,

  set destroyScript [list destroy $wa]
  bind $wa <Enter> [list after cancel $destroyScript]
  bind $wa <Leave> $destroyScript

MGS: My suggestion, as in point 3 above, would be:

  toplevel .l
  bindtags .l [list . bind.l [winfo class .l] all]
  bind bind.l <Leave> [list destroy %W]

RUJ: hello MJ, I am trying to use above code for dragging window but it not working. This is the code giving error of expression syntax.

  set ::moveable 0
  wm overrideredirect $wa 1
  bind $wa <ButtonPress> {set ::moveable 1}
  bind $wa <ButtonRelease> {set ::moveable 0}
  bind $wa <Motion> {if {!$::moveable} {break}; if {%W == [winfo toplevel %W]} {wm geometry [winfo toplevel %W] +[expr %X-5]+[expr %Y-5]} }

Bryan Oakley says: The first part of the solution is to move all that code to a proc. Unless you have a specific reason to do otherwise you should stick to the rule of thumb "never have more than one command in a binding". It makes writing and maintaining code like this soooo much easier.

Try this:

  bind $wa <Motion> [list handleMotionEvent %W %X %Y]
  proc handleMotionEvent {w x y} {
     if {! $::moveable} return
     set top [winfo toplevel $w]
     if {$w ne $top} return

     wm geometry $top +[expr {$x-5}]+[expr {$y-5}]
  }

RUJ: Thanking you. it is working great... I have another problem that how i can drag elements within listbox to change its order or by up-down key. I am using two buttons right now. here is code for moving selected element down.

  listbox $top.lis50 \
        -background gray -listvariable "" ;
  button $top.but01 \
        -pady 0 -text D1 -bd 1 -command movedown lis50}

  proc movedown { listp } {
    variable top ;
    variable uLimit ; 

    global exist_compNames
    set seleIndex ""
    set movecompindex ""
    set seleIndex [$top.$listp curselection]
    set seleIndexlen [llength $seleIndex]
    if {$seleIndex < 0} {
      mvarproc "You have selected nothing"
    } elseif {$seleIndexlen == 1} {
      set movecompindex [lindex $seleIndex end]
      set movecompname [$top.$listp get $seleIndex ]
  #   tk_messageBox -message "movecompindex=$movecompindex movecompname=$movecompname"
      set removeindex [expr $movecompindex +1]
      set removedataname [$top.$listp get $removeindex ]
      set lenall [$top.$listp size]
  #   set lenlist [expr $lenall -1]
  #   tk_messageBox -message "movecompindex=$removeindex movecompname=$lenlist"
      if {$removeindex == $lenall} {
        errorproc "upper limit" 
      } else {
        $top.$listp delete $removeindex
        $top.$listp insert $movecompindex $removedataname
      }
    } else {
      set seleIndexEnd [lindex $seleIndex end]
      set seleIndexStart [lindex $seleIndex 0]
      set removeIndexL [expr $seleIndexEnd +1]
      set removeIndexLdata [$top.$listp get $removeIndexL]
      set lenall [$top.$listp size]
      if {$removeIndexL == $lenall} {
        errorproc "lower limit"
      } else {
        $top.$listp delete $removeIndexL
        $top.$listp insert $seleIndexStart $removeIndexLdata
  #     tk_messageBox -message "$seleIndexEnd"
      }
    }
  }

Neil: Hi. I would like to know if there is any way to set the toplevel window to be a Java frame. I need to know this in order to embed Tcl frames withimn a Java UI. Is there any way this can be done.

MGS [2010/05/14]: Have a look at the output from "wish -help", especially the -use option. See also toplevel.

HarishBansal - 2011-07-25 08:33:32

Hi,

I am using a the below mentioned bind function.

 bind . <Unmap> {unmapper %W}

 proc unmapper { W } {
 if { [string equal [winfo toplevel $W] $W] && \
 [string equal [wm state $W] "iconic"] } {
 puts "Minimizing $W"
 }
 }

Please do let me know what will be the case when this procedure will be called again and again just like in a for loop.