Tkinter - tracking toplevel windows

[Andrew Wheatley]

Jeff:

Thanks for your quick response.  I just figured it out 5 minutes
ago.

Andrew

On Mon, 7 
Apr 2003, Jeff Epler wrote:

> On Mon, Apr 07, 2003 at 11:23:13AM -0700, Andrew Wheatley wrote:
> > I have a Tkinter Gui with a button which generates other toplevel windows.
> > Whenever a toplevel is generated, I append its id to a global list.  What I'd like
> > to do with wm_protocol/WM_DELETE_WINDOW method is remove from the list
> > the window id currently being killed and then destroy the window.
> > 
> > My question is:
> > 
> > How can I tell which window is being destroy when I kill it with the X in the 
> > top right hand corner.
> 
> Arrange to include a reference to the window when in the callback.  For
> example:
> 
>     def close_clicked(t):
>         print "close was clicked on window", t
> 
>     t = Tkinter.Toplevel()
>     t.wm_protocol('WM_DELETE_WINDOW', lambda t=t: close_clicked())
> 
> When WM_DELETE_WINDOW is defined, using window-manager "close"
> functionality (such as ALT-F4, clicking the "X", etc) merely triggers
> the callback, which can override the close event.
> 
> There's also the <Destroy> binding, but this is a little more
> problematic.  You *can* use the .widget attribute of the event, but due
> to a detail of Tk internals*, this binding will be applied to any widget
> inside t.  So below, you'll get two messages:
> 
>     def destroyed(evt):
>         print "window", evt.widget, "was destroyed"
> 
>     t.bind("<Destroy>", destroyed)
>     b = Tkinter.button(t); b.pack()
>     t.destroy()
> 
> So if you're interested only in toplevel windows, do this:
>     def destroyed_smarter(evt):
>         if not evt.widget.wm_toplevel() is evt.widget:
>             return # not actually the window
>         print "window", evt.widget, "was destroyed"
> 
> The <Destroy> event fires after the destruction has begun, so there's no
> opportunity to veto the destruction.
> 
> Jeff
> * See the documentation on "bindtags" for an explanation of why this is
>   so
> 

-- 
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Andrew Wheatley
Imaging Research Laboratories         phone: (519) 663-5777 X34324
JP Robarts Research Institute         FAX  : (519) 663-3403
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http://www.imaging.robarts.ca/~awheat/index.html
email: awheat at imaging.robarts.ca
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