tkinter event object question

Fredrik Lundh fredrik at pythonware.com
Fri Jul 6 09:07:26 CEST 2001


Arun Ramanathan wrote:
> Is there a way by which I can determine which tkinter widget
> actually generated the event.
>
> Example if I had two buttons b1 and b2 initialized as shown below
> and bound to the event handler callme.
>
> -------------------------------
> from Tkinter import *
>
> root = Tk()
>
> def callme(event)
>     print "santa is coming"

    print event.widget

also see table 7-2 on this page:
http://www.pythonware.com/library/tkinter/introduction/events-and-bindings.htm

> b1 = Button(root,text='b1')
> b1.bind("<Button-1>",callme)
> b1.pack()

you shouldn't do this, of course: the right way to handle
button clicks is to use the "command" option.

the command option takes a single callable, so you have
to use a lambda (or a local function) to share callbacks:

    def callme(widget):
        print widget

    b1 = Button(root, text='b1',
        command=lambda b1=b1: callme(b1)
        )

(the b1=b1 thing captures the current value of b1, so we can
pass it to the callback when the lambda is executed)

also see:
http://www.pythonware.com/library/tkinter/introduction/button.htm

> b2= Button(root,text='b2')
> b2.bind("<Button-1>",callme)
> b2.pack()
>
> root.mainloop()
> ------------------------------

</F>

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