Is it possible to call a function from a Tkinter widget.bind and include args???

[Eric Brunel]

Hi,

G. Willoughby wrote:

> Is it possible to call a function from a Tkinter widget.bind and include
> args???
> i.e. i want to do something like this:
> 
> def printButtonAndCoords(event, button):
>     print "you rolled over %s and coords are %d:%d" % button, event.x,
> eventy
> 
> Button1.bind("<Enter>", printButtonAndCoords("button1"))
> Button2.bind("<Enter>", printButtonAndCoords("button2"))
> 
> is this possible???

Since you didn't mention your Python version, maybe the lambda stuff 
provided by Martin and Fredrik won't work (with pre-2.0 versions, the 
lambda may not have the printButtonAndCoords function in its namespace, 
isn't it?).
So here is another solution I used quite a lot. with pre-2.0 Python It 
involves the creation of a callback class:

class GenericCallback:
  def __init__(self, callback, *firstArgs):
    self.__callback = callback
    self.__firstArgs = firstArgs
  def __call__(self, *lastArgs):
    apply(self.__callback, self.__firstArgs + lastArgs)

Then you make your binding like follows:

Button1.bind("<Enter>", GenericCallback(printButtonAndCoords, "button1"))

Your printButtonAndCoords function should then take the string as first 
argument and the Tkinter event as second. The binding will "call" the 
instance of GenericCallback, i.e. call its __call__ method, which will in 
turn call printButtonAndCoords with the arguments provided in the 
constructor, then in the actual call.

The GenericCallback class is also generic enough to have many other uses 
(in fact everywhere you must provide a function).

HTH
 - eric -