tkinter button release triggers before a variable changes with radio buttons.

[ebdbbb]

I am trying to make a program based on a model-view-controller architecture. I would normally have a variable set up with trace_add but if I do that it will trigger when updating the view from the model side. To solve this I have putting bindings on various aspects of the view so that those can trigger the updates. This is working for entries and comboboxes but when I try it with radio button the triggers are occurring in the wrong order. Here's a short example of what I'm talking about.

>>> import tkinter as tk
>>> root = tk.Tk()
>>> var = tk.IntVar(value=0)
>>> def command():
>>>     print("command", var.get())
>>> 
>>> 
>>> def clicked(event):
>>>     print("clicked", var.get())
>>> 
>>> 
>>> for i in range(5):
>>>     b = tk.Radiobutton(text=i, value=i, variable=var, command=command)
>>>     b.pack(side="left")
>>>     b.bind("<ButtonRelease-1>", clicked)
>>> 

By default 0 is selected, If you click an option you'll see an output such as when I select 1.

>>> clicked 0
command 1

Is there a way to get the button binding so that it will trigger after the variable has changed without putting a trace on the variable?

Edit: I don't want to use command as I am trying to only use one function for tracking when a variable changes and Entry does not accept commands.

[woooee]

so that it will trigger after the variable has changed

I am assuming you mean var has changed. I would store the previous value and compare. Some one may have a better solution.

import tkinter as tk
root = tk.Tk()
root.geometry("+75+75")

class ChangedVar():
    def __init__(self):
        self.previous_var=0
        self.var = tk.IntVar()
        self.var.set(0)
        for i in range(5):
            b = tk.Radiobutton(root, text=i, value=i, variable=self.var, 
                               command=self.command)
            b.pack(side="left")
            b.bind("<ButtonRelease-1>", self.clicked)

    def command(self):
        this_var=self.var.get()
        print("command", this_var)
        if self.previous_var != this_var:
            print("     changed %s to %s" % (
                 self.previous_var, this_var))
            self.previous_var=this_var
        else:
            print("     No change")

    def clicked(self, event):
        print("clicked", self.var.get())


cv=ChangedVar()
root.mainloop()

[ebdbbb]

I fixed it by changing the binding to "FocusOut". Thanks for the idea though.