How to get PMW counter to call a function when value changes

[DaveJ]

Hi,
I have implemented a number of megawidget counters, and I would like them to call a function when their values change. Is this possible?

So far, I have only been able to get the counters to call my function when I enter keystrokes in the entryfield (excluding the up and down arrow keys, which do nothing). Here's a snippet:

myCounter.component('entryfield').bind("<Key>",myFunc)

I would like the function to also be called when I click the uparrow and downarrow objects. However, if I do:

myCounter.component('uparrow').bind("<Button 1>",myFunc)

then the uparrow loses its normal operation (I can put myCounter.incre ment() in myFunc, but when I click and hold the button, the counter only increments once, unlike the normal PMW counter behavior)

I also tried using entryfield_comm and, but that only handles <Enter> key events.

myCounter = Pmw.Counter(myFrame,
    datatype = {'counter': 'real'},
    entryfield_validate = {'validator': 'real', 'min': 0.0, 'max': 10.0},
    entryfield_value = 2.0,
    entryfield_command = myFunc,
    entry_justify = 'center',
    entry_width = 4,
    orient = 'vertical',
    increment = 0.1,
    labelpos = 'w',
    label_text = 'My text')

So, is there a way for the PMW counter to call a function when its value changes?

Thanks in advance for your help

[bvdet]

Try this:

myCounter.component('uparrow').bind("<Button 1>",myFunc, add="+")

[DaveJ]

Bvdet,
Thank you; I'm extremely impressed! That works perfectly. Can you tell me how you figured that out so I know where to look in the future? I just ran help(Button.bin d), and it mentions add, but it doesn't say anything about the values that add can take. Thanks again.

[bvdet]

Check the Python documentation "Tkinter — Python interface to Tcl/Tk" section "24.1.6.7. Bindings and Events".