description |
The Widget callback package Wcb provides general solution to widget validation, input manipulation, limitation, etc. It enables users to associate arbitrary commands with some Tk entry, tile entry, BWidget Entry, spinbox, tile combobox, listbox, tablelist, text, and ctext widget operations. These commands will be invoked automatically in the global scope whenever the respective widget operation is executed, either before and/or after. Before-callbacks can cancel the respective widget command or modify its arguments. |