1 try:
2 # python 3.x
3 import tkinter as tk
4 except ImportError:
5 # python 2.x
6 import Tkinter as tk
7
8 class Example(tk.Frame):
9
10 def __init__(self, parent):
11 tk.Frame.__init__(self, parent)
12
13 # valid percent substitutions (from the Tk entry man page)
14 # %d = Type of action (1=insert, 0=delete, -1 for others)
15 # %i = index of char string to be inserted/deleted, or -1
16 # %P = value of the entry if the edit is allowed
17 # %s = value of entry prior to editing
18 # %S = the text string being inserted or deleted, if any
19 # %v = the type of validation that is currently set
20 # %V = the type of validation that triggered the callback
21 # (key, focusin, focusout, forced)
22 # %W = the tk name of the widget
23
24 vcmd = (self.register(self.onValidate),
25 '%d', '%i', '%P', '%s', '%S', '%v', '%V', '%W')
26 self.entry = tk.Entry(self, validate="key", validatecommand=vcmd)
27 self.text = tk.Text(self, height=10, width=40)
28 self.entry.pack(side="top", fill="x")
29 self.text.pack(side="bottom", fill="both", expand=True)
30
31 def onValidate(self, d, i, P, s, S, v, V, W):
32 self.text.delete("1.0", "end")
33 self.text.insert("end","OnValidate:\n")
34 self.text.insert("end","d='%s'\n" % d)
35 self.text.insert("end","i='%s'\n" % i)
36 self.text.insert("end","P='%s'\n" % P)
37 self.text.insert("end","s='%s'\n" % s)
38 self.text.insert("end","S='%s'\n" % S)
39 self.text.insert("end","v='%s'\n" % v)
40 self.text.insert("end","V='%s'\n" % V)
41 self.text.insert("end","W='%s'\n" % W)
42
43 # Disallow anything but lowercase letters
44 valid = (S.lower() == S)
45 if not valid:
46 self.bell()
47 return valid
48
49 if __name__ == "__main__":
50 root = tk.Tk()
51 Example(root).pack(fill="both", expand=True)
52 root.mainloop()
