CODEWITHSUNDEEP
pythontkintertext
Jason Yang
Jason Yang

Reputation: 13061

How can I get the correct value of INSERT after 'BackSpace' striked in Text widget?

The value of INSERT will be changed after pressing the BackSpace key, but I got the old position. How can I get the action-after position.

For example:

Th|is is a book.

"|" is the cursor, and the value of INSERT is 1.2

When BackSpace pressed, I got a 1.2 firstly in event handler of , then the cursor moved to 1.1

The same, when I typed This is a book T => 1.0, h => 1.1, ......, I think it should be T => 1.1, h => 1.2, ......

There are lot of Keys to change the cursor position, I cannot get the final position to reduce INSERT always by 0.1

Is there any way to get the final position ? or the handler can work after Text widget ? 

from tkinter import *

def action(event):
    print(event)
    position = t.index(INSERT)
    print(position)

root = Tk()
t = Text(root)
t.bind('<Key>', action)
t.pack()

root.mainloop()

expect: 1.1 actual result: 1.2

Upvotes: 0

Views: 40

Answers (1)

j_4321
j_4321

Reputation: 16169

This is because the event '<Key>' is triggered before the key effect is processed. Events directly bound to the widget always occur before class events, and the edition of the text in the widget is a class binding to the keyboard.

What you want is a binding to '<KeyRelease>', which will be triggered after the key is processed:

from tkinter import *

def action(event):
    print(event)
    position = t.index(INSERT)
    print(position)

root = Tk()
t = Text(root)
t.bind('<KeyRelease>', action)
t.pack()

root.mainloop()

Upvotes: 2

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