How to stop copy, paste, and backspace in text widget in tkinter?
Sometimes, in a tkinter GUI application, we may want to restrict the user from copying, pasting, and/or backspacing the contents of a Text widget. This can be useful, for example, when we want to make sure that the user only enters valid or necessary information into the Text widget.
One way to achieve this is by setting a custom binding for the events that correspond to these actions. Specifically, we can bind the <Key>
event to a function that checks whether the key pressed corresponds to one of these actions, and prevent the default behavior (i.e., copying, pasting, or backspacing) if it does.
Here’s an example code snippet that demonstrates how to do this:
import tkinter as tk
def restrict(event):
if event.keysym in ['BackSpace', 'Control_L', 'Control_R', 'c', 'C', 'v', 'V']:
# prevent default behavior
return 'break'
root = tk.Tk()
text = tk.Text(root)
text.pack()
# bind <Key> event to restrict function
text.bind('<Key>', restrict)
root.mainloop()
In this code, we define a restrict
function that takes an event
parameter, representing the event that triggered it. We then check whether the keysym
attribute of the event (i.e., the name of the key pressed) corresponds to any of the keys that we want to restrict (BackSpace
, Control
, c
, and v
for copy and paste, C
and V
for uppercase versions). If it does, we return the string 'break'
, which prevents the default behavior of the Text widget for that event.
We then create a Text
widget and pack it into the root window. Finally, we bind the <Key>
event to the restrict
function, which sets the customized behavior for the Text widget.
Note that this example only restricts the actions for the <Key>
event, which corresponds to keys being pressed. Other ways of modifying the Text widget’s contents (such as using the context menu or the Edit menu on macOS) may still allow copying, pasting, or backspacing. To fully restrict these actions, we would need to set custom bindings for the <Control-c>
, <Control-v>
, and <BackSpace>
events, for example.
Conclusion
In summary, we can restrict copying, pasting, and backspacing in a tkinter Text widget by setting a custom binding for the <Key>
event and checking whether the pressed key corresponds to one of these actions. By returning 'break'
, we prevent the Text widget from executing its default behavior for that event. This can be useful when we want to enforce data validation or restrict user input in our GUI application.