Sent when a text view needs to determine if text in a specified range should be changed.
- macOS 10.0+
The text view sending the message. This is the first text view in a series shared by a layout manager, not necessarily the text view displaying the selected text.
The range of characters to be replaced.
The characters that will replace the characters in
nilif only text attributes are being changed.
YES to allow the replacement, or
NO to reject the change.
If a delegate implements this method and not its multiple-selection replacement,
text, it is called with an appropriate range and string. If a delegate implements the new method, then this one is ignored.