The text object requesting permission to begin editing.
YES if the text object should proceed to make changes. If the delegate returns NO, the text object abandons the editing operation.
The default behavior of this method is to return the value obtained from control:textShouldBeginEditing:, unless the delegate doesn’t respond to that method, in which case it returns YES, thereby allowing text editing to proceed.
This method is invoked to let the NSTextField respond to impending changes to its text. This method’s default behavior is to send control:textShouldBeginEditing: to the receiver’s delegate (passing the receiver and textObject as parameters).