Invoked when users press keys with predefined bindings in a cell of the specified control.
- macOS 10.0+
The control whose cell initiated the message. If the control contains multiple cells, the one that initiated the message is usually the selected cell.
The field editor of the control.
The selector that was associated with the binding.
true if the delegate object handles the key binding; otherwise,
These bindings are usually implemented as methods (
command) defined in the
NSResponder class; examples of such key bindings are arrow keys (for directional movement) and the Escape key (for name completion). By implementing this method, the delegate can override the default implementation of
command and supply its own behavior.
For example, the default method for completing partially typed pathnames or symbols (usually when users press the Escape key) is complete(_:). The default implementation of the
complete(_:) method (in
NSResponder) does nothing. The delegate could evaluate the method in the
command parameter and, if it’s
complete(_:), get the current string from the
text parameter and then expand it, or display a list of potential completions, or do whatever else is appropriate.