Posted whenever the pop-up list of the NSComboBox is going to be displayed.
The notification object is the NSComboBox whose pop-up window will be displayed. This notification does not contain a userInfo dictionary.
Available in Mac OS X v10.0 and later.
- Available in Monobjc Bridge: 10.6 (For Mac OS X 10.6 and later), 10.5 (For Mac OS X 10.5 and later)