Setting a Menu Item’s Key Equivalent
You can assign a keyboard equivalent to an NSMenuItem
instance, so that when the user types a character the menu item sends its action. The keyboard equivalent is defined in two parts. First is the basic key equivalent, which must be a Unicode character that can be generated by a single key press without modifier keys (Shift excepted). It is also possible to use a sequence of Unicode characters so long as the user’s key mapping is able to generate the sequence with a single key press. The basic key equivalent is set using setKeyEquivalent:
and returned by keyEquivalent
. The second part defines the modifier keys that must also be pressed. This is set using setKeyEquivalentModifierMask:
and returned by keyEquivalentModifierMask
. The modifier mask by default includes NSCommandKeyMask
, and may also include the masks for the Shift, Option, or other modifier keys. Specifying keyboard equivalents in two parts allows you to define a modified keyboard equivalent without having to know which character is generated by the basic key plus the modifier. For example, you can define the keyboard equivalent Command-Option-f without having to know which character is generated by typing Option-f.
Certain methods in NSMenuItem
can override assigned keyboard equivalents with those the user has specified in the defaults system. The setUsesUserKeyEquivalents:
method turns this behavior on or off, and usesUserKeyEquivalents
returns its status. To determine the user-defined key equivalent for an NSMenuItem object, invoke the userKeyEquivalent
instance method. If user-defined key equivalents are active and an NSMenuItem
object has a user-defined key equivalent, its keyEquivalent
method returns the user-defined key equivalent and not the one set using setKeyEquivalent:
.
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