The amount by which the receiver changes its value when the user Option-drags the slider knob.
- macOS 10.0+
By default, the value of this property is
-1, and the receiver behaves no differently with the Option key down than with it up. The value of this property must fit the range of values the slider can represent—for example, if the slider has a minimum value of
5 and a maximum value of
10, the value should be between