altIncrementValue
The amount by which the slider changes its value when the user Option-drags the slider knob.
Declaration
var altIncrementValue: Double { get set }Discussion
By default, the value of this property is -1.0, and the slider 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 0 and 5.