Spin Event 420
Applies To: Spinner UpDown

Description

If enabled, this event is generated when the user clicks one of the spin buttons in a Spinner object. The event is reported before the value of the Thumb property has been updated. You may disable the operation of the spin buttons by disabling this event. You may selectively prevent the user selecting a particular value by returning 0 from a callback function. You may also return a modified event message as a result in order to set the Thumb property to a different value.

The event message reported as the result of ⎕DQ, or supplied as the right argument to your callback function, is a 4-element vector as follows :

[1] Object ref or character vector
[2] Event 'Spin' or 420
[3] Thumb value Integer. The new value of the Thumb property resulting from the user pressing one of the spin buttons.
[4] Adjustment Integer. The amount by which the new value of the Thumb differs from its previous value.