The application uses this message to customize the slider for a specific use. In setting the shaft dimensions, only the breadth of the slider can be set. The length of the shaft is always determined by the number of increments and the spacing between increments, both of which are set for the primary scale when the slider is created.

Positioning of the shaft within the slider window could be used by applications that cannot use the default positioning provided by the slider control.

Setting of the slider arm dimensions could be used by applications that need a larger slider arm, such as touch screen applications.

Setting the slider arm position can be used to:

• Set the initial value of the slider before it becomes visible.

• Change the value when it is tied to another control, such as an entry field.

• Show the value of a quantity when the slider is being used to monitor an event, such as a read-only slider being used as a progress indicator.