VCheckScaleEvents - checks events in the multi-resolution scales.
int *event_waiting; /*RETURN*/
VCheckScaleEvents checks events in the multi-resolution scales.
VCheckScaleEvents checks for the events in the event queue. The events
checked are MotionNotify, or Left or Middle button presses; if these events
are detected, VCheckScaleEvents returns 1 to *event_waiting else 0 to
*event_waiting. This indicates that a new value has been selected by the
user and updating for the previous value should be aborted.
0 - work successfully.
event_waiting - returns 1 to indicate there is an event waiting, and 0
for no event waiting.
A call to VSelectScaleVlaue should be active. During a call to the
update function passed to VSelectScaleValue, calls to VCheckScaleEvents may
be made. If an event is waiting, return to VSelectScaleValue.