INQUIRE INPUT QUEUE OVERFLOW (PHOP,WSOP,*,*)

Purpose

Use Inquire Input Queue Overflow to inquire identification of the event report causing the event queue overflow.

Once the event queue overflow occurs, the graPHIGS API will not add more events to the event queue until the application clears the overflow situation by emptying the event queue. The application can make the event queue empty by using the Await Event or Flush Device Events subroutines.

If the event queue has overflowed since Open PHIGS or the last invocation of this subroutine, then the graPHIGS API returns the identification of the logical input device that caused the overflow. Logical input device classes include: LOCATOR, STROKE, VALUATOR, CHOICE, PICK, and STRING.

The graPHIGS API does not report the event queue overflow to the application when the overflow occurs. It is reported on the next invocation of the following subroutines which may change the contents of the event queue:

• Await Event
• Flush Device Events
• Close Workstation

If the information is available, then the graPHIGS API sets the error indicator to zero and returns the values in the output parameters. If the information is unavailable, then the values returned in the output parameters are unpredictable and the graPHIGS API sets the error indicator to one of the following errors:

3

Function Requires State (PHOP,WSOP,*,*)

257

Input Queue Has Not Overflowed

258

Input Queue Has Overflowed, But Workstation Is Closed

Language Bindings

C

Output Parameters

FORTRAN

Output Parameters