ENABLE_EVENTS(3G)

NAME

enable_events − enable queuing of events from the named input device

SYNOPSIS

C Syntax:

void enable_events(fildes,class,ordinal);
int fildes,class,ordinal;

FORTRAN77 Syntax:

subroutine enable_events(fildes,class,ordinal)
integer*4 fildes,class,ordinal

Pascal Syntax:

procedure enable_events(fildes,class,ordinal:integer);

DESCRIPTION

Input Parameters

fildes Integer file descriptor returned by gopen when an I/O path to a graphics device is opened.

class One of the following device classes: LOCATOR, CHOICE, or ALL. The integer values assigned to these class designators are found in the Starbase include file used with your programs.

ordinal Logical device number ranging from 1 to the number of devices in the specified class. LOCATOR and CHOICE devices have device-dependent ordinal values. See inquire_input_capabilities for details. If class equals ALL, ordinal is ignored.

Discussion

Enable_events enables the queuing of events into the event queue from the device specified by fildes, class, and ordinal. A single event queue is used by all system graphics input devices.

If class is set to ALL, ordinal is ignored and events are enabled for all logical devices of this fildes.

When any event occurs, an event report is placed in the common event queue and appropriate signals sent. The event queue can be examined by using the await_event call.

Any resources needed to enable and generate events are acquired or allocated at this time. Enable events on a logical device does not affect the state of other devices on the same physical device.

DEFAULTS

All devices are initially disabled for event generation.

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