NAME

REQUEST VALUATOR − request an operator interaction with a valuator device

SYNOPSIS

C Syntax

void
preq_val ( ws, dev, in_status, value )
Pintws;workstation identifier
Pintdev;valuator device number
Pin_status∗in_status;OUT input status
Pfloat∗value;OUT value

Required PHIGS Operating States

(PHOP, WSOP, ∗, ∗)

DESCRIPTION

Purpose

Use REQUEST VALUATOR to request an operator interaction with a specified valuator device. The device must be in request mode. See SET VALUATOR MODE and INITIALIZE VALUATOR for more information.  See the Available Devices section of INITIALIZE VALUATOR for a description of the available valuator devices. 

The request suspends PHIGS until the specified device is triggered or the operator performs a BREAK.  A BREAK is performed by typing the CONTROL and D keys simultaneously (^D). 

C Input Parameters

wsWorkstation identifier. An integer specifying the workstation with which the requested valuator device is associated. 

devThe device number of the requested valuator device.  See the Available Devices section of INITIALIZE VALUATOR for a description of the available valuator devices. 

C Output Parameter

in_status
A pointer to the location to store the request status. Pin_status is defined in phigs.h as follows:

typedef enum {
PIN_STATUS_NONE,
PIN_STATUS_OK,
PIN_STATUS_NO_IN
} Pin_status;

valueA pointer to the location to store the valuator value. 

Execution

REQUEST VALUATOR requests a logical input value from the specified valuator device. The specified device must be in request mode. See SET VALUATOR MODE for more information. 

REQUEST VALUATOR creates a measure process for the specified device and suspends PHIGS until the device is triggered or the operator issues a BREAK.  A BREAK is generated by the operator by depressing the CONTROL and D keys simultaneously (^D). 

If a BREAK occurs, a status of PIN_STATUS_NO_IN is returned and the valuator data is undefined.  If a status of PIN_STATUS_OK is returned, the valuator data is available.  In either case, the measure process is then terminated and PHIGS processing resumes. 

See INITIALIZE VALUATOR for a description of the available valuator devices. 

ERRORS

003Ignoring function, function requires state (PHOP, WSOP, ∗, ∗)

054Ignoring function, the specified workstation is not open

061Ignoring function, specified workstation is neither of category INPUT nor of category OUTIN

250Ignoring function, the specified device is not available on the specified workstation

251Ignoring function, the function requires the input device to be in REQUEST mode

SEE ALSO

INITIALIZE VALUATOR (3P)
SET VALUATOR MODE (3P)

September 02, 1992