Initializing logical input devices

GDDM V3R2 Base Application Programming Guide

Initializing logical input devices

GDDM V3R2 Base Application Programming Guide
SC33-0867-01

Initializing a logical input device means defining its characteristics. For a locator, for instance, you can specify its echo type and its initial position on the screen, and for a pick device, the pick aperture. There are no variable characteristics of choice devices, so these cannot be initialized.

The initialization values are taken from three sources:

The parameters of optional initialization calls, namely GSILOC for the locator, GSIPIK for the pick device, GSISTR for the string device, and GSISTK for the stroke device.
Other optional calls, namely GSIDVF (initial data value, float) and GSIDVI (initial data value, integer). These calls are used to specify some less frequently used initialization parameters.
GDDM-defined defaults.

The complete set of characteristics is determined from these three sources when a device is enabled. All the required initialization and data-record calls must therefore be issued before the GSENAB call. Your program is in error if it issues any of them for an enabled device.

You can reinitialize a logical input device at any time by disabling it and then reenabling it.

You can issue as many initialization calls (GSILOC, GSIPIK, GSISTR, GSISTK, GSIDVF, and GSIDVI) as you choose while the device is not enabled. This means that you can specify a characteristic and later delete or respecify it, if the device has not yet been enabled, or has been enabled and is now disabled again. Information about undoing the effects of the initialization calls is given in their descriptions in GDDM Base Application Programming Reference book.

Subtopics:

Notices | Terms of use | Support | Contact z/OS