list_17_08.c

This source code has been tested under OpenWindows 2.0, Sun s X11/NeWS server. For Xlib programs th

/***********************************************************************
**                                                                    **
**  listing_17_08.c                                                   **
**                                                                    **
**  Digital clock program, implemented using a label updated by a     **
**  timeout callback.                                                 **
**                                                                    **
***********************************************************************/


#include <time.h>
#include <Xm/Label.h>


void	TimeoutCB();			/* FORWARD Definitions	      */


Widget	appshell,
	the_label;


void main( argc, argv )
    int     argc;
    char    *argv[];
{
    appshell = XtInitialize( argv[0], "Listing_17_08", NULL, 0, &argc, argv );

    the_label = XmCreateLabel( appshell, "TheLabel", NULL, 0 );
    XtManageChild( the_label );

    XtAddTimeOut( 1000, TimeoutCB, the_label );

    XtRealizeWidget( appshell );
    XtMainLoop();
}



void TimeoutCB( w, id )
    Widget	    w;			/* Note implicit caddr_t cast */
    XtIntervalId    *id;		/* Ignored		      */
{
    long	    clock;		/* The raw time value...      */
    struct tm	    *the_time;		/* Converted to localtime...  */
    char	    lcl_str[256];       /* Converted to text...       */
    XmString	    xms;		/* Converted for the widget   */
    Arg		    the_arg;


    XtAddTimeOut( 1000, TimeoutCB, the_label );

    clock    = time( NULL );
    the_time = localtime( &clock );
    sprintf( lcl_str, "%02d:%02d:%02d", the_time->tm_hour,
					the_time->tm_min,
					the_time->tm_sec );
    xms = XmStringCreate( lcl_str, XmSTRING_DEFAULT_CHARSET );
    XtSetArg( the_arg, XmNlabelString, xms );
    XtSetValues( w, &the_arg, 1 );

    XmStringFree( xms );
}