#include <X11/extensions/Xinerama.h> /* global count to prevent repeated error messages */int count_error = 0; static voidwritemessage(Display *dpy, Window win, int screen){	int len, line_len, width, height, s_width, s_height, i, j, k, tab_replace, tab_size;	XGCValues gr_values;	XFontStruct *fontinfo;	XColor color, dummy;	XineramaScreenInfo *xsi;	GC gc;	fontinfo = XLoadQueryFont(dpy, font_name); 	if (fontinfo == NULL) {		if (count_error == 0) {			fprintf(stderr, "slock: Unable to load font \"%s\"\n", font_name);			fprintf(stderr, "slock: Try listing fonts with 'slock -f'\n");			count_error++;		}		return;	} 	tab_size = 8 * XTextWidth(fontinfo, " ", 1); 	XAllocNamedColor(dpy, DefaultColormap(dpy, screen),		text_color, &color, &dummy); 	gr_values.font = fontinfo->fid;	gr_values.foreground = color.pixel;	gc=XCreateGC(dpy,win,GCFont+GCForeground, &gr_values); 	/*  To prevent "Uninitialized" warnings. */	xsi = NULL; 	/*	 * Start formatting and drawing text	 */ 	len = strlen(message); 	/* Max max line length (cut at '\n') */	line_len = 0;	k = 0;	for (i = j = 0; i < len; i++) {		if (message[i] == '\n') {			if (i - j > line_len)				line_len = i - j;			k++;			i++;			j = i;		}	}	/* If there is only one line */	if (line_len == 0)		line_len = len; 	if (XineramaIsActive(dpy)) {		xsi = XineramaQueryScreens(dpy, &i);		s_width = xsi[0].width;		s_height = xsi[0].height;	} else {		s_width = DisplayWidth(dpy, screen);		s_height = DisplayHeight(dpy, screen);	} 	height = s_height*3/7 - (k*20)/3;	width  = (s_width - XTextWidth(fontinfo, message, line_len))/2; 	/* Look for '\n' and print the text between them. */	for (i = j = k = 0; i <= len; i++) {		/* i == len is the special case for the last line */		if (i == len || message[i] == '\n') {			tab_replace = 0;			while (message[j] == '\t' && j < i) {				tab_replace++;				j++;			} 			XDrawString(dpy, win, gc, width + tab_size*tab_replace, height + 20*k, message + j, i - j);			while (i < len && message[i] == '\n') {				i++;				j = i;				k++;			}		}	} 	/* xsi should not be NULL anyway if Xinerama is active, but to be safe */	if (XineramaIsActive(dpy) && xsi != NULL)		XFree(xsi);}