From b46028b2797b886154258dcafe71c349cdc68b43 Mon Sep 17 00:00:00 2001
From: Blair Drummond <blair.robert.drummond@gmail.com>
Date: Wed, 2 Oct 2019 14:59:00 -0400
Subject: [PATCH] Add a message command. Fixes old version's bugs.

---
 config.def.h |   9 ++++
 config.mk    |   2 +-
 slock.1      |   7 +++
 slock.c      | 120 +++++++++++++++++++++++++++++++++++++++++++++++++--
 4 files changed, 133 insertions(+), 5 deletions(-)

diff --git a/config.def.h b/config.def.h
index 9855e21..c2a0ab2 100644
--- a/config.def.h
+++ b/config.def.h
@@ -10,3 +10,12 @@ static const char *colorname[NUMCOLS] = {
 
 /* treat a cleared input like a wrong password (color) */
 static const int failonclear = 1;
+
+/* default message */
+static const char * message = "Suckless: Software that sucks less.";
+
+/* text color */
+static const char * text_color = "#ffffff";
+
+/* text size (must be a valid size) */
+static const char * font_name = "6x10";
diff --git a/config.mk b/config.mk
index 74429ae..c4ccf66 100644
--- a/config.mk
+++ b/config.mk
@@ -12,7 +12,7 @@ X11LIB = /usr/X11R6/lib
 
 # includes and libs
 INCS = -I. -I/usr/include -I${X11INC}
-LIBS = -L/usr/lib -lc -lcrypt -L${X11LIB} -lX11 -lXext -lXrandr
+LIBS = -L/usr/lib -lc -lcrypt -L${X11LIB} -lX11 -lXext -lXrandr -lXinerama
 
 # flags
 CPPFLAGS = -DVERSION=\"${VERSION}\" -D_DEFAULT_SOURCE -DHAVE_SHADOW_H
diff --git a/slock.1 b/slock.1
index 82cdcd6..946165f 100644
--- a/slock.1
+++ b/slock.1
@@ -6,6 +6,8 @@
 .Sh SYNOPSIS
 .Nm
 .Op Fl v
+.Op Fl f
+.Op Fl m Ar message
 .Op Ar cmd Op Ar arg ...
 .Sh DESCRIPTION
 .Nm
@@ -16,6 +18,11 @@ is executed after the screen has been locked.
 .Bl -tag -width Ds
 .It Fl v
 Print version information to stdout and exit.
+.It Fl f
+List all valid X fonts and exit.
+.It Fl m Ar message
+Overrides default slock lock message.
+.TP
 .El
 .Sh SECURITY CONSIDERATIONS
 To make sure a locked screen can not be bypassed by switching VTs
diff --git a/slock.c b/slock.c
index 5ae738c..610929b 100644
--- a/slock.c
+++ b/slock.c
@@ -15,6 +15,7 @@
 #include <unistd.h>
 #include <sys/types.h>
 #include <X11/extensions/Xrandr.h>
+#include <X11/extensions/Xinerama.h>
 #include <X11/keysym.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
@@ -24,6 +25,9 @@
 
 char *argv0;
 
+/* global count to prevent repeated error messages */
+int count_error = 0;
+
 enum {
 	INIT,
 	INPUT,
@@ -83,6 +87,98 @@ dontkillme(void)
 }
 #endif
 
+static void
+writemessage(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);
+}
+
+
+
 static const char *
 gethash(void)
 {
@@ -194,6 +290,7 @@ readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
 					                     locks[screen]->win,
 					                     locks[screen]->colors[color]);
 					XClearWindow(dpy, locks[screen]->win);
+					writemessage(dpy, locks[screen]->win, screen);
 				}
 				oldc = color;
 			}
@@ -300,7 +397,7 @@ lockscreen(Display *dpy, struct xrandr *rr, int screen)
 static void
 usage(void)
 {
-	die("usage: slock [-v] [cmd [arg ...]]\n");
+	die("usage: slock [-v] [-f] [-m message] [cmd [arg ...]]\n");
 }
 
 int
@@ -313,12 +410,25 @@ main(int argc, char **argv) {
 	gid_t dgid;
 	const char *hash;
 	Display *dpy;
-	int s, nlocks, nscreens;
+	int i, s, nlocks, nscreens;
+	int count_fonts;
+	char **font_names;
 
 	ARGBEGIN {
 	case 'v':
 		fprintf(stderr, "slock-"VERSION"\n");
 		return 0;
+	case 'm':
+		message = EARGF(usage());
+		break;
+	case 'f':
+		if (!(dpy = XOpenDisplay(NULL)))
+			die("slock: cannot open display\n");
+		font_names = XListFonts(dpy, "*", 10000 /* list 10000 fonts*/, &count_fonts);
+		for (i=0; i<count_fonts; i++) {
+			fprintf(stderr, "%s\n", *(font_names+i));
+		}
+		return 0;
 	default:
 		usage();
 	} ARGEND
@@ -363,10 +473,12 @@ main(int argc, char **argv) {
 	if (!(locks = calloc(nscreens, sizeof(struct lock *))))
 		die("slock: out of memory\n");
 	for (nlocks = 0, s = 0; s < nscreens; s++) {
-		if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL)
+		if ((locks[s] = lockscreen(dpy, &rr, s)) != NULL) {
+			writemessage(dpy, locks[s]->win, s);
 			nlocks++;
-		else
+		} else {
 			break;
+		}
 	}
 	XSync(dpy, 0);
 
-- 
2.20.1

