From 95463f58beb669d9221881deac3b6df7d9c4f162 Mon Sep 17 00:00:00 2001
From: Klemens Nanni <kl3@posteo.org>
Date: Fri, 2 Sep 2016 14:53:30 +0200
Subject: [PATCH] Indicate the state of CapsLock through a different color

---
 config.def.h |  1 +
 slock.c      | 15 ++++++++++++---
 2 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/config.def.h b/config.def.h
index 9855e21..6288856 100644
--- a/config.def.h
+++ b/config.def.h
@@ -6,6 +6,7 @@ static const char *colorname[NUMCOLS] = {
 	[INIT] =   "black",     /* after initialization */
 	[INPUT] =  "#005577",   /* during input */
 	[FAILED] = "#CC3333",   /* wrong password */
+	[CAPS] = "red",         /* CapsLock on */
 };
 
 /* treat a cleared input like a wrong password (color) */
diff --git a/slock.c b/slock.c
index d55eb3d..d7804f1 100644
--- a/slock.c
+++ b/slock.c
@@ -18,6 +18,7 @@
 #include <X11/keysym.h>
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
+#include <X11/XKBlib.h>
 
 #include "arg.h"
 #include "util.h"
@@ -28,6 +29,7 @@ enum {
 	INIT,
 	INPUT,
 	FAILED,
+	CAPS,
 	NUMCOLS
 };
 
@@ -130,16 +132,20 @@ readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
 {
 	XRRScreenChangeNotifyEvent *rre;
 	char buf[32], passwd[256], *inputhash;
-	int num, screen, running, failure, oldc;
-	unsigned int len, color;
+	int caps, num, screen, running, failure, oldc;
+	unsigned int len, color, indicators;
 	KeySym ksym;
 	XEvent ev;
 
 	len = 0;
+	caps = 0;
 	running = 1;
 	failure = 0;
 	oldc = INIT;
 
+	if (!XkbGetIndicatorState(dpy, XkbUseCoreKbd, &indicators))
+		caps = indicators & 1;
+
 	while (running && !XNextEvent(dpy, &ev)) {
 		if (ev.type == KeyPress) {
 			explicit_bzero(&buf, sizeof(buf));
@@ -179,6 +185,9 @@ readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
 				if (len)
 					passwd[len--] = '\0';
 				break;
+			case XK_Caps_Lock:
+				caps = !caps;
+				break;
 			default:
 				if (num && !iscntrl((int)buf[0]) &&
 				    (len + num < sizeof(passwd))) {
@@ -187,7 +196,7 @@ readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
 				}
 				break;
 			}
-			color = len ? INPUT : ((failure || failonclear) ? FAILED : INIT);
+			color = len ? (caps ? CAPS : INPUT) : (failure || failonclear ? FAILED : INIT);
 			if (running && oldc != color) {
 				for (screen = 0; screen < nscreens; screen++) {
 					XSetWindowBackground(dpy,
-- 
2.11.0