From 2f6938b87a09abcd41fd6792a40b0bd7b088f41a Mon Sep 17 00:00:00 2001
From: bsuth <bsuth701@gmail.com>
Date: Tue, 27 Dec 2022 12:44:23 +0900
Subject: [PATCH] Use centered squares to indicate lock state

Instead of changing the color of the entire screen to indicate the
current lock state, draw centered squares on each monitor and change the
square colors.

This patch requires xrandr to be active and otherwise defaults to the
original slock behavior.
---
 config.def.h |  6 +++++-
 slock.c      | 58 +++++++++++++++++++++++++++++++++++++++++++++-------
 2 files changed, 56 insertions(+), 8 deletions(-)

diff --git a/config.def.h b/config.def.h
index 9855e21..e7106fb 100644
--- a/config.def.h
+++ b/config.def.h
@@ -3,10 +3,14 @@ static const char *user  = "nobody";
 static const char *group = "nogroup";
 
 static const char *colorname[NUMCOLS] = {
-	[INIT] =   "black",     /* after initialization */
+	[BG] =     "black",     /* background */
+	[INIT] =   "#4f525c",   /* after initialization */
 	[INPUT] =  "#005577",   /* during input */
 	[FAILED] = "#CC3333",   /* wrong password */
 };
 
 /* treat a cleared input like a wrong password (color) */
 static const int failonclear = 1;
+
+/* size of square in px */
+static const int squaresize = 50;
diff --git a/slock.c b/slock.c
index 5ae738c..0750768 100644
--- a/slock.c
+++ b/slock.c
@@ -25,6 +25,7 @@
 char *argv0;
 
 enum {
+	BG,
 	INIT,
 	INPUT,
 	FAILED,
@@ -36,6 +37,8 @@ struct lock {
 	Window root, win;
 	Pixmap pmap;
 	unsigned long colors[NUMCOLS];
+	GC gc;
+	XRRScreenResources *rrsr;
 };
 
 struct xrandr {
@@ -124,6 +127,44 @@ gethash(void)
 	return hash;
 }
 
+static void
+draw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
+     unsigned int color)
+{
+	int screen, crtc;
+	XRRCrtcInfo* rrci;
+
+	if (rr->active) {
+		for (screen = 0; screen < nscreens; screen++) {
+			XSetWindowBackground(dpy, locks[screen]->win,locks[screen]->colors[BG]);
+			XClearWindow(dpy, locks[screen]->win);
+			XSetForeground(dpy, locks[screen]->gc, locks[screen]->colors[color]);
+			for (crtc = 0; crtc < locks[screen]->rrsr->ncrtc; ++crtc) {
+				rrci = XRRGetCrtcInfo(dpy,
+				                      locks[screen]->rrsr,
+				                      locks[screen]->rrsr->crtcs[crtc]);
+				/* skip disabled crtc */
+				if (rrci->noutput > 0)
+					XFillRectangle(dpy,
+					               locks[screen]->win,
+					               locks[screen]->gc,
+					               rrci->x + (rrci->width - squaresize) / 2,
+					               rrci->y + (rrci->height - squaresize) / 2,
+					               squaresize,
+					               squaresize);
+				XRRFreeCrtcInfo(rrci);
+			}
+		}
+	} else {
+		for (screen = 0; screen < nscreens; screen++) {
+			XSetWindowBackground(dpy,
+			                     locks[screen]->win,
+			                     locks[screen]->colors[color]);
+			XClearWindow(dpy, locks[screen]->win);
+		}
+	}
+}
+
 static void
 readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
        const char *hash)
@@ -189,12 +230,7 @@ readpw(Display *dpy, struct xrandr *rr, struct lock **locks, int nscreens,
 			}
 			color = len ? INPUT : ((failure || failonclear) ? FAILED : INIT);
 			if (running && oldc != color) {
-				for (screen = 0; screen < nscreens; screen++) {
-					XSetWindowBackground(dpy,
-					                     locks[screen]->win,
-					                     locks[screen]->colors[color]);
-					XClearWindow(dpy, locks[screen]->win);
-				}
+				draw(dpy, rr, locks, nscreens, color);
 				oldc = color;
 			}
 		} else if (rr->active && ev.type == rr->evbase + RRScreenChangeNotify) {
@@ -228,6 +264,7 @@ lockscreen(Display *dpy, struct xrandr *rr, int screen)
 	XColor color, dummy;
 	XSetWindowAttributes wa;
 	Cursor invisible;
+	XGCValues gcvalues;
 
 	if (dpy == NULL || screen < 0 || !(lock = malloc(sizeof(struct lock))))
 		return NULL;
@@ -243,7 +280,7 @@ lockscreen(Display *dpy, struct xrandr *rr, int screen)
 
 	/* init */
 	wa.override_redirect = 1;
-	wa.background_pixel = lock->colors[INIT];
+	wa.background_pixel = lock->colors[BG];
 	lock->win = XCreateWindow(dpy, lock->root, 0, 0,
 	                          DisplayWidth(dpy, lock->screen),
 	                          DisplayHeight(dpy, lock->screen),
@@ -255,6 +292,10 @@ lockscreen(Display *dpy, struct xrandr *rr, int screen)
 	invisible = XCreatePixmapCursor(dpy, lock->pmap, lock->pmap,
 	                                &color, &color, 0, 0);
 	XDefineCursor(dpy, lock->win, invisible);
+	lock->gc = XCreateGC(dpy, lock->win, 0, &gcvalues);
+	XSetForeground(dpy, lock->gc, lock->colors[INIT]);
+	if (rr->active)
+		lock->rrsr = XRRGetScreenResourcesCurrent(dpy, lock->root);
 
 	/* Try to grab mouse pointer *and* keyboard for 600ms, else fail the lock */
 	for (i = 0, ptgrab = kbgrab = -1; i < 6; i++) {
@@ -388,6 +429,9 @@ main(int argc, char **argv) {
 		}
 	}
 
+	/* draw the initial rectangle */
+	draw(dpy, &rr, locks, nscreens, INIT);
+
 	/* everything is now blank. Wait for the correct password */
 	readpw(dpy, &rr, locks, nscreens, hash);
 
-- 
2.39.0