From 18fc7793b0bb2f9a93d39fe69a72d40122e151eb Mon Sep 17 00:00:00 2001
From: "Avi Halachmi (:avih)" <avihpit@yahoo.com>
Date: Mon, 15 Oct 2018 01:06:01 +0300
Subject: [PATCH] add visual bell with few rendering modes

- Inverse the whole terminal - "standard" visual-bell, a bit jarring.
- Inverse outer (border) cells - much less jarring, yet plenty visible.
- Inverse the bottom-right corner only.
- Inverse cells according to custom logic.
---
 config.def.h |  8 ++++++++
 x.c          | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 43 insertions(+)

diff --git a/config.def.h b/config.def.h
index fdbacfd..fe07204 100644
--- a/config.def.h
+++ b/config.def.h
@@ -69,6 +69,14 @@ static unsigned int cursorthickness = 2;
  */
 static int bellvolume = 0;
 
+/* visual-bell timeout in ms (0 to disable visual-bell) */
+static int vbelltimeout = 150;
+
+/* choose predefined visual-bell cells to inverse, or define your own logic */
+#define VBCELL x==0 || x==right || y==0 || y==bottom  /* border */
+// #define VBCELL 1  /* all cells - whole screen */
+// #define VBCELL y==bottom && x>right-2  /* bottom-right */
+
 /* default TERM value */
 char *termname = "st-256color";
 
diff --git a/x.c b/x.c
index 1dc44d6..44d5a8d 100644
--- a/x.c
+++ b/x.c
@@ -1592,6 +1592,27 @@ xsettitle(char *p)
 	XFree(prop.value);
 }
 
+
+static int vbellset = 0; /* 1 during visual bell, 0 otherwise */
+static struct timespec lastvbell = {0};
+
+static int
+isvbellcell(int x, int y)
+{
+	int right = win.tw / win.cw - 1, bottom = win.th / win.ch - 1;
+	return VBCELL;  /* logic condition defined at config.h */
+}
+
+static void
+vbellbegin() {
+	clock_gettime(CLOCK_MONOTONIC, &lastvbell);
+	if (vbellset)
+		return;
+	vbellset = 1;
+	redraw();
+	XFlush(xw.dpy);
+}
+
 int
 xstartdraw(void)
 {
@@ -1613,6 +1634,8 @@ xdrawline(Line line, int x1, int y1, int x2)
 			continue;
 		if (selected(x, y1))
 			new.mode ^= ATTR_REVERSE;
+		if (vbellset && isvbellcell(x, y1))
+			new.mode ^= ATTR_REVERSE;
 		if (i > 0 && ATTRCMP(base, new)) {
 			xdrawglyphfontspecs(specs, base, i, ox, y1);
 			specs += i;
@@ -1714,6 +1737,8 @@ xbell(void)
 		xseturgency(1);
 	if (bellvolume)
 		XkbBell(xw.dpy, xw.win, bellvolume, (Atom)NULL);
+	if (vbelltimeout)
+		vbellbegin();
 }
 
 void
@@ -1959,6 +1984,16 @@ run(void)
 			}
 		}
 
+		if (vbellset) {
+			double remain = vbelltimeout - TIMEDIFF(now, lastvbell);
+			if (remain <= 0) {
+				vbellset = 0;
+				redraw();
+			} else if (timeout < 0 || remain < timeout) {
+				timeout = remain;
+			}
+		}
+
 		draw();
 		XFlush(xw.dpy);
 		drawing = 0;

base-commit: 045a0fab4f80b57f4a982ae6bc5f33fe21d66111
-- 
2.17.1