From: Alexander Arch <aa@manpager.org>
Subject: tmux: add an option to use the "hardware" cursor in the status line
To: tech@openbsd.org
Date: Sun, 11 Aug 2024 14:11:44 +0400

Hello, tech@!

At the moment the cursor behaviour in different tmux modes is not very
consistent. You can set the cursor-style option, but that will only work
inside a pane. In command prompt, for example, the cursor gets hidden,
and is emulated with GRID_ATTR_REVERSE instead.

I wondered how hard it would be to add an option to avoid the behaviour,
and it turns out not that hard. The diff below adds a boolean option
status-emulate-cursor.

I'd like to know if there's any interest in adding such options.
Comments?

Thank you.

-- 
lexu

Index: options-table.c
===================================================================
RCS file: /var/cvs/src/usr.bin/tmux/options-table.c,v
diff -u -p -r1.175 options-table.c
--- options-table.c	4 Aug 2024 09:35:30 -0000	1.175
+++ options-table.c	11 Aug 2024 10:01:03 -0000
@@ -798,6 +798,13 @@ const struct options_table_entry options
 	  .text = "Style of the status line."
 	},
 
+	{ .name = "status-emulate-cursor",
+	  .type = OPTIONS_TABLE_FLAG,
+	  .scope = OPTIONS_TABLE_SERVER,
+	  .default_num = 1,
+	  .text = "Whether to emulate the status line cursor."
+	},
+
 	{ .name = "update-environment",
 	  .type = OPTIONS_TABLE_STRING,
 	  .scope = OPTIONS_TABLE_SESSION,
Index: server-client.c
===================================================================
RCS file: /var/cvs/src/usr.bin/tmux/server-client.c,v
diff -u -p -r1.405 server-client.c
--- server-client.c	10 Apr 2024 07:29:15 -0000	1.405
+++ server-client.c	11 Aug 2024 09:49:41 -0000
@@ -2396,7 +2396,8 @@ server_client_reset_state(struct client 
 				cy = tty->sy - n;
 		}
 		cx = c->prompt_cursor;
-		mode &= ~MODE_CURSOR;
+		if (options_get_number(global_options, "status-emulate-cursor"))
+			mode &= ~MODE_CURSOR;
 	} else if (c->overlay_draw == NULL) {
 		cursor = 0;
 		tty_window_offset(tty, &ox, &oy, &sx, &sy);
Index: status.c
===================================================================
RCS file: /var/cvs/src/usr.bin/tmux/status.c,v
diff -u -p -r1.242 status.c
--- status.c	15 May 2024 08:39:30 -0000	1.242
+++ status.c	11 Aug 2024 09:49:47 -0000
@@ -644,8 +644,11 @@ status_prompt_set(struct client *c, stru
 	c->prompt_type = prompt_type;
 	c->prompt_mode = PROMPT_ENTRY;
 
-	if (~flags & PROMPT_INCREMENTAL)
-		c->tty.flags |= (TTY_NOCURSOR|TTY_FREEZE);
+	if (~flags & PROMPT_INCREMENTAL) {
+		if (options_get_number(global_options, "status-emulate-cursor"))
+			c->tty.flags |= TTY_NOCURSOR;
+		c->tty.flags |= TTY_FREEZE;
+	}
 	c->flags |= CLIENT_REDRAWSTATUS;
 
 	if (flags & PROMPT_INCREMENTAL)
@@ -744,7 +747,8 @@ status_prompt_redraw(struct client *c)
 	format_free(ft);
 
 	memcpy(&cursorgc, &gc, sizeof cursorgc);
-	cursorgc.attr ^= GRID_ATTR_REVERSE;
+	if (options_get_number(global_options, "status-emulate-cursor"))
+		cursorgc.attr ^= GRID_ATTR_REVERSE;
 
 	start = format_width(c->prompt_string);
 	if (start > c->tty.sx)
Index: tmux.1
===================================================================
RCS file: /var/cvs/src/usr.bin/tmux/tmux.1,v
diff -u -p -r1.947 tmux.1
--- tmux.1	4 Aug 2024 09:01:18 -0000	1.947
+++ tmux.1	11 Aug 2024 09:59:42 -0000
@@ -4349,6 +4349,13 @@ For how to specify
 see the
 .Sx STYLES
 section.
+.It Xo Ic status-emulate-cursor
+.Op Ic on | off
+.Xc
+If enabled (the default), the status line cursor is emulated with reverse-video.
+Otherwise, the normal
+.Qq hardware
+cursor is used.
 .It Ic update-environment[] Ar variable
 Set list of environment variables to be copied into the session environment
 when a new session is created or an existing session is attached.