Add message-line option to control where message and prompt go, from

Varun Kumar E in GitHub issue 3324.

options-table.c

@@ -42,6 +42,9 @@ static const char *options_table_clock_mode_style_list[] = {
 static const char *options_table_status_list[] = {
 	"off", "on", "2", "3", "4", "5", NULL
 };
+static const char *options_table_message_line_list[] = {
+	"0", "1", "2", "3", "4", NULL
+};
 static const char *options_table_status_keys_list[] = {
 	"emacs", "vi", NULL
 };
@@ -542,13 +545,21 @@ const struct options_table_entry options_table[] = {
 		  "'mode-keys' is set to 'vi'."
 	},
 
+	{ .name = "message-line",
+	  .type = OPTIONS_TABLE_CHOICE,
+	  .scope = OPTIONS_TABLE_SESSION,
+	  .choices = options_table_message_line_list,
+	  .default_num = 0,
+	  .text = "Position (line) of messages and the command prompt."
+	},
+
 	{ .name = "message-style",
 	  .type = OPTIONS_TABLE_STRING,
 	  .scope = OPTIONS_TABLE_SESSION,
 	  .default_str = "bg=yellow,fg=black",
 	  .flags = OPTIONS_TABLE_IS_STYLE,
 	  .separator = ",",
-	  .text = "Style of the command prompt."
+	  .text = "Style of messages and the command prompt."
 	},
 
 	{ .name = "mouse",

status.c

@@ -263,6 +263,17 @@ status_line_size(struct client *c)
 	return (s->statuslines);
 }
 
+/* Get the prompt line number for client's session. 1 means at the bottom. */
+static u_int
+status_prompt_line_at(struct client *c)
+{
+	struct session	*s = c->session;
+
+	if (c->flags & (CLIENT_STATUSOFF|CLIENT_CONTROL))
+		return (1);
+	return (options_get_number(s->options, "status-prompt-line"));
+}
+
 /* Get window at window list position. */
 struct style_range *
 status_get_range(struct client *c, u_int x, u_int y)
@@ -533,7 +544,7 @@ status_message_redraw(struct client *c)
 	struct session		*s = c->session;
 	struct screen		 old_screen;
 	size_t			 len;
-	u_int			 lines, offset;
+	u_int			 lines, offset, messageline;
 	struct grid_cell	 gc;
 	struct format_tree	*ft;
 
@@ -546,6 +557,10 @@ status_message_redraw(struct client *c)
 		lines = 1;
 	screen_init(sl->active, c->tty.sx, lines, 0);
 
+	messageline = status_prompt_line_at(c);
+	if (messageline > lines - 1)
+		messageline = lines - 1;
+
 	len = screen_write_strlen("%s", c->message_string);
 	if (len > c->tty.sx)
 		len = c->tty.sx;
@@ -555,11 +570,11 @@ status_message_redraw(struct client *c)
 	format_free(ft);
 
 	screen_write_start(&ctx, sl->active);
-	screen_write_fast_copy(&ctx, &sl->screen, 0, 0, c->tty.sx, lines - 1);
+	screen_write_fast_copy(&ctx, &sl->screen, 0, 0, c->tty.sx, lines);
-	screen_write_cursormove(&ctx, 0, lines - 1, 0);
+	screen_write_cursormove(&ctx, 0, messageline, 0);
 	for (offset = 0; offset < c->tty.sx; offset++)
 		screen_write_putc(&ctx, &gc, ' ');
-	screen_write_cursormove(&ctx, 0, lines - 1, 0);
+	screen_write_cursormove(&ctx, 0, messageline, 0);
 	if (c->message_ignore_styles)
 		screen_write_nputs(&ctx, len, &gc, "%s", c->message_string);
 	else
@@ -695,7 +710,7 @@ status_prompt_redraw(struct client *c)
 	struct session		*s = c->session;
 	struct screen		 old_screen;
 	u_int			 i, lines, offset, left, start, width;
-	u_int			 pcursor, pwidth;
+	u_int			 pcursor, pwidth, promptline;
 	struct grid_cell	 gc, cursorgc;
 	struct format_tree	*ft;
 
@@ -708,6 +723,10 @@ status_prompt_redraw(struct client *c)
 		lines = 1;
 	screen_init(sl->active, c->tty.sx, lines, 0);
 
+	promptline = status_prompt_line_at(c);
+	if (promptline > lines - 1)
+		promptline = lines - 1;
+
 	ft = format_create_defaults(NULL, c, NULL, NULL, NULL);
 	if (c->prompt_mode == PROMPT_COMMAND)
 		style_apply(&gc, s->options, "message-command-style", ft);
@@ -723,13 +742,13 @@ status_prompt_redraw(struct client *c)
 		start = c->tty.sx;
 
 	screen_write_start(&ctx, sl->active);
-	screen_write_fast_copy(&ctx, &sl->screen, 0, 0, c->tty.sx, lines - 1);
+	screen_write_fast_copy(&ctx, &sl->screen, 0, 0, c->tty.sx, lines);
-	screen_write_cursormove(&ctx, 0, lines - 1, 0);
+	screen_write_cursormove(&ctx, 0, promptline, 0);
 	for (offset = 0; offset < c->tty.sx; offset++)
 		screen_write_putc(&ctx, &gc, ' ');
-	screen_write_cursormove(&ctx, 0, lines - 1, 0);
+	screen_write_cursormove(&ctx, 0, promptline, 0);
 	format_draw(&ctx, &gc, start, c->prompt_string, NULL, 0);
-	screen_write_cursormove(&ctx, start, lines - 1, 0);
+	screen_write_cursormove(&ctx, start, promptline, 0);
 
 	left = c->tty.sx - start;
 	if (left == 0)

tmux.1

@@ -3873,6 +3873,10 @@ For how to specify
 see the
 .Sx STYLES
 section.
+.It Xo Ic message-line
+.Op Ic 0 | 1 | 2 | 3 | 4
+.Xc
+Set line on which status line messages and the command prompt are shown.
 .It Ic message-style Ar style
 Set status line message style.
 This is used for messages and for the command prompt.