Add option to include status text in the pane borders. If

pane-border-status is set to "top" or "bottom" (rather than "off"),
every pane has a permanent top or bottom border containing the text from
pane-border-format.

Based on a diff sent long ago by Jonathan Slenders, mostly rewritten and
simplified by me.

8 files changed, 239 insertions, 35 deletions

diff --git a/cmd-set-option.c b/cmd-set-option.c
index b1771436..6fc6c8ba 100644
--- a/cmd-set-option.c
+++ b/cmd-set-option.c
@@ -201,6 +201,12 @@ cmd_set_option_exec(struct cmd *self, struct cmd_q *cmdq)
 	if (strcmp(oe->name, "monitor-silence") == 0)
 		alerts_reset_all();
 
+	/* When the pane-border-status option has been changed, resize panes. */
+	if (strcmp(oe->name, "pane-border-status") == 0) {
+		RB_FOREACH(w, windows, &windows)
+			layout_fix_panes(w, w->sx, w->sy);
+	}
+
 	/* Update sizes and redraw. May not need it but meh. */
 	recalculate_sizes();
 	TAILQ_FOREACH(c, &clients, entry) {
diff --git a/layout.c b/layout.c
index 31dce95c..a73ba527 100644
--- a/layout.c
+++ b/layout.c
@@ -32,8 +32,11 @@
  * cell a pointer to its parent cell.
  */
 
-int	layout_resize_pane_grow(struct layout_cell *, enum layout_type, int);
-int	layout_resize_pane_shrink(struct layout_cell *, enum layout_type, int);
+static int	layout_resize_pane_grow(struct layout_cell *, enum layout_type,
+		    int);
+static int	layout_resize_pane_shrink(struct layout_cell *,
+		    enum layout_type, int);
+static int	layout_need_status(struct layout_cell *, int);
 
 struct layout_cell *
 layout_create_cell(struct layout_cell *lcparent)
@@ -163,6 +166,30 @@ layout_fix_offsets(struct layout_cell *lc)
 	}
 }
 
+/*
+ * Returns 1 if we need to reserve space for the pane status line. This is the
+ * case for the most upper panes only.
+ */
+static int
+layout_need_status(struct layout_cell *lc, int at_top)
+{
+	struct layout_cell	*first_lc;
+
+	if (lc->parent) {
+		if (lc->parent->type == LAYOUT_LEFTRIGHT)
+			return (layout_need_status(lc->parent, at_top));
+
+		if (at_top)
+			first_lc = TAILQ_FIRST(&lc->parent->cells);
+		else
+			first_lc = TAILQ_LAST(&lc->parent->cells,layout_cells);
+		if (lc == first_lc)
+			return (layout_need_status(lc->parent, at_top));
+		return (0);
+	}
+	return (1);
+}
+
 /* Update pane offsets and sizes based on their cells. */
 void
 layout_fix_panes(struct window *w, u_int wsx, u_int wsy)
@@ -170,13 +197,25 @@ layout_fix_panes(struct window *w, u_int wsx, u_int wsy)
 	struct window_pane	*wp;
 	struct layout_cell	*lc;
 	u_int			 sx, sy;
+	int			 shift, status, at_top;
 
+	status = options_get_number(w->options, "pane-border-status");
+	at_top = (status == 1);
 	TAILQ_FOREACH(wp, &w->panes, entry) {
 		if ((lc = wp->layout_cell) == NULL)
 			continue;
+
+		if (status != 0)
+			shift = layout_need_status(lc, at_top);
+		else
+			shift = 0;
+
 		wp->xoff = lc->xoff;
 		wp->yoff = lc->yoff;
 
+		if (shift && at_top)
+			wp->yoff += 1;
+
 		/*
 		 * Layout cells are limited by the smallest size of other cells
 		 * within the same row or column; if this isn't the case
@@ -214,6 +253,9 @@ layout_fix_panes(struct window *w, u_int wsx, u_int wsy)
 				sy = lc->sy;
 		}
 
+		if (shift)
+			sy -= 1;
+
 		window_pane_resize(wp, sx, sy);
 	}
 }
@@ -520,7 +562,7 @@ layout_resize_pane(struct window_pane *wp, enum layout_type type, int change)
 }
 
 /* Helper function to grow pane. */
-int
+static int
 layout_resize_pane_grow(struct layout_cell *lc, enum layout_type type,
     int needed)
 {
@@ -561,7 +603,7 @@ layout_resize_pane_grow(struct layout_cell *lc, enum layout_type type,
 }
 
 /* Helper function to shrink pane. */
-int
+static int
 layout_resize_pane_shrink(struct layout_cell *lc, enum layout_type type,
     int needed)
 {
diff --git a/options-table.c b/options-table.c
index af0f41ed..c55ce715 100644
--- a/options-table.c
+++ b/options-table.c
@@ -51,6 +51,9 @@ const char *options_table_status_position_list[] = {
 const char *options_table_bell_action_list[] = {
 	"none", "any", "current", "other", NULL
 };
+const char *options_table_pane_status_list[] = {
+	"off", "top", "bottom", NULL
+};
 
 /* Server options. */
 const struct options_table_entry options_table[] = {
@@ -693,6 +696,19 @@ const struct options_table_entry options_table[] = {
 	  .style = "pane-border-style"
 	},
 
+	{ .name = "pane-border-format",
+	  .type = OPTIONS_TABLE_STRING,
+	  .scope = OPTIONS_TABLE_WINDOW,
+	  .default_str = "#{?pane_active,#[reverse],}#{pane_index}#[default] \"#{pane_title}\""
+	},
+
+	{ .name = "pane-border-status",
+	  .type = OPTIONS_TABLE_CHOICE,
+	  .scope = OPTIONS_TABLE_WINDOW,
+	  .choices = options_table_pane_status_list,
+	  .default_num = 0
+	},
+
 	{ .name = "pane-border-style",
 	  .type = OPTIONS_TABLE_STYLE,
 	  .scope = OPTIONS_TABLE_WINDOW,
diff --git a/screen-redraw.c b/screen-redraw.c
index 952a8515..694f6c27 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -24,12 +24,16 @@
 
 int	screen_redraw_cell_border1(struct window_pane *, u_int, u_int);
 int	screen_redraw_cell_border(struct client *, u_int, u_int);
-int	screen_redraw_check_cell(struct client *, u_int, u_int,
+int	screen_redraw_check_cell(struct client *, u_int, u_int, int,
 	    struct window_pane **);
-int	screen_redraw_check_is(u_int, u_int, int, struct window *,
+int	screen_redraw_check_is(u_int, u_int, int, int, struct window *,
 	    struct window_pane *, struct window_pane *);
 
-void	screen_redraw_draw_borders(struct client *, int, u_int);
+int 	screen_redraw_make_pane_status(struct client *, struct window *,
+	    struct window_pane *);
+void	screen_redraw_draw_pane_status(struct client *, int);
+
+void	screen_redraw_draw_borders(struct client *, int, int, u_int);
 void	screen_redraw_draw_panes(struct client *, u_int);
 void	screen_redraw_draw_status(struct client *, u_int);
 void	screen_redraw_draw_number(struct client *, struct window_pane *, u_int);
@@ -50,6 +54,10 @@ void	screen_redraw_draw_number(struct client *, struct window_pane *, u_int);
 
 #define CELL_BORDERS " xqlkmjwvtun~"
 
+#define CELL_STATUS_OFF 0
+#define CELL_STATUS_TOP 1
+#define CELL_STATUS_BOTTOM 2
+
 /* Check if cell is on the border of a particular pane. */
 int
 screen_redraw_cell_border1(struct window_pane *wp, u_int px, u_int py)
@@ -64,15 +72,15 @@ screen_redraw_cell_border1(struct window_pane *wp, u_int px, u_int py)
 		if (wp->xoff != 0 && px == wp->xoff - 1)
 			return (1);
 		if (px == wp->xoff + wp->sx)
-			return (1);
+			return (2);
 	}
 
 	/* Top/bottom borders. */
 	if ((wp->xoff == 0 || px >= wp->xoff - 1) && px <= wp->xoff + wp->sx) {
 		if (wp->yoff != 0 && py == wp->yoff - 1)
-			return (1);
+			return (3);
 		if (py == wp->yoff + wp->sy)
-			return (1);
+			return (4);
 	}
 
 	/* Outside pane. */
@@ -92,7 +100,7 @@ screen_redraw_cell_border(struct client *c, u_int px, u_int py)
 		if (!window_pane_visible(wp))
 			continue;
 		if ((retval = screen_redraw_cell_border1(wp, px, py)) != -1)
-			return (retval);
+			return (!!retval);
 	}
 
 	return (0);
@@ -100,16 +108,33 @@ screen_redraw_cell_border(struct client *c, u_int px, u_int py)
 
 /* Check if cell inside a pane. */
 int
-screen_redraw_check_cell(struct client *c, u_int px, u_int py,
+screen_redraw_check_cell(struct client *c, u_int px, u_int py, int pane_status,
     struct window_pane **wpp)
 {
 	struct window		*w = c->session->curw->window;
 	struct window_pane	*wp;
 	int			 borders;
+	u_int			 right, line;
 
 	if (px > w->sx || py > w->sy)
 		return (CELL_OUTSIDE);
 
+	if (pane_status != CELL_STATUS_OFF) {
+		TAILQ_FOREACH(wp, &w->panes, entry) {
+			if (!window_pane_visible(wp))
+				continue;
+
+			if (pane_status == CELL_STATUS_TOP)
+				line = wp->yoff - 1;
+			else
+				line = wp->yoff + wp->sy;
+			right = wp->xoff + 2 + wp->status_size - 1;
+
+			if (py == line && px >= wp->xoff + 2 && px <= right)
+				return (CELL_INSIDE);
+		}
+	}
+
 	TAILQ_FOREACH(wp, &w->panes, entry) {
 		if (!window_pane_visible(wp))
 			continue;
@@ -135,8 +160,13 @@ screen_redraw_check_cell(struct client *c, u_int px, u_int py,
 			borders |= 8;
 		if (px <= w->sx && screen_redraw_cell_border(c, px + 1, py))
 			borders |= 4;
-		if (py == 0 || screen_redraw_cell_border(c, px, py - 1))
-			borders |= 2;
+		if (pane_status == CELL_STATUS_TOP) {
+			if (py != 0 && screen_redraw_cell_border(c, px, py - 1))
+				borders |= 2;
+		} else {
+			if (py == 0 || screen_redraw_cell_border(c, px, py - 1))
+				borders |= 2;
+		}
 		if (py <= w->sy && screen_redraw_cell_border(c, px, py + 1))
 			borders |= 1;
 
@@ -177,11 +207,18 @@ screen_redraw_check_cell(struct client *c, u_int px, u_int py,
 
 /* Check if the border of a particular pane. */
 int
-screen_redraw_check_is(u_int px, u_int py, int type, struct window *w,
-    struct window_pane *wantwp, struct window_pane *wp)
+screen_redraw_check_is(u_int px, u_int py, int type, int pane_status,
+    struct window *w, struct window_pane *wantwp, struct window_pane *wp)
 {
+	int	border;
+
 	/* Is this off the active pane border? */
-	if (screen_redraw_cell_border1(wantwp, px, py) != 1)
+	border = screen_redraw_cell_border1(wantwp, px, py);
+	if (border == 0 || border == -1)
+		return (0);
+	if (pane_status == CELL_STATUS_TOP && border == 4)
+		return (0);
+	if (pane_status == CELL_STATUS_BOTTOM && border == 3)
 		return (0);
 
 	/* If there are more than two panes, that's enough. */
@@ -192,6 +229,10 @@ screen_redraw_check_is(u_int px, u_int py, int type, struct window *w,
 	if (wp == NULL || (type == CELL_OUTSIDE || type == CELL_INSIDE))
 		return (1);
 
+	/* With status lines mark the entire line. */
+	if (pane_status != CELL_STATUS_OFF)
+		return (1);
+
 	/* Check if the pane covers the whole width. */
 	if (wp->xoff == 0 && wp->sx == w->sx) {
 		/* This can either be the top pane or the bottom pane. */
@@ -214,7 +255,77 @@ screen_redraw_check_is(u_int px, u_int py, int type, struct window *w,
 		return (0);
 	}
 
-	return (type);
+	return (1);
+}
+
+/* Update pane status. */
+int
+screen_redraw_make_pane_status(struct client *c, struct window *w,
+    struct window_pane *wp)
+{
+	struct grid_cell	 gc;
+	const char		*fmt;
+	struct format_tree	*ft;
+	char			*out;
+	size_t			 outlen, old_size = wp->status_size;
+	struct screen_write_ctx	 ctx;
+
+	if (wp == w->active)
+		style_apply(&gc, w->options, "pane-active-border-style");
+	else
+		style_apply(&gc, w->options, "pane-border-style");
+
+	fmt = options_get_string(w->options, "pane-border-format");
+
+	ft = format_create(NULL, 0);
+	format_defaults(ft, c, NULL, NULL, wp);
+
+	screen_free(&wp->status_screen);
+	screen_init(&wp->status_screen, wp->sx, 1, 0);
+	wp->status_screen.mode = 0;
+
+	out = format_expand(ft, fmt);
+	outlen = screen_write_cstrlen("%s", out);
+	if (outlen > wp->sx - 4)
+		outlen = wp->sx - 4;
+	screen_resize(&wp->status_screen, outlen, 1, 0);
+
+	screen_write_start(&ctx, NULL, &wp->status_screen);
+	screen_write_cursormove(&ctx, 0, 0);
+	screen_write_clearline(&ctx);
+	screen_write_cnputs(&ctx, outlen, &gc, "%s", out);
+	screen_write_stop(&ctx);
+
+	format_free(ft);
+
+	wp->status_size = outlen;
+	return (wp->status_size != old_size);
+}
+
+/* Draw pane status. */
+void
+screen_redraw_draw_pane_status(struct client *c, int pane_status)
+{
+	struct window		*w = c->session->curw->window;
+	struct options		*oo = c->session->options;
+	struct tty		*tty = &c->tty;
+	struct window_pane	*wp;
+	int			 spos;
+	u_int			 yoff;
+
+	spos = options_get_number(oo, "status-position");
+	TAILQ_FOREACH(wp, &w->panes, entry) {
+		if (pane_status == CELL_STATUS_TOP)
+			yoff = wp->yoff - 1;
+		else
+			yoff = wp->yoff + wp->sy;
+		if (spos == 0)
+			yoff += 1;
+
+		tty_draw_line(tty, NULL, &wp->status_screen, 0, wp->xoff + 2,
+		    yoff);
+	}
+	tty_cursor(tty, 0, 0);
 }
 
 /* Redraw entire screen. */
@@ -222,10 +333,12 @@ void
 screen_redraw_screen(struct client *c, int draw_panes, int draw_status,
     int draw_borders)
 {
-	struct options	*oo = c->session->options;
-	struct tty	*tty = &c->tty;
-	u_int		 top;
-	int	 	 status, spos;
+	struct options		*oo = c->session->options;
+	struct tty		*tty = &c->tty;
+	struct window		*w = c->session->curw->window;
+	struct window_pane	*wp;
+	u_int			 top;
+	int	 		 status, pane_status, spos;
 
 	/* Suspended clients should not be updated. */
 	if (c->flags & CLIENT_SUSPENDED)
@@ -243,12 +356,24 @@ screen_redraw_screen(struct client *c, int draw_panes, int draw_status,
 	if (!status)
 		draw_status = 0;
 
+	/* Update pane status lines. */
+	pane_status = options_get_number(w->options, "pane-border-status");
+	if (pane_status != CELL_STATUS_OFF && (draw_borders || draw_status)) {
+		TAILQ_FOREACH(wp, &w->panes, entry) {
+			if (screen_redraw_make_pane_status(c, w, wp))
+				draw_borders = draw_status = 1;
+		}
+	}
+
+	/* Draw the elements. */
 	if (draw_borders)
-		screen_redraw_draw_borders(c, status, top);
+		screen_redraw_draw_borders(c, status, pane_status, top);
 	if (draw_panes)
 		screen_redraw_draw_panes(c, top);
 	if (draw_status)
 		screen_redraw_draw_status(c, top);
+	if (pane_status != CELL_STATUS_OFF && (draw_borders || draw_status))
+		screen_redraw_draw_pane_status(c, pane_status);
 	tty_reset(tty);
 }
 
@@ -272,7 +397,8 @@ screen_redraw_pane(struct client *c, struct window_pane *wp)
 
 /* Draw the borders. */
 void
-screen_redraw_draw_borders(struct client *c, int status, u_int top)
+screen_redraw_draw_borders(struct client *c, int status, int pane_status,
+    u_int top)
 {
 	struct session		*s = c->session;
 	struct window		*w = s->curw->window;
@@ -323,16 +449,17 @@ screen_redraw_draw_borders(struct client *c, int status, u_int top)
 
 	for (j = 0; j < tty->sy - status; j++) {
 		for (i = 0; i < tty->sx; i++) {
-			type = screen_redraw_check_cell(c, i, j, &wp);
+			type = screen_redraw_check_cell(c, i, j, pane_status,
+			    &wp);
 			if (type == CELL_INSIDE)
 				continue;
 			if (type == CELL_OUTSIDE && small &&
 			    i > msgx && j == msgy)
 				continue;
-			active = screen_redraw_check_is(i, j, type, w,
-			    w->active, wp);
+			active = screen_redraw_check_is(i, j, type, pane_status,
+			    w, w->active, wp);
 			if (server_is_marked(s, s->curw, marked_pane.wp) &&
-			    screen_redraw_check_is(i, j, type, w,
+			    screen_redraw_check_is(i, j, type, pane_status, w,
 			    marked_pane.wp, wp)) {
 				if (active)
 					tty_attributes(tty, &m_active_gc, NULL);
diff --git a/server-client.c b/server-client.c
index 9dad52fe..08f48b31 100644
--- a/server-client.c
+++ b/server-client.c
@@ -921,7 +921,7 @@ server_client_check_redraw(struct client *c)
 	struct session		*s = c->session;
 	struct tty		*tty = &c->tty;
 	struct window_pane	*wp;
-	int		 	 flags, redraw;
+	int		 	 flags, masked, redraw;
 
 	if (c->flags & (CLIENT_CONTROL|CLIENT_SUSPENDED))
 		return;
@@ -961,15 +961,15 @@ server_client_check_redraw(struct client *c)
 		}
 	}
 
-	if (c->flags & CLIENT_BORDERS) {
+	masked = c->flags & (CLIENT_BORDERS|CLIENT_STATUS);
+	if (masked != 0)
 		tty_update_mode(tty, tty->mode, NULL);
+	if (masked == CLIENT_BORDERS)
 		screen_redraw_screen(c, 0, 0, 1);
-	}
-
-	if (c->flags & CLIENT_STATUS) {
-		tty_update_mode(tty, tty->mode, NULL);
+	else if (masked == CLIENT_STATUS)
 		screen_redraw_screen(c, 0, 1, 0);
-	}
+	else if (masked != 0)
+		screen_redraw_screen(c, 0, 1, 1);
 
 	tty->flags = (tty->flags & ~(TTY_FREEZE|TTY_NOCURSOR)) | flags;
 	tty_update_mode(tty, tty->mode, NULL);
diff --git a/tmux.1 b/tmux.1
index 0aeefc32..a5956f18 100644
--- a/tmux.1
+++ b/tmux.1
@@ -3065,6 +3065,14 @@ Like
 .Ic base-index ,
 but set the starting index for pane numbers.
 .Pp
+.It Ic pane-border-format Ar format
+Set the text shown in pane border status lines.
+.Pp
+.It Xo Ic pane-border-status
+.Op Ic off | top | bottom
+.Xc
+Turn pane border status lines off or set their position.
+.Pp
 .It Ic pane-border-style Ar style
 Set the pane border style for panes aside from the active pane.
 For how to specify
diff --git a/tmux.h b/tmux.h
index d6cf114e..f81ed127 100644
--- a/tmux.h
+++ b/tmux.h
@@ -894,6 +894,9 @@ struct window_pane {
 	struct screen	*screen;
 	struct screen	 base;
 
+	struct screen	 status_screen;
+	size_t		 status_size;
+
 	/* Saved in alternative screen mode. */
 	u_int		 saved_cx;
 	u_int		 saved_cy;
diff --git a/window.c b/window.c
index ff90906f..ad7f36d9 100644
--- a/window.c
+++ b/window.c
@@ -764,6 +764,8 @@ window_pane_create(struct window *w, u_int sx, u_int sy, u_int hlimit)
 	screen_init(&wp->base, sx, sy, hlimit);
 	wp->screen = &wp->base;
 
+	screen_init(&wp->status_screen, 1, 1, 0);
+
 	if (gethostname(host, sizeof host) == 0)
 		screen_set_title(&wp->base, host);