Add an option to set the pane border lines style from a choice of single

lines (ACS or UTF-8), double or heavy (UTF-8), simple (plain ASCII) or
number (the pane numbers). Lines that won't work on a non-UTF-8 terminal
are translated back into ACS when they are output.

7 files changed, 239 insertions, 56 deletions

diff --git a/format-draw.c b/format-draw.c
index bd32b2a8..ec98ba95 100644
--- a/format-draw.c
+++ b/format-draw.c
@@ -600,7 +600,8 @@ format_draw(struct screen_write_ctx *octx, const struct grid_cell *base,
 
 		/* If this style pushed or popped the default, update it. */
 		if (sy.default_type == STYLE_DEFAULT_PUSH) {
-			memcpy(&current_default, &saved_sy.gc, sizeof current_default);
+			memcpy(&current_default, &saved_sy.gc,
+			    sizeof current_default);
 			sy.default_type = STYLE_DEFAULT_BASE;
 		} else if (sy.default_type == STYLE_DEFAULT_POP) {
 			memcpy(&current_default, base, sizeof current_default);
diff --git a/options-table.c b/options-table.c
index b1c4ec1b..4ac0d0c3 100644
--- a/options-table.c
+++ b/options-table.c
@@ -60,6 +60,9 @@ static const char *options_table_visual_bell_list[] = {
 static const char *options_table_pane_status_list[] = {
 	"off", "top", "bottom", NULL
 };
+static const char *options_table_pane_lines_list[] = {
+	"single", "double", "heavy", "simple", "number", NULL
+};
 static const char *options_table_set_clipboard_list[] = {
 	"off", "external", "on", NULL
 };
@@ -904,6 +907,14 @@ const struct options_table_entry options_table[] = {
 	  .text = "Format of text in the pane status lines."
 	},
 
+	{ .name = "pane-border-lines",
+	  .type = OPTIONS_TABLE_CHOICE,
+	  .scope = OPTIONS_TABLE_WINDOW,
+	  .choices = options_table_pane_lines_list,
+	  .default_num = PANE_LINES_SINGLE,
+	  .text = "Type of the pane type lines."
+	},
+
 	{ .name = "pane-border-status",
 	  .type = OPTIONS_TABLE_CHOICE,
 	  .scope = OPTIONS_TABLE_WINDOW,
diff --git a/screen-redraw.c b/screen-redraw.c
index ffa7aecf..002970e9 100644
--- a/screen-redraw.c
+++ b/screen-redraw.c
@@ -45,8 +45,36 @@ static void	screen_redraw_draw_pane(struct screen_redraw_ctx *,
 
 #define CELL_BORDERS " xqlkmjwvtun~"
 
-const struct grid_cell screen_redraw_border_cell = {
-	{ { ' ' }, 0, 1, 1 }, GRID_ATTR_CHARSET, 0, 8, 8, 0
+static const struct utf8_data screen_redraw_double_borders[] = {
+	{ "", 0, 0, 0 },
+	{ "\342\225\221", 0, 3, 1 }, /* U+2551 */
+	{ "\342\225\220", 0, 3, 1 }, /* U+2550 */
+	{ "\342\225\224", 0, 3, 1 }, /* U+2554 */
+	{ "\342\225\227", 0, 3, 1 }, /* U+2557 */
+	{ "\342\225\232", 0, 3, 1 }, /* U+255A */
+	{ "\342\225\235", 0, 3, 1 }, /* U+255D */
+	{ "\342\225\246", 0, 3, 1 }, /* U+2566 */
+	{ "\342\225\251", 0, 3, 1 }, /* U+2569 */
+	{ "\342\225\240", 0, 3, 1 }, /* U+2560 */
+	{ "\342\225\243", 0, 3, 1 }, /* U+2563 */
+	{ "\342\225\254", 0, 3, 1 }, /* U+256C */
+	{ "\302\267",     0, 2, 1 }  /* U+00B7 */
+};
+
+static const struct utf8_data screen_redraw_heavy_borders[] = {
+	{ "", 0, 0, 0 },
+	{ "\342\224\203", 0, 3, 1 }, /* U+2503 */
+	{ "\342\224\201", 0, 3, 1 }, /* U+2501 */
+	{ "\342\224\223", 0, 3, 1 }, /* U+2513 */
+	{ "\342\224\217", 0, 3, 1 }, /* U+250F */
+	{ "\342\224\227", 0, 3, 1 }, /* U+2517 */
+	{ "\342\224\233", 0, 3, 1 }, /* U+251B */
+	{ "\342\224\263", 0, 3, 1 }, /* U+2533 */
+	{ "\342\224\273", 0, 3, 1 }, /* U+253B */
+	{ "\342\224\243", 0, 3, 1 }, /* U+2523 */
+	{ "\342\224\253", 0, 3, 1 }, /* U+252B */
+	{ "\342\225\213", 0, 3, 1 }, /* U+254B */
+	{ "\302\267",     0, 2, 1 }  /* U+00B7 */
 };
 
 enum screen_redraw_border_type {
@@ -55,6 +83,45 @@ enum screen_redraw_border_type {
 	SCREEN_REDRAW_BORDER
 };
 
+/* Get cell border character. */
+static void
+screen_redraw_border_set(struct window_pane *wp, int pane_lines, int cell_type,
+    struct grid_cell *gc)
+{
+	u_int	idx;
+
+	switch (pane_lines) {
+	case PANE_LINES_NUMBER:
+		if (cell_type == CELL_OUTSIDE) {
+			gc->attr |= GRID_ATTR_CHARSET;
+			utf8_set(&gc->data, CELL_BORDERS[CELL_OUTSIDE]);
+			break;
+		}
+		gc->attr &= ~GRID_ATTR_CHARSET;
+		if (wp != NULL && window_pane_index(wp, &idx) == 0)
+			utf8_set(&gc->data, '0' + (idx % 10));
+		else
+			utf8_set(&gc->data, '*');
+		break;
+	case PANE_LINES_DOUBLE:
+		gc->attr &= ~GRID_ATTR_CHARSET;
+		utf8_copy(&gc->data, &screen_redraw_double_borders[cell_type]);
+		break;
+	case PANE_LINES_HEAVY:
+		gc->attr &= ~GRID_ATTR_CHARSET;
+		utf8_copy(&gc->data, &screen_redraw_heavy_borders[cell_type]);
+		break;
+	case PANE_LINES_SIMPLE:
+		gc->attr &= ~GRID_ATTR_CHARSET;
+		utf8_set(&gc->data, " |-+++++++++."[cell_type]);
+		break;
+	default:
+		gc->attr |= GRID_ATTR_CHARSET;
+		utf8_set(&gc->data, CELL_BORDERS[cell_type]);
+		break;
+	}
+}
+
 /* Return if window has only two panes. */
 static int
 screen_redraw_two_panes(struct window *w, int direction)
@@ -317,7 +384,7 @@ screen_redraw_check_is(u_int px, u_int py, int pane_status,
 /* Update pane status. */
 static int
 screen_redraw_make_pane_status(struct client *c, struct window *w,
-    struct window_pane *wp)
+    struct window_pane *wp, int pane_lines)
 {
 	struct grid_cell	 gc;
 	const char		*fmt;
@@ -348,9 +415,9 @@ screen_redraw_make_pane_status(struct client *c, struct window *w,
 
 	screen_write_start(&ctx, &wp->status_screen);
 
-	gc.attr |= GRID_ATTR_CHARSET;
+	screen_redraw_border_set(wp, pane_lines, CELL_TOPBOTTOM, &gc);
 	for (i = 0; i < width; i++)
-		screen_write_putc(&ctx, &gc, 'q');
+		screen_write_cell(&ctx, &gc);
 	gc.attr &= ~GRID_ATTR_CHARSET;
 
 	screen_write_cursormove(&ctx, 0, 0, 0);
@@ -436,7 +503,7 @@ screen_redraw_update(struct client *c, int flags)
 	struct window		*w = c->session->curw->window;
 	struct window_pane	*wp;
 	struct options		*wo = w->options;
-	int			 redraw;
+	int			 redraw, lines;
 
 	if (c->message_string != NULL)
 		redraw = status_message_redraw(c);
@@ -451,9 +518,10 @@ screen_redraw_update(struct client *c, int flags)
 		flags |= CLIENT_REDRAWOVERLAY;
 
 	if (options_get_number(wo, "pane-border-status") != PANE_STATUS_OFF) {
+		lines = options_get_number(wo, "pane-border-lines");
 		redraw = 0;
 		TAILQ_FOREACH(wp, &w->panes, entry) {
-			if (screen_redraw_make_pane_status(c, w, wp))
+			if (screen_redraw_make_pane_status(c, w, wp, lines))
 				redraw = 1;
 		}
 		if (redraw)
@@ -483,6 +551,7 @@ screen_redraw_set_context(struct client *c, struct screen_redraw_ctx *ctx)
 	ctx->statuslines = lines;
 
 	ctx->pane_status = options_get_number(wo, "pane-border-status");
+	ctx->pane_lines = options_get_number(wo, "pane-border-lines");
 
 	tty_window_offset(&c->tty, &ctx->ox, &ctx->oy, &ctx->sx, &ctx->sy);
 
@@ -560,7 +629,6 @@ screen_redraw_draw_borders_style(struct screen_redraw_ctx *ctx, u_int x,
 	struct window		*w = s->curw->window;
 	struct window_pane	*active = server_client_get_pane(c);
 	struct options		*oo = w->options;
-	struct grid_cell	*gc;
 	struct format_tree	*ft;
 
 	if (wp->border_gc_set)
@@ -568,18 +636,13 @@ screen_redraw_draw_borders_style(struct screen_redraw_ctx *ctx, u_int x,
 	wp->border_gc_set = 1;
 
 	ft = format_create_defaults(NULL, c, s, s->curw, wp);
-	gc = &wp->border_gc;
-
-	if (screen_redraw_check_is(x, y, ctx->pane_status, active)) {
-		style_apply(gc, oo, "pane-active-border-style", ft);
-		gc->attr |= GRID_ATTR_CHARSET;
-	} else {
-		style_apply(gc, oo, "pane-border-style", ft);
-		gc->attr |= GRID_ATTR_CHARSET;
-	}
-
+	if (screen_redraw_check_is(x, y, ctx->pane_status, active))
+		style_apply(&wp->border_gc, oo, "pane-active-border-style", ft);
+	else
+		style_apply(&wp->border_gc, oo, "pane-border-style", ft);
 	format_free(ft);
-	return (gc);
+
+	return (&wp->border_gc);
 }
 
 /* Draw a border cell. */
@@ -590,39 +653,37 @@ screen_redraw_draw_borders_cell(struct screen_redraw_ctx *ctx, u_int i, u_int j)
 	struct session		*s = c->session;
 	struct tty		*tty = &c->tty;
 	struct window_pane	*wp;
-	u_int			 type, x = ctx->ox + i, y = ctx->oy + j;
+	u_int			 cell_type, x = ctx->ox + i, y = ctx->oy + j;
 	int			 pane_status = ctx->pane_status;
-	const struct grid_cell	*gc;
-	struct grid_cell	 copy;
+	struct grid_cell	 gc;
+	const struct grid_cell	*tmp;
 
 	if (c->overlay_check != NULL && !c->overlay_check(c, x, y))
 		return;
 
-	type = screen_redraw_check_cell(c, x, y, pane_status, &wp);
-	if (type == CELL_INSIDE)
+	cell_type = screen_redraw_check_cell(c, x, y, pane_status, &wp);
+	if (cell_type == CELL_INSIDE)
 		return;
 
 	if (wp == NULL)
-		gc = &screen_redraw_border_cell;
+		memcpy(&gc, &grid_default_cell, sizeof gc);
 	else {
-		gc = screen_redraw_draw_borders_style(ctx, x, y, wp);
-		if (gc == NULL)
+		tmp = screen_redraw_draw_borders_style(ctx, x, y, wp);
+		if (tmp == NULL)
 			return;
+		memcpy(&gc, tmp, sizeof gc);
 
 		if (server_is_marked(s, s->curw, marked_pane.wp) &&
-		    screen_redraw_check_is(x, y, pane_status, marked_pane.wp)) {
-			memcpy(&copy, gc, sizeof copy);
-			copy.attr ^= GRID_ATTR_REVERSE;
-			gc = &copy;
-		}
+		    screen_redraw_check_is(x, y, pane_status, marked_pane.wp))
+			gc.attr ^= GRID_ATTR_REVERSE;
 	}
+	screen_redraw_border_set(wp, ctx->pane_lines, cell_type, &gc);
 
-	tty_attributes(tty, gc, &grid_default_cell, NULL);
 	if (ctx->statustop)
 		tty_cursor(tty, i, ctx->statuslines + j);
 	else
 		tty_cursor(tty, i, j);
-	tty_putc(tty, CELL_BORDERS[type]);
+	tty_cell(tty, &gc, &grid_default_cell, NULL);
 }
 
 /* Draw the borders. */
diff --git a/tmux.1 b/tmux.1
index 0b03becc..421f8889 100644
--- a/tmux.1
+++ b/tmux.1
@@ -3924,6 +3924,28 @@ but set the starting index for pane numbers.
 .It Ic pane-border-format Ar format
 Set the text shown in pane border status lines.
 .Pp
+.It Ic pane-border-lines Ar type
+Set the type of characters used for drawing pane borders.
+.Ar type
+may be one of:
+.Bl -tag -width Ds
+.It single
+single lines using ACS or UTF-8 characters
+.It double
+double lines using UTF-8 characters
+.It heavy
+heavy lines using UTF-8 characters
+.It simple
+simple ASCII characters
+.It number
+the pane number
+.El
+.Pp
+.Ql double
+and
+.Ql heavy
+will fall back to standard ACS line drawing when UTF-8 is not supported.
+.Pp
 .It Xo Ic pane-border-status
 .Op Ic off | top | bottom
 .Xc
diff --git a/tmux.h b/tmux.h
index 921a51f9..a413e0cf 100644
--- a/tmux.h
+++ b/tmux.h
@@ -820,6 +820,7 @@ struct screen_redraw_ctx {
 	int		 statustop;
 
 	int		 pane_status;
+	int		 pane_lines;
 
 	u_int		 sx;
 	u_int		 sy;
@@ -1050,6 +1051,13 @@ TAILQ_HEAD(winlink_stack, winlink);
 #define PANE_STATUS_TOP 1
 #define PANE_STATUS_BOTTOM 2
 
+/* Pane border lines option. */
+#define PANE_LINES_SINGLE 0
+#define PANE_LINES_DOUBLE 1
+#define PANE_LINES_HEAVY 2
+#define PANE_LINES_SIMPLE 3
+#define PANE_LINES_NUMBER 4
+
 /* Layout direction. */
 enum layout_type {
 	LAYOUT_LEFTRIGHT,
@@ -2030,6 +2038,8 @@ void	tty_putcode_ptr2(struct tty *, enum tty_code_code, const void *,
 void	tty_puts(struct tty *, const char *);
 void	tty_putc(struct tty *, u_char);
 void	tty_putn(struct tty *, const void *, size_t, u_int);
+void	tty_cell(struct tty *, const struct grid_cell *,
+	    const struct grid_cell *, int *);
 int	tty_init(struct tty *, struct client *, int);
 void	tty_resize(struct tty *);
 void	tty_set_size(struct tty *, u_int, u_int, u_int, u_int);
@@ -2103,6 +2113,7 @@ void		 tty_default_features(int *, const char *, u_int);
 /* tty-acs.c */
 int		 tty_acs_needed(struct tty *);
 const char	*tty_acs_get(struct tty *, u_char);
+int		 tty_acs_reverse_get(struct tty *, const char *, size_t);
 
 /* tty-keys.c */
 void		tty_keys_build(struct tty *);
diff --git a/tty-acs.c b/tty-acs.c
index 3e811103..63eccb93 100644
--- a/tty-acs.c
+++ b/tty-acs.c
@@ -19,11 +19,10 @@
 #include <sys/types.h>
 
 #include <stdlib.h>
+#include <string.h>
 
 #include "tmux.h"
 
-static int	tty_acs_cmp(const void *, const void *);
-
 /* Table mapping ACS entries to UTF-8. */
 struct tty_acs_entry {
 	u_char	 	 key;
@@ -68,14 +67,65 @@ static const struct tty_acs_entry tty_acs_table[] = {
 	{ '~', "\302\267" }		/* bullet */
 };
 
+/* Table mapping UTF-8 to ACS entries. */
+struct tty_acs_reverse_entry {
+	const char	*string;
+	u_char		 key;
+};
+static const struct tty_acs_reverse_entry tty_acs_reverse2[] = {
+	{ "\302\267", '~' }
+};
+static const struct tty_acs_reverse_entry tty_acs_reverse3[] = {
+	{ "\342\224\200", 'q' },
+	{ "\342\224\201", 'q' },
+	{ "\342\224\202", 'x' },
+	{ "\342\224\203", 'x' },
+	{ "\342\224\214", 'l' },
+	{ "\342\224\217", 'k' },
+	{ "\342\224\220", 'k' },
+	{ "\342\224\223", 'l' },
+	{ "\342\224\224", 'm' },
+	{ "\342\224\227", 'm' },
+	{ "\342\224\230", 'j' },
+	{ "\342\224\233", 'j' },
+	{ "\342\224\234", 't' },
+	{ "\342\224\243", 't' },
+	{ "\342\224\244", 'u' },
+	{ "\342\224\253", 'u' },
+	{ "\342\224\263", 'w' },
+	{ "\342\224\264", 'v' },
+	{ "\342\224\273", 'v' },
+	{ "\342\224\274", 'n' },
+	{ "\342\225\213", 'n' },
+	{ "\342\225\220", 'q' },
+	{ "\342\225\221", 'x' },
+	{ "\342\225\224", 'l' },
+	{ "\342\225\227", 'k' },
+	{ "\342\225\232", 'm' },
+	{ "\342\225\235", 'j' },
+	{ "\342\225\240", 't' },
+	{ "\342\225\243", 'u' },
+	{ "\342\225\246", 'w' },
+	{ "\342\225\251", 'v' },
+	{ "\342\225\254", 'n' },
+};
+
 static int
 tty_acs_cmp(const void *key, const void *value)
 {
 	const struct tty_acs_entry	*entry = value;
-	u_char				 ch;
+	int				 test = *(u_char *)key;
 
-	ch = *(u_char *) key;
-	return (ch - entry->key);
+	return (test - entry->key);
+}
+
+static int
+tty_acs_reverse_cmp(const void *key, const void *value)
+{
+	const struct tty_acs_reverse_entry	*entry = value;
+	const char				*test = key;
+
+	return (strcmp(test, entry->string));
 }
 
 /* Should this terminal use ACS instead of UTF-8 line drawing? */
@@ -104,11 +154,11 @@ tty_acs_needed(struct tty *tty)
 	return (1);
 }
 
-/* Retrieve ACS to output as a string. */
+/* Retrieve ACS to output as UTF-8. */
 const char *
 tty_acs_get(struct tty *tty, u_char ch)
 {
-	struct tty_acs_entry	*entry;
+	const struct tty_acs_entry	*entry;
 
 	/* Use the ACS set instead of UTF-8 if needed. */
 	if (tty_acs_needed(tty)) {
@@ -124,3 +174,24 @@ tty_acs_get(struct tty *tty, u_char ch)
 		return (NULL);
 	return (entry->string);
 }
+
+/* Reverse UTF-8 into ACS. */
+int
+tty_acs_reverse_get(__unused struct tty *tty, const char *s, size_t slen)
+{
+	const struct tty_acs_reverse_entry	*table, *entry;
+	u_int					 items;
+
+	if (slen == 2) {
+		table = tty_acs_reverse2;
+		items = nitems(tty_acs_reverse2);
+	} else if (slen == 3) {
+		table = tty_acs_reverse3;
+		items = nitems(tty_acs_reverse3);
+	} else
+		return (-1);
+	entry = bsearch(s, table, items, sizeof table[0], tty_acs_reverse_cmp);
+	if (entry == NULL)
+		return (-1);
+	return (entry->key);
+}
diff --git a/tty.c b/tty.c
index a4f2acee..99996dfa 100644
--- a/tty.c
+++ b/tty.c
@@ -65,8 +65,6 @@ static void	tty_emulate_repeat(struct tty *, enum tty_code_code,
 		    enum tty_code_code, u_int);
 static void	tty_repeat_space(struct tty *, u_int);
 static void	tty_draw_pane(struct tty *, const struct tty_ctx *, u_int);
-static void	tty_cell(struct tty *, const struct grid_cell *,
-		    const struct grid_cell *, int *);
 static void	tty_default_attributes(struct tty *, const struct grid_cell *,
 		    int *, u_int);
 
@@ -1243,7 +1241,7 @@ static const struct grid_cell *
 tty_check_codeset(struct tty *tty, const struct grid_cell *gc)
 {
 	static struct grid_cell	new;
-	u_int			n;
+	int			c;
 
 	/* Characters less than 0x7f are always fine, no matter what. */
 	if (gc->data.size == 1 && *gc->data.data < 0x7f)
@@ -1252,14 +1250,21 @@ tty_check_codeset(struct tty *tty, const struct grid_cell *gc)
 	/* UTF-8 terminal and a UTF-8 character - fine. */
 	if (tty->client->flags & CLIENT_UTF8)
 		return (gc);
+	memcpy(&new, gc, sizeof new);
+
+	/* See if this can be mapped to an ACS character. */
+	c = tty_acs_reverse_get(tty, gc->data.data, gc->data.size);
+	if (c != -1) {
+		utf8_set(&new.data, c);
+		new.attr |= GRID_ATTR_CHARSET;
+		return (&new);
+	}
 
 	/* Replace by the right number of underscores. */
-	n = gc->data.width;
-	if (n > UTF8_SIZE)
-		n = UTF8_SIZE;
-	memcpy(&new, gc, sizeof new);
-	new.data.size = n;
-	memset(new.data.data, '_', n);
+	new.data.size = gc->data.width;
+	if (new.data.size > UTF8_SIZE)
+		new.data.size = UTF8_SIZE;
+	memset(new.data.data, '_', new.data.size);
 	return (&new);
 }
 
@@ -1924,7 +1929,7 @@ tty_cmd_syncstart(struct tty *tty, __unused const struct tty_ctx *ctx)
 	tty_sync_start(tty);
 }
 
-static void
+void
 tty_cell(struct tty *tty, const struct grid_cell *gc,
     const struct grid_cell *defaults, int *palette)
 {
@@ -1940,12 +1945,13 @@ tty_cell(struct tty *tty, const struct grid_cell *gc,
 	if (gc->flags & GRID_FLAG_PADDING)
 		return;
 
-	/* Set the attributes. */
-	tty_attributes(tty, gc, defaults, palette);
-
-	/* Get the cell and if ASCII write with putc to do ACS translation. */
+	/* Check the output codeset and apply attributes. */
 	gcp = tty_check_codeset(tty, gc);
+	tty_attributes(tty, gcp, defaults, palette);
+
+	/* If it is a single character, write with putc to handle ACS. */
 	if (gcp->data.size == 1) {
+		tty_attributes(tty, gcp, defaults, palette);
 		if (*gcp->data.data < 0x20 || *gcp->data.data == 0x7f)
 			return;
 		tty_putc(tty, *gcp->data.data);