Add two new style parameters, width and pad, which apply to scrollbars.

From Michael Grant, GitHub issue 4241.

layout.c

@@ -291,7 +291,7 @@ layout_fix_panes(struct window *w, struct window_pane *skip)
 {
 	struct window_pane	*wp;
 	struct layout_cell	*lc;
-	int			 status, scrollbars, sb_pos;
+	int			 status, scrollbars, sb_pos, sb_w, sb_pad;
 	u_int			 sx, sy;
 
 	status = options_get_number(w->options, "pane-border-status");
@@ -314,11 +314,26 @@ layout_fix_panes(struct window *w, struct window_pane *skip)
 		}
 
 		if (window_pane_show_scrollbar(wp, scrollbars)) {
+			sb_w = wp->scrollbar_style.width;
+			sb_pad = wp->scrollbar_style.pad;
+			if (sb_w < 1)
+				sb_w = 1;
+			if (sb_pad < 0)
+				sb_pad = 0;
 			if (sb_pos == PANE_SCROLLBARS_LEFT) {
-				sx = sx - PANE_SCROLLBARS_WIDTH;
+				if ((int)sx - sb_w < PANE_MINIMUM) {
-				wp->xoff = wp->xoff + PANE_SCROLLBARS_WIDTH;
+					wp->xoff = wp->xoff +
+					    (int)sx - PANE_MINIMUM;
+					sx = PANE_MINIMUM;
+				} else {
+					sx = sx - sb_w - sb_pad;
+					wp->xoff = wp->xoff + sb_w + sb_pad;
+				}
 			} else /* sb_pos == PANE_SCROLLBARS_RIGHT */
-				sx = sx - PANE_SCROLLBARS_WIDTH;
+				if ((int)sx - sb_w - sb_pad < PANE_MINIMUM)
+					sx = PANE_MINIMUM;
+				else
+					sx = sx - sb_w - sb_pad;
 			wp->flags |= PANE_REDRAWSCROLLBAR;
 		}
 
@@ -353,6 +368,7 @@ layout_resize_check(struct window *w, struct layout_cell *lc,
     enum layout_type type)
 {
 	struct layout_cell	*lcchild;
+	struct style		*sb_style = &w->active->scrollbar_style;
 	u_int			 available, minimum;
 	int			 status, scrollbars;
 
@@ -364,7 +380,8 @@ layout_resize_check(struct window *w, struct layout_cell *lc,
 		if (type == LAYOUT_LEFTRIGHT) {
 			available = lc->sx;
 			if (scrollbars)
-				minimum = PANE_MINIMUM + PANE_SCROLLBARS_WIDTH;
+				minimum = PANE_MINIMUM + sb_style->width +
+				    sb_style->pad;
 			else
 				minimum = PANE_MINIMUM;
 		} else {
@@ -891,11 +908,12 @@ struct layout_cell *
 layout_split_pane(struct window_pane *wp, enum layout_type type, int size,
     int flags)
 {
-	struct layout_cell     *lc, *lcparent, *lcnew, *lc1, *lc2;
+	struct layout_cell	*lc, *lcparent, *lcnew, *lc1, *lc2;
-	u_int			sx, sy, xoff, yoff, size1, size2, minimum;
+	struct style		*sb_style = &wp->scrollbar_style;
-	u_int			new_size, saved_size, resize_first = 0;
+	u_int			 sx, sy, xoff, yoff, size1, size2, minimum;
-	int			full_size = (flags & SPAWN_FULLSIZE), status;
+	u_int			 new_size, saved_size, resize_first = 0;
-	int			scrollbars;
+	int			 full_size = (flags & SPAWN_FULLSIZE), status;
+	int			 scrollbars;
 
 	/*
 	 * If full_size is specified, add a new cell at the top of the window
@@ -917,9 +935,10 @@ layout_split_pane(struct window_pane *wp, enum layout_type type, int size,
 	/* Check there is enough space for the two new panes. */
 	switch (type) {
 	case LAYOUT_LEFTRIGHT:
-		if (scrollbars)
+		if (scrollbars) {
-			minimum = PANE_MINIMUM * 2 + PANE_SCROLLBARS_WIDTH;
+			minimum = PANE_MINIMUM * 2 + sb_style->width +
-		else
+			    sb_style->pad;
+		} else
 			minimum = PANE_MINIMUM * 2 + 1;
 		if (sx < minimum)
 			return (NULL);
@@ -1081,6 +1100,7 @@ int
 layout_spread_cell(struct window *w, struct layout_cell *parent)
 {
 	struct layout_cell	*lc;
+	struct style		*sb_style = &w->active->scrollbar_style;
 	u_int			 number, each, size, this;
 	int			 change, changed, status, scrollbars;
 
@@ -1094,7 +1114,7 @@ layout_spread_cell(struct window *w, struct layout_cell *parent)
 
 	if (parent->type == LAYOUT_LEFTRIGHT) {
 		if (scrollbars)
-			size = parent->sx - PANE_SCROLLBARS_WIDTH;
+			size = parent->sx - sb_style->width + sb_style->pad;
 		else
 			size = parent->sx;
 	}

options-table.c

@@ -1187,7 +1187,7 @@ const struct options_table_entry options_table[] = {
 	{ .name = "pane-scrollbars-style",
 	  .type = OPTIONS_TABLE_STRING,
 	  .scope = OPTIONS_TABLE_WINDOW|OPTIONS_TABLE_PANE,
-	  .default_str = "bg=black,fg=white",
+	  .default_str = "bg=black,fg=white,width=1,pad=0",
 	  .flags = OPTIONS_TABLE_IS_STYLE,
 	  .separator = ",",
 	  .text = "Style of the pane scrollbar."

options.c

@@ -1177,6 +1177,15 @@ options_push_changes(const char *name)
 		RB_FOREACH(w, windows, &windows)
 			layout_fix_panes(w, NULL);
 	}
+	if (strcmp(name, "pane-scrollbars-style") == 0) {
+		RB_FOREACH(wp, window_pane_tree, &all_window_panes) {
+			style_set_scrollbar_style_from_option(
+			    &wp->scrollbar_style, wp->options);
+		}
+		RB_FOREACH(w, windows, &windows)
+			layout_fix_panes(w, NULL);
+	}
+
 	if (strcmp(name, "input-buffer-size") == 0)
 		input_set_buffer_size(options_get_number(global_options, name));
 	RB_FOREACH(s, sessions, &sessions)

screen-redraw.c

@@ -138,7 +138,7 @@ screen_redraw_pane_border(struct screen_redraw_ctx *ctx, struct window_pane *wp,
 
 	/* Are scrollbars enabled? */
 	if (window_pane_show_scrollbar(wp, pane_scrollbars))
-		sb_w = PANE_SCROLLBARS_WIDTH;
+		sb_w = wp->scrollbar_style.width + wp->scrollbar_style.pad;
 
 	/*
 	 * Left/right borders. The wp->sy / 2 test is to colour only half the
@@ -171,7 +171,7 @@ screen_redraw_pane_border(struct screen_redraw_ctx *ctx, struct window_pane *wp,
 	} else {
 		if (sb_pos == PANE_SCROLLBARS_LEFT) {
 			if ((wp->xoff - sb_w == 0 || px >= wp->xoff - sb_w) &&
-			    (px <= ex || (sb_w != 0 && px - 1 == ex))) {
+			    (px <= ex || (sb_w != 0 && px < ex + sb_w))) {
 				if (wp->yoff != 0 && py == wp->yoff - 1)
 					return (SCREEN_REDRAW_BORDER_TOP);
 				if (py == ey)
@@ -179,7 +179,7 @@ screen_redraw_pane_border(struct screen_redraw_ctx *ctx, struct window_pane *wp,
 			}
 		} else { /* sb_pos == PANE_SCROLLBARS_RIGHT */
 			if ((wp->xoff == 0 || px >= wp->xoff) &&
-			    (px <= ex || (sb_w != 0 && px - 1 == ex))) {
+			    (px <= ex || (sb_w != 0 && px < ex + sb_w))) {
 				if (wp->yoff != 0 && py == wp->yoff - 1)
 					return (SCREEN_REDRAW_BORDER_TOP);
 				if (py == ey)
@@ -324,7 +324,7 @@ screen_redraw_check_cell(struct screen_redraw_ctx *ctx, u_int px, u_int py,
 	int			 border, pane_scrollbars = ctx->pane_scrollbars;
 	u_int			 right, line;
 	int			 sb_pos = ctx->pane_scrollbars_pos;
-	int			 sb_w = PANE_SCROLLBARS_WIDTH;
+	int			 sb_w;
 
 	*wpp = NULL;
 
@@ -374,6 +374,8 @@ screen_redraw_check_cell(struct screen_redraw_ctx *ctx, u_int px, u_int py,
 			 * pane is at the top then py == 0 to sy; if the pane
 			 * is not at the top, then yoff to yoff + sy.
 			 */
+			sb_w = wp->scrollbar_style.width +
+			    wp->scrollbar_style.pad;
 			if ((pane_status && py != line) ||
 			    (wp->yoff == 0 && py < wp->sy) ||
 			     (py >= wp->yoff && py < wp->yoff + wp->sy)) {
@@ -944,7 +946,9 @@ screen_redraw_draw_pane_scrollbar(struct screen_redraw_ctx *ctx,
 	double		 percent_view;
 	u_int		 sb = ctx->pane_scrollbars, total_height, sb_h = wp->sy;
 	u_int		 sb_pos = ctx->pane_scrollbars_pos, slider_h, slider_y;
-	u_int		 sb_w = PANE_SCROLLBARS_WIDTH, cm_y, cm_size;
+	int		 sb_w = wp->scrollbar_style.width;
+	int		 sb_pad = wp->scrollbar_style.pad;
+	int		 cm_y, cm_size, xoff = wp->xoff, ox = ctx->ox;
 	int		 sb_x, sb_y = (int)(wp->yoff - ctx->oy); /* sb top */
 
 	if (window_pane_mode(wp) == WINDOW_PANE_NO_MODE) {
@@ -967,9 +971,9 @@ screen_redraw_draw_pane_scrollbar(struct screen_redraw_ctx *ctx,
 	}
 
 	if (sb_pos == PANE_SCROLLBARS_LEFT)
-		sb_x = (int)wp->xoff - sb_w - ctx->ox;
+		sb_x = xoff - sb_w - sb_pad - ox;
 	else
-		sb_x = (int)wp->xoff + wp->sx - ctx->ox;
+		sb_x = xoff + wp->sx - ox;
 
 	if (slider_h < 1)
 		slider_h = 1;
@@ -990,39 +994,42 @@ screen_redraw_draw_scrollbar(struct screen_redraw_ctx *ctx,
     u_int slider_h, u_int slider_y)
 {
 	struct client		*c = ctx->c;
-	struct window		*w = wp->window;
 	struct tty		*tty = &c->tty;
 	struct grid_cell	 gc, slgc, *gcp;
-	u_int			 i, j, sb_w = PANE_SCROLLBARS_WIDTH;
+	struct style		*sb_style = &wp->scrollbar_style;
-	u_int			 pad_col = 0;
+	u_int			 i, j, imax, jmax;
+	u_int			 sb_w = sb_style->width, sb_pad = sb_style->pad;
 	int			 px, py, ox = ctx->ox, oy = ctx->oy;
-	int                      sb_pad = PANE_SCROLLBARS_PADDING, sx = ctx->sx;
+	int			 sx = ctx->sx, sy = ctx->sy, xoff = wp->xoff;
-	int			 sy = ctx->sy, xoff = wp->xoff, yoff = wp->yoff;
+	int			 yoff = wp->yoff;
-
-	/* Set up default style. */
-	style_apply(&gc, w->options, "pane-scrollbars-style", NULL);
-	utf8_set(&gc.data, ' ');
 
 	/* Set up style for slider. */
+	gc = sb_style->gc;
 	memcpy(&slgc, &gc, sizeof slgc);
+	slgc.fg = gc.bg;
 	slgc.bg = gc.fg;
 
-	if (sb_pad != 0) {
+	imax = sb_w + sb_pad;
-		if (sb_pos == PANE_SCROLLBARS_RIGHT)
+	if ((int)imax + sb_x > sx)
-			pad_col = 0;
+		imax = sx - sb_x;
-		else
+	jmax = sb_h;
-			pad_col = sb_w - 1;
+	if ((int)jmax + sb_y > sy)
-	}
+		jmax = sy - sb_y;
 
-	for (i = 0; i < sb_w; i++) {
+	for (j = 0; j < jmax; j++) {
-		for (j = 0; j < sb_h; j++) {
+		py = sb_y + j;
+		for (i = 0; i < imax; i++) {
 			px = sb_x + i;
-			py = sb_y + j;
+			if (px < xoff - ox - (int)sb_w - (int)sb_pad ||
-			if (px < xoff - ox - 1 || px >= sx || px < 0 ||
+			    px >= sx || px < 0 ||
-			    py < yoff - oy - 1 || py >= sy || py < 0)
+			    py < yoff - oy - 1 ||
+			    py >= sy || py < 0)
 				continue;
 			tty_cursor(tty, px, py);
-			if (sb_pad && i == pad_col) {
+			if ((sb_pos == PANE_SCROLLBARS_LEFT &&
+			    i >= sb_w && i < sb_w + sb_pad) ||
+			    (sb_pos == PANE_SCROLLBARS_RIGHT &&
+			     i < sb_pad)) {
 				tty_cell(tty, &grid_default_cell,
 				    &grid_default_cell, NULL, NULL);
 			} else {

server-client.c

@@ -581,7 +581,7 @@ server_client_check_mouse(struct client *c, struct key_event *event)
 	struct window_pane	*wp, *fwp;
 	u_int			 x, y, b, sx, sy, px, py, line = 0, sb_pos;
 	u_int			 sl_top, sl_bottom, sl_mpos = 0;
-	int			 ignore = 0, sb, sb_w, pane_status;
+	int			 ignore = 0, sb, sb_w, sb_pad, pane_status;
 	key_code		 key;
 	struct timeval		 tv;
 	struct style_range	*sr;
@@ -783,10 +783,15 @@ have_event:
 
 			/* Try the scrollbar next to a pane. */
 			sb = options_get_number(wo, "pane-scrollbars");
-			if (window_pane_show_scrollbar(wp, sb))
+			sb_pos = options_get_number(wo,
-				sb_w = PANE_SCROLLBARS_WIDTH;
+			    "pane-scrollbars-position");
-			else
+			if (window_pane_show_scrollbar(wp, sb)) {
+				sb_w = wp->scrollbar_style.width;
+				sb_pad = wp->scrollbar_style.pad;
+			} else {
 				sb_w = 0;
+				sb_pad = 0;
+			}
 			pane_status = options_get_number(wo,
 			    "pane-border-status");
 			if (pane_status == PANE_STATUS_TOP)
@@ -795,8 +800,9 @@ have_event:
 				line = wp->yoff + wp->sy;
 
 			/*
-			 * Check if py could lie within a scrollbar. If the
+			 * Check if py could lie within a scrollbar
-			 * pane is at the top, then py is 0; if not then the
+			 * (but not within the padding). If the pane is
+			 * at the top, then py is 0; if not then the
 			 * top, then yoff to yoff + sy.
 			 */
 			if ((pane_status != PANE_STATUS_OFF && py != line) ||
@@ -805,11 +811,11 @@ have_event:
 				sb_pos = options_get_number(wo,
 				    "pane-scrollbars-position");
 				if ((sb_pos == PANE_SCROLLBARS_RIGHT &&
-				    (px >= wp->xoff + wp->sx &&
+				    (px >= wp->xoff + wp->sx + sb_pad &&
-				    px < wp->xoff + wp->sx + sb_w)) ||
+				    px < wp->xoff + wp->sx + sb_pad + sb_w)) ||
 				    (sb_pos == PANE_SCROLLBARS_LEFT &&
-				    (px >= wp->xoff - sb_w &&
+				    (px >= wp->xoff - sb_pad - sb_w &&
-				    px < wp->xoff))) {
+				    px < wp->xoff - sb_pad))) {
 					sl_top = wp->yoff + wp->sb_slider_y;
 					sl_bottom = (wp->yoff +
 					    wp->sb_slider_y +

style.c

@@ -39,6 +39,8 @@ static struct style style_default = {
 
 	STYLE_RANGE_NONE, 0, "",
 
+	STYLE_WIDTH_DEFAULT, STYLE_PAD_DEFAULT,
+
 	STYLE_DEFAULT_BASE
 };
 
@@ -216,6 +218,16 @@ style_parse(struct style *sy, const struct grid_cell *base, const char *in)
 			if ((value = attributes_fromstring(tmp + 2)) == -1)
 				goto error;
 			sy->gc.attr &= ~value;
+		} else if (end > 6 && strncasecmp(tmp, "width=", 6) == 0) {
+                        n = strtonum(tmp + 6, 0, UINT_MAX, &errstr);
+                        if (errstr != NULL)
+                                goto error;
+                        sy->width = (int)n;
+		} else if (end > 4 && strncasecmp(tmp, "pad=", 4) == 0) {
+                        n = strtonum(tmp + 4, 0, UINT_MAX, &errstr);
+                        if (errstr != NULL)
+                                goto error;
+                        sy->pad = (int)n;
 		} else {
 			if ((value = attributes_fromstring(tmp)) == -1)
 				goto error;
@@ -326,7 +338,16 @@ style_tostring(struct style *sy)
 		    attributes_tostring(gc->attr));
 		comma = ",";
 	}
-
+        if (sy->width >= 0) {
+                xsnprintf(s + off, sizeof s - off, "%swidth=%u", comma,
+		    sy->width);
+		comma = ",";
+	}
+        if (sy->pad >= 0) {
+                xsnprintf(s + off, sizeof s - off, "%spad=%u", comma,
+		    sy->pad);
+		comma = ",";
+	}
 	if (*s == '\0')
 		return ("default");
 	return (s);
@@ -381,3 +402,24 @@ style_copy(struct style *dst, struct style *src)
 {
 	memcpy(dst, src, sizeof *dst);
 }
+
+void
+style_set_scrollbar_style_from_option(struct style *sb_style, struct options *oo)
+{
+	struct style	*sy;
+
+	sy = options_string_to_style(oo, "pane-scrollbars-style", NULL);
+	if (sy == NULL) {
+		style_set(sb_style, &grid_default_cell);
+		sb_style->width = PANE_SCROLLBARS_DEFAULT_WIDTH;
+		sb_style->pad = PANE_SCROLLBARS_DEFAULT_PADDING;
+		utf8_set(&sb_style->gc.data, PANE_SCROLLBARS_CHARACTER);
+	} else {
+		style_copy(sb_style, sy);
+		if (sb_style->width < 1)
+			sb_style->width = PANE_SCROLLBARS_DEFAULT_WIDTH;
+		if (sb_style->pad < 0)
+			sb_style->pad = PANE_SCROLLBARS_DEFAULT_PADDING;
+		utf8_set(&sb_style->gc.data, PANE_SCROLLBARS_CHARACTER);
+	}
+}

tmux.1

@@ -5071,7 +5071,12 @@ see the
 section.
 The foreground colour is used for the slider, the background for the rest of the
 scrollbar.
-Attributes are ignored.
+The
+.Ar width
+attribute sets the width of the scrollbar and the
+.Ar pad
+attribute the padding between the scrollbar and the pane.
+Other attributes are ignored.
 .Pp
 .It Xo Ic pane-scrollbars-position
 .Op Ic left | right

tmux.h

@@ -863,6 +863,10 @@ struct style_range {
 };
 TAILQ_HEAD(style_ranges, style_range);
 
+/* Default style width and pad. */
+#define STYLE_WIDTH_DEFAULT -1
+#define STYLE_PAD_DEFAULT -1
+
 /* Style default. */
 enum style_default_type {
 	STYLE_DEFAULT_BASE,
@@ -883,6 +887,9 @@ struct style {
 	u_int			range_argument;
 	char			range_string[16];
 
+	int			width;
+	int			pad;
+
 	enum style_default_type	default_type;
 };
 
@@ -1164,6 +1171,8 @@ struct window_pane {
 	int		 control_bg;
 	int		 control_fg;
 
+	struct style	 scrollbar_style;
+
 	TAILQ_ENTRY(window_pane) entry;  /* link in list of all panes */
 	TAILQ_ENTRY(window_pane) sentry; /* link in list of last visited */
 	RB_ENTRY(window_pane) tree_entry;
@@ -1268,9 +1277,10 @@ TAILQ_HEAD(winlink_stack, winlink);
 #define PANE_SCROLLBARS_RIGHT 0
 #define PANE_SCROLLBARS_LEFT 1
 
-/* Pane scrollbars width and padding. */
+/* Pane scrollbars width, padding and fill character. */
-#define PANE_SCROLLBARS_WIDTH 1
+#define PANE_SCROLLBARS_DEFAULT_PADDING 0
-#define PANE_SCROLLBARS_PADDING 0
+#define PANE_SCROLLBARS_DEFAULT_WIDTH 1
+#define PANE_SCROLLBARS_CHARACTER ' '
 
 /* True if screen in alternate screen. */
 #define SCREEN_IS_ALTERNATE(s) ((s)->saved_grid != NULL)
@@ -3469,6 +3479,8 @@ void		 style_apply(struct grid_cell *, struct options *,
 		     const char *, struct format_tree *);
 void		 style_set(struct style *, const struct grid_cell *);
 void		 style_copy(struct style *, struct style *);
+void		 style_set_scrollbar_style_from_option(struct style *,
+		     struct options *);
 
 /* spawn.c */
 struct winlink	*spawn_window(struct spawn_context *, char **);

window.c

@@ -596,9 +596,10 @@ window_get_active_at(struct window *w, u_int x, u_int y)
 
 		if (pane_scrollbars == PANE_SCROLLBARS_ALWAYS ||
 		    (pane_scrollbars == PANE_SCROLLBARS_MODAL &&
-		     window_pane_mode(wp) != WINDOW_PANE_NO_MODE))
+		     window_pane_mode(wp) != WINDOW_PANE_NO_MODE)) {
-			sb_w = PANE_SCROLLBARS_WIDTH;
+			sb_w = wp->scrollbar_style.width +
-		else
+			    wp->scrollbar_style.pad;
+		} else
 			sb_w = 0;
 
 		if (sb_pos == PANE_SCROLLBARS_LEFT) {
@@ -961,6 +962,9 @@ window_pane_create(struct window *w, u_int sx, u_int sy, u_int hlimit)
 	wp->control_bg = -1;
 	wp->control_fg = -1;
 
+	style_set_scrollbar_style_from_option(&wp->scrollbar_style,
+	    wp->options);
+
 	colour_palette_init(&wp->palette);
 	colour_palette_from_option(&wp->palette, wp->options);