Add a mark in copy mode. Set with set-mark command (bound to 'X') by default

and the mark and cursor position are swapped with 'jump-to-mark' (bound to
M-x). The line containing the mark is shown in copy-mode-mark-style with the
horizontal position in reverse.

From Anindya Mukherjee in GitHub issue 2209.

key-bindings.c

@@ -426,6 +426,7 @@ key_bindings_init(void)
 		"bind -Tcopy-mode N send -X search-reverse",
 		"bind -Tcopy-mode R send -X rectangle-toggle",
 		"bind -Tcopy-mode T command-prompt -1p'(jump to backward)' 'send -X jump-to-backward \"%%%\"'",
+		"bind -Tcopy-mode X send -X set-mark",
 		"bind -Tcopy-mode f command-prompt -1p'(jump forward)' 'send -X jump-forward \"%%%\"'",
 		"bind -Tcopy-mode g command-prompt -p'(goto line)' 'send -X goto-line \"%%%\"'",
 		"bind -Tcopy-mode n send -X search-again",
@@ -467,6 +468,7 @@ key_bindings_init(void)
 		"bind -Tcopy-mode M-r send -X middle-line",
 		"bind -Tcopy-mode M-v send -X page-up",
 		"bind -Tcopy-mode M-w send -X copy-pipe-and-cancel",
+		"bind -Tcopy-mode M-x send -X jump-to-mark",
 		"bind -Tcopy-mode 'M-{' send -X previous-paragraph",
 		"bind -Tcopy-mode 'M-}' send -X next-paragraph",
 		"bind -Tcopy-mode M-Up send -X halfpage-up",
@@ -521,6 +523,7 @@ key_bindings_init(void)
 		"bind -Tcopy-mode-vi T command-prompt -1p'(jump to backward)' 'send -X jump-to-backward \"%%%\"'",
 		"bind -Tcopy-mode-vi V send -X select-line",
 		"bind -Tcopy-mode-vi W send -X next-space",
+		"bind -Tcopy-mode-vi X send -X set-mark",
 		"bind -Tcopy-mode-vi ^ send -X back-to-indentation",
 		"bind -Tcopy-mode-vi b send -X previous-word",
 		"bind -Tcopy-mode-vi e send -X next-word-end",
@@ -554,6 +557,7 @@ key_bindings_init(void)
 		"bind -Tcopy-mode-vi Down send -X cursor-down",
 		"bind -Tcopy-mode-vi Left send -X cursor-left",
 		"bind -Tcopy-mode-vi Right send -X cursor-right",
+		"bind -Tcopy-mode-vi M-x send -X jump-to-mark",
 		"bind -Tcopy-mode-vi C-Up send -X scroll-up",
 		"bind -Tcopy-mode-vi C-Down send -X scroll-down",
 	};

options-table.c

@@ -794,6 +794,15 @@ const struct options_table_entry options_table[] = {
 	  .text = "Style of the current search match in copy mode."
 	},
 
+	{ .name = "copy-mode-mark-style",
+	  .type = OPTIONS_TABLE_STRING,
+	  .scope = OPTIONS_TABLE_WINDOW,
+	  .default_str = "bg=red,fg=black",
+	  .flags = OPTIONS_TABLE_IS_STYLE,
+	  .separator = ",",
+	  .text = "Style of the marked line in copy mode."
+	},
+
 	{ .name = "main-pane-height",
 	  .type = OPTIONS_TABLE_STRING,
 	  .scope = OPTIONS_TABLE_WINDOW,

tmux.1

@@ -1555,6 +1555,7 @@ The following commands are supported in copy mode:
 .It Li "jump-reverse" Ta "," Ta ","
 .It Li "jump-to-backward <to>" Ta "T" Ta ""
 .It Li "jump-to-forward <to>" Ta "t" Ta ""
+.It Li "jump-to-mark" Ta "M-x" Ta "M-x"
 .It Li "middle-line" Ta "M" Ta "M-r"
 .It Li "next-matching-bracket" Ta "%" Ta "M-C-f"
 .It Li "next-paragraph" Ta "}" Ta "M-}"
@@ -1585,6 +1586,7 @@ The following commands are supported in copy mode:
 .It Li "search-reverse" Ta "N" Ta "N"
 .It Li "select-line" Ta "V" Ta ""
 .It Li "select-word" Ta "" Ta ""
+.It Li "set-mark" Ta "X" Ta "X"
 .It Li "start-of-line" Ta "0" Ta "C-a"
 .It Li "stop-selection" Ta "" Ta ""
 .It Li "top-line" Ta "H" Ta "M-R"
@@ -3817,6 +3819,14 @@ see the
 .Sx STYLES
 section.
 .Pp
+.It Ic copy-mode-mark-style Ar style
+Set the style of the line containing the mark in copy mode.
+For how to specify
+.Ar style ,
+see the
+.Sx STYLES
+section.
+.Pp
 .It Ic copy-mode-current-match-style Ar style
 Set the style of the current search match in copy mode.
 For how to specify

window-copy.c

@@ -131,6 +131,7 @@ static void	window_copy_rectangle_toggle(struct window_mode_entry *);
 static void	window_copy_move_mouse(struct mouse_event *);
 static void	window_copy_drag_update(struct client *, struct mouse_event *);
 static void	window_copy_drag_release(struct client *, struct mouse_event *);
+static void	window_copy_jump_to_mark(struct window_mode_entry *);
 
 const struct window_mode window_copy_mode = {
 	.name = "copy-mode",
@@ -254,6 +255,10 @@ struct window_copy_mode_data {
 	u_int		 lastcx; 	/* position in last line w/ content */
 	u_int		 lastsx;	/* size of last line w/ content */
 
+	u_int		 mx;		/* mark position */
+	u_int		 my;
+	int		 showmark;
+
 	int		 searchtype;
 	int		 searchregex;
 	char		*searchstr;
@@ -424,6 +429,9 @@ window_copy_init(struct window_mode_entry *wme,
 
 	data->screen.cx = data->cx;
 	data->screen.cy = data->cy;
+	data->mx = data->cx;
+	data->my = screen_hsize(data->backing) + data->cy - data->oy;
+	data->showmark = 0;
 
 	screen_write_start(&ctx, &data->screen);
 	for (i = 0; i < screen_size_y(&data->screen); i++)
@@ -448,6 +456,9 @@ window_copy_view_init(struct window_mode_entry *wme,
 
 	data->backing = s = xmalloc(sizeof *data->backing);
 	screen_init(s, screen_size_x(base), screen_size_y(base), UINT_MAX);
+	data->mx = data->cx;
+	data->my = screen_hsize(data->backing) + data->cy - data->oy;
+	data->showmark = 0;
 
 	return (&data->screen);
 }
@@ -1733,6 +1744,17 @@ window_copy_cmd_select_word(struct window_copy_cmd_state *cs)
 	return (WINDOW_COPY_CMD_REDRAW);
 }
 
+static enum window_copy_cmd_action
+window_copy_cmd_set_mark(struct window_copy_cmd_state *cs)
+{
+	struct window_copy_mode_data	*data = cs->wme->data;
+
+	data->mx = data->cx;
+	data->my = screen_hsize(data->backing) + data->cy - data->oy;
+	data->showmark = 1;
+	return (WINDOW_COPY_CMD_REDRAW);
+}
+
 static enum window_copy_cmd_action
 window_copy_cmd_start_of_line(struct window_copy_cmd_state *cs)
 {
@@ -1877,6 +1899,15 @@ window_copy_cmd_jump_to_forward(struct window_copy_cmd_state *cs)
 	return (WINDOW_COPY_CMD_NOTHING);
 }
 
+static enum window_copy_cmd_action
+window_copy_cmd_jump_to_mark(struct window_copy_cmd_state *cs)
+{
+	struct window_mode_entry	*wme = cs->wme;
+
+	window_copy_jump_to_mark(wme);
+	return (WINDOW_COPY_CMD_NOTHING);
+}
+
 static enum window_copy_cmd_action
 window_copy_cmd_search_backward(struct window_copy_cmd_state *cs)
 {
@@ -2154,6 +2185,8 @@ static const struct {
 	  window_copy_cmd_jump_to_backward },
 	{ "jump-to-forward", 1, 1, 1,
 	  window_copy_cmd_jump_to_forward },
+	{ "jump-to-mark", 0, 0, 0,
+	  window_copy_cmd_jump_to_mark },
 	{ "middle-line", 0, 0, 1,
 	  window_copy_cmd_middle_line },
 	{ "next-matching-bracket", 0, 0, 0,
@@ -2214,6 +2247,8 @@ static const struct {
 	  window_copy_cmd_select_line },
 	{ "select-word", 0, 0, 0,
 	  window_copy_cmd_select_word },
+	{ "set-mark", 0, 0, 0,
+	  window_copy_cmd_set_mark },
 	{ "start-of-line", 0, 0, 1,
 	  window_copy_cmd_start_of_line },
 	{ "stop-selection", 0, 0, 0,
@@ -3129,11 +3164,26 @@ window_copy_match_at_cursor(struct window_copy_mode_data *data)
 static void
 window_copy_update_style(struct window_mode_entry *wme, u_int fx, u_int fy,
     struct grid_cell *gc, const struct grid_cell *mgc,
-    const struct grid_cell *cgc)
+    const struct grid_cell *cgc, const struct grid_cell *mkgc)
 {
 	struct window_copy_mode_data	*data = wme->data;
 	u_int				 mark, start, end, cy, cursor, current;
 	u_int				 sx = screen_size_x(data->backing);
+	int				 inv = 0;
+
+	if (data->showmark && fy == data->my) {
+		gc->attr = mkgc->attr;
+		if (fx == data->mx)
+			inv = 1;
+		if (inv) {
+			gc->fg = mkgc->bg;
+			gc->bg = mkgc->fg;
+		}
+		else {
+			gc->fg = mkgc->fg;
+			gc->bg = mkgc->bg;
+		}
+	}
 
 	if (data->searchmark == NULL)
 		return;
@@ -3150,21 +3200,34 @@ window_copy_update_style(struct window_mode_entry *wme, u_int fx, u_int fy,
 		window_copy_match_start_end(data, cursor, &start, &end);
 		if (current >= start && current <= end) {
 			gc->attr = cgc->attr;
+			if (inv) {
+				gc->fg = cgc->bg;
+				gc->bg = cgc->fg;
+			}
+			else {
 				gc->fg = cgc->fg;
 				gc->bg = cgc->bg;
+			}
 			return;
 		}
 	}
 
 	gc->attr = mgc->attr;
+	if (inv) {
+		gc->fg = mgc->bg;
+		gc->bg = mgc->fg;
+	}
+	else {
 		gc->fg = mgc->fg;
 		gc->bg = mgc->bg;
+	}
 }
 
 static void
 window_copy_write_one(struct window_mode_entry *wme,
     struct screen_write_ctx *ctx, u_int py, u_int fy, u_int nx,
-    const struct grid_cell *mgc, const struct grid_cell *cgc)
+    const struct grid_cell *mgc, const struct grid_cell *cgc,
+    const struct grid_cell *mkgc)
 {
 	struct window_copy_mode_data	*data = wme->data;
 	struct grid			*gd = data->backing->grid;
@@ -3175,7 +3238,8 @@ window_copy_write_one(struct window_mode_entry *wme,
 	for (fx = 0; fx < nx; fx++) {
 		grid_get_cell(gd, fx, fy, &gc);
 		if (fx + gc.data.width <= nx) {
-			window_copy_update_style(wme, fx, fy, &gc, mgc, cgc);
+			window_copy_update_style(wme, fx, fy, &gc, mgc, cgc,
+			    mkgc);
 			screen_write_cell(ctx, &gc);
 		}
 	}
@@ -3189,7 +3253,7 @@ window_copy_write_line(struct window_mode_entry *wme,
 	struct window_copy_mode_data	*data = wme->data;
 	struct screen			*s = &data->screen;
 	struct options			*oo = wp->window->options;
-	struct grid_cell		 gc, mgc, cgc;
+	struct grid_cell		 gc, mgc, cgc, mkgc;
 	char				 hdr[512];
 	size_t				 size = 0;
 	u_int				 hsize = screen_hsize(data->backing);
@@ -3200,6 +3264,8 @@ window_copy_write_line(struct window_mode_entry *wme,
 	mgc.flags |= GRID_FLAG_NOPALETTE;
 	style_apply(&cgc, oo, "copy-mode-current-match-style", NULL);
 	cgc.flags |= GRID_FLAG_NOPALETTE;
+	style_apply(&mkgc, oo, "copy-mode-mark-style", NULL);
+	mkgc.flags |= GRID_FLAG_NOPALETTE;
 
 	if (py == 0 && s->rupper < s->rlower && !data->hide_position) {
 		if (data->searchmark == NULL) {
@@ -3233,7 +3299,7 @@ window_copy_write_line(struct window_mode_entry *wme,
 
 	if (size < screen_size_x(s)) {
 		window_copy_write_one(wme, ctx, py, hsize - data->oy + py,
-		    screen_size_x(s) - size, &mgc, &cgc);
+		    screen_size_x(s) - size, &mgc, &cgc, &mkgc);
 	}
 
 	if (py == data->cy && data->cx == screen_size_x(s)) {
@@ -4687,3 +4753,26 @@ window_copy_drag_release(struct client *c, struct mouse_event *m)
 	data = wme->data;
 	evtimer_del(&data->dragtimer);
 }
+
+static void
+window_copy_jump_to_mark(struct window_mode_entry *wme)
+{
+	struct window_copy_mode_data	*data = wme->data;
+	u_int				 tmx, tmy;
+
+	tmx = data->cx;
+	tmy = screen_hsize(data->backing) + data->cy - data->oy;
+	data->cx = data->mx;
+	if (data->my < screen_hsize(data->backing)) {
+		data->cy = 0;
+		data->oy = screen_hsize(data->backing) - data->my;
+	} else {
+		data->cy = data->my - screen_hsize(data->backing);
+		data->oy = 0;
+	}
+	data->mx = tmx;
+	data->my = tmy;
+	data->showmark = 1;
+	window_copy_update_selection(wme, 0, 0);
+	window_copy_redraw_screen(wme);
+}