Add a "latest" window-size option which tries to size windows based on

the most recently used client. From Tommie Gannert in GitHub issue 1869
based on earlier changes from me.

cmd-break-pane.c

@@ -81,6 +81,7 @@ cmd_break_pane_exec(struct cmd *self, struct cmdq_item *item)
 	wp->flags |= PANE_STYLECHANGED;
 	TAILQ_INSERT_HEAD(&w->panes, wp, entry);
 	w->active = wp;
+	w->latest = c;
 
 	if (!args_has(args, 'n')) {
 		name = default_window_name(w);

cmd-new-session.c

@@ -259,6 +259,7 @@ cmd_new_session_exec(struct cmd *self, struct cmdq_item *item)
 	memset(&sc, 0, sizeof sc);
 	sc.item = item;
 	sc.s = s;
+	sc.c = c;
 
 	sc.name = args_get(args, 'n');
 	sc.argc = args->argc;

cmd-new-window.c

@@ -72,6 +72,7 @@ cmd_new_window_exec(struct cmd *self, struct cmdq_item *item)
 	memset(&sc, 0, sizeof sc);
 	sc.item = item;
 	sc.s = s;
+	sc.c = c;
 
 	sc.name = args_get(args, 'n');
 	sc.argc = args->argc;

cmd-respawn-window.c

@@ -59,6 +59,7 @@ cmd_respawn_window_exec(struct cmd *self, struct cmdq_item *item)
 	sc.item = item;
 	sc.s = s;
 	sc.wl = wl;
+	sc.c = cmd_find_client(item, NULL, 1);
 
 	sc.name = NULL;
 	sc.argc = args->argc;

options-table.c

@@ -64,7 +64,7 @@ static const char *options_table_set_clipboard_list[] = {
 	"off", "external", "on", NULL
 };
 static const char *options_table_window_size_list[] = {
-	"largest", "smallest", "manual", NULL
+	"largest", "smallest", "manual", "latest", NULL
 };
 
 /* Status line format. */

resize.c

@@ -149,14 +149,121 @@ done:
 		*sy = WINDOW_MAXIMUM;
 }
 
+void
+recalculate_size(struct window *w)
+{
+	struct session	*s;
+	struct client	*c;
+	u_int		 sx, sy, cx, cy;
+	int		 type, current, has, changed;
+
+	if (w->active == NULL)
+		return;
+	log_debug("%s: @%u is %u,%u", __func__, w->id, w->sx, w->sy);
+
+	type = options_get_number(w->options, "window-size");
+	current = options_get_number(w->options, "aggressive-resize");
+
+	changed = 1;
+	switch (type) {
+	case WINDOW_SIZE_LARGEST:
+		sx = sy = 0;
+		TAILQ_FOREACH(c, &clients, entry) {
+			if (ignore_client_size(c))
+				continue;
+			s = c->session;
+
+			if (current)
+				has = (s->curw->window == w);
+			else
+				has = session_has(s, w);
+			if (!has)
+				continue;
+
+			cx = c->tty.sx;
+			cy = c->tty.sy - status_line_size(c);
+
+			if (cx > sx)
+				sx = cx;
+			if (cy > sy)
+				sy = cy;
+		}
+		if (sx == 0 || sy == 0)
+			changed = 0;
+		break;
+	case WINDOW_SIZE_SMALLEST:
+		sx = sy = UINT_MAX;
+		TAILQ_FOREACH(c, &clients, entry) {
+			if (ignore_client_size(c))
+				continue;
+			s = c->session;
+
+			if (current)
+				has = (s->curw->window == w);
+			else
+				has = session_has(s, w);
+			if (!has)
+				continue;
+
+			cx = c->tty.sx;
+			cy = c->tty.sy - status_line_size(c);
+
+			if (cx < sx)
+				sx = cx;
+			if (cy < sy)
+				sy = cy;
+		}
+		if (sx == UINT_MAX || sy == UINT_MAX)
+			changed = 0;
+		break;
+	case WINDOW_SIZE_LATEST:
+		sx = sy = UINT_MAX;
+		TAILQ_FOREACH(c, &clients, entry) {
+			if (ignore_client_size(c))
+				continue;
+			if (c != w->latest)
+				continue;
+			s = c->session;
+
+			if (current)
+				has = (s->curw->window == w);
+			else
+				has = session_has(s, w);
+			if (!has)
+				continue;
+
+			cx = c->tty.sx;
+			cy = c->tty.sy - status_line_size(c);
+
+			if (cx < sx)
+				sx = cx;
+			if (cy < sy)
+				sy = cy;
+		}
+		if (sx == UINT_MAX || sy == UINT_MAX)
+			changed = 0;
+		break;
+	case WINDOW_SIZE_MANUAL:
+		changed = 0;
+		break;
+	}
+	if (changed && w->sx == sx && w->sy == sy)
+		changed = 0;
+
+	if (!changed) {
+		tty_update_window_offset(w);
+		return;
+	}
+	log_debug("%s: @%u changed to %u,%u", __func__, w->id, sx, sy);
+	resize_window(w, sx, sy);
+}
+
 void
 recalculate_sizes(void)
 {
 	struct session	*s;
 	struct client	*c;
 	struct window	*w;
-	u_int		 sx, sy, cx, cy;
-	int		 type, current, has, changed;
 
 	/*
 	 * Clear attached count and update saved status line information for
@@ -183,74 +290,6 @@ recalculate_sizes(void)
 	}
 
 	/* Walk each window and adjust the size. */
-	RB_FOREACH(w, windows, &windows) {
-		if (w->active == NULL)
-			continue;
-		log_debug("%s: @%u is %u,%u", __func__, w->id, w->sx, w->sy);
-
-		type = options_get_number(w->options, "window-size");
-		if (type == WINDOW_SIZE_MANUAL)
-			continue;
-		current = options_get_number(w->options, "aggressive-resize");
-
-		changed = 1;
-		if (type == WINDOW_SIZE_LARGEST) {
-			sx = sy = 0;
-			TAILQ_FOREACH(c, &clients, entry) {
-				if (ignore_client_size(c))
-					continue;
-				s = c->session;
-
-				if (current)
-					has = (s->curw->window == w);
-				else
-					has = session_has(s, w);
-				if (!has)
-					continue;
-
-				cx = c->tty.sx;
-				cy = c->tty.sy - status_line_size(c);
-
-				if (cx > sx)
-					sx = cx;
-				if (cy > sy)
-					sy = cy;
-			}
-			if (sx == 0 || sy == 0)
-				changed = 0;
-		} else {
-			sx = sy = UINT_MAX;
-			TAILQ_FOREACH(c, &clients, entry) {
-				if (ignore_client_size(c))
-					continue;
-				s = c->session;
-
-				if (current)
-					has = (s->curw->window == w);
-				else
-					has = session_has(s, w);
-				if (!has)
-					continue;
-
-				cx = c->tty.sx;
-				cy = c->tty.sy - status_line_size(c);
-
-				if (cx < sx)
-					sx = cx;
-				if (cy < sy)
-					sy = cy;
-			}
-			if (sx == UINT_MAX || sy == UINT_MAX)
-				changed = 0;
-		}
-		if (w->sx == sx && w->sy == sy)
-			changed = 0;
-
-		if (!changed) {
-			tty_update_window_offset(w);
-			continue;
-		}
-		log_debug("%s: @%u changed to %u,%u", __func__, w->id, sx, sy);
-		resize_window(w, sx, sy);
-	}
+	RB_FOREACH(w, windows, &windows)
+		recalculate_size(w);
 }

server-client.c

@@ -996,6 +996,24 @@ server_client_assume_paste(struct session *s)
 	return (0);
 }
 
+/* Has the latest client changed? */
+static void
+server_client_update_latest(struct client *c)
+{
+	struct window	*w;
+
+	if (c->session == NULL)
+		return;
+	w = c->session->curw->window;
+
+	if (w->latest == c)
+		return;
+	w->latest = c;
+
+	if (options_get_number(w->options, "window-size") == WINDOW_SIZE_LATEST)
+		recalculate_size(w);
+}
+
 /*
  * Handle data key input from client. This owns and can modify the key event it
  * is given and is responsible for freeing it.
@@ -1192,6 +1210,8 @@ forward_key:
 		window_pane_key(wp, c, s, wl, key, m);
 
 out:
+	if (s != NULL)
+		server_client_update_latest(c);
 	free(event);
 	return (CMD_RETURN_NORMAL);
 }
@@ -1737,6 +1757,7 @@ server_client_dispatch(struct imsg *imsg, void *arg)
 
 		if (c->flags & CLIENT_CONTROL)
 			break;
+		server_client_update_latest(c);
 		server_client_clear_overlay(c);
 		tty_resize(&c->tty);
 		recalculate_sizes();

spawn.c

@@ -164,6 +164,7 @@ spawn_window(struct spawn_context *sc, char **cause)
 		if (s->curw == NULL)
 			s->curw = sc->wl;
 		sc->wl->session = s;
+		w->latest = sc->c;
 		winlink_set_window(sc->wl, w);
 	} else
 		w = NULL;

tmux.1

@@ -3659,7 +3659,7 @@ see the
 section.
 .Pp
 .It Xo Ic window-size
-.Ar largest | Ar smallest | Ar manual
+.Ar largest | Ar smallest | Ar manual | Ar latest
 .Xc
 Configure how
 .Nm
@@ -3674,6 +3674,10 @@ If
 the size of a new window is set from the
 .Ic default-size
 option and windows are resized automatically.
+With
+.Ar latest ,
+.Nm
+uses the size of the client that had the most recent activity.
 See also the
 .Ic resize-window
 command and the

tmux.h

@@ -905,6 +905,7 @@ RB_HEAD(window_pane_tree, window_pane);
 /* Window structure. */
 struct window {
 	u_int		 id;
+	void		*latest;
 
 	char		*name;
 	struct event	 name_event;
@@ -970,6 +971,7 @@ TAILQ_HEAD(winlink_stack, winlink);
 #define WINDOW_SIZE_LARGEST 0
 #define WINDOW_SIZE_SMALLEST 1
 #define WINDOW_SIZE_MANUAL 2
+#define WINDOW_SIZE_LATEST 3
 
 /* Pane border status option. */
 #define PANE_STATUS_OFF 0
@@ -1670,6 +1672,7 @@ struct spawn_context {
 
 	struct session		 *s;
 	struct winlink		 *wl;
+	struct client		 *c;
 
 	struct window_pane	 *wp0;
 	struct layout_cell	 *lc;
@@ -2195,6 +2198,7 @@ void	 status_prompt_save_history(void);
 void	 resize_window(struct window *, u_int, u_int);
 void	 default_window_size(struct session *, struct window *, u_int *,
 	     u_int *, int);
+void	 recalculate_size(struct window *);
 void	 recalculate_sizes(void);
 
 /* input.c */