Change focus to be driven by events rather than walking all panes at end

of event loop, this way the ordering of in and out can be enforced.
GitHub issue 2808.

cmd-attach-session.c

@@ -124,17 +124,9 @@ cmd_attach_session(struct cmdq_item *item, const char *tflag, int dflag,
 		if (!Eflag)
 			environ_update(s->options, c->environ, s->environ);
 
-		c->session = s;
+		server_client_set_session(c, s);
 		if (~cmdq_get_flags(item) & CMDQ_STATE_REPEAT)
 			server_client_set_key_table(c, NULL);
-		tty_update_client_offset(c);
-		status_timer_start(c);
-		notify_client("client-session-changed", c);
-		session_update_activity(s, NULL);
-		gettimeofday(&s->last_attached_time, NULL);
-		server_redraw_client(c);
-		s->curw->flags &= ~WINLINK_ALERTFLAGS;
-		s->curw->window->latest = c;
 	} else {
 		if (server_client_open(c, &cause) != 0) {
 			cmdq_error(item, "open terminal failed: %s", cause);
@@ -156,25 +148,14 @@ cmd_attach_session(struct cmdq_item *item, const char *tflag, int dflag,
 		if (!Eflag)
 			environ_update(s->options, c->environ, s->environ);
 
-		c->session = s;
+		server_client_set_session(c, s);
 		server_client_set_key_table(c, NULL);
-		tty_update_client_offset(c);
-		status_timer_start(c);
-		notify_client("client-session-changed", c);
-		session_update_activity(s, NULL);
-		gettimeofday(&s->last_attached_time, NULL);
-		server_redraw_client(c);
-		s->curw->flags &= ~WINLINK_ALERTFLAGS;
-		s->curw->window->latest = c;
 
 		if (~c->flags & CLIENT_CONTROL)
 			proc_send(c->peer, MSG_READY, -1, NULL, 0);
 		notify_client("client-attached", c);
 		c->flags |= CLIENT_ATTACHED;
 	}
-	recalculate_sizes();
-	alerts_check_session(s);
-	server_update_socket();
 
 	return (CMD_RETURN_NORMAL);
 }

cmd-new-session.c

@@ -329,18 +329,10 @@ cmd_new_session_exec(struct cmd *self, struct cmdq_item *item)
 				proc_send(c->peer, MSG_READY, -1, NULL, 0);
 		} else if (c->session != NULL)
 			c->last_session = c->session;
-		c->session = s;
+		server_client_set_session(c, s);
 		if (~cmdq_get_flags(item) & CMDQ_STATE_REPEAT)
 			server_client_set_key_table(c, NULL);
-		tty_update_client_offset(c);
-		status_timer_start(c);
-		notify_client("client-session-changed", c);
-		session_update_activity(s, NULL);
-		gettimeofday(&s->last_attached_time, NULL);
-		server_redraw_client(c);
 	}
-	recalculate_sizes();
-	server_update_socket();
 
 	/*
 	 * If there are still configuration file errors to display, put the new

cmd-switch-client.c

@@ -134,23 +134,9 @@ cmd_switch_client_exec(struct cmd *self, struct cmdq_item *item)
 	if (!args_has(args, 'E'))
 		environ_update(s->options, tc->environ, s->environ);
 
-	if (tc->session != NULL && tc->session != s)
-		tc->last_session = tc->session;
-	tc->session = s;
+	server_client_set_session(tc, s);
 	if (~cmdq_get_flags(item) & CMDQ_STATE_REPEAT)
 		server_client_set_key_table(tc, NULL);
-	tty_update_client_offset(tc);
-	status_timer_start(tc);
-	notify_client("client-session-changed", tc);
-	session_update_activity(s, NULL);
-	gettimeofday(&s->last_attached_time, NULL);
-
-	server_check_unattached();
-	server_redraw_client(tc);
-	s->curw->flags &= ~WINLINK_ALERTFLAGS;
-	s->curw->window->latest = tc;
-	recalculate_sizes();
-	alerts_check_session(s);
 
 	return (CMD_RETURN_NORMAL);
 }

input.c

@@ -1792,8 +1792,12 @@ input_csi_dispatch_sm_private(struct input_ctx *ictx)
 			if (sctx->s->mode & MODE_FOCUSON)
 				break;
 			screen_write_mode_set(sctx, MODE_FOCUSON);
-			if (wp != NULL)
-				wp->flags |= PANE_FOCUSPUSH; /* force update */
+			if (wp == NULL)
+				break;
+			if (wp->flags & PANE_FOCUSED)
+				bufferevent_write(wp->event, "\033[I", 3);
+			else
+				bufferevent_write(wp->event, "\033[O", 3);
 			break;
 		case 1005:
 			screen_write_mode_set(sctx, MODE_MOUSE_UTF8);

server-client.c

@@ -33,7 +33,6 @@
 #include "tmux.h"
 
 static void	server_client_free(int, short, void *);
-static void	server_client_check_pane_focus(struct window_pane *);
 static void	server_client_check_pane_resize(struct window_pane *);
 static void	server_client_check_pane_buffer(struct window_pane *);
 static void	server_client_check_window_resize(struct window *);
@@ -301,9 +300,8 @@ server_client_attached_lost(struct client *c)
 			s = loop->session;
 			if (loop == c || s == NULL || s->curw->window != w)
 				continue;
-			if (found == NULL ||
-			    timercmp(&loop->activity_time, &found->activity_time,
-			    >))
+			if (found == NULL || timercmp(&loop->activity_time,
+			    &found->activity_time, >))
 				found = loop;
 		}
 		if (found != NULL)
@@ -311,6 +309,40 @@ server_client_attached_lost(struct client *c)
 	}
 }
 
+
+/* Set client session. */
+void
+server_client_set_session(struct client *c, struct session *s)
+{
+	struct session	*old = c->session;
+
+	if (s != NULL && c->session != NULL && c->session != s)
+		c->last_session = c->session;
+	else if (s == NULL)
+		c->last_session = NULL;
+	c->session = s;
+	c->flags |= CLIENT_FOCUSED;
+	recalculate_sizes();
+
+	if (old != NULL && old->curw != NULL)
+		window_update_focus(old->curw->window);
+	if (s != NULL) {
+		window_update_focus(s->curw->window);
+		session_update_activity(s, NULL);
+		gettimeofday(&s->last_attached_time, NULL);
+		s->curw->flags &= ~WINLINK_ALERTFLAGS;
+		s->curw->window->latest = c;
+		alerts_check_session(s);
+		tty_update_client_offset(c);
+		status_timer_start(c);
+		notify_client("client-session-changed", c);
+		server_redraw_client(c);
+	}
+
+	server_check_unattached();
+	server_update_socket();
+}
+
 /* Lost a client. */
 void
 server_client_lost(struct client *c)
@@ -1389,7 +1421,6 @@ server_client_loop(void)
 	struct client		*c;
 	struct window		*w;
 	struct window_pane	*wp;
-	int			 focus;
 
 	/* Check for window resize. This is done before redrawing. */
 	RB_FOREACH(w, windows, &windows)
@@ -1407,14 +1438,11 @@ server_client_loop(void)
 
 	/*
 	 * Any windows will have been redrawn as part of clients, so clear
-	 * their flags now. Also check pane focus and resize.
+	 * their flags now.
 	 */
-	focus = options_get_number(global_options, "focus-events");
 	RB_FOREACH(w, windows, &windows) {
 		TAILQ_FOREACH(wp, &w->panes, entry) {
 			if (wp->fd != -1) {
-				if (focus)
-					server_client_check_pane_focus(wp);
 				server_client_check_pane_resize(wp);
 				server_client_check_pane_buffer(wp);
 			}
@@ -1615,54 +1643,6 @@ out:
 		bufferevent_enable(wp->event, EV_READ);
 }
 
-/* Check whether pane should be focused. */
-static void
-server_client_check_pane_focus(struct window_pane *wp)
-{
-	struct client	*c;
-	int		 push;
-
-	/* Do we need to push the focus state? */
-	push = wp->flags & PANE_FOCUSPUSH;
-	wp->flags &= ~PANE_FOCUSPUSH;
-
-	/* If we're not the active pane in our window, we're not focused. */
-	if (wp->window->active != wp)
-		goto not_focused;
-
-	/*
-	 * If our window is the current window in any focused clients with an
-	 * attached session, we're focused.
-	 */
-	TAILQ_FOREACH(c, &clients, entry) {
-		if (c->session == NULL || !(c->flags & CLIENT_FOCUSED))
-			continue;
-		if (c->session->attached == 0)
-			continue;
-
-		if (c->session->curw->window == wp->window)
-			goto focused;
-	}
-
-not_focused:
-	if (push || (wp->flags & PANE_FOCUSED)) {
-		if (wp->base.mode & MODE_FOCUSON)
-			bufferevent_write(wp->event, "\033[O", 3);
-		notify_pane("pane-focus-out", wp);
-	}
-	wp->flags &= ~PANE_FOCUSED;
-	return;
-
-focused:
-	if (push || !(wp->flags & PANE_FOCUSED)) {
-		if (wp->base.mode & MODE_FOCUSON)
-			bufferevent_write(wp->event, "\033[I", 3);
-		notify_pane("pane-focus-in", wp);
-		session_update_activity(c->session, NULL);
-	}
-	wp->flags |= PANE_FOCUSED;
-}
-
 /*
  * Update cursor position and mode settings. The scroll region and attributes
  * are cleared when idle (waiting for an event) as this is the most likely time
@@ -2078,7 +2058,7 @@ server_client_dispatch(struct imsg *imsg, void *arg)
 	case MSG_EXITING:
 		if (datalen != 0)
 			fatalx("bad MSG_EXITING size");
-		c->session = NULL;
+		server_client_set_session(c, NULL);
 		tty_close(&c->tty);
 		proc_send(c->peer, MSG_EXITED, -1, NULL, 0);
 		break;

server-fn.c

@@ -445,21 +445,9 @@ server_destroy_session(struct session *s)
 	TAILQ_FOREACH(c, &clients, entry) {
 		if (c->session != s)
 			continue;
-		if (s_new == NULL) {
-			c->session = NULL;
+		server_client_set_session(c, NULL);
+		if (s_new == NULL)
 			c->flags |= CLIENT_EXIT;
-		} else {
-			c->last_session = NULL;
-			c->session = s_new;
-			server_client_set_key_table(c, NULL);
-			tty_update_client_offset(c);
-			status_timer_start(c);
-			notify_client("client-session-changed", c);
-			session_update_activity(s_new, NULL);
-			gettimeofday(&s_new->last_attached_time, NULL);
-			server_redraw_client(c);
-			alerts_check_session(s_new);
-		}
 	}
 	recalculate_sizes();
 }

session.c

@@ -489,6 +489,8 @@ session_last(struct session *s)
 int
 session_set_current(struct session *s, struct winlink *wl)
 {
+	struct winlink	*old = s->curw;
+
 	if (wl == NULL)
 		return (-1);
 	if (wl == s->curw)
@@ -497,6 +499,10 @@ session_set_current(struct session *s, struct winlink *wl)
 	winlink_stack_remove(&s->lastw, wl);
 	winlink_stack_push(&s->lastw, s->curw);
 	s->curw = wl;
+	if (options_get_number(global_options, "focus-events")) {
+		window_update_focus(old->window);
+		window_update_focus(wl->window);
+	}
 	winlink_clear_flags(wl);
 	window_update_activity(wl->window);
 	tty_update_window_offset(wl->window);

tmux.h

@@ -1004,7 +1004,7 @@ struct window_pane {
 #define PANE_FOCUSED 0x4
 /* 0x8 unused */
 /* 0x10 unused */
-#define PANE_FOCUSPUSH 0x20
+/* 0x20 unused */
 #define PANE_INPUTOFF 0x40
 #define PANE_CHANGED 0x80
 #define PANE_EXITED 0x100
@@ -2506,6 +2506,7 @@ int	 server_client_handle_key(struct client *, struct key_event *);
 struct client *server_client_create(int);
 int	 server_client_open(struct client *, char **);
 void	 server_client_unref(struct client *);
+void	 server_client_set_session(struct client *, struct session *);
 void	 server_client_lost(struct client *);
 void	 server_client_suspend(struct client *);
 void	 server_client_detach(struct client *, enum msgtype);
@@ -2826,6 +2827,8 @@ struct window_pane *window_find_string(struct window *, const char *);
 int		 window_has_pane(struct window *, struct window_pane *);
 int		 window_set_active_pane(struct window *, struct window_pane *,
 		     int);
+void		 window_update_focus(struct window *);
+void		 window_pane_update_focus(struct window_pane *);
 void		 window_redraw_active_switch(struct window *,
 		     struct window_pane *);
 struct window_pane *window_add_pane(struct window *, struct window_pane *,

tty-keys.c

@@ -821,11 +821,13 @@ complete_key:
 
 	/* Check for focus events. */
 	if (key == KEYC_FOCUS_OUT) {
-		tty->client->flags &= ~CLIENT_FOCUSED;
+		c->flags &= ~CLIENT_FOCUSED;
+		window_update_focus(c->session->curw->window);
 		notify_client("client-focus-out", c);
 	} else if (key == KEYC_FOCUS_IN) {
-		tty->client->flags |= CLIENT_FOCUSED;
+		c->flags |= CLIENT_FOCUSED;
 		notify_client("client-focus-in", c);
+		window_update_focus(c->session->curw->window);
 	}
 
 	/* Fire the key. */

window.c

@@ -458,6 +458,52 @@ window_has_pane(struct window *w, struct window_pane *wp)
 	return (0);
 }
 
+void
+window_update_focus(struct window *w)
+{
+	if (w != NULL) {
+		log_debug("%s: @%u", __func__, w->id);
+		window_pane_update_focus(w->active);
+	}
+}
+
+void
+window_pane_update_focus(struct window_pane *wp)
+{
+	struct client	*c;
+	int		 focused = 0;
+
+	if (wp != NULL) {
+		if (wp != wp->window->active)
+			focused = 0;
+		else {
+			TAILQ_FOREACH(c, &clients, entry) {
+				if (c->session != NULL &&
+				    c->session->attached != 0 &&
+				    (c->flags & CLIENT_FOCUSED) &&
+				    c->session->curw->window == wp->window) {
+					focused = 1;
+					break;
+				}
+			}
+		}
+		if (!focused && (wp->flags & PANE_FOCUSED)) {
+			log_debug("%s: %%%u focus out", __func__, wp->id);
+			if (wp->base.mode & MODE_FOCUSON)
+				bufferevent_write(wp->event, "\033[O", 3);
+			notify_pane("pane-focus-out", wp);
+			wp->flags &= ~PANE_FOCUSED;
+		} else if (focused && (~wp->flags & PANE_FOCUSED)) {
+			log_debug("%s: %%%u focus in", __func__, wp->id);
+			if (wp->base.mode & MODE_FOCUSON)
+				bufferevent_write(wp->event, "\033[I", 3);
+			notify_pane("pane-focus-in", wp);
+			wp->flags |= PANE_FOCUSED;
+		} else
+			log_debug("%s: %%%u focus unchanged", __func__, wp->id);
+	}
+}
+
 int
 window_set_active_pane(struct window *w, struct window_pane *wp, int notify)
 {
@@ -471,6 +517,11 @@ window_set_active_pane(struct window *w, struct window_pane *wp, int notify)
 	w->active->active_point = next_active_point++;
 	w->active->flags |= PANE_CHANGED;
 
+	if (options_get_number(global_options, "focus-events")) {
+		window_pane_update_focus(w->last);
+		window_pane_update_focus(w->active);
+	}
+
 	tty_update_window_offset(w);
 
 	if (notify)