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.

1 files changed, 52 insertions, 1 deletions

diff --git a/usr.bin/tmux/window.c b/usr.bin/tmux/window.c
index fbf3da32fbe..69257a3ddff 100644
--- a/usr.bin/tmux/window.c
+++ b/usr.bin/tmux/window.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window.c,v 1.273 2021/08/11 20:49:55 nicm Exp $ */
+/* $OpenBSD: window.c,v 1.274 2021/08/13 06:52:51 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicholas.marriott@gmail.com>
@@ -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)