Handle focus events from the terminal, from Aaron Jensen.

server-client.c

@@ -17,6 +17,7 @@
  */
 
 #include <sys/types.h>
+#include <sys/ioctl.h>
 
 #include <event.h>
 #include <fcntl.h>
@@ -28,6 +29,8 @@
 
 #include "tmux.h"
 
+void	server_client_check_focus(struct window_pane *);
+void	server_client_check_resize(struct window_pane *);
 void	server_client_check_mouse(struct client *, struct window_pane *);
 void	server_client_repeat_timer(int, short, void *);
 void	server_client_check_exit(struct client *);
@@ -94,6 +97,8 @@ server_client_create(int fd)
 	c->tty.mouse.event = MOUSE_EVENT_UP;
 	c->tty.mouse.flags = 0;
 
+	c->flags |= CLIENT_FOCUSED;
+
 	evtimer_set(&c->repeat_timer, server_client_repeat_timer, c);
 
 	for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
@@ -495,7 +500,7 @@ server_client_loop(void)
 
 	/*
 	 * Any windows will have been redrawn as part of clients, so clear
-	 * their flags now.
+	 * their flags now. Also check pane focus and resize.
 	 */
 	for (i = 0; i < ARRAY_LENGTH(&windows); i++) {
 		w = ARRAY_ITEM(&windows, i);
@@ -503,11 +508,92 @@ server_client_loop(void)
 			continue;
 
 		w->flags &= ~WINDOW_REDRAW;
-		TAILQ_FOREACH(wp, &w->panes, entry)
+		TAILQ_FOREACH(wp, &w->panes, entry) {
+			server_client_check_focus(wp);
+			server_client_check_resize(wp);
 			wp->flags &= ~PANE_REDRAW;
+		}
 	}
 }
 
+/* Check if pane should be resized. */
+void
+server_client_check_resize(struct window_pane *wp)
+{
+	struct winsize	ws;
+
+	if (wp->fd == -1 || !(wp->flags & PANE_RESIZE))
+		return;
+
+	memset(&ws, 0, sizeof ws);
+	ws.ws_col = wp->sx;
+	ws.ws_row = wp->sy;
+
+	if (ioctl(wp->fd, TIOCSWINSZ, &ws) == -1) {
+#ifdef __sun
+		/*
+		 * Some versions of Solaris apparently can return an error when
+		 * resizing; don't know why this happens, can't reproduce on
+		 * other platforms and ignoring it doesn't seem to cause any
+		 * issues.
+		 */
+		if (errno != EINVAL)
+#endif
+		fatal("ioctl failed");
+	}
+
+	wp->flags &= ~PANE_RESIZE;
+}
+
+/* Check whether pane should be focused. */
+void
+server_client_check_focus(struct window_pane *wp)
+{
+	u_int		 i;
+	struct client	*c;
+
+	/* If we don't care about focus, forget it. */
+	if (!(wp->base.mode & MODE_FOCUSON))
+		return;
+
+	/* If we're not the active pane in our window, we're not focused. */
+	if (wp->window->active != wp)
+		goto not_focused;
+
+	/* If we're in a mode, we're not focused. */
+	if (wp->screen != &wp->base)
+		goto not_focused;
+
+	/*
+	 * If our window is the current window in any focused clients with an
+	 * attached session, we're focused.
+	 */
+	for (i = 0; i < ARRAY_LENGTH(&clients); i++) {
+		c = ARRAY_ITEM(&clients, i);
+		if (c == NULL || c->session == NULL)
+			continue;
+
+		if (!(c->flags & CLIENT_FOCUSED))
+			continue;
+		if (c->session->flags & SESSION_UNATTACHED)
+			continue;
+
+		if (c->session->curw->window == wp->window)
+			goto focused;
+	}
+
+not_focused:
+	if (wp->flags & PANE_FOCUSED)
+		bufferevent_write(wp->event, "\033[O", 3);
+	wp->flags &= ~PANE_FOCUSED;
+	return;
+
+focused:
+	if (!(wp->flags & PANE_FOCUSED))
+		bufferevent_write(wp->event, "\033[I", 3);
+	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

tmux.h

@@ -241,6 +241,9 @@ enum key_code {
 	KEYC_KP_ENTER,
 	KEYC_KP_ZERO,
 	KEYC_KP_PERIOD,
+
+	KEYC_FOCUS_IN,
+	KEYC_FOCUS_OUT,
 };
 
 /* Termcap codes. */
@@ -669,6 +672,7 @@ struct mode_key_table {
 #define MODE_MOUSE_UTF8 0x100
 #define MODE_MOUSE_SGR 0x200
 #define MODE_BRACKETPASTE 0x400
+#define MODE_FOCUSON 0x800
 
 #define ALL_MOUSE_MODES (MODE_MOUSE_STANDARD|MODE_MOUSE_BUTTON|MODE_MOUSE_ANY)
 
@@ -930,6 +934,8 @@ struct window_pane {
 	int		 flags;
 #define PANE_REDRAW 0x1
 #define PANE_DROP 0x2
+#define PANE_FOCUSED 0x4
+#define PANE_RESIZE 0x8
 
 	char		*cmd;
 	char		*shell;
@@ -1317,6 +1323,7 @@ struct client {
 #define CLIENT_READONLY 0x800
 #define CLIENT_REDRAWWINDOW 0x1000
 #define CLIENT_CONTROL 0x2000
+#define CLIENT_FOCUSED 0x4000
 	int		 flags;
 
 	struct event	 identify_timer;
@@ -1729,7 +1736,7 @@ struct cmd	*cmd_parse(int, char **, char **);
 size_t		 cmd_print(struct cmd *, char *, size_t);
 struct session	*cmd_current_session(struct cmd_ctx *, int);
 struct client	*cmd_current_client(struct cmd_ctx *);
-struct client	*cmd_find_client(struct cmd_ctx *, const char *);
+struct client	*cmd_find_client(struct cmd_ctx *, const char *, int);
 struct session	*cmd_find_session(struct cmd_ctx *, const char *, int);
 struct winlink	*cmd_find_window(
 		     struct cmd_ctx *, const char *, struct session **);

tty-keys.c

@@ -174,6 +174,10 @@ const struct tty_default_key_raw tty_default_raw_keys[] = {
 	{ "\033[8@", KEYC_END|KEYC_CTRL|KEYC_SHIFT },
 	{ "\033[6@", KEYC_NPAGE|KEYC_CTRL|KEYC_SHIFT },
 	{ "\033[5@", KEYC_PPAGE|KEYC_CTRL|KEYC_SHIFT },
+
+	/* Focus tracking. */
+	{ "\033[I", KEYC_FOCUS_IN },
+	{ "\033[O", KEYC_FOCUS_OUT },
 };
 
 /* Default terminfo(5) keys. */
@@ -559,6 +563,15 @@ complete_key:
 		evtimer_del(&tty->key_timer);
 	tty->flags &= ~TTY_TIMER;
 
+	/* Check for focus events. */
+	if (key == KEYC_FOCUS_OUT) {
+		tty->client->flags &= ~CLIENT_FOCUSED;
+		return (1);
+	} else if (key == KEYC_FOCUS_IN) {
+		tty->client->flags |= CLIENT_FOCUSED;
+		return (1);
+	}
+
 	/* Fire the key. */
 	if (key != KEYC_NONE)
 		server_client_handle_key(tty->client, key);

tty.c

@@ -221,7 +221,7 @@ tty_start_tty(struct tty *tty)
 		tty_puts(tty, "\033[?1000l\033[?1006l\033[?1005l");
 
 	if (tty_term_has(tty->term, TTYC_XT))
-		tty_puts(tty, "\033[c\033[>4;1m");
+		tty_puts(tty, "\033[c\033[>4;1m\033[?1004h");
 
 	tty->cx = UINT_MAX;
 	tty->cy = UINT_MAX;
@@ -284,7 +284,7 @@ tty_stop_tty(struct tty *tty)
 		tty_raw(tty, "\033[?1000l\033[?1006l\033[?1005l");
 
 	if (tty_term_has(tty->term, TTYC_XT))
-		tty_raw(tty, "\033[>4m");
+		tty_raw(tty, "\033[>4m\033[?1004l");
 
 	tty_raw(tty, tty_term_string(tty->term, TTYC_RMCUP));