Add mode 2031 support (automatic dark/light mode).

Co-Author: Nicholas Marriott <nicholas.marriott@gmail.com>

colour.c

@@ -182,6 +182,38 @@ colour_tostring(int c)
 	return ("invalid");
 }
 
+/* Convert background colour to theme. */
+enum client_theme
+colour_totheme(int c)
+{
+	int	r, g, b, brightness;
+
+	if (c == -1)
+		return (THEME_UNKNOWN);
+
+	if (c & COLOUR_FLAG_RGB) {
+		r = (c >> 16) & 0xff;
+		g = (c >> 8) & 0xff;
+		b = (c >> 0) & 0xff;
+
+		brightness = r + g + b;
+		if (brightness > 382)
+			return (THEME_LIGHT);
+		return (THEME_DARK);
+	}
+
+	if (c & COLOUR_FLAG_256)
+		return (colour_totheme(colour_256toRGB(c)));
+
+	switch (c) {
+	case 0:
+		return (THEME_DARK);
+	case 7:
+		return (THEME_LIGHT);
+	}
+	return (THEME_UNKNOWN);
+}
+
 /* Convert colour from string. */
 int
 colour_fromstring(const char *s)

format.c

@@ -1544,6 +1544,23 @@ format_cb_client_written(struct format_tree *ft)
 	return (NULL);
 }
 
+/* Callback for client_theme. */
+static void *
+format_cb_client_theme(struct format_tree *ft)
+{
+	if (ft->c != NULL) {
+		switch (ft->c->theme) {
+		case THEME_DARK:
+			return (xstrdup("dark"));
+		case THEME_LIGHT:
+			return (xstrdup("light"));
+		case THEME_UNKNOWN:
+			return (NULL);
+		}
+	}
+	return (NULL);
+}
+
 /* Callback for config_files. */
 static void *
 format_cb_config_files(__unused struct format_tree *ft)
@@ -2881,6 +2898,9 @@ static const struct format_table_entry format_table[] = {
 	{ "client_termtype", FORMAT_TABLE_STRING,
 	  format_cb_client_termtype
 	},
+	{ "client_theme", FORMAT_TABLE_STRING,
+	  format_cb_client_theme
+	},
 	{ "client_tty", FORMAT_TABLE_STRING,
 	  format_cb_client_tty
 	},

input-keys.c

@@ -307,6 +307,12 @@ static struct input_key_entry input_key_defaults[] = {
 	{ .key = KEYC_DC|KEYC_BUILD_MODIFIERS,
 	  .data = "\033[3;_~"
 	},
+	{ .key = KEYC_REPORT_DARK_THEME,
+	  .data = "\033[?997;1n"
+	},
+	{ .key = KEYC_REPORT_LIGHT_THEME,
+	  .data = "\033[?997;2n"
+	},
 };
 static const key_code input_key_modifiers[] = {
 	0,

input.c

@@ -133,7 +133,7 @@ static void printflike(2, 3) input_reply(struct input_ctx *, const char *, ...);
 static void	input_set_state(struct input_ctx *,
 		    const struct input_transition *);
 static void	input_reset_cell(struct input_ctx *);
-
+static void	input_report_current_theme(struct input_ctx *);
 static void	input_osc_4(struct input_ctx *, const char *);
 static void	input_osc_8(struct input_ctx *, const char *);
 static void	input_osc_10(struct input_ctx *, const char *);
@@ -243,6 +243,7 @@ enum input_csi_type {
 	INPUT_CSI_DECSTBM,
 	INPUT_CSI_DL,
 	INPUT_CSI_DSR,
+	INPUT_CSI_DSR_PRIVATE,
 	INPUT_CSI_ECH,
 	INPUT_CSI_ED,
 	INPUT_CSI_EL,
@@ -251,6 +252,7 @@ enum input_csi_type {
 	INPUT_CSI_IL,
 	INPUT_CSI_MODOFF,
 	INPUT_CSI_MODSET,
+	INPUT_CSI_QUERY_PRIVATE,
 	INPUT_CSI_RCP,
 	INPUT_CSI_REP,
 	INPUT_CSI_RM,
@@ -259,8 +261,8 @@ enum input_csi_type {
 	INPUT_CSI_SD,
 	INPUT_CSI_SGR,
 	INPUT_CSI_SM,
-	INPUT_CSI_SM_PRIVATE,
 	INPUT_CSI_SM_GRAPHICS,
+	INPUT_CSI_SM_PRIVATE,
 	INPUT_CSI_SU,
 	INPUT_CSI_TBC,
 	INPUT_CSI_VPA,
@@ -304,6 +306,8 @@ static const struct input_table_entry input_csi_table[] = {
 	{ 'm', ">", INPUT_CSI_MODSET },
 	{ 'n', "",  INPUT_CSI_DSR },
 	{ 'n', ">", INPUT_CSI_MODOFF },
+	{ 'n', "?", INPUT_CSI_DSR_PRIVATE },
+	{ 'p', "?$", INPUT_CSI_QUERY_PRIVATE },
 	{ 'q', " ", INPUT_CSI_DECSCUSR },
 	{ 'q', ">", INPUT_CSI_XDA },
 	{ 'r', "",  INPUT_CSI_DECSTBM },
@@ -1531,6 +1535,20 @@ input_csi_dispatch(struct input_ctx *ictx)
 		if (n != -1)
 			screen_write_deleteline(sctx, n, bg);
 		break;
+	case INPUT_CSI_DSR_PRIVATE:
+		switch (input_get(ictx, 0, 0, 0)) {
+		case 996:
+			input_report_current_theme(ictx);
+			break;
+		}
+		break;
+	case INPUT_CSI_QUERY_PRIVATE:
+		switch (input_get(ictx, 0, 0, 0)) {
+		case 2031:
+			input_reply(ictx, "\033[?2031;2$y");
+			break;
+		}
+		break;
 	case INPUT_CSI_DSR:
 		switch (input_get(ictx, 0, 0, 0)) {
 		case -1:
@@ -1781,6 +1799,9 @@ input_csi_dispatch_rm_private(struct input_ctx *ictx)
 		case 2004:
 			screen_write_mode_clear(sctx, MODE_BRACKETPASTE);
 			break;
+		case 2031:
+			screen_write_mode_clear(sctx, MODE_THEME_UPDATES);
+			break;
 		default:
 			log_debug("%s: unknown '%c'", __func__, ictx->ch);
 			break;
@@ -1876,6 +1897,9 @@ input_csi_dispatch_sm_private(struct input_ctx *ictx)
 		case 2004:
 			screen_write_mode_set(sctx, MODE_BRACKETPASTE);
 			break;
+		case 2031:
+			screen_write_mode_set(sctx, MODE_THEME_UPDATES);
+			break;
 		default:
 			log_debug("%s: unknown '%c'", __func__, ictx->ch);
 			break;
@@ -2697,84 +2721,6 @@ bad:
 	free(id);
 }
 
-/*
- * Get a client with a foreground for the pane. There isn't much to choose
- * between them so just use the first.
- */
-static int
-input_get_fg_client(struct window_pane *wp)
-{
-	struct window	*w = wp->window;
-	struct client	*loop;
-
-	TAILQ_FOREACH(loop, &clients, entry) {
-		if (loop->flags & CLIENT_UNATTACHEDFLAGS)
-			continue;
-		if (loop->session == NULL || !session_has(loop->session, w))
-			continue;
-		if (loop->tty.fg == -1)
-			continue;
-		return (loop->tty.fg);
-	}
-	return (-1);
-}
-
-/* Get a client with a background for the pane. */
-static int
-input_get_bg_client(struct window_pane *wp)
-{
-	struct window	*w = wp->window;
-	struct client	*loop;
-
-	TAILQ_FOREACH(loop, &clients, entry) {
-		if (loop->flags & CLIENT_UNATTACHEDFLAGS)
-			continue;
-		if (loop->session == NULL || !session_has(loop->session, w))
-			continue;
-		if (loop->tty.bg == -1)
-			continue;
-		return (loop->tty.bg);
-	}
-	return (-1);
-}
-
-/*
- * If any control mode client exists that has provided a bg color, return it.
- * Otherwise, return -1.
- */
-static int
-input_get_bg_control_client(struct window_pane *wp)
-{
-	struct client	*c;
-
-	if (wp->control_bg == -1)
-		return (-1);
-
-	TAILQ_FOREACH(c, &clients, entry) {
-		if (c->flags & CLIENT_CONTROL)
-			return (wp->control_bg);
-	}
-	return (-1);
-}
-
-/*
- * If any control mode client exists that has provided a fg color, return it.
- * Otherwise, return -1.
- */
-static int
-input_get_fg_control_client(struct window_pane *wp)
-{
-	struct client	*c;
-
-	if (wp->control_fg == -1)
-		return (-1);
-
-	TAILQ_FOREACH(c, &clients, entry) {
-		if (c->flags & CLIENT_CONTROL)
-			return (wp->control_fg);
-	}
-	return (-1);
-}
 
 /* Handle the OSC 10 sequence for setting and querying foreground colour. */
 static void
@@ -2787,11 +2733,11 @@ input_osc_10(struct input_ctx *ictx, const char *p)
 	if (strcmp(p, "?") == 0) {
 		if (wp == NULL)
 			return;
-		c = input_get_fg_control_client(wp);
+		c = window_pane_get_fg_control_client(wp);
 		if (c == -1) {
 			tty_default_colours(&defaults, wp);
 			if (COLOUR_DEFAULT(defaults.fg))
-				c = input_get_fg_client(wp);
+				c = window_pane_get_fg(wp);
 			else
 				c = defaults.fg;
 		}
@@ -2832,20 +2778,12 @@ static void
 input_osc_11(struct input_ctx *ictx, const char *p)
 {
 	struct window_pane	*wp = ictx->wp;
-	struct grid_cell	 defaults;
 	int			 c;
 
 	if (strcmp(p, "?") == 0) {
 		if (wp == NULL)
 			return;
-		c = input_get_bg_control_client(wp);
-		if (c == -1) {
-			tty_default_colours(&defaults, wp);
-			if (COLOUR_DEFAULT(defaults.bg))
-				c = input_get_bg_client(wp);
-			else
-				c = defaults.bg;
-		}
+		c = window_pane_get_bg(wp);
 		input_osc_colour_reply(ictx, 11, c);
 		return;
 	}
@@ -3064,3 +3002,18 @@ input_set_buffer_size(size_t buffer_size)
 	log_debug("%s: %lu -> %lu", __func__, input_buffer_size, buffer_size);
 	input_buffer_size = buffer_size;
 }
+
+static void
+input_report_current_theme(struct input_ctx *ictx)
+{
+	switch (window_pane_get_theme(ictx->wp)) {
+		case THEME_DARK:
+			input_reply(ictx, "\033[?997;1n");
+			break;
+		case THEME_LIGHT:
+			input_reply(ictx, "\033[?997;2n");
+			break;
+		case THEME_UNKNOWN:
+			break;
+	}
+}

options-table.c

@@ -1454,6 +1454,8 @@ const struct options_table_entry options_table[] = {
 	OPTIONS_TABLE_HOOK("client-focus-out", ""),
 	OPTIONS_TABLE_HOOK("client-resized", ""),
 	OPTIONS_TABLE_HOOK("client-session-changed", ""),
+	OPTIONS_TABLE_HOOK("client-light-theme", ""),
+	OPTIONS_TABLE_HOOK("client-dark-theme", ""),
 	OPTIONS_TABLE_HOOK("command-error", ""),
 	OPTIONS_TABLE_PANE_HOOK("pane-died", ""),
 	OPTIONS_TABLE_PANE_HOOK("pane-exited", ""),

screen-redraw.c

@@ -878,6 +878,9 @@ screen_redraw_draw_pane(struct screen_redraw_ctx *ctx, struct window_pane *wp)
 
 	log_debug("%s: %s @%u %%%u", __func__, c->name, w->id, wp->id);
 
+	if (wp->flags & PANE_STYLECHANGED)
+		window_pane_send_theme_update(wp);
+
 	if (wp->xoff + wp->sx <= ctx->ox || wp->xoff >= ctx->ox + ctx->sx)
 		return;
 	if (ctx->statustop)

server-client.c

@@ -56,11 +56,11 @@ static void	server_client_set_title(struct client *);
 static void	server_client_set_path(struct client *);
 static void	server_client_reset_state(struct client *);
 static void	server_client_update_latest(struct client *);
-
 static void	server_client_dispatch(struct imsg *, void *);
 static void	server_client_dispatch_command(struct client *, struct imsg *);
 static void	server_client_dispatch_identify(struct client *, struct imsg *);
 static void	server_client_dispatch_shell(struct client *);
+static void	server_client_report_theme(struct client *, enum client_theme);
 
 /* Compare client windows. */
 static int
@@ -299,6 +299,7 @@ server_client_create(int fd)
 
 	c->tty.sx = 80;
 	c->tty.sy = 24;
+	c->theme = THEME_UNKNOWN;
 
 	status_init(c);
 	c->flags |= CLIENT_FOCUSED;
@@ -2383,6 +2384,16 @@ server_client_key_callback(struct cmdq_item *item, void *data)
 		event->key = key;
 	}
 
+	/* Handle theme reporting keys. */
+	if (key == KEYC_REPORT_LIGHT_THEME) {
+		server_client_report_theme(c, THEME_LIGHT);
+		goto out;
+	}
+	if (key == KEYC_REPORT_DARK_THEME) {
+		server_client_report_theme(c, THEME_DARK);
+		goto out;
+	}
+
 	/* Find affected pane. */
 	if (!KEYC_IS_MOUSE(key) || cmd_find_from_mouse(&fs, m, 0) != 0)
 		cmd_find_from_client(&fs, c, 0);
@@ -3909,3 +3920,21 @@ out:
 	if (!parse)
 		free(msg);
 }
+
+static void
+server_client_report_theme(struct client *c, enum client_theme theme)
+{
+	if (theme == THEME_LIGHT) {
+		c->theme = THEME_LIGHT;
+		notify_client("client-light-theme", c);
+	} else {
+		c->theme = THEME_DARK;
+		notify_client("client-dark-theme", c);
+	}
+
+	/*
+	 * Request foregroundand background colour again. Don't forward 2031 to
+	 * panes until a response is received.
+	 */
+	tty_puts(&c->tty, "\033]10;?\033\\\033]11;?\033\\");
+}

tmux.h

@@ -377,6 +377,10 @@ enum {
 	KEYC_KP_ZERO,
 	KEYC_KP_PERIOD,
 
+	/* Theme reporting. */
+	KEYC_REPORT_DARK_THEME,
+	KEYC_REPORT_LIGHT_THEME,
+
 	/* End of special keys. */
 	KEYC_BASE_END
 };
@@ -644,6 +648,7 @@ enum tty_code_code {
 #define MODE_CURSOR_VERY_VISIBLE 0x10000
 #define MODE_CURSOR_BLINKING_SET 0x20000
 #define MODE_KEYS_EXTENDED_2 0x40000
+#define MODE_THEME_UPDATES 0x80000
 
 #define ALL_MODES 0xffffff
 #define ALL_MOUSE_MODES (MODE_MOUSE_STANDARD|MODE_MOUSE_BUTTON|MODE_MOUSE_ALL)
@@ -1863,6 +1868,12 @@ struct overlay_ranges {
 	u_int	nx[OVERLAY_MAX_RANGES];
 };
 
+enum client_theme {
+	THEME_UNKNOWN,
+	THEME_LIGHT,
+	THEME_DARK
+};
+
 /* Client connection. */
 typedef int (*prompt_input_cb)(struct client *, void *, const char *, int);
 typedef void (*prompt_free_cb)(void *);
@@ -1922,6 +1933,7 @@ struct client {
 	struct mouse_event	 click_event;
 
 	struct status_line	 status;
+	enum client_theme	 theme;
 
 #define CLIENT_TERMINAL 0x1
 #define CLIENT_LOGIN 0x2
@@ -2929,6 +2941,8 @@ void	 input_parse_screen(struct input_ctx *, struct screen *,
 void	 input_reply_clipboard(struct bufferevent *, const char *, size_t,
 	     const char *);
 void	 input_set_buffer_size(size_t);
+int 	 input_get_bg_client(struct window_pane *);
+int 	 input_get_bg_control_client(struct window_pane *);
 
 /* input-key.c */
 void	 input_key_build(void);
@@ -2943,7 +2957,8 @@ int	 colour_join_rgb(u_char, u_char, u_char);
 void	 colour_split_rgb(int, u_char *, u_char *, u_char *);
 int	 colour_force_rgb(int);
 const char *colour_tostring(int);
-int	 colour_fromstring(const char *s);
+enum client_theme colour_totheme(int);
+int	 colour_fromstring(const char *);
 int	 colour_256toRGB(int);
 int	 colour_256to16(int);
 int	 colour_byname(const char *);
@@ -3244,6 +3259,9 @@ void		 window_set_fill_character(struct window *);
 void		 window_pane_default_cursor(struct window_pane *);
 int		 window_pane_mode(struct window_pane *);
 int		 window_pane_show_scrollbar(struct window_pane *, int);
+int		 window_pane_get_bg(struct window_pane *);
+enum client_theme window_pane_get_theme(struct window_pane *);
+void		 window_pane_send_theme_update(struct window_pane *);
 
 /* layout.c */
 u_int		 layout_count_cells(struct layout_cell *);

tty-keys.c

@@ -59,6 +59,7 @@ static int	tty_keys_device_attributes2(struct tty *, const char *, size_t,
 		    size_t *);
 static int	tty_keys_extended_device_attributes(struct tty *, const char *,
 		    size_t, size_t *);
+static void	tty_keys_send_theme_updates(struct tty *);
 
 /* A key tree entry. */
 struct tty_key {
@@ -213,6 +214,10 @@ static const struct tty_default_key_raw tty_default_raw_keys[] = {
 
 	/* Extended keys. */
 	{ "\033[1;5Z", '\011'|KEYC_CTRL|KEYC_SHIFT },
+
+	/* Theme reporting. */
+	{ "\033[?997;1n", KEYC_REPORT_DARK_THEME },
+	{ "\033[?997;2n", KEYC_REPORT_LIGHT_THEME },
 };
 
 /* Default xterm keys. */
@@ -791,10 +796,12 @@ tty_keys_next(struct tty *tty)
 	switch (tty_keys_colours(tty, buf, len, &size, &tty->fg, &tty->bg)) {
 	case 0:		/* yes */
 		key = KEYC_UNKNOWN;
+		tty_keys_send_theme_updates(tty);
 		goto complete_key;
 	case -1:	/* no, or not valid */
 		break;
 	case 1:		/* partial */
+		tty_keys_send_theme_updates(tty);
 		goto partial_key;
 	}
 
@@ -1679,3 +1686,16 @@ tty_keys_colours(struct tty *tty, const char *buf, size_t len, size_t *size,
 
 	return (0);
 }
+
+/* Update theme in every pane for client's session. */
+static void
+tty_keys_send_theme_updates(struct tty *tty)
+{
+	struct window_pane	*wp;
+	struct winlink		*wl;
+
+	RB_FOREACH(wl, winlinks, &tty->client->session->windows) {
+		TAILQ_FOREACH(wp, &wl->window->panes, entry)
+			window_pane_send_theme_update(wp);
+	}
+}

tty.c

@@ -356,6 +356,11 @@ tty_start_tty(struct tty *tty)
 	if (tty_term_has(tty->term, TTYC_ENBP))
 		tty_putcode(tty, TTYC_ENBP);
 
+	if (tty->term->flags & TERM_VT100LIKE) {
+		tty_puts(tty, "\033[?2031h"); /* Subscribe for theme updates. */
+		tty_puts(tty, "\033[?996n"); /* Request theme right away. */
+	}
+
 	evtimer_set(&tty->start_timer, tty_start_timer_callback, tty);
 	evtimer_add(&tty->start_timer, &tv);
 
@@ -468,6 +473,9 @@ tty_stop_tty(struct tty *tty)
 		tty_raw(tty, tty_term_string(tty->term, TTYC_DSMG));
 	tty_raw(tty, tty_term_string(tty->term, TTYC_RMCUP));
 
+	if (tty->term->flags & TERM_VT100LIKE)
+		tty_raw(tty, "\033[?2031l");
+
 	setblocking(c->fd, 1);
 }
 

window.c

@@ -1756,3 +1756,157 @@ window_pane_show_scrollbar(struct window_pane *wp, int sb_option)
 		return (1);
 	return (0);
 }
+
+int
+window_pane_get_bg(struct window_pane *wp)
+{
+	int			c;
+	struct grid_cell	defaults;
+
+	c = window_pane_get_bg_control_client(wp);
+	if (c == -1) {
+		tty_default_colours(&defaults, wp);
+		if (COLOUR_DEFAULT(defaults.bg))
+			c = window_get_bg_client(wp);
+		else
+			c = defaults.bg;
+	}
+	return (c);
+}
+
+/* Get a client with a background for the pane. */
+int
+window_get_bg_client(struct window_pane *wp)
+{
+	struct window	*w = wp->window;
+	struct client	*loop;
+
+	TAILQ_FOREACH(loop, &clients, entry) {
+		if (loop->flags & CLIENT_UNATTACHEDFLAGS)
+			continue;
+		if (loop->session == NULL || !session_has(loop->session, w))
+			continue;
+		if (loop->tty.bg == -1)
+			continue;
+		return (loop->tty.bg);
+	}
+	return (-1);
+}
+
+/*
+ * If any control mode client exists that has provided a bg color, return it.
+ * Otherwise, return -1.
+ */
+int
+window_pane_get_bg_control_client(struct window_pane *wp)
+{
+	struct client	*c;
+
+	if (wp->control_bg == -1)
+		return (-1);
+
+	TAILQ_FOREACH(c, &clients, entry) {
+		if (c->flags & CLIENT_CONTROL)
+			return (wp->control_bg);
+	}
+	return (-1);
+}
+
+/*
+ * Get a client with a foreground for the pane. There isn't much to choose
+ * between them so just use the first.
+ */
+int
+window_pane_get_fg(struct window_pane *wp)
+{
+	struct window	*w = wp->window;
+	struct client	*loop;
+
+	TAILQ_FOREACH(loop, &clients, entry) {
+		if (loop->flags & CLIENT_UNATTACHEDFLAGS)
+			continue;
+		if (loop->session == NULL || !session_has(loop->session, w))
+			continue;
+		if (loop->tty.fg == -1)
+			continue;
+		return (loop->tty.fg);
+	}
+	return (-1);
+}
+
+/*
+ * If any control mode client exists that has provided a fg color, return it.
+ * Otherwise, return -1.
+ */
+int
+window_pane_get_fg_control_client(struct window_pane *wp)
+{
+	struct client	*c;
+
+	if (wp->control_fg == -1)
+		return (-1);
+
+	TAILQ_FOREACH(c, &clients, entry) {
+		if (c->flags & CLIENT_CONTROL)
+			return (wp->control_fg);
+	}
+	return (-1);
+}
+
+enum client_theme
+window_pane_get_theme(struct window_pane *wp)
+{
+	struct window		*w = wp->window;
+	struct client		*loop;
+	enum client_theme	 theme;
+	int			 found_light = 0, found_dark = 0;
+
+	/*
+	 * Derive theme from pane background color, if it's not the default
+	 * colour.
+	 */
+	theme = colour_totheme(window_pane_get_bg(wp));
+	if (theme != THEME_UNKNOWN)
+		return (theme);
+
+	/* Try to find a client that has a theme. */
+	TAILQ_FOREACH(loop, &clients, entry) {
+		if (loop->flags & CLIENT_UNATTACHEDFLAGS)
+			continue;
+		if (loop->session == NULL || !session_has(loop->session, w))
+			continue;
+		switch (loop->theme) {
+		case THEME_LIGHT:
+			found_light = 1;
+			break;
+		case THEME_DARK:
+			found_dark = 1;
+			break;
+		case THEME_UNKNOWN:
+			break;
+		}
+	}
+
+	if (found_dark && !found_light)
+		return (THEME_DARK);
+	if (found_light && !found_dark)
+		return (THEME_LIGHT);
+	return (THEME_UNKNOWN);
+}
+
+void
+window_pane_send_theme_update(struct window_pane *wp)
+{
+	if (~wp->screen->mode & MODE_THEME_UPDATES)
+		return;
+	switch (window_pane_get_theme(wp)) {
+	case THEME_LIGHT:
+		input_key_pane(wp, KEYC_REPORT_LIGHT_THEME, NULL);
+		break;
+	case THEME_DARK:
+		input_key_pane(wp, KEYC_REPORT_LIGHT_THEME, NULL);
+		break;
+	case THEME_UNKNOWN:
+		break;
+	}
+}