Add resize-pane -Z to temporary zoom the active pane to occupy the full

window or unzoom (restored to the normal layout) if it already zoomed,
bound to C-b z by default. The pane is unzoomed on pretty much any
excuse whatsoever.

We considered making this a new layout but the requirements are quite
different from layouts so decided it is better as a special case. Each
current layout cell is saved, a temporary one-cell layout generated and
all except the active pane set to NULL.

Prompted by suggestions and scripts from several. Thanks to Aaron Jensen
and Thiago Padilha for testing an earlier version.

16 files changed, 108 insertions, 10 deletions

diff --git a/cmd-break-pane.c b/cmd-break-pane.c
index 27ae1624..bac332a2 100644
--- a/cmd-break-pane.c
+++ b/cmd-break-pane.c
@@ -63,6 +63,8 @@ cmd_break_pane_exec(struct cmd *self, struct cmd_q *cmdq)
 	}
 
 	w = wl->window;
+	server_unzoom_window(w);
+
 	TAILQ_REMOVE(&w->panes, wp, entry);
 	if (wp == w->active) {
 		w->active = w->last;
@@ -82,7 +84,7 @@ cmd_break_pane_exec(struct cmd *self, struct cmd_q *cmdq)
 	name = default_window_name(w);
 	window_set_name(w, name);
 	free(name);
-	layout_init(w);
+	layout_init(w, wp);
 
 	base_idx = options_get_number(&s->options, "base-index");
 	wl = session_attach(s, w, -1 - base_idx, &cause); /* can't fail */
diff --git a/cmd-join-pane.c b/cmd-join-pane.c
index 2e7a59cd..cf17e7d9 100644
--- a/cmd-join-pane.c
+++ b/cmd-join-pane.c
@@ -92,11 +92,13 @@ join_pane(struct cmd *self, struct cmd_q *cmdq, int not_same_window)
 		return (CMD_RETURN_ERROR);
 	dst_w = dst_wl->window;
 	dst_idx = dst_wl->idx;
+	server_unzoom_window(dst_w);
 
 	src_wl = cmd_find_pane(cmdq, args_get(args, 's'), NULL, &src_wp);
 	if (src_wl == NULL)
 		return (CMD_RETURN_ERROR);
 	src_w = src_wl->window;
+	server_unzoom_window(src_w);
 
 	if (not_same_window && src_w == dst_w) {
 		cmdq_error(cmdq, "can't join a pane to its own window");
diff --git a/cmd-kill-pane.c b/cmd-kill-pane.c
index 1aa776d9..ba3bfd20 100644
--- a/cmd-kill-pane.c
+++ b/cmd-kill-pane.c
@@ -47,6 +47,7 @@ cmd_kill_pane_exec(struct cmd *self, struct cmd_q *cmdq)
 
 	if ((wl = cmd_find_pane(cmdq, args_get(args, 't'), NULL, &wp)) == NULL)
 		return (CMD_RETURN_ERROR);
+	server_unzoom_window(wl->window);
 
 	if (window_count_panes(wl->window) == 1) {
 		/* Only one pane, kill the window. */
diff --git a/cmd-resize-pane.c b/cmd-resize-pane.c
index f31e3258..41c15269 100644
--- a/cmd-resize-pane.c
+++ b/cmd-resize-pane.c
@@ -31,8 +31,8 @@ enum cmd_retval	 cmd_resize_pane_exec(struct cmd *, struct cmd_q *);
 
 const struct cmd_entry cmd_resize_pane_entry = {
 	"resize-pane", "resizep",
-	"DLRt:Ux:y:", 0, 1,
-	"[-DLRU] [-x width] [-y height] " CMD_TARGET_PANE_USAGE " [adjustment]",
+	"DLRt:Ux:y:Z", 0, 1,
+	"[-DLRUZ] [-x width] [-y height] " CMD_TARGET_PANE_USAGE " [adjustment]",
 	0,
 	cmd_resize_pane_key_binding,
 	NULL,
@@ -75,6 +75,10 @@ cmd_resize_pane_key_binding(struct cmd *self, int key)
 		self->args = args_create(1, "5");
 		args_set(self->args, 'R', NULL);
 		break;
+	case 'z':
+		self->args = args_create(0);
+		args_set(self->args, 'Z', NULL);
+		break;
 	default:
 		self->args = args_create(0);
 		break;
@@ -86,6 +90,7 @@ cmd_resize_pane_exec(struct cmd *self, struct cmd_q *cmdq)
 {
 	struct args		*args = self->args;
 	struct winlink		*wl;
+	struct window		*w;
 	const char	       	*errstr;
 	char			*cause;
 	struct window_pane	*wp;
@@ -94,6 +99,18 @@ cmd_resize_pane_exec(struct cmd *self, struct cmd_q *cmdq)
 
 	if ((wl = cmd_find_pane(cmdq, args_get(args, 't'), NULL, &wp)) == NULL)
 		return (CMD_RETURN_ERROR);
+	w = wl->window;
+
+	if (args_has(args, 'Z')) {
+		if (w->flags & WINDOW_ZOOMED)
+			window_unzoom(w);
+		else
+			window_zoom(wp);
+		server_redraw_window(w);
+		server_status_window(w);
+		return (CMD_RETURN_NORMAL);
+	}
+	server_unzoom_window(w);
 
 	if (args->argc == 0)
 		adjust = 1;
diff --git a/cmd-respawn-window.c b/cmd-respawn-window.c
index 646882b0..a446794b 100644
--- a/cmd-respawn-window.c
+++ b/cmd-respawn-window.c
@@ -87,7 +87,7 @@ cmd_respawn_window_exec(struct cmd *self, struct cmd_q *cmdq)
 		server_destroy_pane(wp);
 		return (CMD_RETURN_ERROR);
 	}
-	layout_init(w);
+	layout_init(w, wp);
 	window_pane_reset_mode(wp);
 	screen_reinit(&wp->base);
 	input_init(wp);
diff --git a/cmd-select-layout.c b/cmd-select-layout.c
index 4b01a69d..aa73e500 100644
--- a/cmd-select-layout.c
+++ b/cmd-select-layout.c
@@ -92,6 +92,7 @@ cmd_select_layout_exec(struct cmd *self, struct cmd_q *cmdq)
 
 	if ((wl = cmd_find_window(cmdq, args_get(args, 't'), NULL)) == NULL)
 		return (CMD_RETURN_ERROR);
+	server_unzoom_window(wl->window);
 
 	next = self->entry == &cmd_next_layout_entry;
 	if (args_has(self->args, 'n'))
diff --git a/cmd-select-pane.c b/cmd-select-pane.c
index 459e98cf..77be368f 100644
--- a/cmd-select-pane.c
+++ b/cmd-select-pane.c
@@ -80,6 +80,7 @@ cmd_select_pane_exec(struct cmd *self, struct cmd_q *cmdq)
 			return (CMD_RETURN_ERROR);
 		}
 
+		server_unzoom_window(wl->window);
 		window_set_active_pane(wl->window, wl->window->last);
 		server_status_window(wl->window);
 		server_redraw_window_borders(wl->window);
@@ -90,6 +91,7 @@ cmd_select_pane_exec(struct cmd *self, struct cmd_q *cmdq)
 	if ((wl = cmd_find_pane(cmdq, args_get(args, 't'), NULL, &wp)) == NULL)
 		return (CMD_RETURN_ERROR);
 
+	server_unzoom_window(wp->window);
 	if (!window_pane_visible(wp)) {
 		cmdq_error(cmdq, "pane not visible");
 		return (CMD_RETURN_ERROR);
diff --git a/cmd-split-window.c b/cmd-split-window.c
index 87c0e6bc..e3d6f6ea 100644
--- a/cmd-split-window.c
+++ b/cmd-split-window.c
@@ -73,6 +73,7 @@ cmd_split_window_exec(struct cmd *self, struct cmd_q *cmdq)
 	if ((wl = cmd_find_pane(cmdq, args_get(args, 't'), &s, &wp)) == NULL)
 		return (CMD_RETURN_ERROR);
 	w = wl->window;
+	server_unzoom_window(w);
 
 	environ_init(&env);
 	environ_copy(&global_environ, &env);
diff --git a/cmd-swap-pane.c b/cmd-swap-pane.c
index ae875946..e7ea6242 100644
--- a/cmd-swap-pane.c
+++ b/cmd-swap-pane.c
@@ -63,6 +63,7 @@ cmd_swap_pane_exec(struct cmd *self, struct cmd_q *cmdq)
 	if (dst_wl == NULL)
 		return (CMD_RETURN_ERROR);
 	dst_w = dst_wl->window;
+	server_unzoom_window(dst_w);
 
 	if (!args_has(args, 's')) {
 		src_w = dst_w;
@@ -82,6 +83,7 @@ cmd_swap_pane_exec(struct cmd *self, struct cmd_q *cmdq)
 			return (CMD_RETURN_ERROR);
 		src_w = src_wl->window;
 	}
+	server_unzoom_window(src_w);
 
 	if (src_wp == dst_wp)
 		return (CMD_RETURN_NORMAL);
diff --git a/input-keys.c b/input-keys.c
index 23549e32..d7e8513d 100644
--- a/input-keys.c
+++ b/input-keys.c
@@ -219,7 +219,8 @@ input_mouse(struct window_pane *wp, struct session *s, struct mouse_event *m)
 		 */
 		if (m->sgr && (wp->screen->mode & MODE_MOUSE_SGR)) {
 			len = xsnprintf(buf, sizeof buf, "\033[<%d;%d;%d%c",
-			    m->sgr_xb, m->x + 1, m->y + 1, m->sgr_rel ? 'm' : 'M');
+			    m->sgr_xb, m->x + 1, m->y + 1,
+			    m->sgr_rel ? 'm' : 'M');
 		} else if (wp->screen->mode & MODE_MOUSE_UTF8) {
 			len = xsnprintf(buf, sizeof buf, "\033[M");
 			len += utf8_split2(m->xb + 32, &buf[len]);
diff --git a/key-bindings.c b/key-bindings.c
index 4e889b7e..625ffddf 100644
--- a/key-bindings.c
+++ b/key-bindings.c
@@ -150,6 +150,7 @@ key_bindings_init(void)
 		{ 't', 			  0, &cmd_clock_mode_entry },
 		{ 'w', 			  0, &cmd_choose_window_entry },
 		{ 'x', 			  0, &cmd_confirm_before_entry },
+		{ 'z',			  0, &cmd_resize_pane_entry },
 		{ '{',			  0, &cmd_swap_pane_entry },
 		{ '}',			  0, &cmd_swap_pane_entry },
 		{ '~',			  0, &cmd_show_messages_entry },
diff --git a/layout.c b/layout.c
index f08580b7..4dd3756c 100644
--- a/layout.c
+++ b/layout.c
@@ -374,13 +374,13 @@ layout_destroy_cell(struct layout_cell *lc, struct layout_cell **lcroot)
 }
 
 void
-layout_init(struct window *w)
+layout_init(struct window *w, struct window_pane *wp)
 {
 	struct layout_cell	*lc;
 
 	lc = w->layout_root = layout_create_cell(NULL);
 	layout_set_size(lc, w->sx, w->sy, 0, 0);
-	layout_make_leaf(lc, TAILQ_FIRST(&w->panes));
+	layout_make_leaf(lc, wp);
 
 	layout_fix_panes(w, w->sx, w->sy);
 }
diff --git a/resize.c b/resize.c
index d398ab37..b5196c1c 100644
--- a/resize.c
+++ b/resize.c
@@ -50,7 +50,7 @@ recalculate_sizes(void)
 	struct window		*w;
 	struct window_pane	*wp;
 	u_int			 i, j, ssx, ssy, has, limit;
-	int			 flag, has_status;
+	int			 flag, has_status, is_zoomed;
 
 	RB_FOREACH(s, sessions, &sessions) {
 		has_status = options_get_number(&s->options, "status");
@@ -123,12 +123,16 @@ recalculate_sizes(void)
 
 		if (w->sx == ssx && w->sy == ssy)
 			continue;
-
 		log_debug("window size %u,%u (was %u,%u)", ssx, ssy, w->sx,
 		    w->sy);
 
+		is_zoomed = w->flags & WINDOW_ZOOMED;
+		if (is_zoomed)
+			window_unzoom(w);
 		layout_resize(w, ssx, ssy);
 		window_resize(w, ssx, ssy);
+		if (is_zoomed && window_pane_visible(w->active))
+			window_zoom(w->active);
 
 		/*
 		 * If the current pane is now not visible, move to the next
diff --git a/server-client.c b/server-client.c
index 6f29000b..64af442a 100644
--- a/server-client.c
+++ b/server-client.c
@@ -384,6 +384,7 @@ server_client_handle_key(struct client *c, int key)
 	if (c->flags & CLIENT_IDENTIFY && key >= '0' && key <= '9') {
 		if (c->flags & CLIENT_READONLY)
 			return;
+		window_unzoom(w);
 		wp = window_pane_at_index(w, key - '0');
 		if (wp != NULL && window_pane_visible(wp))
 			window_set_active_pane(w, wp);
diff --git a/server-fn.c b/server-fn.c
index b9217ef2..874afffb 100644
--- a/server-fn.c
+++ b/server-fn.c
@@ -377,6 +377,7 @@ server_destroy_pane(struct window_pane *wp)
 		return;
 	}
 
+	server_unzoom_window(w);
 	layout_close_pane(wp);
 	window_remove_pane(w, wp);
 
@@ -588,3 +589,11 @@ server_set_stdin_callback(struct client *c, void (*cb)(struct client *, int,
 
 	return (0);
 }
+
+void
+server_unzoom_window(struct window *w)
+{
+	window_unzoom(w);
+	server_redraw_window(w);
+	server_status_window(w);
+}
diff --git a/window.c b/window.c
index dfece2ee..38af88f9 100644
--- a/window.c
+++ b/window.c
@@ -319,7 +319,7 @@ window_create(const char *name, const char *cmd, const char *shell,
 
 	w = window_create1(sx, sy);
 	wp = window_add_pane(w, hlimit);
-	layout_init(w);
+	layout_init(w, wp);
 
 	if (*cmd != '\0') {
 		prefix = options_get_string(&w->options, "command-prefix");
@@ -348,6 +348,8 @@ window_destroy(struct window *w)
 {
 	u_int	i;
 
+	window_unzoom(w);
+
 	if (window_index(w, &i) != 0)
 		fatalx("index not found");
 	ARRAY_SET(&windows, i, NULL);
@@ -470,6 +472,54 @@ window_find_string(struct window *w, const char *s)
 	return (window_get_active_at(w, x, y));
 }
 
+int
+window_zoom(struct window_pane *wp)
+{
+	struct window		*w = wp->window;
+	struct window_pane	*wp1;
+
+	if (w->flags & WINDOW_ZOOMED)
+		return (-1);
+
+	if (!window_pane_visible(wp))
+		return (-1);
+	if (w->active != wp)
+		window_set_active_pane(w, wp);
+
+	TAILQ_FOREACH(wp1, &w->panes, entry) {
+		wp1->saved_layout_cell = wp1->layout_cell;
+		wp1->layout_cell = NULL;
+	}
+
+	w->saved_layout_root = w->layout_root;
+	layout_init(w, wp);
+	w->flags |= WINDOW_ZOOMED;
+
+	return (0);
+}
+
+int
+window_unzoom(struct window *w)
+{
+	struct window_pane	*wp, *wp1;
+
+	if (!(w->flags & WINDOW_ZOOMED))
+		return (-1);
+	wp = w->active;
+
+	w->flags &= ~WINDOW_ZOOMED;
+	layout_free(w);
+	w->layout_root = w->saved_layout_root;
+
+	TAILQ_FOREACH(wp1, &w->panes, entry) {
+		wp1->layout_cell = wp1->saved_layout_cell;
+		wp1->saved_layout_cell = NULL;
+	}
+	layout_fix_panes(w, w->sx, w->sy);
+
+	return (0);
+}
+
 struct window_pane *
 window_add_pane(struct window *w, u_int hlimit)
 {
@@ -600,6 +650,8 @@ window_printable_flags(struct session *s, struct winlink *wl)
 		flags[pos++] = '*';
 	if (wl == TAILQ_FIRST(&s->lastw))
 		flags[pos++] = '-';
+	if (wl->window->flags & WINDOW_ZOOMED)
+		flags[pos++] = 'Z';
 	if (pos == 0)
 		flags[pos++] = ' ';
 	flags[pos] = '\0';
@@ -1027,6 +1079,8 @@ window_pane_visible(struct window_pane *wp)
 {
 	struct window	*w = wp->window;
 
+	if (wp->layout_cell == NULL)
+		return (0);
 	if (wp->xoff >= w->sx || wp->yoff >= w->sy)
 		return (0);
 	if (wp->xoff + wp->sx > w->sx || wp->yoff + wp->sy > w->sy)