Improved layout code.

Each window now has a tree of layout cells associated with it. In this tree,
each node is either a horizontal or vertical cell containing a list of other
cells running from left-to-right or top-to-bottom, or a leaf cell which is
associated with a pane.

The major functional changes are:

- panes may now be split arbitrarily both horizontally (splitw -h, C-b %) and
  vertically (splitw -v, C-b ");
- panes may be resized both horizontally and vertically (resizep -L/-R/-U/-D,
  bound to C-b left/right/up/down and C-b M-left/right/up/down);
- layouts are now applied and then may be modified by resizing or splitting
  panes, rather than being fixed and reapplied when the window is resized or
  panes are added;
- manual-vertical layout is no longer necessary, and active-only layout is gone
  (but may return in future);
- the main-pane layouts now reduce the size of the main pane to fit all panes
  if possible.

Thanks to all who tested.

25 files changed, 1282 insertions, 620 deletions

diff --git a/usr.bin/tmux/Makefile b/usr.bin/tmux/Makefile
index 7411d963c53..9f371d71814 100644
--- a/usr.bin/tmux/Makefile
+++ b/usr.bin/tmux/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.8 2009/07/17 18:45:08 nicm Exp $
+# $OpenBSD: Makefile,v 1.9 2009/07/19 13:21:40 nicm Exp $
 
 PROG=	tmux
 SRCS=	attributes.c buffer-poll.c buffer.c cfg.c client-fn.c \
@@ -27,7 +27,7 @@ SRCS=	attributes.c buffer-poll.c buffer.c cfg.c client-fn.c \
 	cmd-switch-client.c cmd-unbind-key.c cmd-unlink-window.c \
 	cmd-up-pane.c cmd-display-message.c cmd.c \
 	colour.c grid-view.c grid.c input-keys.c \
-	input.c key-bindings.c key-string.c layout-manual.c layout.c log.c \
+	input.c key-bindings.c key-string.c layout-set.c layout.c log.c \
 	mode-key.c names.c options-cmd.c options.c paste.c procname.c \
 	resize.c screen-redraw.c screen-write.c screen.c server-fn.c \
 	server-msg.c server.c session.c status.c tmux.c tty-keys.c tty-term.c \
diff --git a/usr.bin/tmux/cmd-break-pane.c b/usr.bin/tmux/cmd-break-pane.c
index 186bb0226f7..b77e1536276 100644
--- a/usr.bin/tmux/cmd-break-pane.c
+++ b/usr.bin/tmux/cmd-break-pane.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-break-pane.c,v 1.2 2009/07/13 23:11:35 nicm Exp $ */
+/* $OpenBSD: cmd-break-pane.c,v 1.3 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -74,17 +74,17 @@ cmd_break_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 		if (wl->window->active == NULL)
 			wl->window->active = TAILQ_NEXT(wp, entry);
 	}
- 	layout_refresh(wl->window, 0);
+ 	layout_close_pane(wp);
 
  	w = wp->window = window_create1(s->sx, s->sy);
  	TAILQ_INSERT_HEAD(&w->panes, wp, entry);
  	w->active = wp;
  	w->name = default_window_name(w);
+	layout_init(w);
 
  	wl = session_attach(s, w, -1, &cause); /* can't fail */
  	if (!(data->chflags & CMD_CHFLAG('d')))
  		session_select(s, wl->idx);
- 	layout_refresh(w, 0);
 
 	server_redraw_session(s);
 
diff --git a/usr.bin/tmux/cmd-choose-window.c b/usr.bin/tmux/cmd-choose-window.c
index 7a3e7a9fece..99f7f7a67bc 100644
--- a/usr.bin/tmux/cmd-choose-window.c
+++ b/usr.bin/tmux/cmd-choose-window.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-choose-window.c,v 1.3 2009/07/17 07:05:58 nicm Exp $ */
+/* $OpenBSD: cmd-choose-window.c,v 1.4 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -76,8 +76,8 @@ cmd_choose_window_exec(struct cmd *self, struct cmd_ctx *ctx)
 		idx++;
 
 		window_choose_add(wl->window->active,
-		    wm->idx, "%3d: %s [%ux%u %s] (%u panes)", wm->idx, w->name,
-		    w->sx, w->sy, layout_name(w), window_count_panes(w));
+		    wm->idx, "%3d: %s [%ux%u] (%u panes)",
+		    wm->idx, w->name, w->sx, w->sy, window_count_panes(w));
 	}
 
 	cdata = xmalloc(sizeof *cdata);
diff --git a/usr.bin/tmux/cmd-down-pane.c b/usr.bin/tmux/cmd-down-pane.c
index d93fe3dc3a3..b9b4b24eae0 100644
--- a/usr.bin/tmux/cmd-down-pane.c
+++ b/usr.bin/tmux/cmd-down-pane.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-down-pane.c,v 1.3 2009/07/14 07:23:36 nicm Exp $ */
+/* $OpenBSD: cmd-down-pane.c,v 1.4 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -54,7 +54,6 @@ cmd_down_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 		w->active = TAILQ_NEXT(w->active, entry);
 		if (w->active == NULL)
 			w->active = TAILQ_FIRST(&w->panes);
-		layout_refresh(w, 1);
 	} while (!window_pane_visible(w->active));
 
 	return (0);
diff --git a/usr.bin/tmux/cmd-kill-pane.c b/usr.bin/tmux/cmd-kill-pane.c
index ca642e5df8c..319da2bcbf6 100644
--- a/usr.bin/tmux/cmd-kill-pane.c
+++ b/usr.bin/tmux/cmd-kill-pane.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-kill-pane.c,v 1.3 2009/07/17 20:37:03 nicm Exp $ */
+/* $OpenBSD: cmd-kill-pane.c,v 1.4 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -66,8 +66,8 @@ cmd_kill_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 		return (0);
 	}
 
+	layout_close_pane(wp);
 	window_remove_pane(wl->window, wp);
 	server_redraw_window(wl->window);
-	layout_refresh(wl->window, 0);
 	return (0);
 }
diff --git a/usr.bin/tmux/cmd-list-windows.c b/usr.bin/tmux/cmd-list-windows.c
index fa76fc7fbd6..62c4fdc5dd4 100644
--- a/usr.bin/tmux/cmd-list-windows.c
+++ b/usr.bin/tmux/cmd-list-windows.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-list-windows.c,v 1.2 2009/07/13 23:11:35 nicm Exp $ */
+/* $OpenBSD: cmd-list-windows.c,v 1.3 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -78,9 +78,8 @@ cmd_list_windows_exec(struct cmd *self, struct cmd_ctx *ctx)
 			else
 				name = "unknown";
 			ctx->print(ctx,
-			    "     %s [%ux%u %s] [history %u/%u, %llu bytes]",
-			    name, wp->sx, wp->sy, layout_name(w), gd->hsize,
-			    gd->hlimit, size);
+			    "     %s [%ux%u] [history %u/%u, %llu bytes]",
+			    name, wp->sx, wp->sy, gd->hsize, gd->hlimit, size);
 		}
 	}
 
diff --git a/usr.bin/tmux/cmd-next-layout.c b/usr.bin/tmux/cmd-next-layout.c
index f9b073ba4b8..d791344b86f 100644
--- a/usr.bin/tmux/cmd-next-layout.c
+++ b/usr.bin/tmux/cmd-next-layout.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-next-layout.c,v 1.2 2009/07/13 23:11:35 nicm Exp $ */
+/* $OpenBSD: cmd-next-layout.c,v 1.3 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -44,12 +44,13 @@ cmd_next_layout_exec(struct cmd *self, struct cmd_ctx *ctx)
 {
 	struct cmd_target_data	*data = self->data;
 	struct winlink		*wl;
+	u_int			 layout;
 
 	if ((wl = cmd_find_window(ctx, data->target, NULL)) == NULL)
 		return (-1);
 
-	layout_next(wl->window);
-	ctx->info(ctx, "layout now: %s", layout_name(wl->window));
+	layout = layout_set_next(wl->window);
+	ctx->info(ctx, "arranging in: %s", layout_set_name(layout));
 
 	return (0);
 }
diff --git a/usr.bin/tmux/cmd-previous-layout.c b/usr.bin/tmux/cmd-previous-layout.c
index 0652bab3e54..032402846e5 100644
--- a/usr.bin/tmux/cmd-previous-layout.c
+++ b/usr.bin/tmux/cmd-previous-layout.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-previous-layout.c,v 1.2 2009/07/13 23:11:35 nicm Exp $ */
+/* $OpenBSD: cmd-previous-layout.c,v 1.3 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -44,12 +44,13 @@ cmd_previous_layout_exec(struct cmd *self, struct cmd_ctx *ctx)
 {
 	struct cmd_target_data	*data = self->data;
 	struct winlink		*wl;
-
+	u_int			 layout;
+	
 	if ((wl = cmd_find_window(ctx, data->target, NULL)) == NULL)
 		return (-1);
 
-	layout_previous(wl->window);
-	ctx->info(ctx, "layout now: %s", layout_name(wl->window));
+	layout = layout_set_previous(wl->window);
+	ctx->info(ctx, "arranging in: %s", layout_set_name(layout));
 
 	return (0);
 }
diff --git a/usr.bin/tmux/cmd-resize-pane.c b/usr.bin/tmux/cmd-resize-pane.c
index 217c9638ecd..4a5c48a0eac 100644
--- a/usr.bin/tmux/cmd-resize-pane.c
+++ b/usr.bin/tmux/cmd-resize-pane.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-resize-pane.c,v 1.2 2009/07/13 23:11:35 nicm Exp $ */
+/* $OpenBSD: cmd-resize-pane.c,v 1.3 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -32,7 +32,8 @@ int	cmd_resize_pane_exec(struct cmd *, struct cmd_ctx *);
 const struct cmd_entry cmd_resize_pane_entry = {
 	"resize-pane", "resizep",
 	CMD_PANE_WINDOW_USAGE "[-DU] [adjustment]",
-	CMD_ARG01, CMD_CHFLAG('D')|CMD_CHFLAG('U'),
+	CMD_ARG01,
+	CMD_CHFLAG('D')|CMD_CHFLAG('L')|CMD_CHFLAG('R')|CMD_CHFLAG('U'),
 	cmd_resize_pane_init,
 	cmd_pane_parse,
 	cmd_resize_pane_exec,
@@ -50,15 +51,31 @@ cmd_resize_pane_init(struct cmd *self, int key)
 	cmd_pane_init(self, key);
 	data = self->data;
 
+	if (key == KEYC_ADDCTL(KEYC_UP))
+		data->chflags |= CMD_CHFLAG('U');
 	if (key == KEYC_ADDCTL(KEYC_DOWN))
 		data->chflags |= CMD_CHFLAG('D');
+	if (key == KEYC_ADDCTL(KEYC_LEFT))
+		data->chflags |= CMD_CHFLAG('L');
+	if (key == KEYC_ADDCTL(KEYC_RIGHT))
+		data->chflags |= CMD_CHFLAG('R');
 
-	if (key == KEYC_ADDESC(KEYC_UP))
+	if (key == KEYC_ADDESC(KEYC_UP)) {
+		data->chflags |= CMD_CHFLAG('U');
 		data->arg = xstrdup("5");
+	}
 	if (key == KEYC_ADDESC(KEYC_DOWN)) {
 		data->chflags |= CMD_CHFLAG('D');
 		data->arg = xstrdup("5");
 	}
+	if (key == KEYC_ADDESC(KEYC_LEFT)) {
+		data->chflags |= CMD_CHFLAG('L');
+		data->arg = xstrdup("5");
+	}
+	if (key == KEYC_ADDESC(KEYC_RIGHT)) {
+		data->chflags |= CMD_CHFLAG('R');
+		data->arg = xstrdup("5");
+	}
 }
 
 int
@@ -92,12 +109,14 @@ cmd_resize_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 		}
 	}
 
-	if (!(data->chflags & CMD_CHFLAG('D')))
-		adjust = -adjust;
-	if (layout_resize(wp, adjust) != 0) {
-		ctx->error(ctx, "layout %s "
-		    "does not support resizing", layout_name(wp->window));
-		return (-1);
+	if (data->chflags & (CMD_CHFLAG('L')|CMD_CHFLAG('R'))) {
+		if (data->chflags & CMD_CHFLAG('L'))
+			adjust = -adjust;
+		layout_resize_pane(wp, LAYOUT_LEFTRIGHT, adjust);
+	} else {
+		if (data->chflags & CMD_CHFLAG('U'))
+			adjust = -adjust;
+		layout_resize_pane(wp, LAYOUT_TOPBOTTOM, adjust);
 	}
 	server_redraw_window(wl->window);
 
diff --git a/usr.bin/tmux/cmd-respawn-window.c b/usr.bin/tmux/cmd-respawn-window.c
index 55e820ee3e2..a64e186c7d9 100644
--- a/usr.bin/tmux/cmd-respawn-window.c
+++ b/usr.bin/tmux/cmd-respawn-window.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-respawn-window.c,v 1.2 2009/07/13 23:11:35 nicm Exp $ */
+/* $OpenBSD: cmd-respawn-window.c,v 1.3 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2008 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -70,6 +70,7 @@ cmd_respawn_window_exec(struct cmd *self, struct cmd_ctx *ctx)
 
 	wp = TAILQ_FIRST(&w->panes);
 	TAILQ_REMOVE(&w->panes, wp, entry);
+	layout_free(w);
  	window_destroy_panes(w);
 	TAILQ_INSERT_HEAD(&w->panes, wp, entry);
 	window_pane_resize(wp, w->sx, w->sy);
@@ -78,6 +79,7 @@ cmd_respawn_window_exec(struct cmd *self, struct cmd_ctx *ctx)
 		xfree(cause);
 		return (-1);
 	}
+	layout_init(w);
 	screen_reinit(&wp->base);
 
 	recalculate_sizes();
diff --git a/usr.bin/tmux/cmd-rotate-window.c b/usr.bin/tmux/cmd-rotate-window.c
index dd728565c47..1b8ec77f52e 100644
--- a/usr.bin/tmux/cmd-rotate-window.c
+++ b/usr.bin/tmux/cmd-rotate-window.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-rotate-window.c,v 1.6 2009/07/14 07:23:36 nicm Exp $ */
+/* $OpenBSD: cmd-rotate-window.c,v 1.7 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -59,6 +59,7 @@ cmd_rotate_window_exec(struct cmd *self, struct cmd_ctx *ctx)
 	struct winlink		*wl;
 	struct window		*w;
 	struct window_pane	*wp, *wp2;
+	struct layout_cell	*lc;
 	u_int			 sx, sy, xoff, yoff;
 
 	if ((wl = cmd_find_window(ctx, data->target, NULL)) == NULL)
@@ -70,42 +71,56 @@ cmd_rotate_window_exec(struct cmd *self, struct cmd_ctx *ctx)
 		TAILQ_REMOVE(&w->panes, wp, entry);
 		TAILQ_INSERT_HEAD(&w->panes, wp, entry);
 
+		lc = wp->layout_cell;
 		xoff = wp->xoff; yoff = wp->yoff;
 		sx = wp->sx; sy = wp->sy;
 		TAILQ_FOREACH(wp, &w->panes, entry) {
 			if ((wp2 = TAILQ_NEXT(wp, entry)) == NULL)
 				break;
+			wp->layout_cell = wp2->layout_cell;
+			if (wp->layout_cell != NULL)
+				wp->layout_cell->wp = wp;
 			wp->xoff = wp2->xoff; wp->yoff = wp2->yoff;
 			window_pane_resize(wp, wp2->sx, wp2->sy);
 		}
+		wp->layout_cell = lc;
+		if (wp->layout_cell != NULL)
+			wp->layout_cell->wp = wp;
 		wp->xoff = xoff; wp->yoff = yoff;
 		window_pane_resize(wp, sx, sy);
 
 		if ((wp = TAILQ_PREV(w->active, window_panes, entry)) == NULL)
 			wp = TAILQ_LAST(&w->panes, window_panes);
 		window_set_active_pane(w, wp);
+		server_redraw_window(w);
 	} else {
 		wp = TAILQ_FIRST(&w->panes);
 		TAILQ_REMOVE(&w->panes, wp, entry);
 		TAILQ_INSERT_TAIL(&w->panes, wp, entry);
 
+		lc = wp->layout_cell;
 		xoff = wp->xoff; yoff = wp->yoff;
 		sx = wp->sx; sy = wp->sy;
 		TAILQ_FOREACH_REVERSE(wp, &w->panes, window_panes, entry) {
 			if ((wp2 = TAILQ_PREV(wp, window_panes, entry)) == NULL)
 				break;
+			wp->layout_cell = wp2->layout_cell;
+			if (wp->layout_cell != NULL)
+				wp->layout_cell->wp = wp;
 			wp->xoff = wp2->xoff; wp->yoff = wp2->yoff;
 			window_pane_resize(wp, wp2->sx, wp2->sy);
 		}
+		wp->layout_cell = lc;
+		if (wp->layout_cell != NULL)
+			wp->layout_cell->wp = wp;
 		wp->xoff = xoff; wp->yoff = yoff;
 		window_pane_resize(wp, sx, sy);
 
 		if ((wp = TAILQ_NEXT(w->active, entry)) == NULL)
 			wp = TAILQ_FIRST(&w->panes);
 		window_set_active_pane(w, wp);
+		server_redraw_window(w);
 	}
 
-	layout_refresh(w, 0);
-
 	return (0);
 }
diff --git a/usr.bin/tmux/cmd-select-layout.c b/usr.bin/tmux/cmd-select-layout.c
index d605eb2638e..70dfd1f6e17 100644
--- a/usr.bin/tmux/cmd-select-layout.c
+++ b/usr.bin/tmux/cmd-select-layout.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-select-layout.c,v 1.2 2009/07/13 23:11:35 nicm Exp $ */
+/* $OpenBSD: cmd-select-layout.c,v 1.3 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -49,17 +49,17 @@ cmd_select_layout_init(struct cmd *self, int key)
 	data = self->data;
 
 	switch (key) {
-	case KEYC_ADDESC('0'):
-		data->arg = xstrdup("manual-vertical");
-		break;
 	case KEYC_ADDESC('1'):
 		data->arg = xstrdup("even-horizontal");
 		break;
 	case KEYC_ADDESC('2'):
 		data->arg = xstrdup("even-vertical");
 		break;
-	case KEYC_ADDESC('9'):
-		data->arg = xstrdup("active-only");
+	case KEYC_ADDESC('3'):
+		data->arg = xstrdup("main-horizontal");
+		break;
+	case KEYC_ADDESC('4'):
+		data->arg = xstrdup("main-vertical");
 		break;
 	}
 }
@@ -74,13 +74,13 @@ cmd_select_layout_exec(struct cmd *self, struct cmd_ctx *ctx)
 	if ((wl = cmd_find_window(ctx, data->target, NULL)) == NULL)
 		return (-1);
 
-	if ((layout = layout_lookup(data->arg)) == -1) {
-		ctx->error(ctx, "unknown or ambiguous layout: %s", data->arg);
-		return (-1);
-	}
+	if ((layout = layout_set_lookup(data->arg)) == -1) {
+ 		ctx->error(ctx, "unknown or ambiguous layout: %s", data->arg);
+ 		return (-1);
+ 	}
 
-	if (layout_select(wl->window, layout) == 0)
-		ctx->info(ctx, "layout now: %s", layout_name(wl->window));
+	layout = layout_set_select(wl->window, layout);
+	ctx->info(ctx, "arranging in: %s", layout_set_name(layout));
 
 	return (0);
 }
diff --git a/usr.bin/tmux/cmd-select-pane.c b/usr.bin/tmux/cmd-select-pane.c
index dfed7e9bbe9..463802f2806 100644
--- a/usr.bin/tmux/cmd-select-pane.c
+++ b/usr.bin/tmux/cmd-select-pane.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-select-pane.c,v 1.3 2009/07/14 07:23:36 nicm Exp $ */
+/* $OpenBSD: cmd-select-pane.c,v 1.4 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -63,7 +63,6 @@ cmd_select_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 		return (-1);
 	}
 	window_set_active_pane(wl->window, wp);
-	layout_refresh(wl->window, 1);
 
 	return (0);
 }
diff --git a/usr.bin/tmux/cmd-split-window.c b/usr.bin/tmux/cmd-split-window.c
index 7094649437f..2d7787ab933 100644
--- a/usr.bin/tmux/cmd-split-window.c
+++ b/usr.bin/tmux/cmd-split-window.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-split-window.c,v 1.4 2009/07/13 23:11:35 nicm Exp $ */
+/* $OpenBSD: cmd-split-window.c,v 1.5 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -39,13 +39,14 @@ struct cmd_split_window_data {
 	char	*target;
 	char	*cmd;
 	int	 flag_detached;
+	int	 flag_horizontal;
 	int	 percentage;
-	int	 lines;
+	int	 size;
 };
 
 const struct cmd_entry cmd_split_window_entry = {
 	"split-window", "splitw",
-	"[-d] [-p percentage|-l lines] [-t target-window] [command]",
+	"[-dhv] [-p percentage|-l size] [-t target-window] [command]",
 	0, 0,
 	cmd_split_window_init,
 	cmd_split_window_parse,
@@ -57,7 +58,7 @@ const struct cmd_entry cmd_split_window_entry = {
 };
 
 void
-cmd_split_window_init(struct cmd *self, unused int arg)
+cmd_split_window_init(struct cmd *self, int key)
 {
 	struct cmd_split_window_data	 *data;
 
@@ -65,50 +66,63 @@ cmd_split_window_init(struct cmd *self, unused int arg)
 	data->target = NULL;
 	data->cmd = NULL;
 	data->flag_detached = 0;
+	data->flag_horizontal = 0;
 	data->percentage = -1;
-	data->lines = -1;
+	data->size = -1;
+
+	switch (key) {
+	case '%':
+		data->flag_horizontal = 1;
+		break;		
+	case '"':
+		data->flag_horizontal = 0;
+		break;
+	}
 }
 
 int
 cmd_split_window_parse(struct cmd *self, int argc, char **argv, char **cause)
 {
 	struct cmd_split_window_data	*data;
-	int				 opt, n;
+	int				 opt;
 	const char			*errstr;
 
 	self->entry->init(self, 0);
 	data = self->data;
 
-	while ((opt = getopt(argc, argv, "dl:p:t:")) != -1) {
+	while ((opt = getopt(argc, argv, "dhl:p:t:v")) != -1) {
 		switch (opt) {
 		case 'd':
 			data->flag_detached = 1;
 			break;
+		case 'h':
+			data->flag_horizontal = 1;
+			break;
 		case 't':
 			if (data->target == NULL)
 				data->target = xstrdup(optarg);
 			break;
 		case 'l':
-			if (data->percentage == -1 && data->lines == -1) {
-				n = strtonum(optarg, 1, INT_MAX, &errstr);
-				if (errstr != NULL) {
-					xasprintf(cause, "lines %s", errstr);
-					goto error;
-				}
-				data->lines = n;
+			if (data->percentage != -1 || data->size != -1)
+				break;
+			data->size = strtonum(optarg, 1, INT_MAX, &errstr);
+			if (errstr != NULL) {
+				xasprintf(cause, "size %s", errstr);
+				goto error;
 			}
 			break;
 		case 'p':
-			if (data->lines == -1 && data->percentage == -1) {
-				n = strtonum(optarg, 1, 100, &errstr);
-				if (errstr != NULL) {
-					xasprintf(
-					    cause, "percentage %s", errstr);
-					goto error;
-				}
-				data->percentage = n;
+			if (data->size != -1 || data->percentage != -1)
+				break;
+			data->percentage = strtonum(optarg, 1, 100, &errstr);
+			if (errstr != NULL) {
+				xasprintf(cause, "percentage %s", errstr);
+				goto error;
 			}
 			break;
+		case 'v':
+			data->flag_horizontal = 0;
+			break;
 		default:
 			goto usage;
 		}
@@ -142,7 +156,8 @@ cmd_split_window_exec(struct cmd *self, struct cmd_ctx *ctx)
 	const char		       **env;
 	char		 		*cmd, *cwd, *cause;
 	u_int				 hlimit;
-	int				 lines;
+	int				 size;
+	enum layout_type		 type;
 
 	if ((wl = cmd_find_window(ctx, data->target, &s)) == NULL)
 		return (-1);
@@ -158,19 +173,27 @@ cmd_split_window_exec(struct cmd *self, struct cmd_ctx *ctx)
 	else
 		cwd = ctx->cmdclient->cwd;
 
-	lines = -1;
-	if (data->lines != -1)
-		lines = data->lines;
+	size = -1;
+	if (data->size != -1)
+		size = data->size;
 	else if (data->percentage != -1)
-		lines = (w->active->sy * data->percentage) / 100;
-
+		size = (w->active->sy * data->percentage) / 100;
 	hlimit = options_get_number(&s->options, "history-limit");
-	wp = window_add_pane(w, lines, cmd, cwd, env, hlimit, &cause);
-	if (wp == NULL) {
-		ctx->error(ctx, "create pane failed: %s", cause);
-		xfree(cause);
-		return (-1);
+
+	type = LAYOUT_TOPBOTTOM;
+	if (data->flag_horizontal)
+		type = LAYOUT_LEFTRIGHT;
+
+	wp = window_add_pane(w, hlimit, &cause);
+	if (wp == NULL)
+		goto error;
+	if (window_pane_spawn(wp, cmd, cwd, env, &cause) != 0)
+		goto error;
+	if (layout_split_pane(w->active, type, size, wp) != 0) {
+		cause = xstrdup("pane too small");
+		goto error;
 	}
+
 	server_redraw_window(w);
 
 	if (!data->flag_detached) {
@@ -179,9 +202,15 @@ cmd_split_window_exec(struct cmd *self, struct cmd_ctx *ctx)
 		server_redraw_session(s);
 	} else
 		server_status_session(s);
-	layout_refresh(w, 0);
 
 	return (0);
+
+error:
+	if (wp != NULL)
+		window_remove_pane(w, wp);
+	ctx->error(ctx, "create pane failed: %s", cause);
+	xfree(cause);
+	return (-1);
 }
 
 void
@@ -228,6 +257,8 @@ cmd_split_window_print(struct cmd *self, char *buf, size_t len)
 		return (off);
 	if (off < len && data->flag_detached)
 		off += xsnprintf(buf + off, len - off, " -d");
+	if (off < len && data->flag_horizontal)
+		off += xsnprintf(buf + off, len - off, " -h");
 	if (off < len && data->target != NULL)
 		off += cmd_prarg(buf + off, len - off, " -t ", data->target);
 	if (off < len && data->cmd != NULL)
diff --git a/usr.bin/tmux/cmd-swap-pane.c b/usr.bin/tmux/cmd-swap-pane.c
index 85ecde214fc..2100ba4a188 100644
--- a/usr.bin/tmux/cmd-swap-pane.c
+++ b/usr.bin/tmux/cmd-swap-pane.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-swap-pane.c,v 1.4 2009/07/14 07:23:36 nicm Exp $ */
+/* $OpenBSD: cmd-swap-pane.c,v 1.5 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -157,6 +157,7 @@ cmd_swap_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 	struct winlink			*wl;
 	struct window			*w;
 	struct window_pane		*tmp_wp, *src_wp, *dst_wp;
+	struct layout_cell		*lc;
 	u_int				 xx, yy;
 
 	if (data == NULL)
@@ -207,12 +208,15 @@ cmd_swap_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 	else
 		TAILQ_INSERT_AFTER(&w->panes, tmp_wp, src_wp, entry);
 
+	lc = src_wp->layout_cell;
 	xx = src_wp->xoff;
 	yy = src_wp->yoff;
- 	src_wp->xoff = dst_wp->xoff;
- 	src_wp->yoff = dst_wp->yoff;
- 	dst_wp->xoff = xx;
- 	dst_wp->yoff = yy;
+	src_wp->layout_cell = dst_wp->layout_cell;
+	if (src_wp->layout_cell != NULL)
+		src_wp->layout_cell->wp = src_wp;
+	dst_wp->layout_cell = lc;
+	if (dst_wp->layout_cell != NULL)
+		dst_wp->layout_cell->wp = dst_wp;
 
 	xx = src_wp->sx;
 	yy = src_wp->sy;
@@ -224,8 +228,8 @@ cmd_swap_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 		if (!window_pane_visible(tmp_wp))
 			tmp_wp = src_wp;
 		window_set_active_pane(w, tmp_wp);
-		layout_refresh(w, 0);
 	}
+	server_redraw_window(w);
 
 	return (0);
 }
diff --git a/usr.bin/tmux/cmd-up-pane.c b/usr.bin/tmux/cmd-up-pane.c
index b0e371f7a6d..7c3c06a0cac 100644
--- a/usr.bin/tmux/cmd-up-pane.c
+++ b/usr.bin/tmux/cmd-up-pane.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: cmd-up-pane.c,v 1.3 2009/07/14 07:23:36 nicm Exp $ */
+/* $OpenBSD: cmd-up-pane.c,v 1.4 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -54,7 +54,6 @@ cmd_up_pane_exec(struct cmd *self, struct cmd_ctx *ctx)
 		w->active = TAILQ_PREV(w->active, window_panes, entry);
 		if (w->active == NULL)
 			w->active = TAILQ_LAST(&w->panes, window_panes);
-		layout_refresh(w, 1);
 	} while (!window_pane_visible(w->active));
 
 	return (0);
diff --git a/usr.bin/tmux/key-bindings.c b/usr.bin/tmux/key-bindings.c
index e5e66077cbb..79e7f5e6f25 100644
--- a/usr.bin/tmux/key-bindings.c
+++ b/usr.bin/tmux/key-bindings.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: key-bindings.c,v 1.5 2009/07/17 18:45:08 nicm Exp $ */
+/* $OpenBSD: key-bindings.c,v 1.6 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -93,7 +93,8 @@ key_bindings_init(void)
 	} table[] = {
 		{ ' ',			  0, &cmd_next_layout_entry },
 		{ '!', 			  0, &cmd_break_pane_entry },
-		{ '"', 			  0, &cmd_split_window_entry },
+		{ '"', 			  0, &cmd_split_window_entry },	
+		{ '%', 			  0, &cmd_split_window_entry },	
 		{ '#', 			  0, &cmd_list_buffers_entry },
 		{ '&', 			  0, &cmd_confirm_before_entry },
 		{ ',', 			  0, &cmd_command_prompt_entry },
@@ -132,10 +133,10 @@ key_bindings_init(void)
 		{ '{',			  0, &cmd_swap_pane_entry },
 		{ '}',			  0, &cmd_swap_pane_entry },
 		{ '\002', 		  0, &cmd_send_prefix_entry },
-		{ KEYC_ADDESC('0'),	  0, &cmd_select_layout_entry },
 		{ KEYC_ADDESC('1'),	  0, &cmd_select_layout_entry },
 		{ KEYC_ADDESC('2'),	  0, &cmd_select_layout_entry },
-		{ KEYC_ADDESC('9'),	  0, &cmd_select_layout_entry },
+		{ KEYC_ADDESC('3'),	  0, &cmd_select_layout_entry },
+		{ KEYC_ADDESC('4'),	  0, &cmd_select_layout_entry },
 		{ KEYC_PPAGE, 		  0, &cmd_scroll_mode_entry },
 		{ KEYC_ADDESC('n'), 	  0, &cmd_next_window_entry },
 		{ KEYC_ADDESC('p'), 	  0, &cmd_previous_window_entry },
@@ -143,8 +144,12 @@ key_bindings_init(void)
 		{ KEYC_DOWN, 		  0, &cmd_down_pane_entry },
 		{ KEYC_ADDESC(KEYC_UP),   1, &cmd_resize_pane_entry },
 		{ KEYC_ADDESC(KEYC_DOWN), 1, &cmd_resize_pane_entry },
+		{ KEYC_ADDESC(KEYC_LEFT), 1, &cmd_resize_pane_entry },
+		{ KEYC_ADDESC(KEYC_RIGHT),1, &cmd_resize_pane_entry },
 		{ KEYC_ADDCTL(KEYC_UP),   1, &cmd_resize_pane_entry },
-		{ KEYC_ADDCTL(KEYC_DOWN), 1, &cmd_resize_pane_entry },
+		{ KEYC_ADDCTL(KEYC_DOWN), 1, &cmd_resize_pane_entry },	
+		{ KEYC_ADDCTL(KEYC_LEFT), 1, &cmd_resize_pane_entry },
+		{ KEYC_ADDCTL(KEYC_RIGHT),1, &cmd_resize_pane_entry },
 		{ KEYC_ADDESC('o'),	  0, &cmd_rotate_window_entry },
 		{ '\017',	          0, &cmd_rotate_window_entry },
 	};
diff --git a/usr.bin/tmux/layout-manual.c b/usr.bin/tmux/layout-manual.c
deleted file mode 100644
index c2ee82c3cb2..00000000000
--- a/usr.bin/tmux/layout-manual.c
+++ /dev/null
@@ -1,172 +0,0 @@
-/* $OpenBSD: layout-manual.c,v 1.2 2009/07/14 07:23:36 nicm Exp $ */
-
-/*
- * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
- *
- * Permission to use, copy, modify, and distribute this software for any
- * purpose with or without fee is hereby granted, provided that the above
- * copyright notice and this permission notice appear in all copies.
- *
- * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
- * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
- * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
- * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
- * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
- * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
- * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
- */
-
-#include <sys/types.h>
-
-#include "tmux.h"
-
-void	layout_manual_v_update_offsets(struct window *);
-
-void
-layout_manual_v_refresh(struct window *w, unused int active_only)
-{
-	struct window_pane	*wp;
-	u_int			 npanes, total, height;
-	int			 left;
-
-	if (active_only)
-		return;
-
-	if (TAILQ_EMPTY(&w->panes))
-		return;
-
-	/* Check the new size. */
-	npanes = window_count_panes(w);
-	if (w->sy <= PANE_MINIMUM * npanes) {
-		/* 
-		 * Make the first pane the smaller of the minimum and total (it
-		 * must fit to be visible) and the rest the minimum size.
-		 */
-		height = PANE_MINIMUM;
-		if (height > w->sy)
-			height = w->sy + 1;
-		TAILQ_FOREACH(wp, &w->panes, entry) {
-			if (wp == TAILQ_FIRST(&w->panes))
-				wp->sy = height - 1;
-			else
-				wp->sy = PANE_MINIMUM - 1;
-		}
-		/* And increase the first by the rest if possible. */
-		if (w->sy >= PANE_MINIMUM)
-			TAILQ_FIRST(&w->panes)->sy += 1 + w->sy % PANE_MINIMUM;
-	} else {
-		/* In theory they will all fit. Find the current total. */
-		total = 0;
-		TAILQ_FOREACH(wp, &w->panes, entry)
-			total += wp->sy;
-		total += npanes - 1;
-
-		/* Growing or shrinking? */
-		left = w->sy - total;
-		if (left > 0) {
-			/* Growing. Expand evenly. */
-			while (left > 0) {
-				TAILQ_FOREACH(wp, &w->panes, entry) {
-					wp->sy++;
-					if (--left == 0)
-						break;
-				}
-			}
-		} else {
-			/* Shrinking. Reduce evenly down to minimum. */
-			while (left < 0) {
-				TAILQ_FOREACH(wp, &w->panes, entry) {
-					if (wp->sy <= PANE_MINIMUM - 1)
-						continue;
-					wp->sy--;
-					if (++left == 0)
-						break;
-				}
-			}
-		}
-	}
-
-	/* Now do the resize. */
-	TAILQ_FOREACH(wp, &w->panes, entry) {
-		wp->sy--;
-	    	window_pane_resize(wp, w->sx, wp->sy + 1);
-	}
-
-	/* Fill in the offsets. */
-	layout_manual_v_update_offsets(w);
-
-	/* Switch the active window if necessary. */
-	window_set_active_pane(w, w->active);
-}
-
-void
-layout_manual_v_resize(struct window_pane *wp, int adjust)
-{
-	struct window		*w = wp->window;
-	struct window_pane	*wq;
-
-	if (adjust > 0) {
-		/*
-		 * If this is not the last pane, keep trying to increase size
-		 * and remove it from the next panes. If it is the last, do
-		 * so on the previous pane.
-		 */
-		if (TAILQ_NEXT(wp, entry) == NULL) {
-			if (wp == TAILQ_FIRST(&w->panes)) {
-				/* Only one pane. */
-				return;
-			}
-			wp = TAILQ_PREV(wp, window_panes, entry);
-		}
-		while (adjust-- > 0) {
-			wq = wp;
-			while ((wq = TAILQ_NEXT(wq, entry)) != NULL) {
-				if (wq->sy <= PANE_MINIMUM)
-					continue;
-				window_pane_resize(wq, wq->sx, wq->sy - 1);
-				break;
-			}
-			if (wq == NULL)
-				break;
-			window_pane_resize(wp, wp->sx, wp->sy + 1);
-		}
-	} else {
-		adjust = -adjust;
-		/*
-		 * If this is not the last pane, keep trying to reduce size
-		 * and add to the following pane. If it is the last, do so on
-		 * the previous pane.
-		 */
-		wq = TAILQ_NEXT(wp, entry);
-		if (wq == NULL) {
-			if (wp == TAILQ_FIRST(&w->panes)) {
-				/* Only one pane. */
-				return;
-			}
-			wq = wp;
-			wp = TAILQ_PREV(wq, window_panes, entry);
-		}
-		while (adjust-- > 0) {
-			if (wp->sy <= PANE_MINIMUM)
-				break;
-			window_pane_resize(wq, wq->sx, wq->sy + 1);
-			window_pane_resize(wp, wp->sx, wp->sy - 1);
-		}
-	}
-
-	layout_manual_v_update_offsets(w);
-}
-
-void
-layout_manual_v_update_offsets(struct window *w)
-{
-	struct window_pane     *wp;
-	u_int			yoff;
-
-	yoff = 0;
-	TAILQ_FOREACH(wp, &w->panes, entry) {
-		wp->xoff = 0;
-		wp->yoff = yoff;
-		yoff += wp->sy + 1;
-	}
-}
diff --git a/usr.bin/tmux/layout-set.c b/usr.bin/tmux/layout-set.c
new file mode 100644
index 00000000000..7bdaa8b2851
--- /dev/null
+++ b/usr.bin/tmux/layout-set.c
@@ -0,0 +1,436 @@
+/* $OpenBSD: layout-set.c,v 1.1 2009/07/19 13:21:40 nicm Exp $ */
+
+/*
+ * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER
+ * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
+ * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+
+#include <string.h>
+
+#include "tmux.h"
+
+/*
+ * Set window layouts - predefined methods to arrange windows. These are one-off
+ * and generate a layout tree.
+ */
+
+void	layout_set_even_h(struct window *);
+void	layout_set_even_v(struct window *);
+void	layout_set_main_h(struct window *);
+void	layout_set_main_v(struct window *);
+
+const struct {
+	const char	*name;
+	void	      	(*arrange)(struct window *);
+} layout_sets[] = {
+	{ "even-horizontal", layout_set_even_h },
+	{ "even-vertical", layout_set_even_v },
+	{ "main-horizontal", layout_set_main_h },
+	{ "main-vertical", layout_set_main_v },
+};
+
+const char *
+layout_set_name(u_int layout)
+{
+	return (layout_sets[layout].name);
+}
+
+int
+layout_set_lookup(const char *name)
+{
+	u_int	i;
+	int	matched = -1;
+
+	for (i = 0; i < nitems(layout_sets); i++) {
+		if (strncmp(layout_sets[i].name, name, strlen(name)) == 0) {
+			if (matched != -1)	/* ambiguous */
+				return (-1);
+			matched = i;
+		}
+	}
+
+	return (matched);
+}
+
+u_int
+layout_set_select(struct window *w, u_int layout)
+{
+	if (layout > nitems(layout_sets) - 1)
+		layout = nitems(layout_sets) - 1;
+
+	if (layout_sets[layout].arrange != NULL)
+		layout_sets[layout].arrange(w);
+
+	w->layout = layout;
+	return (layout);
+}
+
+u_int
+layout_set_next(struct window *w)
+{
+	u_int	layout = w->layout;
+
+	if (layout_sets[layout].arrange != NULL)
+		layout_sets[layout].arrange(w);
+
+	w->layout++;
+	if (w->layout > nitems(layout_sets) - 1)
+		w->layout = 0;
+	return (layout);
+}
+
+u_int
+layout_set_previous(struct window *w)
+{
+	u_int	layout = w->layout;
+
+	if (layout_sets[layout].arrange != NULL)
+		layout_sets[layout].arrange(w);
+
+	if (w->layout == 0)
+		w->layout = nitems(layout_sets) - 1;
+	else
+		w->layout--;
+	return (layout);
+}
+
+void
+layout_set_even_h(struct window *w)
+{
+	struct window_pane	*wp;
+	struct layout_cell	*lc, *lcnew;
+	u_int			 i, n, width, xoff;
+
+	layout_print_cell(w->layout_root, __func__, 1);
+
+	/* Get number of panes. */
+	n = window_count_panes(w);
+	if (n <= 1)
+		return;
+
+	/* How many can we fit? */
+	if (w->sx / n < PANE_MINIMUM + 1) {
+		width = PANE_MINIMUM + 1;
+		n = UINT_MAX;
+	} else
+		width = w->sx / n;
+
+	/* Free the old root and construct a new. */
+	layout_free(w);
+	lc = w->layout_root = layout_create_cell(NULL);
+	layout_set_size(lc, w->sx, w->sy, 0, 0);
+	layout_make_node(lc, LAYOUT_LEFTRIGHT);
+
+	/* Build new leaf cells. */
+	i = xoff = 0;
+	TAILQ_FOREACH(wp, &w->panes, entry) {
+		/* Create child cell. */
+		lcnew = layout_create_cell(lc);
+		layout_set_size(lcnew, width - 1, w->sy, xoff, 0);
+		layout_make_leaf(lcnew, wp);
+		TAILQ_INSERT_TAIL(&lc->cells, lcnew, entry);
+
+		i++;
+		xoff += width;
+	}
+
+	/* Allocate any remaining space. */
+	if (w->sx > xoff - 1) {
+		lc = TAILQ_LAST(&lc->cells, layout_cells);
+		layout_resize_adjust(lc, LAYOUT_LEFTRIGHT, w->sx - (xoff - 1));
+	}
+
+	/* Fix cell offsets. */
+	layout_fix_offsets(lc);
+	layout_fix_panes(w, w->sx, w->sy);
+
+	layout_print_cell(w->layout_root, __func__, 1);
+
+	server_redraw_window(w);
+}
+
+void
+layout_set_even_v(struct window *w)
+{
+	struct window_pane	*wp;
+	struct layout_cell	*lc, *lcnew;
+	u_int			 i, n, height, yoff;
+
+	layout_print_cell(w->layout_root, __func__, 1);
+
+	/* Get number of panes. */
+	n = window_count_panes(w);
+	if (n <= 1)
+		return;
+
+	/* How many can we fit? */
+	if (w->sy / n < PANE_MINIMUM + 1) {
+		height = PANE_MINIMUM + 1;
+		n = UINT_MAX;
+	} else
+		height = w->sy / n;
+
+	/* Free the old root and construct a new. */
+	layout_free(w);
+	lc = w->layout_root = layout_create_cell(NULL);
+	layout_set_size(lc, w->sx, w->sy, 0, 0);
+	layout_make_node(lc, LAYOUT_TOPBOTTOM);
+
+	/* Build new leaf cells. */
+	i = yoff = 0;
+	TAILQ_FOREACH(wp, &w->panes, entry) {
+		/* Create child cell. */
+		lcnew = layout_create_cell(lc);
+		layout_set_size(lcnew, w->sx, height - 1, 0, yoff);
+		layout_make_leaf(lcnew, wp);
+		TAILQ_INSERT_TAIL(&lc->cells, lcnew, entry);
+
+		i++;
+		yoff += height;
+	}
+
+	/* Allocate any remaining space. */
+	if (w->sy > yoff - 1) {
+		lc = TAILQ_LAST(&lc->cells, layout_cells);
+		layout_resize_adjust(lc, LAYOUT_TOPBOTTOM, w->sy - (yoff - 1));
+	}
+
+	/* Fix cell offsets. */
+	layout_fix_offsets(lc);
+	layout_fix_panes(w, w->sx, w->sy);
+
+	layout_print_cell(w->layout_root, __func__, 1);
+
+	server_redraw_window(w);
+}
+
+void
+layout_set_main_h(struct window *w)
+{
+	struct window_pane	*wp;
+	struct layout_cell	*lc, *lcmain, *lcrow, *lcchild;
+	u_int			 n, mainheight, width, height, used;
+	u_int			 i, j, columns, rows, totalrows;
+
+	layout_print_cell(w->layout_root, __func__, 1);
+
+	/* Get number of panes. */
+	n = window_count_panes(w);
+	if (n <= 1)
+		return;
+	n--;	/* take off main pane */
+
+	/* How many rows and columns will be needed? */
+	columns = w->sx / (PANE_MINIMUM + 1);	/* maximum columns */
+	rows = 1 + (n - 1) / columns;
+	columns = 1 + (n - 1) / rows;
+	width = w->sx / columns;
+
+	/* Get the main pane height and add one for separator line. */
+	mainheight = options_get_number(&w->options, "main-pane-height") + 1;
+	if (mainheight < PANE_MINIMUM + 1)
+		mainheight = PANE_MINIMUM + 1;
+
+	/* Try and make everything fit. */
+	totalrows = rows * (PANE_MINIMUM + 1) - 1;
+	if (mainheight + totalrows > w->sy) {
+		if (totalrows + PANE_MINIMUM + 1 > w->sy)
+			mainheight = PANE_MINIMUM + 2;
+		else
+			mainheight = w->sy - totalrows;
+		height = PANE_MINIMUM + 1;
+	} else
+		height = (w->sy - mainheight) / rows;
+
+	/* Free old tree and create a new root. */
+	layout_free(w);
+	lc = w->layout_root = layout_create_cell(NULL);
+	layout_set_size(lc, w->sx, mainheight + rows * height, 0, 0);
+	layout_make_node(lc, LAYOUT_TOPBOTTOM);
+
+	/* Create the main pane. */
+	lcmain = layout_create_cell(lc);
+	layout_set_size(lcmain, w->sx, mainheight - 1, 0, 0);
+	layout_make_leaf(lcmain, TAILQ_FIRST(&w->panes));
+	TAILQ_INSERT_TAIL(&lc->cells, lcmain, entry);
+
+	/* Create a grid of the remaining cells. */
+	wp = TAILQ_NEXT(TAILQ_FIRST(&w->panes), entry);
+	for (j = 0; j < rows; j++) {
+		/* If this is the last cell, all done. */
+		if (wp == NULL)
+			break;
+
+		/* Create the new row. */
+		lcrow = layout_create_cell(lc);
+		layout_set_size(lcrow, w->sx, height - 1, 0, 0);
+		TAILQ_INSERT_TAIL(&lc->cells, lcrow, entry);
+
+		/* If only one column, just use the row directly. */
+		if (columns == 1) {
+			layout_make_leaf(lcrow, wp);
+			wp = TAILQ_NEXT(wp, entry);
+			continue;
+		}
+
+ 		/* Add in the columns. */
+		layout_make_node(lcrow, LAYOUT_LEFTRIGHT);
+		for (i = 0; i < columns; i++) {
+			/* Create and add a pane cell. */
+			lcchild = layout_create_cell(lcrow);
+			layout_set_size(lcchild, width - 1, height - 1, 0, 0);
+			layout_make_leaf(lcchild, wp);
+			TAILQ_INSERT_TAIL(&lcrow->cells, lcchild, entry);
+
+			/* Move to the next cell. */
+			if ((wp = TAILQ_NEXT(wp, entry)) == NULL)
+				break;
+		}
+
+		/* Adjust the row to fit the full width if necessary. */
+		if (i == columns)
+			i--;
+ 		used = ((i + 1) * width) - 1;
+ 		if (w->sx <= used)
+ 			continue;
+ 		lcchild = TAILQ_LAST(&lcrow->cells, layout_cells);
+ 		layout_resize_adjust(lcchild, LAYOUT_LEFTRIGHT, w->sx - used);
+	}
+
+	/* Adjust the last row height to fit if necessary. */
+	used = mainheight + (rows * height) - 1;
+	if (w->sy > used) {
+		lcrow = TAILQ_LAST(&lc->cells, layout_cells);
+		layout_resize_adjust(lcrow, LAYOUT_TOPBOTTOM, w->sy - used);
+	}
+
+	/* Fix cell offsets. */
+	layout_fix_offsets(lc);
+	layout_fix_panes(w, w->sx, w->sy);
+
+	layout_print_cell(w->layout_root, __func__, 1);
+
+	server_redraw_window(w);
+}
+
+void
+layout_set_main_v(struct window *w)
+{
+	struct window_pane	*wp;
+	struct layout_cell	*lc, *lcmain, *lccolumn, *lcchild;
+	u_int			 n, mainwidth, width, height, used;
+	u_int			 i, j, columns, rows, totalcolumns;
+
+	layout_print_cell(w->layout_root, __func__, 1);
+
+	/* Get number of panes. */
+	n = window_count_panes(w);
+	if (n <= 1)
+		return;
+	n--;	/* take off main pane */
+
+	/* How many rows and columns will be needed? */
+	rows = w->sy / (PANE_MINIMUM + 1);	/* maximum rows */
+	columns = 1 + (n - 1) / rows;
+	rows = 1 + (n - 1) / columns;
+	height = w->sy / rows;
+
+	/* Get the main pane width and add one for separator line. */
+	mainwidth = options_get_number(&w->options, "main-pane-width") + 1;
+	if (mainwidth < PANE_MINIMUM + 1)
+		mainwidth = PANE_MINIMUM + 1;
+
+	/* Try and make everything fit. */
+	totalcolumns = columns * (PANE_MINIMUM + 1) - 1;
+	if (mainwidth + totalcolumns > w->sx) {
+		if (totalcolumns + PANE_MINIMUM + 1 > w->sx)
+			mainwidth = PANE_MINIMUM + 2;
+		else
+			mainwidth = w->sx - totalcolumns;
+		width = PANE_MINIMUM + 1;
+	} else
+		width = (w->sx - mainwidth) / columns;
+
+	/* Free old tree and create a new root. */
+	layout_free(w);
+	lc = w->layout_root = layout_create_cell(NULL);
+	layout_set_size(lc, mainwidth + columns * width, w->sy, 0, 0);
+	layout_make_node(lc, LAYOUT_LEFTRIGHT);
+
+	/* Create the main pane. */
+	lcmain = layout_create_cell(lc);
+	layout_set_size(lcmain, mainwidth - 1, w->sy, 0, 0);
+	layout_make_leaf(lcmain, TAILQ_FIRST(&w->panes));
+	TAILQ_INSERT_TAIL(&lc->cells, lcmain, entry);
+
+	/* Create a grid of the remaining cells. */
+	wp = TAILQ_NEXT(TAILQ_FIRST(&w->panes), entry);
+	for (j = 0; j < columns; j++) {
+		/* If this is the last cell, all done. */
+		if (wp == NULL)
+			break;
+
+		/* Create the new column. */
+		lccolumn = layout_create_cell(lc);
+		layout_set_size(lccolumn, width - 1, w->sy, 0, 0);
+		TAILQ_INSERT_TAIL(&lc->cells, lccolumn, entry);
+
+		/* If only one row, just use the row directly. */
+		if (rows == 1) {
+			layout_make_leaf(lccolumn, wp);
+			wp = TAILQ_NEXT(wp, entry);
+			continue;
+		}
+
+		/* Add in the rows. */
+		layout_make_node(lccolumn, LAYOUT_TOPBOTTOM);
+		for (i = 0; i < rows; i++) {
+			/* Create and add a pane cell. */
+			lcchild = layout_create_cell(lccolumn);
+			layout_set_size(lcchild, width - 1, height - 1, 0, 0);
+			layout_make_leaf(lcchild, wp);
+			TAILQ_INSERT_TAIL(&lccolumn->cells, lcchild, entry);
+
+			/* Move to the next cell. */
+			if ((wp = TAILQ_NEXT(wp, entry)) == NULL)
+				break;
+		}
+
+		/* Adjust the column to fit the full height if necessary. */
+		if (i == rows)
+			i--;
+		used = ((i + 1) * height) - 1;
+ 		if (w->sy <= used)
+ 			continue;
+ 		lcchild = TAILQ_LAST(&lccolumn->cells, layout_cells);
+ 		layout_resize_adjust(lcchild, LAYOUT_TOPBOTTOM, w->sy - used);
+	}
+
+	/* Adjust the last column width to fit if necessary. */
+	used = mainwidth + (columns * width) - 1;
+	if (w->sx > used) {
+		lccolumn = TAILQ_LAST(&lc->cells, layout_cells);
+		layout_resize_adjust(lccolumn, LAYOUT_LEFTRIGHT, w->sx - used);
+	}
+
+	/* Fix cell offsets. */
+	layout_fix_offsets(lc);
+	layout_fix_panes(w, w->sx, w->sy);
+
+	layout_print_cell(w->layout_root, __func__, 1);
+
+	server_redraw_window(w);
+}
diff --git a/usr.bin/tmux/layout.c b/usr.bin/tmux/layout.c
index f4511e06286..e71a9bfd26e 100644
--- a/usr.bin/tmux/layout.c
+++ b/usr.bin/tmux/layout.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: layout.c,v 1.2 2009/07/14 07:23:36 nicm Exp $ */
+/* $OpenBSD: layout.c,v 1.3 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2009 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -18,349 +18,632 @@
 
 #include <sys/types.h>
 
-#include <string.h>
+#include <stdlib.h>
 
 #include "tmux.h"
 
 /*
- * Each layout has two functions, _refresh to relayout the panes and _resize to
- * resize a single pane.
+ * The window layout is a tree of cells each of which can be one of: a
+ * left-right container for a list of cells, a top-bottom container for a list
+ * of cells, or a container for a window pane.
  *
- * Second argument (int) to _refresh is 1 if the only change has been that the
- * active pane has changed. If 0 then panes, active pane or both may have
- * changed.
+ * Each window has a pointer to the root of its layout tree (containing its
+ * panes), every pane has a pointer back to the cell containing it, and each
+ * cell a pointer to its parent cell.
  */
 
-void	layout_active_only_refresh(struct window *, int);
-void	layout_even_h_refresh(struct window *, int);
-void	layout_even_v_refresh(struct window *, int);
-void	layout_main_h_refresh(struct window *, int);
-void	layout_main_v_refresh(struct window *, int);
-
-const struct {
-	const char     *name;
-	void		(*refresh)(struct window *, int);
-	void		(*resize)(struct window_pane *, int);
-} layouts[] = {
-	{ "manual-vertical", layout_manual_v_refresh, layout_manual_v_resize },
-	{ "active-only", layout_active_only_refresh, NULL },
-	{ "even-horizontal", layout_even_h_refresh, NULL },
-	{ "even-vertical", layout_even_v_refresh, NULL },
-	{ "main-horizontal", layout_main_h_refresh, NULL },
-	{ "main-vertical", layout_main_v_refresh, NULL },
-};
-
-const char *
-layout_name(struct window *w)
+int	layout_resize_pane_grow(struct layout_cell *, enum layout_type, int);
+int	layout_resize_pane_shrink(struct layout_cell *, enum layout_type, int);
+
+struct layout_cell *
+layout_create_cell(struct layout_cell *lcparent)
 {
-	return (layouts[w->layout].name);
+	struct layout_cell	*lc;
+
+	lc = xmalloc(sizeof *lc);
+	lc->type = LAYOUT_WINDOWPANE;
+	lc->parent = lcparent;
+
+	TAILQ_INIT(&lc->cells);
+	
+	lc->sx = UINT_MAX;
+	lc->sy = UINT_MAX;
+	
+	lc->xoff = UINT_MAX;
+	lc->yoff = UINT_MAX;
+	
+	lc->wp = NULL;
+
+	return (lc);
 }
 
-int
-layout_lookup(const char *name)
+void
+layout_free_cell(struct layout_cell *lc)
 {
-	u_int	i;
-	int	matched = -1;
-
-	for (i = 0; i < nitems(layouts); i++) {
-		if (strncmp(layouts[i].name, name, strlen(name)) == 0) {
-			if (matched != -1)	/* ambiguous */
-				return (-1);
-			matched = i;
+	struct layout_cell	*lcchild;
+
+	switch (lc->type) {
+	case LAYOUT_LEFTRIGHT:
+	case LAYOUT_TOPBOTTOM:
+		while (!TAILQ_EMPTY(&lc->cells)) {
+			lcchild = TAILQ_FIRST(&lc->cells);
+			TAILQ_REMOVE(&lc->cells, lcchild, entry);
+			layout_free_cell(lcchild);
 		}
+		break;
+	case LAYOUT_WINDOWPANE:
+		if (lc->wp != NULL)
+			lc->wp->layout_cell = NULL;
+		break;
 	}
 
-	return (matched);
+	xfree(lc);
 }
 
-int
-layout_select(struct window *w, u_int layout)
+void
+layout_print_cell(struct layout_cell *lc, const char *hdr, u_int n)
 {
-	if (layout > nitems(layouts) - 1 || layout == w->layout)
-		return (-1);
-	w->layout = layout;
-
-	layout_refresh(w, 0);
-	return (0);
+	struct layout_cell	*lcchild;
+
+	log_debug(
+	    "%s:%*s%p type %u [parent %p] wp=%p [%u,%u %ux%u]", hdr, n, " ", lc,
+	    lc->type, lc->parent, lc->wp, lc->xoff, lc->yoff, lc->sx, lc->sy);
+	switch (lc->type) {
+	case LAYOUT_LEFTRIGHT:
+	case LAYOUT_TOPBOTTOM:
+		TAILQ_FOREACH(lcchild, &lc->cells, entry)
+		    	layout_print_cell(lcchild, hdr, n + 1);
+		break;
+	case LAYOUT_WINDOWPANE:
+		break;
+	}
 }
 
 void
-layout_next(struct window *w)
+layout_set_size(
+    struct layout_cell *lc, u_int sx, u_int sy, u_int xoff, u_int yoff)
 {
-	w->layout++;
-	if (w->layout > nitems(layouts) - 1)
-		w->layout = 0;
-	layout_refresh(w, 0);
+	lc->sx = sx;
+	lc->sy = sy;
+
+	lc->xoff = xoff;
+	lc->yoff = yoff;
 }
 
 void
-layout_previous(struct window *w)
+layout_make_leaf(struct layout_cell *lc, struct window_pane *wp)
 {
-	if (w->layout == 0)
-		w->layout = nitems(layouts) - 1;
-	else
-		w->layout--;
-	layout_refresh(w, 0);
+	lc->type = LAYOUT_WINDOWPANE;
+
+	TAILQ_INIT(&lc->cells);
+
+	wp->layout_cell = lc;
+	lc->wp = wp;
 }
 
 void
-layout_refresh(struct window *w, int active_only)
+layout_make_node(struct layout_cell *lc, enum layout_type type)
 {
-	layouts[w->layout].refresh(w, active_only);
-	server_redraw_window(w);
-}
+	if (type == LAYOUT_WINDOWPANE)
+		fatalx("bad layout type");
+	lc->type = type;
 
-int
-layout_resize(struct window_pane *wp, int adjust)
-{
-	struct window	*w = wp->window;
+	TAILQ_INIT(&lc->cells);
 
-	if (layouts[w->layout].resize == NULL)
-		return (-1);
-	layouts[w->layout].resize(wp, adjust);
-	return (0);
+	if (lc->wp != NULL)
+		lc->wp->layout_cell = NULL;
+	lc->wp = NULL;
 }
 
+/* Fix cell offsets based on their sizes. */
 void
-layout_active_only_refresh(struct window *w, unused int active_only)
+layout_fix_offsets(struct layout_cell *lc)
 {
-	struct window_pane	*wp;
-	u_int			 xoff;
-
-	xoff = w->sx;
-	TAILQ_FOREACH(wp, &w->panes, entry) {
-		/* Put the active pane on screen and the rest to the right. */
-		if (wp == w->active)
-			wp->xoff = 0;
-		else {
-			wp->xoff = xoff;
-			xoff += w->sx;
+	struct layout_cell	*lcchild;
+	u_int			 xoff, yoff;
+
+	if (lc->type == LAYOUT_LEFTRIGHT) {
+		xoff = lc->xoff;
+		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
+			lcchild->xoff = xoff;
+			lcchild->yoff = lc->yoff;
+			if (lcchild->type != LAYOUT_WINDOWPANE)
+				layout_fix_offsets(lcchild);
+			xoff += lcchild->sx + 1;
+		}
+	} else {
+		yoff = lc->yoff;
+		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
+			lcchild->xoff = lc->xoff;
+			lcchild->yoff = yoff;
+			if (lcchild->type != LAYOUT_WINDOWPANE)
+				layout_fix_offsets(lcchild);
+			yoff += lcchild->sy + 1;
 		}
-		wp->yoff = 0;
-		window_pane_resize(wp, w->sx, w->sy);
 	}
 }
 
+/* Update pane offsets and sizes based on their cells. */
 void
-layout_even_h_refresh(struct window *w, int active_only)
+layout_fix_panes(struct window *w, u_int wsx, u_int wsy)
 {
 	struct window_pane	*wp;
-	u_int			 i, n, width, xoff;
+	struct layout_cell	*lc;
+	u_int			 sx, sy;
 
-	if (active_only)
-		return;
+	TAILQ_FOREACH(wp, &w->panes, entry) {
+		if ((lc = wp->layout_cell) == NULL)
+			continue;
+		wp->xoff = lc->xoff;
+		wp->yoff = lc->yoff;
+
+		/*
+		 * Layout cells are limited by the smallest size of other cells
+		 * within the same row or column; if this isn't the case
+		 * resizing becomes difficult.
+		 *
+		 * However, panes do not have to take up their entire cell, so
+		 * they can be cropped to the window edge if the layout
+		 * overflows and they are partly visible.
+		 *
+		 * This stops cells being hidden unnecessarily.
+		 */
+
+		/*
+		 * Work out the horizontal size. If the pane is actually
+		 * outside the window or the entire pane is already visible,
+		 * don't crop.
+		 */
+		if (lc->xoff >= wsx || lc->xoff + lc->sx < wsx)
+			sx = lc->sx;
+		else {
+			sx = wsx - lc->xoff;
+			if (sx < 1)
+				sx = lc->sx;
+		}
+		
+		/* 
+		 * Similarly for the vertical size; the minimum vertical size
+		 * is two because scroll regions cannot be one line.
+		 */
+		if (lc->yoff >= wsy || lc->yoff + lc->sy < wsy)
+			sy = lc->sy;
+		else {
+			sy = wsy - lc->yoff;
+			if (sy < 2)
+				sy = lc->sy;
+		}
 
-	/* If the screen is too small, show active only. */
-	if (w->sx < PANE_MINIMUM || w->sy < PANE_MINIMUM) {
-		layout_active_only_refresh(w, active_only);
-		return;
+		window_pane_resize(wp, sx, sy);
 	}
+}
 
-	/* Get number of panes. */
-	n = window_count_panes(w);
-	if (n == 0)
-		return;
-
-	/* How many can we fit? */
-	if (w->sx / n < PANE_MINIMUM) {
-		width = PANE_MINIMUM;
-		n = UINT_MAX;
-	} else
-		width = w->sx / n;
+/* Calculate how much size is available to be removed from a cell. */
+u_int
+layout_resize_check(struct layout_cell *lc, enum layout_type type)
+{
+	struct layout_cell	*lcchild;
+	u_int			 available, minimum;
 
-	/* Fit the panes. */
-	i = xoff = 0;
-	TAILQ_FOREACH(wp, &w->panes, entry) {
-		wp->xoff = xoff;
-		wp->yoff = 0;
-		if (i != n - 1)
- 			window_pane_resize(wp, width - 1, w->sy);
+	if (lc->type == LAYOUT_WINDOWPANE) {
+		/* Space available in this cell only. */
+		if (type == LAYOUT_LEFTRIGHT)
+			available = lc->sx;
 		else
- 			window_pane_resize(wp, width, w->sy);
-
-		i++;
-		xoff += width;
+			available = lc->sy;
+		
+		if (available > PANE_MINIMUM)
+			available -= PANE_MINIMUM;
+		else
+			available = 0;
+	} else if (lc->type == type) {
+		/* Same type: total of available space in all child cells. */
+		available = 0;
+		TAILQ_FOREACH(lcchild, &lc->cells, entry)
+			available += layout_resize_check(lcchild, type);
+	} else {
+		/* Different type: minimum of available space in child cells. */
+		minimum = UINT_MAX;
+		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
+			available = layout_resize_check(lcchild, type);
+			if (available < minimum)
+				minimum = available;
+		}
+		available = minimum;
 	}
 
-	/* Any space left? */
-	while (xoff++ < w->sx) {
-		wp = TAILQ_LAST(&w->panes, window_panes);
-		window_pane_resize(wp, wp->sx + 1, wp->sy);
-	}
+	return (available);
 }
 
+/*
+ * Adjust cell size evenly, including altering its children. This function
+ * expects the change to have already been bounded to the space available.
+ */
 void
-layout_even_v_refresh(struct window *w, int active_only)
+layout_resize_adjust(struct layout_cell *lc, enum layout_type type, int change)
 {
-	struct window_pane	*wp;
-	u_int			 i, n, height, yoff;
+	struct layout_cell	*lcchild;
 
-	if (active_only)
+	/* Adjust the cell size. */
+	if (type == LAYOUT_LEFTRIGHT)
+		lc->sx += change;
+	else
+		lc->sy += change;
+	
+	/* If this is a leaf cell, that is all that is necessary. */
+	if (type == LAYOUT_WINDOWPANE)
 		return;
 
-	/* If the screen is too small, show active only. */
-	if (w->sx < PANE_MINIMUM || w->sy < PANE_MINIMUM) {
-		layout_active_only_refresh(w, active_only);
+	/* Child cell runs in a different direction. */
+	if (lc->type != type) {
+		TAILQ_FOREACH(lcchild, &lc->cells, entry)
+			layout_resize_adjust(lcchild, type, change);
 		return;
 	}
 
-	/* Get number of panes. */
-	n = window_count_panes(w);
-	if (n == 0)
-		return;
+	/* 
+	 * Child cell runs in the same direction. Adjust each child equally 
+	 * until no further change is possible.
+	 */
+	while (change != 0) {
+		TAILQ_FOREACH(lcchild, &lc->cells, entry) {
+			if (change == 0)
+				break;
+			if (change > 0) {
+				layout_resize_adjust(lcchild, type, 1);
+				change--;
+				continue;
+			}
+			if (layout_resize_check(lcchild, type) > 0) {
+				layout_resize_adjust(lcchild, type, -1);
+				change++;
+			}
+		}
+	}
+}
 
-	/* How many can we fit? */
-	if (w->sy / n < PANE_MINIMUM) {
-		height = PANE_MINIMUM;
-		n = UINT_MAX;
-	} else
-		height = w->sy / n;
+void
+layout_init(struct window *w)
+{
+	struct layout_cell	*lc;
 
-	/* Fit the panes. */
-	i = yoff = 0;
-	TAILQ_FOREACH(wp, &w->panes, entry) {
-		wp->xoff = 0;
-		wp->yoff = yoff;
-		if (i != n - 1)
- 			window_pane_resize(wp, w->sx, height - 1);
-		else
- 			window_pane_resize(wp, w->sx, height);
+	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));
 
-		i++;
-		yoff += height;
-	}
+	layout_fix_panes(w, w->sx, w->sy);
+}
 
-	/* Any space left? */
-	while (yoff++ < w->sy) {
-		wp = TAILQ_LAST(&w->panes, window_panes);
-		window_pane_resize(wp, wp->sx, wp->sy + 1);
+void
+layout_free(struct window *w)
+{
+	layout_free_cell(w->layout_root);
+}
+
+/* Resize the entire layout after window resize. */
+void
+layout_resize(struct window *w, u_int sx, u_int sy)
+{
+	struct layout_cell	*lc = w->layout_root;
+	int			 xlimit, ylimit, xchange, ychange;
+
+	/* 
+	 * Adjust horizontally. Do not attempt to reduce the layout lower than
+	 * the minimum (more than the amount returned by layout_resize_check).
+	 * 
+	 * This can mean that the window size is smaller than the total layout
+	 * size: redrawing this is handled at a higher level, but it does leave
+	 * a problem with growing the window size here: if the current size is
+	 * < the minimum, growing proportionately by adding to each pane is
+	 * wrong as it would keep the layout size larger than the window size.
+	 * Instead, spread the difference between the minimum and the new size
+	 * out proportionately - this should leave the layout fitting the new
+	 * window size.
+	 */
+	xchange = sx - w->sx;
+	xlimit = layout_resize_check(lc, LAYOUT_LEFTRIGHT);
+	if (xchange < 0 && xchange < -xlimit)
+		xchange = -xlimit;
+	if (xlimit == 0) {
+		if (sx <= lc->sx)	/* lc->sx is minimum possible */
+			xchange = 0;
+		else
+			xchange = sx - lc->sx;
 	}
+	if (xchange != 0)
+		layout_resize_adjust(lc, LAYOUT_LEFTRIGHT, xchange);
+
+	/* Adjust vertically in a similar fashion. */
+	ychange = sy - w->sy;
+	ylimit = layout_resize_check(lc, LAYOUT_TOPBOTTOM);
+	if (ychange < 0 && ychange < -ylimit)
+		ychange = -ylimit;
+	if (ylimit == 0) {
+		if (sy <= lc->sy)	/* lc->sy is minimum possible */
+			ychange = 0;
+		else
+			ychange = sy - lc->sy;
+	}
+	if (ychange != 0)
+		layout_resize_adjust(lc, LAYOUT_TOPBOTTOM, ychange);
+	
+	/* Fix cell offsets. */
+	layout_fix_offsets(lc);
+	layout_fix_panes(w, sx, sy);
 }
 
+/* Resize a single pane within the layout. */
 void
-layout_main_v_refresh(struct window *w, int active_only)
+layout_resize_pane(struct window_pane *wp, enum layout_type type, int change)
 {
-	struct window_pane	*wp;
-	u_int			 i, n, mainwidth, height, yoff;
+	struct layout_cell     *lc, *lcparent;
+	int			needed, size;
 
-	if (active_only)
-		return;
+	lc = wp->layout_cell;
 
-	/* Get number of panes. */
-	n = window_count_panes(w);
-	if (n == 0)
+	/* Find next parent of the same type. */
+	lcparent = lc->parent;
+	while (lcparent != NULL && lcparent->type != type) {
+		lc = lcparent;
+		lcparent = lc->parent;
+	}
+	if (lcparent == NULL)
 		return;
 
-	/* Get the main pane width and add one for separator line. */
-	mainwidth = options_get_number(&w->options, "main-pane-width") + 1;
+	/* If this is the last cell, move back one. */
+	if (lc == TAILQ_LAST(&lcparent->cells, layout_cells))
+		lc = TAILQ_PREV(lc, layout_cells, entry);
+
+	/* Grow or shrink the cell. */
+	needed = change;
+	while (needed != 0) {
+		if (change > 0) {
+			size = layout_resize_pane_grow(lc, type, needed);
+			needed -= size;
+		} else {
+			size = layout_resize_pane_shrink(lc, type, needed);
+			needed += size;
+		}
 
-	/* Need >1 pane and minimum columns; if fewer, display active only. */
-	if (n == 1 ||
-	    w->sx < mainwidth + PANE_MINIMUM || w->sy < PANE_MINIMUM) {
-		layout_active_only_refresh(w, active_only);
-		return;
+		if (size == 0)	/* no more change possible */
+			break;
 	}
-	n--;
+	
+	/* Fix cell offsets. */
+	layout_fix_offsets(wp->window->layout_root);
+	layout_fix_panes(wp->window, wp->window->sx, wp->window->sy);
+}
 
-	/* How many can we fit, not including first? */
-	if (w->sy / n < PANE_MINIMUM) {
-		height = PANE_MINIMUM;
-		n = w->sy / PANE_MINIMUM;
-	} else
-		height = w->sy / n;
+int
+layout_resize_pane_grow(
+    struct layout_cell *lc, enum layout_type type, int needed)
+{
+	struct layout_cell	*lcadd, *lcremove;
+	u_int			 size;
+
+	/* Growing. Always add to the current cell. */
+	lcadd = lc;
+			
+	/* Look towards the tail for a suitable cell for reduction. */
+	lcremove = TAILQ_NEXT(lc, entry);
+	while (lcremove != NULL) {
+		size = layout_resize_check(lcremove, type);
+		if (size > 0)
+			break;
+		lcremove = TAILQ_NEXT(lcremove, entry);	
+	}
 
-	/* Fit the panes. */
-	i = yoff = 0;
-	TAILQ_FOREACH(wp, &w->panes, entry) {
-		if (wp == TAILQ_FIRST(&w->panes)) {
-			wp->xoff = 0;
-			wp->yoff = 0;
-			window_pane_resize(wp, mainwidth - 1, w->sy);
-			continue;
+	/* If none found, look towards the head. */
+	if (lcremove == NULL) {
+		lcremove = TAILQ_PREV(lc, layout_cells, entry);
+		while (lcremove != NULL) {
+			size = layout_resize_check(lcremove, type);
+			if (size > 0)
+				break;
+			lcremove = TAILQ_PREV(lcremove, layout_cells, entry);
 		}
-
-		wp->xoff = mainwidth;
-		wp->yoff = yoff;
-		if (i != n - 1)
- 			window_pane_resize(wp, w->sx - mainwidth, height - 1);
-		else
- 			window_pane_resize(wp, w->sx - mainwidth, height);
-
-		i++;
-		yoff += height;
+		if (lcremove == NULL)
+			return (0);
 	}
 
-	/* Any space left? */
-	while (yoff++ < w->sy) {
-		wp = TAILQ_LAST(&w->panes, window_panes);
-		while (wp != NULL && wp == TAILQ_FIRST(&w->panes))
-			wp = TAILQ_PREV(wp, window_panes, entry);
-		if (wp == NULL)
-			break;
-		window_pane_resize(wp, wp->sx, wp->sy + 1);
-	}
+	/* Change the cells. */
+	if (size > (u_int) needed)
+		size = needed;
+	layout_resize_adjust(lcadd, type, size);
+	layout_resize_adjust(lcremove, type, -size);
+	return (size);
 }
 
-void
-layout_main_h_refresh(struct window *w, int active_only)
+int
+layout_resize_pane_shrink(
+    struct layout_cell *lc, enum layout_type type, int needed)
 {
-	struct window_pane	*wp;
-	u_int			 i, n, mainheight, width, xoff;
-
-	if (active_only)
-		return;
-
-	/* Get number of panes. */
-	n = window_count_panes(w);
-	if (n == 0)
-		return;
+	struct layout_cell	*lcadd, *lcremove;
+	u_int			 size;
+
+	/* Shrinking. Find cell to remove from by walking towards head. */
+	lcremove = lc;
+	do {
+		size = layout_resize_check(lcremove, type);
+		if (size != 0)
+			break;
+		lcremove = TAILQ_PREV(lcremove, layout_cells, entry);
+	} while (lcremove != NULL);
+	if (lcremove == NULL)
+		return (0);
+
+	/* And add onto the next cell (from the original cell). */
+	lcadd = TAILQ_NEXT(lc, entry);
+	if (lcadd == NULL)
+		return (0);
+
+	/* Change the cells. */
+	if (size > (u_int) -needed)
+		size = -needed;
+	layout_resize_adjust(lcadd, type, size);
+	layout_resize_adjust(lcremove, type, -size);
+	return (size);
+}
 
-	/* Get the main pane height and add one for separator line. */
-	mainheight = options_get_number(&w->options, "main-pane-height") + 1;
+/* Split a pane into two. size is a hint, or -1 for default half/half split. */
+int
+layout_split_pane(struct window_pane *wp,
+    enum layout_type type, int size, struct window_pane *new_wp)
+{
+	struct layout_cell     *lc, *lcparent, *lcnew;
+	u_int			sx, sy, xoff, yoff, size1, size2;
+
+	lc = wp->layout_cell;
+
+	/* Copy the old cell size. */
+	sx = lc->sx;
+	sy = lc->sy;
+	xoff = lc->xoff;
+	yoff = lc->yoff;
+
+	/* Check there is enough space for the two new panes. */
+	switch (type) {
+	case LAYOUT_LEFTRIGHT:
+		if (sx < PANE_MINIMUM * 2 + 1)
+			return (-1);
+		break;
+	case LAYOUT_TOPBOTTOM:
+		if (sy < PANE_MINIMUM * 2 + 1)
+			return (-1);
+		break;
+	default:
+		fatalx("bad layout type");
+	}
+	
+	if (lc->parent != NULL && lc->parent->type == type) {
+		/*
+		 * If the parent exists and is of the same type as the split,
+		 * create a new cell and insert it after this one.
+		 */
+
+		/* Create the new child cell. */
+		lcnew = layout_create_cell(lc->parent);
+		TAILQ_INSERT_AFTER(&lc->parent->cells, lc, lcnew, entry);
+	} else {
+		/*
+		 * Otherwise create a new parent and insert it.
+		 */
+		
+		/* Create and insert the replacement parent. */
+		lcparent = layout_create_cell(lc->parent);
+		layout_make_node(lcparent, type);
+		layout_set_size(lcparent, sx, sy, xoff, yoff);
+		if (lc->parent == NULL)
+			wp->window->layout_root = lcparent;
+		else
+			TAILQ_REPLACE(&lc->parent->cells, lc, lcparent, entry);
+		
+		/* Insert the old cell. */
+		lc->parent = lcparent;
+		TAILQ_INSERT_HEAD(&lcparent->cells, lc, entry);
+		
+		/* Create the new child cell. */
+		lcnew = layout_create_cell(lcparent);
+		TAILQ_INSERT_TAIL(&lcparent->cells, lcnew, entry);
+	}
 
-	/* Need >1 pane and minimum rows; if fewer, display active only. */
-	if (n == 1 ||
-	    w->sy < mainheight + PANE_MINIMUM || w->sx < PANE_MINIMUM) {
-		layout_active_only_refresh(w, active_only);
-		return;
+	/* Set new cell sizes.  size is the target size or -1 for middle split,
+	 * size1 is the size of the top/left and size2 the bottom/right.
+	 */
+	switch (type) {
+	case LAYOUT_LEFTRIGHT:
+		if (size < 0)
+			size2 = ((sx + 1) / 2) - 1;
+ 		else
+			size2 = size;
+		if (size2 < PANE_MINIMUM)
+			size2 = PANE_MINIMUM;
+		else if (size2 > sx - 2)
+			size2 = sx - 2;
+		size1 = sx - 1 - size2;
+		layout_set_size(lc, size1, sy, xoff, yoff);
+		layout_set_size(lcnew, size2, sy, xoff + lc->sx + 1, yoff);
+		break;
+	case LAYOUT_TOPBOTTOM:
+		if (size < 0)
+			size2 = ((sy + 1) / 2) - 1;
+		else
+			size2 = size;
+		if (size2 < PANE_MINIMUM)
+			size2 = PANE_MINIMUM;
+		else if (size2 > sy - 2)
+			size2 = sy - 2;
+		size1 = sy - 1 - size2;
+		layout_set_size(lc, sx, size1, xoff, yoff);
+		layout_set_size(lcnew, sx, size2, xoff, yoff + lc->sy + 1);
+		break;
+	default:
+		fatalx("bad layout type");
 	}
-	n--;
 
-	/* How many can we fit, not including first? */
-	if (w->sx / n < PANE_MINIMUM) {
-		width = PANE_MINIMUM;
-		n = w->sx / PANE_MINIMUM;
-	} else
-		width = w->sx / n;
+	/* Assign the panes. */
+	layout_make_leaf(lc, wp);
+	layout_make_leaf(lcnew, new_wp);
 
-	/* Fit the panes. */
-	i = xoff = 0;
-	TAILQ_FOREACH(wp, &w->panes, entry) {
-		if (wp == TAILQ_FIRST(&w->panes)) {
-			wp->xoff = 0;
-			wp->yoff = 0;
-			window_pane_resize(wp, w->sx, mainheight - 1);
-			continue;
-		}
+	/* Fix pane offsets and sizes. */
+	layout_fix_panes(wp->window, wp->window->sx, wp->window->sy);
 
-		wp->xoff = xoff;
-		wp->yoff = mainheight;
-		if (i != n - 1)
- 			window_pane_resize(wp, width - 1, w->sy - mainheight);
-		else
- 			window_pane_resize(wp, width - 1, w->sy - mainheight);
+	return (0);
+}
 
-		i++;
-		xoff += width;
+/* Destroy the layout associated with a pane and redistribute the space. */
+void
+layout_close_pane(struct window_pane *wp)
+{
+	struct layout_cell     *lc, *lcother, *lcparent;
+
+	lc = wp->layout_cell;
+	lcparent = lc->parent;
+
+	/* 
+	 * If no parent, this is the last pane so window close is imminent and
+	 * there is no need to resize anything.
+	 */
+	if (lcparent == NULL) {
+		layout_free_cell(lc);
+		wp->window->layout_root = NULL;
+		return;
 	}
 
-	/* Any space left? */
-	while (xoff++ < w->sx + 1) {
-		wp = TAILQ_LAST(&w->panes, window_panes);
-		while (wp != NULL && wp == TAILQ_FIRST(&w->panes))
-			wp = TAILQ_PREV(wp, window_panes, entry);
-		if (wp == NULL)
-			break;
-		window_pane_resize(wp, wp->sx + 1, wp->sy);
+	/* Merge the space into the previous or next cell. */
+	if (lc == TAILQ_FIRST(&lcparent->cells))
+		lcother = TAILQ_NEXT(lc, entry);
+	else
+		lcother = TAILQ_PREV(lc, layout_cells, entry);
+	if (lcparent->type == LAYOUT_LEFTRIGHT)
+		layout_resize_adjust(lcother, lcparent->type, lc->sx + 1);
+	else
+		layout_resize_adjust(lcother, lcparent->type, lc->sy + 1);
+
+	/* Remove this from the parent's list. */
+	TAILQ_REMOVE(&lcparent->cells, lc, entry);
+	layout_free_cell(lc);
+	
+	/* 
+	 * If the parent now has one cell, remove the parent from the tree and
+	 * replace it by that cell.
+	 */
+	lc = TAILQ_FIRST(&lcparent->cells);
+	if (TAILQ_NEXT(lc, entry) == NULL) {
+		TAILQ_REMOVE(&lcparent->cells, lc, entry);
+
+		lc->parent = lcparent->parent;
+		if (lc->parent == NULL) {
+			lc->xoff = 0; lc->yoff = 0;
+			wp->window->layout_root = lc;
+		} else
+			TAILQ_REPLACE(&lc->parent->cells, lcparent, lc, entry);
+
+		layout_free_cell(lcparent);
 	}
+
+	/* Fix pane offsets and sizes. */
+	layout_fix_offsets(wp->window->layout_root);
+	layout_fix_panes(wp->window, wp->window->sx, wp->window->sy);
 }
+
diff --git a/usr.bin/tmux/resize.c b/usr.bin/tmux/resize.c
index 29d9f883bbb..7f5aaa48aac 100644
--- a/usr.bin/tmux/resize.c
+++ b/usr.bin/tmux/resize.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: resize.c,v 1.2 2009/07/14 07:23:36 nicm Exp $ */
+/* $OpenBSD: resize.c,v 1.3 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -132,6 +132,7 @@ recalculate_sizes(void)
 		log_debug(
 		    "window size %u,%u (was %u,%u)", ssx, ssy, w->sx, w->sy);
 
+		layout_resize(w, ssx, ssy);
 		window_resize(w, ssx, ssy);
 
 		/*
@@ -148,6 +149,5 @@ recalculate_sizes(void)
 		}
 
 		server_redraw_window(w);
-		layout_refresh(w, 0);
 	}
 }
diff --git a/usr.bin/tmux/server.c b/usr.bin/tmux/server.c
index 3e4c2adf8a1..a33a5ff91bc 100644
--- a/usr.bin/tmux/server.c
+++ b/usr.bin/tmux/server.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: server.c,v 1.10 2009/07/18 14:59:25 nicm Exp $ */
+/* $OpenBSD: server.c,v 1.11 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -840,7 +840,9 @@ server_handle_client(struct client *c)
 
 	/* Ensure cursor position and mode settings. */
 	status = options_get_number(&c->session->options, "status");
-	if (wp->yoff + s->cy < c->tty.sy - status)
+	if (!window_pane_visible(wp) || wp->yoff + s->cy >= c->tty.sy - status)
+		tty_cursor(&c->tty, 0, 0, 0, 0);
+	else
 		tty_cursor(&c->tty, s->cx, s->cy, wp->xoff, wp->yoff);
 
 	mode = s->mode;
@@ -1072,9 +1074,9 @@ server_check_window(struct window *w)
 		 * pane dies).
 		 */
 		if (wp->fd == -1 && !flag) {
+			layout_close_pane(wp);
 			window_remove_pane(w, wp);
 			server_redraw_window(w);
-			layout_refresh(w, 0);
 		} else 
 			destroyed = 0;
 		wp = wq;
diff --git a/usr.bin/tmux/tmux.1 b/usr.bin/tmux/tmux.1
index 5bf07fa834a..7948f8eeac4 100644
--- a/usr.bin/tmux/tmux.1
+++ b/usr.bin/tmux/tmux.1
@@ -1,4 +1,4 @@
-.\" $OpenBSD: tmux.1,v 1.37 2009/07/18 14:59:25 nicm Exp $
+.\" $OpenBSD: tmux.1,v 1.38 2009/07/19 13:21:40 nicm Exp $
 .\"
 .\" Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
 .\"
@@ -14,7 +14,7 @@
 .\" IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING
 .\" OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 .\"
-.Dd $Mdocdate: July 18 2009 $
+.Dd $Mdocdate: July 19 2009 $
 .Dt TMUX 1
 .Os
 .Sh NAME
@@ -393,15 +393,17 @@ each pane takes up a certain area of the display and is a separate terminal.
 A window may be split into panes using the
 .Ic split-window
 command.
-.Pp
-Panes are numbered beginning from zero; in horizontal layouts zero is the
-leftmost pane and in vertical the topmost.
-.Pp
-Panes may be arranged using several layouts.
-The layout may be cycled with the
-.Ic next-layout
+Windows may be split horizontally (with the
+.Fl h
+flag) or vertically.
+Panes may be resized with the
+.Ic resize-pane
 command (bound to
-.Ql C-space
+.Ql C-up ,
+.Ql C-down
+.Ql C-left
+and
+.Ql C-right
 by default), the current pane may be changed with the
 .Ic up-pane
 and
@@ -410,12 +412,22 @@ commands and the
 .Ic rotate-window
 and
 .Ic swap-pane
-commands may be used to swap panes without changing the window layout.
+commands may be used to swap panes without changing their position.
+Panes are numbered beginning from zero in the order they are created.
+.Pp
+A number of preset
+.Em layouts
+are available.
+These may be selected with the
+.Ic select-layout
+command or cycled with
+.Ic next-layout
+(bound to
+.Ql C-space
+by default); once a layout is chosen, panes within it may be moved and resized as normal.
 .Pp
 The following layouts are supported:
 .Bl -tag -width Ds
-.It Ic active-only
-Only the active pane is shown \(en all other panes are hidden.
 .It Ic even-horizontal
 Panes are spread out evenly from left to right across the window.
 .It Ic even-vertical
@@ -434,11 +446,6 @@ bottom along the right.
 See the
 .Em main-pane-width
 window option.
-.It Ic manual
-Manual layout splits windows vertically (running across); only with this layout
-may panes be resized using the
-.Ic resize-pane
-command.
 .El
 .Sh STATUS LINE
 .Nm
@@ -980,7 +987,7 @@ Rename the current window, or the window at
 if specified, to
 .Ar new-name .
 .It Xo Ic resize-pane
-.Op Fl DU
+.Op Fl DLUR
 .Op Fl p Ar pane-index
 .Op Fl t Ar target-window
 .Op Ar adjustment
@@ -988,11 +995,15 @@ if specified, to
 .D1 (alias: Ic resizep )
 Resize a pane, upward with
 .Fl U
-(the default) or downward with
-.Fl D .
+(the default), downward with
+.Fl D ,
+to the left with
+.Fl L
+and to the right with
+.Fl R.
 The
 .Ar adjustment
-is given in lines (the default is 1).
+is given in lines or cells (the default is 1).
 .It Xo Ic respawn-window
 .Op Fl k
 .Op Fl t Ar target-window
@@ -1520,38 +1531,30 @@ is used.
 Execute commands from
 .Ar path .
 .It Xo Ic split-window
-.Op Fl d
+.Op Fl dhv
 .Oo Fl l
-.Ar lines |
+.Ar size |
 .Fl p Ar percentage Oc
 .Op Fl t Ar target-window
 .Op Ar command
 .Xc
 .D1 (alias: splitw )
-Creates a new window by splitting it vertically.
+Creates a new pane by splitting the active pane:
+.Fl h
+does a horizontal split and
+.Fl v
+a vertical split; if neither is specified,
+.Fl v
+is assumed.
 The
 .Fl l
 and
 .Fl p
-options specify the size of the new window in lines, or as a percentage,
-respectively.
+options specify the size of the new window in lines (for vertical split) or in
+cells (for horizontal split), or as a percentage, respectively.
 All other options have the same meaning as in the
 .Ic new-window
 command.
-.Pp
-A few notes with regard to panes:
-.Bl -enum -compact
-.It
-If attempting to split a window with less than eight lines, an error will be
-shown.
-.It
-If the window is resized, as many panes are shown as can fit without reducing
-them below four lines.
-.It
-The minimum pane size is four lines (including the separator line).
-.It
-The panes are indexed from top (0) to bottom, with no numbers skipped.
-.El
 .It Xo Ic start-server
 .Xc
 .D1 (alias: Ic start )
diff --git a/usr.bin/tmux/tmux.h b/usr.bin/tmux/tmux.h
index 0cc5ca01fb6..be72774fb6d 100644
--- a/usr.bin/tmux/tmux.h
+++ b/usr.bin/tmux/tmux.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: tmux.h,v 1.38 2009/07/18 14:59:25 nicm Exp $ */
+/* $OpenBSD: tmux.h,v 1.39 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -47,8 +47,11 @@ extern const char    *__progname;
 /* Default prompt history length. */
 #define PROMPT_HISTORY 100
 
-/* Minimum pane size. */
-#define PANE_MINIMUM 5	/* includes separator line */
+/* 
+ * Minimum layout cell size, NOT including separator line. The scroll region
+ * cannot be one line in height so this must be at least two.
+ */
+#define PANE_MINIMUM 2
 
 /* Automatic name refresh interval, in milliseconds. */
 #define NAME_INTERVAL 500
@@ -592,6 +595,7 @@ struct window_mode {
 /* Child window structure. */
 struct window_pane {
 	struct window	*window;
+	struct layout_cell *layout_cell;
 
 	u_int		 sx;
 	u_int		 sy;
@@ -635,7 +639,9 @@ struct window {
 
 	struct window_pane *active;
 	struct window_panes panes;
+
 	u_int		 layout;
+	struct layout_cell *layout_root;
 
 	u_int		 sx;
 	u_int		 sy;
@@ -664,6 +670,34 @@ struct winlink {
 RB_HEAD(winlinks, winlink);
 SLIST_HEAD(winlink_stack, winlink);
 
+/* Layout direction. */
+enum layout_type {
+	LAYOUT_LEFTRIGHT,
+	LAYOUT_TOPBOTTOM,
+	LAYOUT_WINDOWPANE
+};
+
+/* Layout cells queue. */
+TAILQ_HEAD(layout_cells, layout_cell);
+
+/* Layout cell. */
+struct layout_cell {
+	enum layout_type type;
+
+	struct layout_cell *parent;
+
+	u_int		 sx;
+	u_int		 sy;
+
+	u_int		 xoff;
+	u_int		 yoff;
+
+	struct window_pane *wp;
+	struct layout_cells cells;
+
+	TAILQ_ENTRY(layout_cell) entry;
+};
+
 /* Paste buffer. */
 struct paste_buffer {
      	char		*data;
@@ -1446,8 +1480,7 @@ struct window	*window_create(const char *, const char *,
 void		 window_destroy(struct window *);
 int		 window_resize(struct window *, u_int, u_int);
 void		 window_set_active_pane(struct window *, struct window_pane *);
-struct window_pane *window_add_pane(struct window *, int,
-		     const char *, const char *, const char **, u_int, char **);
+struct window_pane *window_add_pane(struct window *, u_int, char **);
 void		 window_remove_pane(struct window *, struct window_pane *);
 struct window_pane *window_pane_at_index(struct window *, u_int);
 u_int		 window_pane_index(struct window *, struct window_pane *);
@@ -1467,20 +1500,38 @@ void		 window_pane_mouse(struct window_pane *,
     		     struct client *, u_char, u_char, u_char);
 int		 window_pane_visible(struct window_pane *);
 char		*window_pane_search(
-		     struct window_pane *, const char *, u_int *);
+    		     struct window_pane *, const char *, u_int *);
 
 /* layout.c */
-const char * 	 layout_name(struct window *);
-int		 layout_lookup(const char *);
-void		 layout_refresh(struct window *, int);
-int		 layout_resize(struct window_pane *, int);
-int		 layout_select(struct window *, u_int);
-void		 layout_next(struct window *);
-void		 layout_previous(struct window *);
-
-/* layout-manual.c */
-void		 layout_manual_v_refresh(struct window *, int);
-void		 layout_manual_v_resize(struct window_pane *, int);
+struct layout_cell *layout_create_cell(struct layout_cell *);
+void		 layout_free_cell(struct layout_cell *);
+void		 layout_print_cell(struct layout_cell *, const char *, u_int);
+void		 layout_set_size(
+		     struct layout_cell *, u_int, u_int, u_int, u_int);
+void		 layout_make_leaf(
+		     struct layout_cell *, struct window_pane *);
+void		 layout_make_node(struct layout_cell *, enum layout_type);
+void		 layout_fix_offsets(struct layout_cell *);
+void		 layout_fix_panes(struct window *, u_int, u_int);
+u_int		 layout_resize_check(struct layout_cell *, enum layout_type);
+void		 layout_resize_adjust(
+		     struct layout_cell *, enum layout_type, int);
+void		 layout_init(struct window *);
+void		 layout_free(struct window *);
+void		 layout_resize(struct window *, u_int, u_int);
+void		 layout_resize_pane(
+    		     struct window_pane *, enum layout_type, int);
+int		 layout_split_pane(struct window_pane *,
+		     enum layout_type, int, struct window_pane *);
+void		 layout_close_pane(struct window_pane *);
+
+/* layout-set.c */
+const char	*layout_set_name(u_int);
+int		 layout_set_lookup(const char *);
+u_int		 layout_set_select(struct window *, u_int);
+u_int		 layout_set_next(struct window *);
+u_int		 layout_set_previous(struct window *);
+void		 layout_set_active_changed(struct window *);
 
 /* window-clock.c */
 extern const struct window_mode window_clock_mode;
diff --git a/usr.bin/tmux/window.c b/usr.bin/tmux/window.c
index f4f60fc6f57..c632b1eeba4 100644
--- a/usr.bin/tmux/window.c
+++ b/usr.bin/tmux/window.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: window.c,v 1.13 2009/07/17 18:45:08 nicm Exp $ */
+/* $OpenBSD: window.c,v 1.14 2009/07/19 13:21:40 nicm Exp $ */
 
 /*
  * Copyright (c) 2007 Nicholas Marriott <nicm@users.sourceforge.net>
@@ -35,7 +35,7 @@
 #include "tmux.h"
 
 /*
- * Each window is attached to one or two panes, each of which is a pty. This
+ * Each window is attached to a number of panes, each of which is a pty. This
  * file contains code to handle them.
  *
  * A pane has two buffers attached, these are filled and emptied by the main
@@ -230,8 +230,10 @@ window_create1(u_int sx, u_int sy)
 
 	TAILQ_INIT(&w->panes);
 	w->active = NULL;
-	w->layout = 0;
 
+	w->layout = 0;
+	w->layout_root = NULL;
+	
 	w->sx = sx;
 	w->sy = sy;
 
@@ -254,15 +256,20 @@ struct window *
 window_create(const char *name, const char *cmd, const char *cwd,
     const char **envp, u_int sx, u_int sy, u_int hlimit, char **cause)
 {
-	struct window	*w;
+	struct window		*w;
+	struct window_pane	*wp;
 
 	w = window_create1(sx, sy);
-	if (window_add_pane(w, -1, cmd, cwd, envp, hlimit, cause) == NULL) {
+	if ((wp = window_add_pane(w, hlimit, cause)) == NULL) {
+		window_destroy(w);
+		return (NULL);
+	}
+	layout_init(w);
+	if (window_pane_spawn(wp, cmd, cwd, envp, cause) != 0) {
 		window_destroy(w);
 		return (NULL);
 	}
 	w->active = TAILQ_FIRST(&w->panes);
-
 	if (name != NULL) {
 		w->name = xstrdup(name);
 		options_set_number(&w->options, "automatic-rename", 0);
@@ -282,6 +289,9 @@ window_destroy(struct window *w)
 	while (!ARRAY_EMPTY(&windows) && ARRAY_LAST(&windows) == NULL)
 		ARRAY_TRUNC(&windows, 1);
 
+	if (w->layout_root != NULL)
+		layout_free(w);
+
 	options_free(&w->options);
 
 	window_destroy_panes(w);
@@ -304,7 +314,6 @@ void
 window_set_active_pane(struct window *w, struct window_pane *wp)
 {
 	w->active = wp;
-
 	while (!window_pane_visible(w->active)) {
 		w->active = TAILQ_PREV(w->active, window_panes, entry);
 		if (w->active == NULL)
@@ -315,41 +324,15 @@ window_set_active_pane(struct window *w, struct window_pane *wp)
 }
 
 struct window_pane *
-window_add_pane(struct window *w, int wanty, const char *cmd,
-    const char *cwd, const char **envp, u_int hlimit, char **cause)
+window_add_pane(struct window *w, u_int hlimit, unused char **cause)
 {
 	struct window_pane	*wp;
-	u_int			 sizey;
 
-	if (TAILQ_EMPTY(&w->panes))
-		wanty = w->sy;
-	else {
-		sizey = w->active->sy - 1; /* for separator */
-		if (sizey < PANE_MINIMUM * 2) {
-			*cause = xstrdup("pane too small");
-			return (NULL);
-		}
-
-  		if (wanty == -1)
-			wanty = sizey / 2;
-
-		if (wanty < PANE_MINIMUM)
-			wanty = PANE_MINIMUM;
-		if ((u_int) wanty > sizey - PANE_MINIMUM)
-			wanty = sizey - PANE_MINIMUM;
-
-		window_pane_resize(w->active, w->sx, sizey - wanty);
-	}
-
-	wp = window_pane_create(w, w->sx, wanty, hlimit);
+	wp = window_pane_create(w, w->sx, w->sy, hlimit);
 	if (TAILQ_EMPTY(&w->panes))
 		TAILQ_INSERT_HEAD(&w->panes, wp, entry);
 	else
 		TAILQ_INSERT_AFTER(&w->panes, w->active, wp, entry);
-	if (window_pane_spawn(wp, cmd, cwd, envp, cause) != 0) {
-		window_remove_pane(w, wp);
-		return (NULL);
-	}
 	return (wp);
 }
 
@@ -435,6 +418,8 @@ window_pane_create(struct window *w, u_int sx, u_int sy, u_int hlimit)
 
 	wp->mode = NULL;
 
+	wp->layout_cell = NULL;
+
 	wp->xoff = 0;
  	wp->yoff = 0;