Permit panes to be referred to as "top", "bottom", "top-left" etc, if the right

pane can be identified.

Makefile

@@ -32,7 +32,7 @@ SRCS=	attributes.c cfg.c client.c clock.c \
 	cmd-pipe-pane.c cmd-capture-pane.c cmd.c \
 	colour.c environ.c grid-view.c grid-utf8.c grid.c input-keys.c \
 	imsg.c imsg-buffer.c input.c key-bindings.c key-string.c \
-	layout-set.c layout.c log.c job.c \
+	layout-set.c layout-string.c layout.c log.c job.c \
 	mode-key.c names.c options.c paste.c procname.c \
 	resize.c screen-redraw.c screen-write.c screen.c session.c status.c \
 	server-fn.c server.c server-client.c server-window.c \

cmd.c

@@ -858,9 +858,9 @@ cmd_find_pane(struct cmd_ctx *ctx,
 {
 	struct session		*s;
 	struct winlink		*wl;
-	const char	*period;
+	struct layout_cell	*lc;
+	const char		*period, *errstr;
 	char			*winptr, *paneptr;
-	const char	*errstr;
 	u_int			 idx;
 
 	/* Get the current session. */
@@ -895,20 +895,27 @@ cmd_find_pane(struct cmd_ctx *ctx,
 		*wpp = wl->window->active;
 	else {
 		idx = strtonum(paneptr, 0, INT_MAX, &errstr);
-		if (errstr != NULL) {
-			ctx->error(ctx, "pane %s: %s", errstr, paneptr);
-			goto error;
-		}
+		if (errstr != NULL)
+			goto lookup_string;
 		*wpp = window_pane_at_index(wl->window, idx);
-		if (*wpp == NULL) {
-			ctx->error(ctx, "no such pane: %u", idx);
-			goto error;
-		}
+		if (*wpp == NULL)
+			goto lookup_string;
 	}
 
 	xfree(winptr);
 	return (wl);
 
+lookup_string:
+	/* Try pane string description. */
+	if ((lc = layout_find_string(s->curw->window, paneptr)) == NULL) {
+		ctx->error(ctx, "can't find pane: %s", paneptr);
+		goto error;
+	}
+	*wpp = lc->wp;
+
+	xfree(winptr);
+	return (s->curw);
+
 no_period:
 	/* Try as a pane number alone. */
 	idx = strtonum(arg, 0, INT_MAX, &errstr);
@@ -922,6 +929,12 @@ no_period:
 	return (s->curw);
 
 lookup_window:
+	/* Try pane string description. */
+	if ((lc = layout_find_string(s->curw->window, arg)) != NULL) {
+		*wpp = lc->wp;
+		return (s->curw);
+	}
+
 	/* Try as a window and use the active pane. */
 	if ((wl = cmd_find_window(ctx, arg, sp)) != NULL)
 		*wpp = wl->window->active;

layout-string.c

@@ -0,0 +1,167 @@
+/* $Id$ */
+
+/*
+ * 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 <stdlib.h>
+#include <string.h>
+
+#include "tmux.h"
+
+/*
+ * Figure out the pane position based on a description. Fairly simple right
+ * now, just understands a set of strings: left, right, top, bottom, top-left
+ * top-right, bottom-left, bottom-right.
+ */
+
+struct layout_cell *layout_find_top(struct layout_cell *);
+struct layout_cell *layout_find_bottom(struct layout_cell *);
+struct layout_cell *layout_find_left(struct layout_cell *);
+struct layout_cell *layout_find_right(struct layout_cell *);
+struct layout_cell *layout_find_topleft(struct layout_cell *);
+struct layout_cell *layout_find_topright(struct layout_cell *);
+struct layout_cell *layout_find_bottomleft(struct layout_cell *);
+struct layout_cell *layout_find_bottomright(struct layout_cell *);
+
+/* Find the cell; returns NULL if string not understood. */
+struct layout_cell *
+layout_find_string(struct window *w, const char *s)
+{
+	struct layout_cell	*lc = w->layout_root;
+
+	if (strcasecmp(s, "top") == 0)
+		lc = layout_find_top(lc);
+	else if (strcasecmp(s, "bottom") == 0)
+		lc = layout_find_bottom(lc);
+	else if (strcasecmp(s, "left") == 0)
+		lc = layout_find_left(lc);
+	else if (strcasecmp(s, "right") == 0)
+		lc = layout_find_right(lc);
+	else if (strcasecmp(s, "top-left") == 0)
+		lc = layout_find_topleft(lc);
+	else if (strcasecmp(s, "top-right") == 0)
+		lc = layout_find_topright(lc);
+	else if (strcasecmp(s, "bottom-left") == 0)
+		lc = layout_find_bottomleft(lc);
+	else if (strcasecmp(s, "bottom-right") == 0)
+		lc = layout_find_bottomright(lc);
+
+	if (lc == NULL || lc->type != LAYOUT_WINDOWPANE)
+		return (NULL);
+	return (lc);
+}
+
+/*
+ * Find the top cell. Because splits in the same direction are stored as a
+ * list, this is just the first in the list. Return NULL if no topmost cell.
+ * For an unnested cell (not split), the top cell is always itself.
+ */
+struct layout_cell *
+layout_find_top(struct layout_cell *lc)
+{
+	if (lc->type == LAYOUT_WINDOWPANE)
+		return (lc);
+	else if (lc->type == LAYOUT_TOPBOTTOM)
+		return (TAILQ_FIRST(&lc->cells));
+	return (NULL);
+}
+
+/*
+ * Find the bottom cell. Similarly to the top cell, this is just the last in
+ * the list.
+ */
+struct layout_cell *
+layout_find_bottom(struct layout_cell *lc)
+{
+	if (lc->type == LAYOUT_WINDOWPANE)
+		return (lc);
+	else if (lc->type == LAYOUT_TOPBOTTOM)
+		return (TAILQ_LAST(&lc->cells, layout_cells));
+	return (NULL);
+}
+
+/* Find the left cell. */
+struct layout_cell *
+layout_find_left(struct layout_cell *lc)
+{
+	if (lc->type == LAYOUT_WINDOWPANE)
+		return (lc);
+	else if (lc->type == LAYOUT_LEFTRIGHT)
+		return (TAILQ_FIRST(&lc->cells));
+	return (NULL);
+}
+
+/* Find the right cell. */
+struct layout_cell *
+layout_find_right(struct layout_cell *lc)
+{
+	if (lc->type == LAYOUT_WINDOWPANE)
+		return (lc);
+	else if (lc->type == LAYOUT_LEFTRIGHT)
+		return (TAILQ_LAST(&lc->cells, layout_cells));
+	return (NULL);
+}
+
+/*
+ * Find the top-left cell. This means recursing until there are no more moves
+ * to be made.
+ */
+struct layout_cell *
+layout_find_topleft(struct layout_cell *lc)
+{
+	if (lc->type == LAYOUT_WINDOWPANE)
+		return (lc);
+	lc = TAILQ_FIRST(&lc->cells);
+	return (layout_find_topleft(lc));
+}
+
+/* Find the top-right cell. */
+struct layout_cell *
+layout_find_topright(struct layout_cell *lc)
+{
+	if (lc->type == LAYOUT_WINDOWPANE)
+		return (lc);
+	if (lc->type == LAYOUT_LEFTRIGHT)
+		lc = TAILQ_LAST(&lc->cells, layout_cells);
+	else
+		lc = TAILQ_FIRST(&lc->cells);
+	return (layout_find_topright(lc));
+}
+
+/* Find the bottom-left cell. */
+struct layout_cell *
+layout_find_bottomleft(struct layout_cell *lc)
+{
+	if (lc->type == LAYOUT_WINDOWPANE)
+		return (lc);
+	if (lc->type == LAYOUT_LEFTRIGHT)
+		lc = TAILQ_FIRST(&lc->cells);
+	else
+		lc = TAILQ_LAST(&lc->cells, layout_cells);
+	return (layout_find_bottomleft(lc));
+}
+
+/* Find the bottom-right cell. */
+struct layout_cell *
+layout_find_bottomright(struct layout_cell *lc)
+{
+	if (lc->type == LAYOUT_WINDOWPANE)
+		return (lc);
+	lc = TAILQ_LAST(&lc->cells, layout_cells);
+	return (layout_find_bottomright(lc));
+}

tmux.1

@@ -323,6 +323,16 @@ If neither a colon nor period appears,
 first attempts to use the argument as a pane index; if that fails, it is looked
 up as for
 .Ar target-window .
+One of the strings
+.Em top ,
+.Em bottom ,
+.Em left ,
+.Em right ,
+.Em top-left ,
+.Em top-right ,
+.Em bottom-left or
+.Em bottom-right
+may be used instead of a pane index.
 .Pp
 Multiple commands may be specified together as part of a
 .Em command sequence .

tmux.h

@@ -1844,6 +1844,9 @@ u_int		 layout_set_next(struct window *);
 u_int		 layout_set_previous(struct window *);
 void		 layout_set_active_changed(struct window *);
 
+/* layout-string.c */
+struct layout_cell *layout_find_string(struct window *, const char *);
+
 /* window-clock.c */
 extern const struct window_mode window_clock_mode;