Rewrite of choose mode, both to simplify and tidy the code and to add

some modern features.

Now the common code is in mode-tree.c, which provides an API used by the
three modes now separated into window-{buffer,client,tree}.c. Buffer
mode shows buffers, client mode clients and tree mode a tree of
sessions, windows and panes.

Each mode has a common set of key bindings plus a few that are specific
to the mode. Other changes are:

- each mode has a preview pane: for buffers this is the buffer content
  (very useful), for others it is a preview of the pane;

- items may be sorted in different ways ('O' key);

- multiple items may be tagged and an operation applied to all of them
  (for example, to delete multiple buffers at once);

- in tree mode a command may be run on the selected item (session,
  window, pane) or on tagged items (key ':');

- displayed items may be filtered in tree mode by using a format (this
  is used to implement find-window) (key 'f');

- the custom format (-F) for the display is no longer available;

- shortcut keys change from 0-9, a-z, A-Z which was always a bit weird
  with keys used for other uses to 0-9, M-a to M-z.

Now that the code is simpler, other improvements will come later.

Primary key bindings for each mode are documented under the commands in
the man page (choose-buffer, choose-client, choose-tree).

Parts written by Thomas Adam.

window-client.c

@@ -0,0 +1,335 @@
+/* $OpenBSD$ */
+
+/*
+ * Copyright (c) 2017 Nicholas Marriott <nicholas.marriott@gmail.com>
+ *
+ * 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 <sys/time.h>
+
+#include <stdlib.h>
+#include <string.h>
+
+#include "tmux.h"
+
+static struct screen	*window_client_init(struct window_pane *,
+			     struct cmd_find_state *, struct args *);
+static void		 window_client_free(struct window_pane *);
+static void		 window_client_resize(struct window_pane *, u_int,
+			     u_int);
+static void		 window_client_key(struct window_pane *,
+			     struct client *, struct session *, key_code,
+			     struct mouse_event *);
+
+#define WINDOW_CLIENT_DEFAULT_COMMAND "detach-client -t '%%'"
+
+const struct window_mode window_client_mode = {
+	.name = "client-mode",
+
+	.init = window_client_init,
+	.free = window_client_free,
+	.resize = window_client_resize,
+	.key = window_client_key,
+};
+
+enum window_client_sort_type {
+	WINDOW_CLIENT_BY_NAME,
+	WINDOW_CLIENT_BY_CREATION_TIME,
+	WINDOW_CLIENT_BY_ACTIVITY_TIME,
+};
+static const char *window_client_sort_list[] = {
+	"name",
+	"creation time",
+	"activity time"
+};
+
+struct window_client_itemdata {
+	struct client	*c;
+};
+
+struct window_client_modedata {
+	struct mode_tree_data		 *data;
+	char				 *command;
+
+	struct window_client_itemdata	**item_list;
+	u_int				  item_size;
+};
+
+static struct window_client_itemdata *
+window_client_add_item(struct window_client_modedata *data)
+{
+	struct window_client_itemdata	*item;
+
+	data->item_list = xreallocarray(data->item_list, data->item_size + 1,
+	    sizeof *data->item_list);
+	item = data->item_list[data->item_size++] = xcalloc(1, sizeof *item);
+	return (item);
+}
+
+static void
+window_client_free_item(struct window_client_itemdata *item)
+{
+	server_client_unref(item->c);
+	free(item);
+}
+
+static int
+window_client_cmp_name(const void *a0, const void *b0)
+{
+	const struct window_client_itemdata *const *a = a0;
+	const struct window_client_itemdata *const *b = b0;
+
+	return (strcmp((*a)->c->name, (*b)->c->name));
+}
+
+static int
+window_client_cmp_creation_time(const void *a0, const void *b0)
+{
+	const struct window_client_itemdata *const *a = a0;
+	const struct window_client_itemdata *const *b = b0;
+
+	if (timercmp(&(*a)->c->creation_time, &(*b)->c->creation_time, >))
+		return (-1);
+	if (timercmp(&(*a)->c->creation_time, &(*b)->c->creation_time, <))
+		return (1);
+	return (0);
+}
+
+static int
+window_client_cmp_activity_time(const void *a0, const void *b0)
+{
+	const struct window_client_itemdata *const *a = a0;
+	const struct window_client_itemdata *const *b = b0;
+
+	if (timercmp(&(*a)->c->activity_time, &(*b)->c->activity_time, >))
+		return (-1);
+	if (timercmp(&(*a)->c->activity_time, &(*b)->c->activity_time, <))
+		return (1);
+	return (0);
+}
+
+static void
+window_client_build(void *modedata, u_int sort_type, __unused uint64_t *tag)
+{
+	struct window_client_modedata	*data = modedata;
+	struct window_client_itemdata	*item;
+	u_int				 i;
+	struct client			*c;
+	char				*tim;
+	char				*text;
+
+	for (i = 0; i < data->item_size; i++)
+		window_client_free_item(data->item_list[i]);
+	free(data->item_list);
+	data->item_list = NULL;
+	data->item_size = 0;
+
+	TAILQ_FOREACH(c, &clients, entry) {
+		if (c->session == NULL || (c->flags & (CLIENT_DETACHING)))
+			continue;
+
+		item = window_client_add_item(data);
+		item->c = c;
+
+		c->references++;
+	}
+
+	switch (sort_type) {
+	case WINDOW_CLIENT_BY_NAME:
+		qsort(data->item_list, data->item_size, sizeof *data->item_list,
+		    window_client_cmp_name);
+		break;
+	case WINDOW_CLIENT_BY_CREATION_TIME:
+		qsort(data->item_list, data->item_size, sizeof *data->item_list,
+		    window_client_cmp_creation_time);
+		break;
+	case WINDOW_CLIENT_BY_ACTIVITY_TIME:
+		qsort(data->item_list, data->item_size, sizeof *data->item_list,
+		    window_client_cmp_activity_time);
+		break;
+	}
+
+	for (i = 0; i < data->item_size; i++) {
+		item = data->item_list[i];
+		c = item->c;
+
+		tim = ctime(&c->activity_time.tv_sec);
+		*strchr(tim, '\n') = '\0';
+
+		xasprintf(&text, "session %s (%s)", c->session->name, tim);
+		mode_tree_add(data->data, NULL, item, (uint64_t)c, c->name,
+		    text, -1);
+		free(text);
+	}
+}
+
+static struct screen *
+window_client_draw(__unused void *modedata, void *itemdata, u_int sx, u_int sy)
+{
+	struct window_client_itemdata	*item = itemdata;
+	struct client			*c = item->c;
+	struct window_pane		*wp;
+	static struct screen		 s;
+	struct screen_write_ctx		 ctx;
+
+	if (c->session == NULL || (c->flags & (CLIENT_DEAD|CLIENT_DETACHING)))
+		return (NULL);
+	wp = c->session->curw->window->active;
+
+	screen_init(&s, sx, sy, 0);
+
+	screen_write_start(&ctx, NULL, &s);
+	screen_write_clearscreen(&ctx, 8);
+
+	screen_write_preview(&ctx, &wp->base, sx, sy - 3);
+
+	screen_write_cursormove(&ctx, 0, sy - 2);
+	screen_write_line(&ctx, sx, 0, 0);
+
+	screen_write_cursormove(&ctx, 0, sy - 1);
+	if (c->old_status != NULL)
+		screen_write_copy(&ctx, c->old_status, 0, 0, sx, 1, NULL, NULL);
+	else
+		screen_write_copy(&ctx, &c->status, 0, 0, sx, 1, NULL, NULL);
+
+	screen_write_stop(&ctx);
+	return (&s);
+}
+
+static struct screen *
+window_client_init(struct window_pane *wp, __unused struct cmd_find_state *fs,
+    struct args *args)
+{
+	struct window_client_modedata	*data;
+	struct screen			*s;
+
+	wp->modedata = data = xcalloc(1, sizeof *data);
+
+	if (args == NULL || args->argc == 0)
+		data->command = xstrdup(WINDOW_CLIENT_DEFAULT_COMMAND);
+	else
+		data->command = xstrdup(args->argv[0]);
+
+	data->data = mode_tree_start(wp, window_client_build,
+	    window_client_draw, data, window_client_sort_list,
+	    nitems(window_client_sort_list), &s);
+
+	mode_tree_build(data->data);
+	mode_tree_draw(data->data);
+
+	return (s);
+}
+
+static void
+window_client_free(struct window_pane *wp)
+{
+	struct window_client_modedata	*data = wp->modedata;
+	u_int				 i;
+
+	if (data == NULL)
+		return;
+
+	mode_tree_free(data->data);
+
+	for (i = 0; i < data->item_size; i++)
+		window_client_free_item(data->item_list[i]);
+	free(data->item_list);
+
+	free(data->command);
+	free(data);
+}
+
+static void
+window_client_resize(struct window_pane *wp, u_int sx, u_int sy)
+{
+	struct window_client_modedata	*data = wp->modedata;
+
+	mode_tree_resize(data->data, sx, sy);
+}
+
+static void
+window_client_do_detach(void* modedata, void *itemdata, key_code key)
+{
+	struct window_client_modedata	*data = modedata;
+	struct window_client_itemdata	*item = itemdata;
+
+	if (item == mode_tree_get_current(data->data))
+		mode_tree_down(data->data, 0);
+	if (key == 'd' || key == 'D')
+		server_client_detach(item->c, MSG_DETACH);
+	else if (key == 'x' || key == 'X')
+		server_client_detach(item->c, MSG_DETACHKILL);
+	else if (key == 'z' || key == 'Z')
+		server_client_suspend(item->c);
+}
+
+static void
+window_client_key(struct window_pane *wp, struct client *c,
+    __unused struct session *s, key_code key, struct mouse_event *m)
+{
+	struct window_client_modedata	*data = wp->modedata;
+	struct window_client_itemdata	*item;
+	char				*command, *name;
+	int				 finished;
+
+	/*
+	 * t = toggle tag
+	 * T = tag none
+	 * C-t = tag all
+	 * q = exit
+	 * O = change sort order
+	 *
+	 * d = detach client
+	 * D = detach tagged clients
+	 * x = detach and kill client
+	 * X = detach and kill tagged clients
+	 * z = suspend client
+	 * Z = suspend tagged clients
+	 * Enter = detach client
+	 */
+
+	finished = mode_tree_key(data->data, &key, m);
+	switch (key) {
+	case 'd':
+	case 'x':
+	case 'z':
+		item = mode_tree_get_current(data->data);
+		window_client_do_detach(data, item, key);
+		mode_tree_build(data->data);
+		break;
+	case 'D':
+	case 'X':
+	case 'Z':
+		mode_tree_each_tagged(data->data, window_client_do_detach, key,
+		    0);
+		mode_tree_build(data->data);
+		break;
+	case '\r':
+		item = mode_tree_get_current(data->data);
+		command = xstrdup(data->command);
+		name = xstrdup(item->c->ttyname);
+		window_pane_reset_mode(wp);
+		mode_tree_run_command(c, NULL, command, name);
+		free(name);
+		free(command);
+		return;
+	}
+	if (finished || server_client_how_many() == 0)
+		window_pane_reset_mode(wp);
+	else {
+		mode_tree_draw(data->data);
+		wp->flags |= PANE_REDRAW;
+	}
+}