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.

tmux.h

@@ -40,12 +40,13 @@ extern char   **environ;
 
 struct args;
 struct client;
+struct cmd_find_state;
 struct cmdq_item;
 struct cmdq_list;
 struct environ;
 struct format_job_tree;
 struct input_ctx;
-struct mode_key_cmdstr;
+struct mode_tree_data;
 struct mouse_event;
 struct options;
 struct options_entry;
@@ -693,7 +694,8 @@ struct screen_write_ctx {
 struct window_mode {
 	const char	*name;
 
-	struct screen	*(*init)(struct window_pane *);
+	struct screen	*(*init)(struct window_pane *, struct cmd_find_state *,
+			     struct args *);
 	void		 (*free)(struct window_pane *);
 	void		 (*resize)(struct window_pane *, u_int, u_int);
 	void		 (*key)(struct window_pane *, struct client *,
@@ -1518,6 +1520,7 @@ char		*paste_make_sample(struct paste_buffer *);
 #define FORMAT_PANE 0x80000000U
 #define FORMAT_WINDOW 0x40000000U
 struct format_tree;
+int		 format_true(const char *);
 struct format_tree *format_create(struct client *, struct cmdq_item *, int,
 		     int);
 void		 format_free(struct format_tree *);
@@ -1717,6 +1720,7 @@ void		tty_keys_free(struct tty *);
 key_code	tty_keys_next(struct tty *);
 
 /* arguments.c */
+void		 args_set(struct args *, u_char, const char *);
 struct args	*args_parse(const char *, int, char **);
 void		 args_free(struct args *);
 char		*args_print(struct args *);
@@ -1997,6 +2001,10 @@ void	 screen_write_putc(struct screen_write_ctx *, const struct grid_cell *,
 	     u_char);
 void	 screen_write_copy(struct screen_write_ctx *, struct screen *, u_int,
 	     u_int, u_int, u_int, bitstr_t *, const struct grid_cell *);
+void	 screen_write_line(struct screen_write_ctx *, u_int, int, int);
+void	 screen_write_box(struct screen_write_ctx *, u_int, u_int);
+void	 screen_write_preview(struct screen_write_ctx *, struct screen *, u_int,
+	     u_int);
 void	 screen_write_backspace(struct screen_write_ctx *);
 void	 screen_write_mode_set(struct screen_write_ctx *, int);
 void	 screen_write_mode_clear(struct screen_write_ctx *, int);
@@ -2119,15 +2127,15 @@ void		 window_pane_unset_palette(struct window_pane *, u_int);
 void		 window_pane_reset_palette(struct window_pane *);
 int		 window_pane_get_palette(const struct window_pane *, int);
 int		 window_pane_set_mode(struct window_pane *,
-		     const struct window_mode *);
+		     const struct window_mode *, struct cmd_find_state *,
+		     struct args *);
 void		 window_pane_reset_mode(struct window_pane *);
 void		 window_pane_key(struct window_pane *, struct client *,
 		     struct session *, key_code, struct mouse_event *);
 int		 window_pane_outside(struct window_pane *);
 int		 window_pane_visible(struct window_pane *);
 u_int		 window_pane_search(struct window_pane *, const char *);
-char		*window_pane_search_old(struct window_pane *, const char *,
-		     u_int *);
+
 const char	*window_printable_flags(struct winlink *);
 struct window_pane *window_pane_find_up(struct window_pane *);
 struct window_pane *window_pane_find_down(struct window_pane *);
@@ -2176,10 +2184,43 @@ u_int		 layout_set_select(struct window *, u_int);
 u_int		 layout_set_next(struct window *);
 u_int		 layout_set_previous(struct window *);
 
+/* mode-tree.c */
+u_int	 mode_tree_count_tagged(struct mode_tree_data *);
+void	*mode_tree_get_current(struct mode_tree_data *);
+void	 mode_tree_each_tagged(struct mode_tree_data *, void (*)(void *, void *,
+	     key_code), key_code, int);
+void	 mode_tree_up(struct mode_tree_data *, int);
+void	 mode_tree_down(struct mode_tree_data *, int);
+struct mode_tree_data *mode_tree_start(struct window_pane *,
+	     void (*)(void *, u_int, uint64_t *), struct screen *(*)(void *,
+	     void *, u_int, u_int), void *, const char **, u_int,
+	     struct screen **);
+void	 mode_tree_build(struct mode_tree_data *);
+void	 mode_tree_free(struct mode_tree_data *);
+void	 mode_tree_resize(struct mode_tree_data *, u_int, u_int);
+struct mode_tree_item *mode_tree_add(struct mode_tree_data *,
+	     struct mode_tree_item *, void *, uint64_t, const char *,
+	     const char *, int);
+void	 mode_tree_remove(struct mode_tree_data *, struct mode_tree_item *);
+void	 mode_tree_draw(struct mode_tree_data *);
+int	 mode_tree_key(struct mode_tree_data *, key_code *,
+	     struct mouse_event *);
+void	 mode_tree_run_command(struct client *, struct cmd_find_state *,
+	     const char *, const char *);
+
+/* window-buffer.c */
+extern const struct window_mode window_buffer_mode;
+
+/* window-tree.c */
+extern const struct window_mode window_tree_mode;
+
 /* window-clock.c */
 extern const struct window_mode window_clock_mode;
 extern const char window_clock_table[14][5][5];
 
+/* window-client.c */
+extern const struct window_mode window_client_mode;
+
 /* window-copy.c */
 extern const struct window_mode window_copy_mode;
 void		 window_copy_init_from_pane(struct window_pane *, int);
@@ -2190,24 +2231,6 @@ void		 window_copy_pageup(struct window_pane *, int);
 void		 window_copy_start_drag(struct client *, struct mouse_event *);
 int		 window_copy_scroll_position(struct window_pane *);
 
-/* window-choose.c */
-extern const struct window_mode window_choose_mode;
-void		 window_choose_add(struct window_pane *,
-			 struct window_choose_data *);
-void		 window_choose_ready(struct window_pane *,
-		     u_int, void (*)(struct window_choose_data *));
-struct window_choose_data	*window_choose_data_create (int,
-		     struct client *, struct session *);
-void	window_choose_data_run(struct window_choose_data *);
-struct window_choose_data	*window_choose_add_window(struct window_pane *,
-			struct client *, struct session *, struct winlink *,
-			const char *, const char *, u_int);
-struct window_choose_data	*window_choose_add_session(struct window_pane *,
-			struct client *, struct session *, const char *,
-			const char *, u_int);
-void	window_choose_expand_all(struct window_pane *);
-void	window_choose_set_current(struct window_pane *, u_int);
-
 /* names.c */
 void	 check_window_name(struct window *);
 char	*default_window_name(struct window *);