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.

mode-tree.c

@@ -0,0 +1,705 @@
+/* $OpenBSD$ */
+
+/*
+ * 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 <ctype.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "tmux.h"
+
+struct mode_tree_item;
+TAILQ_HEAD(mode_tree_list, mode_tree_item);
+
+struct mode_tree_data {
+	struct window_pane	 *wp;
+	void			 *modedata;
+
+	const char		**sort_list;
+	u_int			  sort_size;
+	u_int			  sort_type;
+
+	void			 (*buildcb)(void *, u_int, uint64_t *);
+	struct screen		*(*drawcb)(void *, void *, u_int, u_int);
+
+	struct mode_tree_list	  children;
+	struct mode_tree_list	  saved;
+
+	struct mode_tree_line	 *line_list;
+	u_int			  line_size;
+
+	u_int			  depth;
+
+	u_int			  width;
+	u_int			  height;
+
+	u_int			  offset;
+	u_int			  current;
+
+	struct screen		  screen;
+};
+
+struct mode_tree_item {
+	struct mode_tree_item		*parent;
+	void				*itemdata;
+	u_int				 line;
+
+	uint64_t			 tag;
+	const char			*name;
+	const char			*text;
+
+	int				 expanded;
+	int				 tagged;
+
+	struct mode_tree_list		 children;
+	TAILQ_ENTRY(mode_tree_item)	 entry;
+};
+
+struct mode_tree_line {
+	struct mode_tree_item		*item;
+	u_int				 depth;
+	int				 last;
+	int				 flat;
+};
+
+static void mode_tree_free_items(struct mode_tree_list *);
+
+static struct mode_tree_item *
+mode_tree_find_item(struct mode_tree_list *mtl, uint64_t tag)
+{
+	struct mode_tree_item	*mti, *child;
+
+	TAILQ_FOREACH(mti, mtl, entry) {
+		if (mti->tag == tag)
+			return (mti);
+		child = mode_tree_find_item(&mti->children, tag);
+		if (child != NULL)
+			return (child);
+	}
+	return (NULL);
+}
+
+static void
+mode_tree_free_item(struct mode_tree_item *mti)
+{
+	mode_tree_free_items(&mti->children);
+
+	free((void *)mti->name);
+	free((void *)mti->text);
+
+	free(mti);
+}
+
+static void
+mode_tree_free_items(struct mode_tree_list *mtl)
+{
+	struct mode_tree_item	*mti, *mti1;
+
+	TAILQ_FOREACH_SAFE(mti, mtl, entry, mti1) {
+		TAILQ_REMOVE(mtl, mti, entry);
+		mode_tree_free_item(mti);
+	}
+}
+
+static void
+mode_tree_clear_lines(struct mode_tree_data *mtd)
+{
+	free(mtd->line_list);
+	mtd->line_list = NULL;
+	mtd->line_size = 0;
+}
+
+static void
+mode_tree_build_lines(struct mode_tree_data *mtd,
+    struct mode_tree_list *mtl, u_int depth)
+{
+	struct mode_tree_item	*mti;
+	struct mode_tree_line	*line;
+	u_int			 i;
+	int			 flat = 1;
+
+	mtd->depth = depth;
+	TAILQ_FOREACH(mti, mtl, entry) {
+		mtd->line_list = xreallocarray(mtd->line_list,
+		    mtd->line_size + 1, sizeof *mtd->line_list);
+
+		line = &mtd->line_list[mtd->line_size++];
+		line->item = mti;
+		line->depth = depth;
+		line->last = (mti == TAILQ_LAST(mtl, mode_tree_list));
+
+		mti->line = (mtd->line_size - 1);
+		if (!TAILQ_EMPTY(&mti->children))
+			flat = 0;
+		if (mti->expanded)
+			mode_tree_build_lines(mtd, &mti->children, depth + 1);
+	}
+	TAILQ_FOREACH(mti, mtl, entry) {
+		for (i = 0; i < mtd->line_size; i++) {
+			line = &mtd->line_list[i];
+			if (line->item == mti)
+				line->flat = flat;
+		}
+	}
+}
+
+static void
+mode_tree_clear_tagged(struct mode_tree_list *mtl)
+{
+	struct mode_tree_item	*mti;
+
+	TAILQ_FOREACH(mti, mtl, entry) {
+		mti->tagged = 0;
+		mode_tree_clear_tagged(&mti->children);
+	}
+}
+
+void
+mode_tree_up(struct mode_tree_data *mtd, int wrap)
+{
+	if (mtd->current == 0) {
+		if (wrap) {
+			mtd->current = mtd->line_size - 1;
+			if (mtd->line_size >= mtd->height)
+				mtd->offset = mtd->line_size - mtd->height;
+		}
+	} else {
+		mtd->current--;
+		if (mtd->current < mtd->offset)
+			mtd->offset--;
+	}
+}
+
+void
+mode_tree_down(struct mode_tree_data *mtd, int wrap)
+{
+	if (mtd->current == mtd->line_size - 1) {
+		if (wrap) {
+			mtd->current = 0;
+			mtd->offset = 0;
+		}
+	} else {
+		mtd->current++;
+		if (mtd->current > mtd->offset + mtd->height - 1)
+			mtd->offset++;
+	}
+}
+
+void *
+mode_tree_get_current(struct mode_tree_data *mtd)
+{
+	return (mtd->line_list[mtd->current].item->itemdata);
+}
+
+u_int
+mode_tree_count_tagged(struct mode_tree_data *mtd)
+{
+	struct mode_tree_item	*mti;
+	u_int			 i, tagged;
+
+	tagged = 0;
+	for (i = 0; i < mtd->line_size; i++) {
+		mti = mtd->line_list[i].item;
+		if (mti->tagged)
+			tagged++;
+	}
+	return (tagged);
+}
+
+void
+mode_tree_each_tagged(struct mode_tree_data *mtd, void (*cb)(void *, void *,
+    key_code), key_code key, int current)
+{
+	struct mode_tree_item	*mti;
+	u_int			 i;
+	int			 fired;
+
+	fired = 0;
+	for (i = 0; i < mtd->line_size; i++) {
+		mti = mtd->line_list[i].item;
+		if (mti->tagged) {
+			fired = 1;
+			cb(mtd->modedata, mti->itemdata, key);
+		}
+	}
+	if (!fired && current) {
+		mti = mtd->line_list[mtd->current].item;
+		cb(mtd->modedata, mti->itemdata, key);
+	}
+}
+
+struct mode_tree_data *
+mode_tree_start(struct window_pane *wp, void (*buildcb)(void *, u_int,
+    uint64_t *), struct screen *(*drawcb)(void *, void *, u_int, u_int),
+    void *modedata, const char **sort_list, u_int sort_size, struct screen **s)
+{
+	struct mode_tree_data	*mtd;
+
+	mtd = xcalloc(1, sizeof *mtd);
+	mtd->wp = wp;
+	mtd->modedata = modedata;
+
+	mtd->sort_list = sort_list;
+	mtd->sort_size = sort_size;
+	mtd->sort_type = 0;
+
+	mtd->buildcb = buildcb;
+	mtd->drawcb = drawcb;
+
+	TAILQ_INIT(&mtd->children);
+
+	*s = &mtd->screen;
+	screen_init(*s, screen_size_x(&wp->base), screen_size_y(&wp->base), 0);
+	(*s)->mode &= ~MODE_CURSOR;
+
+	return (mtd);
+}
+
+void
+mode_tree_build(struct mode_tree_data *mtd)
+{
+	struct screen	*s = &mtd->screen;
+	uint64_t	 tag;
+	u_int		 i;
+
+	if (mtd->line_list != NULL)
+		tag = mtd->line_list[mtd->current].item->tag;
+	else
+		tag = 0;
+
+	TAILQ_CONCAT(&mtd->saved, &mtd->children, entry);
+	TAILQ_INIT(&mtd->children);
+
+	mtd->buildcb(mtd->modedata, mtd->sort_type, &tag);
+
+	mode_tree_free_items(&mtd->saved);
+	TAILQ_INIT(&mtd->saved);
+
+	mode_tree_clear_lines(mtd);
+	mode_tree_build_lines(mtd, &mtd->children, 0);
+
+	for (i = 0; i < mtd->line_size; i++) {
+		if (mtd->line_list[i].item->tag == tag)
+			break;
+	}
+	if (i != mtd->line_size)
+		mtd->current = i;
+	else {
+		mtd->current = 0;
+		mtd->offset = 0;
+	}
+
+	mtd->width = screen_size_x(s);
+	mtd->height = (screen_size_y(s) / 3) * 2;
+	if (mtd->height > mtd->line_size)
+		mtd->height = screen_size_y(s) / 2;
+	if (mtd->height < 10)
+		mtd->height = screen_size_y(s);
+	if (screen_size_y(s) - mtd->height < 2)
+		mtd->height = screen_size_y(s);
+}
+
+void
+mode_tree_free(struct mode_tree_data *mtd)
+{
+	mode_tree_free_items(&mtd->children);
+	mode_tree_clear_lines(mtd);
+	screen_free(&mtd->screen);
+	free(mtd);
+}
+
+void
+mode_tree_resize(struct mode_tree_data *mtd, u_int sx, u_int sy)
+{
+	struct screen	*s = &mtd->screen;
+
+	screen_resize(s, sx, sy, 0);
+
+	mode_tree_build(mtd);
+	mode_tree_draw(mtd);
+
+	mtd->wp->flags |= PANE_REDRAW;
+}
+
+struct mode_tree_item *
+mode_tree_add(struct mode_tree_data *mtd, struct mode_tree_item *parent,
+    void *itemdata, uint64_t tag, const char *name, const char *text,
+    int expanded)
+{
+	struct mode_tree_item	*mti, *saved;
+
+	log_debug("%s: %llu, %s %s", __func__, (unsigned long long)tag,
+	    name, text);
+
+	mti = xcalloc(1, sizeof *mti);
+	mti->parent = parent;
+	mti->itemdata = itemdata;
+
+	mti->tag = tag;
+	mti->name = xstrdup(name);
+	mti->text = xstrdup(text);
+
+	saved = mode_tree_find_item(&mtd->saved, tag);
+	if (saved != NULL) {
+		if (parent == NULL || (parent != NULL && parent->expanded))
+			mti->tagged = saved->tagged;
+		mti->expanded = saved->expanded;
+	} else if (expanded == -1)
+		mti->expanded = 1;
+	else
+		mti->expanded = expanded;
+
+	TAILQ_INIT(&mti->children);
+
+	if (parent != NULL)
+		TAILQ_INSERT_TAIL(&parent->children, mti, entry);
+	else
+		TAILQ_INSERT_TAIL(&mtd->children, mti, entry);
+
+	return (mti);
+}
+
+void
+mode_tree_remove(struct mode_tree_data *mtd, struct mode_tree_item *mti)
+{
+	struct mode_tree_item	*parent = mti->parent;
+
+	if (parent != NULL)
+		TAILQ_REMOVE(&parent->children, mti, entry);
+	else
+		TAILQ_REMOVE(&mtd->children, mti, entry);
+	mode_tree_free_item(mti);
+}
+
+void
+mode_tree_draw(struct mode_tree_data *mtd)
+{
+	struct window_pane	*wp = mtd->wp;
+	struct screen		*s = &mtd->screen, *box;
+	struct mode_tree_line	*line;
+	struct mode_tree_item	*mti;
+	struct options		*oo = wp->window->options;
+	struct screen_write_ctx	 ctx;
+	struct grid_cell	 gc0, gc;
+	u_int			 w, h, i, j, sy, box_x, box_y;
+	char			*text, *start, key[7];
+	const char		*tag, *symbol;
+	size_t			 size;
+	int			 keylen;
+
+	if (mtd->line_size == 0)
+		return;
+
+	memcpy(&gc0, &grid_default_cell, sizeof gc0);
+	memcpy(&gc, &grid_default_cell, sizeof gc);
+	style_apply(&gc, oo, "mode-style");
+
+	w = mtd->width;
+	h = mtd->height;
+
+	screen_write_start(&ctx, NULL, s);
+	screen_write_clearscreen(&ctx, 8);
+
+	if (mtd->line_size > 10)
+		keylen = 6;
+	else
+		keylen = 4;
+
+	for (i = 0; i < mtd->line_size; i++) {
+		if (i < mtd->offset)
+			continue;
+		if (i > mtd->offset + h - 1)
+			break;
+
+		line = &mtd->line_list[i];
+		mti = line->item;
+
+		screen_write_cursormove(&ctx, 0, i - mtd->offset);
+
+		if (i < 10)
+			snprintf(key, sizeof key, "(%c)", '0' + i);
+		else if (i < 36)
+			snprintf(key, sizeof key, "(M-%c)", 'a' + (i - 10));
+		else
+			*key = '\0';
+
+		if (line->flat)
+			symbol = "";
+		else if (TAILQ_EMPTY(&mti->children))
+			symbol = "  ";
+		else if (mti->expanded)
+			symbol = "- ";
+		else
+			symbol = "+ ";
+
+		if (line->depth == 0)
+			start = xstrdup(symbol);
+		else {
+			size = (4 * line->depth) + 32;
+
+			start = xcalloc(1, size);
+			for (j = 1; j < line->depth; j++) {
+				if (mti->parent != NULL &&
+				    mtd->line_list[mti->parent->line].last)
+					strlcat(start, "    ", size);
+				else
+					strlcat(start, "\001x\001   ", size);
+			}
+			if (line->last)
+				strlcat(start, "\001mq\001> ", size);
+			else
+				strlcat(start, "\001tq\001> ", size);
+			strlcat(start, symbol, size);
+		}
+
+		if (mti->tagged)
+			tag = "*";
+		else
+			tag = "";
+		xasprintf(&text, "%-*s%s%s%s: %s", keylen, key, start,
+		    mti->name, tag, mti->text);
+		free(start);
+
+		if (mti->tagged) {
+			gc.attr ^= GRID_ATTR_BRIGHT;
+			gc0.attr ^= GRID_ATTR_BRIGHT;
+		}
+
+		if (i != mtd->current) {
+			screen_write_puts(&ctx, &gc0, "%.*s", w, text);
+			screen_write_clearendofline(&ctx, 8);
+		} else
+			screen_write_puts(&ctx, &gc, "%-*.*s", w, w, text);
+		free(text);
+
+		if (mti->tagged) {
+			gc.attr ^= GRID_ATTR_BRIGHT;
+			gc0.attr ^= GRID_ATTR_BRIGHT;
+		}
+	}
+
+	sy = screen_size_y(s);
+	if (sy <= 4 || h <= 4 || sy - h <= 4 || w <= 4) {
+		screen_write_stop(&ctx);
+		return;
+	}
+
+	line = &mtd->line_list[mtd->current];
+	mti = line->item;
+
+	screen_write_cursormove(&ctx, 0, h);
+	screen_write_box(&ctx, w, sy - h);
+
+	xasprintf(&text, " %s (sort: %s) ", mti->name,
+	    mtd->sort_list[mtd->sort_type]);
+	if (w - 2 >= strlen(text)) {
+		screen_write_cursormove(&ctx, 1, h);
+		screen_write_puts(&ctx, &gc0, "%s", text);
+	}
+	free(text);
+
+	box_x = w - 4;
+	box_y = sy - h - 2;
+
+	box = mtd->drawcb(mtd->modedata, mti->itemdata, box_x, box_y);
+	if (box != NULL) {
+		screen_write_cursormove(&ctx, 2, h + 1);
+		screen_write_copy(&ctx, box, 0, 0, box_x, box_y, NULL, NULL);
+
+		screen_free(box);
+	}
+
+	screen_write_stop(&ctx);
+}
+
+int
+mode_tree_key(struct mode_tree_data *mtd, key_code *key, struct mouse_event *m)
+{
+	struct mode_tree_line	*line;
+	struct mode_tree_item	*current, *parent;
+	u_int			 i, x, y;
+	int			 choice;
+	key_code		 tmp;
+
+	if (*key == KEYC_MOUSEDOWN1_PANE) {
+		if (cmd_mouse_at(mtd->wp, m, &x, &y, 0) != 0) {
+			*key = KEYC_NONE;
+			return (0);
+		}
+		if (x > mtd->width || y > mtd->height) {
+			*key = KEYC_NONE;
+			return (0);
+		}
+		if (mtd->offset + y < mtd->line_size) {
+			mtd->current = mtd->offset + y;
+			*key = '\r';
+			return (0);
+		}
+	}
+
+	line = &mtd->line_list[mtd->current];
+	current = line->item;
+
+	choice = -1;
+	if (*key >= '0' && *key <= '9')
+		choice = (*key) - '0';
+	else if (((*key) & KEYC_MASK_MOD) == KEYC_ESCAPE) {
+		tmp = (*key) & KEYC_MASK_KEY;
+		if (tmp >= 'a' && tmp <= 'z')
+			choice = 10 + (tmp - 'a');
+	}
+	if (choice != -1) {
+		if ((u_int)choice > mtd->line_size - 1) {
+			*key = KEYC_NONE;
+			return (0);
+		}
+		mtd->current = choice;
+		*key = '\r';
+		return (0);
+	}
+
+	switch (*key) {
+	case 'q':
+	case '\033': /* Escape */
+		return (1);
+	case KEYC_UP:
+	case 'k':
+	case KEYC_WHEELUP_PANE:
+		mode_tree_up(mtd, 1);
+		break;
+	case KEYC_DOWN:
+	case 'j':
+	case KEYC_WHEELDOWN_PANE:
+		mode_tree_down(mtd, 1);
+		break;
+	case KEYC_PPAGE:
+	case '\002': /* C-b */
+		for (i = 0; i < mtd->height; i++) {
+			if (mtd->current == 0)
+				break;
+			mode_tree_up(mtd, 1);
+		}
+		break;
+	case KEYC_NPAGE:
+	case '\006': /* C-f */
+		for (i = 0; i < mtd->height; i++) {
+			if (mtd->current == mtd->line_size - 1)
+				break;
+			mode_tree_down(mtd, 1);
+		}
+		break;
+	case KEYC_HOME:
+		mtd->current = 0;
+		mtd->offset = 0;
+		break;
+	case KEYC_END:
+		mtd->current = mtd->line_size - 1;
+		if (mtd->current > mtd->height - 1)
+			mtd->offset = mtd->current - mtd->height;
+		else
+			mtd->offset = 0;
+		break;
+	case 't':
+		/*
+		 * Do not allow parents and children to both be tagged: untag
+		 * all parents and children of current.
+		 */
+		if (!current->tagged) {
+			parent = current->parent;
+			while (parent != NULL) {
+				parent->tagged = 0;
+				parent = parent->parent;
+			}
+			mode_tree_clear_tagged(&current->children);
+			current->tagged = 1;
+		} else
+			current->tagged = 0;
+		mode_tree_down(mtd, 0);
+		break;
+	case 'T':
+		for (i = 0; i < mtd->line_size; i++)
+			mtd->line_list[i].item->tagged = 0;
+		break;
+	case '\024': /* C-t */
+		for (i = 0; i < mtd->line_size; i++) {
+			if (mtd->line_list[i].item->parent == NULL)
+				mtd->line_list[i].item->tagged = 1;
+			else
+				mtd->line_list[i].item->tagged = 0;
+		}
+		break;
+	case 'O':
+		mtd->sort_type++;
+		if (mtd->sort_type == mtd->sort_size)
+			mtd->sort_type = 0;
+		mode_tree_build(mtd);
+		break;
+	case KEYC_LEFT:
+	case '-':
+		if (line->flat || !current->expanded)
+			current = current->parent;
+		if (current == NULL)
+			mode_tree_up(mtd, 0);
+		else {
+			current->expanded = 0;
+			mtd->current = current->line;
+			mode_tree_build(mtd);
+		}
+		break;
+	case KEYC_RIGHT:
+	case '+':
+		if (line->flat || current->expanded)
+			mode_tree_down(mtd, 0);
+		else if (!line->flat) {
+			current->expanded = 1;
+			mode_tree_build(mtd);
+		}
+		break;
+	}
+	return (0);
+}
+
+void
+mode_tree_run_command(struct client *c, struct cmd_find_state *fs,
+    const char *template, const char *name)
+{
+	struct cmdq_item	*new_item;
+	struct cmd_list		*cmdlist;
+	char			*command, *cause;
+
+	command = cmd_template_replace(template, name, 1);
+	if (command == NULL || *command == '\0')
+		return;
+
+	cmdlist = cmd_string_parse(command, NULL, 0, &cause);
+	if (cmdlist == NULL) {
+		if (cause != NULL && c != NULL) {
+			*cause = toupper((u_char)*cause);
+			status_message_set(c, "%s", cause);
+		}
+		free(cause);
+	} else {
+		new_item = cmdq_get_command(cmdlist, fs, NULL, 0);
+		cmdq_append(c, new_item);
+		cmd_list_free(cmdlist);
+	}
+
+	free(command);
+}