kconfig: menuconfig: simplify global jump key assignment

Commit 95ac9b3b58 ("menuconfig: Assign jump keys per-page instead
of globally") injected a lot of hacks to the bottom of the textbox
infrastructure.

I reverted many of them without changing the behavior. (almost)
Now, the key markers are inserted when constructing the search result
instead of updating the text buffer on-the-fly.

The buffer passed to the textbox got back to a constant string.
The ugly casts from (const char *) to (char *) went away.

A disadvantage is that the same key numbers might be displayed multiple
times in the dialog if you use a huge window (but I believe it is
unlikely to happen).

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Jesse Taube <Mr.Bossman075@gmail.com>

scripts/kconfig/lkc.h

@@ -101,6 +101,7 @@ const char *menu_get_prompt(struct menu *menu);
 struct menu *menu_get_parent_menu(struct menu *menu);
 bool menu_has_help(struct menu *menu);
 const char *menu_get_help(struct menu *menu);
+int get_jump_key_char(void);
 struct gstr get_relations_str(struct symbol **sym_arr, struct list_head *head);
 void menu_get_ext_help(struct menu *menu, struct gstr *help);
 

scripts/kconfig/lxdialog/dialog.h

@@ -196,13 +196,9 @@ int first_alpha(const char *string, const char *exempt);
 int dialog_yesno(const char *title, const char *prompt, int height, int width);
 int dialog_msgbox(const char *title, const char *prompt, int height,
 		  int width, int pause);
-
-
-typedef void (*update_text_fn)(char *buf, size_t start, size_t end, void
-			       *_data);
-int dialog_textbox(const char *title, char *tbuf, int initial_height,
-		   int initial_width, int *keys, int *_vscroll, int *_hscroll,
-		   update_text_fn update_text, void *data);
+int dialog_textbox(const char *title, const char *tbuf, int initial_height,
+		   int initial_width, int *_vscroll, int *_hscroll,
+		   int (*extra_key_cb)(int, size_t, size_t, void *), void *data);
 int dialog_menu(const char *title, const char *prompt,
 		const void *selected, int *s_scroll);
 int dialog_checklist(const char *title, const char *prompt, int height,

scripts/kconfig/lxdialog/textbox.c

@@ -10,8 +10,8 @@
 
 static int hscroll;
 static int begin_reached, end_reached, page_length;
-static char *buf;
-static char *page;
+static const char *buf, *page;
+static size_t start, end;
 
 /*
  * Go back 'n' lines in text. Called by dialog_textbox().
@@ -98,21 +98,10 @@ static void print_line(WINDOW *win, int row, int width)
 /*
  * Print a new page of text.
  */
-static void print_page(WINDOW *win, int height, int width, update_text_fn
-		       update_text, void *data)
+static void print_page(WINDOW *win, int height, int width)
 {
 	int i, passed_end = 0;
 
-	if (update_text) {
-		char *end;
-
-		for (i = 0; i < height; i++)
-			get_line();
-		end = page;
-		back_lines(height);
-		update_text(buf, page - buf, end - buf, data);
-	}
-
 	page_length = 0;
 	for (i = 0; i < height; i++) {
 		print_line(win, i, width);
@@ -142,24 +131,26 @@ static void print_position(WINDOW *win)
  * refresh window content
  */
 static void refresh_text_box(WINDOW *dialog, WINDOW *box, int boxh, int boxw,
-			     int cur_y, int cur_x, update_text_fn update_text,
-			     void *data)
+			     int cur_y, int cur_x)
 {
-	print_page(box, boxh, boxw, update_text, data);
+	start = page - buf;
+
+	print_page(box, boxh, boxw);
 	print_position(dialog);
 	wmove(dialog, cur_y, cur_x);	/* Restore cursor position */
 	wrefresh(dialog);
+
+	end = page - buf;
 }
 
 /*
  * Display text from a file in a dialog box.
  *
  * keys is a null-terminated array
- * update_text() may not add or remove any '\n' or '\0' in tbuf
  */
-int dialog_textbox(const char *title, char *tbuf, int initial_height,
-		   int initial_width, int *keys, int *_vscroll, int *_hscroll,
-		   update_text_fn update_text, void *data)
+int dialog_textbox(const char *title, const char *tbuf, int initial_height,
+		   int initial_width, int *_vscroll, int *_hscroll,
+		   int (*extra_key_cb)(int, size_t, size_t, void *), void *data)
 {
 	int i, x, y, cur_x, cur_y, key = 0;
 	int height, width, boxh, boxw;
@@ -239,8 +230,7 @@ int dialog_textbox(const char *title, char *tbuf, int initial_height,
 
 	/* Print first page of text */
 	attr_clear(box, boxh, boxw, dlg.dialog.atr);
-	refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x, update_text,
-			 data);
+	refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);
 
 	while (!done) {
 		key = wgetch(dialog);
@@ -259,8 +249,7 @@ int dialog_textbox(const char *title, char *tbuf, int initial_height,
 				begin_reached = 1;
 				page = buf;
 				refresh_text_box(dialog, box, boxh, boxw,
-						 cur_y, cur_x, update_text,
-						 data);
+						 cur_y, cur_x);
 			}
 			break;
 		case 'G':	/* Last page */
@@ -270,8 +259,7 @@ int dialog_textbox(const char *title, char *tbuf, int initial_height,
 			/* point to last char in buf */
 			page = buf + strlen(buf);
 			back_lines(boxh);
-			refresh_text_box(dialog, box, boxh, boxw, cur_y,
-					 cur_x, update_text, data);
+			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);
 			break;
 		case 'K':	/* Previous line */
 		case 'k':
@@ -280,8 +268,7 @@ int dialog_textbox(const char *title, char *tbuf, int initial_height,
 				break;
 
 			back_lines(page_length + 1);
-			refresh_text_box(dialog, box, boxh, boxw, cur_y,
-					 cur_x, update_text, data);
+			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);
 			break;
 		case 'B':	/* Previous page */
 		case 'b':
@@ -290,8 +277,7 @@ int dialog_textbox(const char *title, char *tbuf, int initial_height,
 			if (begin_reached)
 				break;
 			back_lines(page_length + boxh);
-			refresh_text_box(dialog, box, boxh, boxw, cur_y,
-					 cur_x, update_text, data);
+			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);
 			break;
 		case 'J':	/* Next line */
 		case 'j':
@@ -300,8 +286,7 @@ int dialog_textbox(const char *title, char *tbuf, int initial_height,
 				break;
 
 			back_lines(page_length - 1);
-			refresh_text_box(dialog, box, boxh, boxw, cur_y,
-					 cur_x, update_text, data);
+			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);
 			break;
 		case KEY_NPAGE:	/* Next page */
 		case ' ':
@@ -310,8 +295,7 @@ int dialog_textbox(const char *title, char *tbuf, int initial_height,
 				break;
 
 			begin_reached = 0;
-			refresh_text_box(dialog, box, boxh, boxw, cur_y,
-					 cur_x, update_text, data);
+			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);
 			break;
 		case '0':	/* Beginning of line */
 		case 'H':	/* Scroll left */
@@ -326,8 +310,7 @@ int dialog_textbox(const char *title, char *tbuf, int initial_height,
 				hscroll--;
 			/* Reprint current page to scroll horizontally */
 			back_lines(page_length);
-			refresh_text_box(dialog, box, boxh, boxw, cur_y,
-					 cur_x, update_text, data);
+			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);
 			break;
 		case 'L':	/* Scroll right */
 		case 'l':
@@ -337,8 +320,7 @@ int dialog_textbox(const char *title, char *tbuf, int initial_height,
 			hscroll++;
 			/* Reprint current page to scroll horizontally */
 			back_lines(page_length);
-			refresh_text_box(dialog, box, boxh, boxw, cur_y,
-					 cur_x, update_text, data);
+			refresh_text_box(dialog, box, boxh, boxw, cur_y, cur_x);
 			break;
 		case KEY_ESC:
 			if (on_key_esc(dialog) == KEY_ESC)
@@ -351,11 +333,9 @@ int dialog_textbox(const char *title, char *tbuf, int initial_height,
 			on_key_resize();
 			goto do_resize;
 		default:
-			for (i = 0; keys[i]; i++) {
-				if (key == keys[i]) {
-					done = true;
-					break;
-				}
+			if (extra_key_cb && extra_key_cb(key, start, end, data)) {
+				done = true;
+				break;
 			}
 		}
 	}

scripts/kconfig/mconf.c

@@ -288,6 +288,7 @@ static int single_menu_mode;
 static int show_all_options;
 static int save_and_exit;
 static int silent;
+static int jump_key_char;
 
 static void conf(struct menu *menu, struct menu *active_menu);
 
@@ -348,19 +349,19 @@ static void reset_subtitle(void)
 	set_dialog_subtitles(subtitles);
 }
 
-static int show_textbox_ext(const char *title, char *text, int r, int c, int
-			    *keys, int *vscroll, int *hscroll, update_text_fn
-			    update_text, void *data)
+static int show_textbox_ext(const char *title, const char *text, int r, int c,
+			    int *vscroll, int *hscroll,
+			    int (*extra_key_cb)(int, size_t, size_t, void *),
+			    void *data)
 {
 	dialog_clear();
-	return dialog_textbox(title, text, r, c, keys, vscroll, hscroll,
-			      update_text, data);
+	return dialog_textbox(title, text, r, c, vscroll, hscroll,
+			      extra_key_cb, data);
 }
 
 static void show_textbox(const char *title, const char *text, int r, int c)
 {
-	show_textbox_ext(title, (char *) text, r, c, (int []) {0}, NULL, NULL,
-			 NULL, NULL);
+	show_textbox_ext(title, text, r, c, NULL, NULL, NULL, NULL);
 }
 
 static void show_helptext(const char *title, const char *text)
@@ -381,35 +382,51 @@ static void show_help(struct menu *menu)
 
 struct search_data {
 	struct list_head *head;
-	struct menu **targets;
-	int *keys;
+	struct menu *target;
 };
 
-static void update_text(char *buf, size_t start, size_t end, void *_data)
+static int next_jump_key(int key)
+{
+	if (key < '1' || key > '9')
+		return '1';
+
+	key++;
+
+	if (key > '9')
+		key = '1';
+
+	return key;
+}
+
+static int handle_search_keys(int key, size_t start, size_t end, void *_data)
 {
 	struct search_data *data = _data;
 	struct jump_key *pos;
-	int k = 0;
+
+	if (key < '1' || key > '9')
+		return 0;
 
 	list_for_each_entry(pos, data->head, entries) {
-		if (pos->offset >= start && pos->offset < end) {
-			char header[4];
+		if (pos->offset < start)
+			continue;
 
-			if (k < JUMP_NB) {
-				int key = '0' + (pos->index % JUMP_NB) + 1;
+		if (pos->offset >= end)
+			break;
 
-				sprintf(header, "(%c)", key);
-				data->keys[k] = key;
-				data->targets[k] = pos->target;
-				k++;
-			} else {
-				sprintf(header, "   ");
-			}
-
-			memcpy(buf + pos->offset, header, sizeof(header) - 1);
+		if (key == '1' + (pos->index % JUMP_NB)) {
+			data->target = pos->target;
+			return 1;
 		}
 	}
-	data->keys[k] = 0;
+
+	return 0;
+}
+
+int get_jump_key_char(void)
+{
+	jump_key_char = next_jump_key(jump_key_char);
+
+	return jump_key_char;
 }
 
 static void search_conf(void)
@@ -456,26 +473,23 @@ static void search_conf(void)
 	sym_arr = sym_re_search(dialog_input);
 	do {
 		LIST_HEAD(head);
-		struct menu *targets[JUMP_NB];
-		int keys[JUMP_NB + 1], i;
 		struct search_data data = {
 			.head = &head,
-			.targets = targets,
-			.keys = keys,
 		};
 		struct jump_key *pos, *tmp;
 
+		jump_key_char = 0;
 		res = get_relations_str(sym_arr, &head);
 		set_subtitle();
 		dres = show_textbox_ext("Search Results", str_get(&res), 0, 0,
-					keys, &vscroll, &hscroll, &update_text,
-					&data);
+					&vscroll, &hscroll,
+					handle_search_keys, &data);
 		again = false;
-		for (i = 0; i < JUMP_NB && keys[i]; i++)
-			if (dres == keys[i]) {
-				conf(targets[i]->parent, targets[i]);
-				again = true;
-			}
+		if (dres >= '1' && dres <= '9') {
+			assert(data.target != NULL);
+			conf(data.target->parent, data.target);
+			again = true;
+		}
 		str_free(&res);
 		list_for_each_entry_safe(pos, tmp, &head, entries)
 			free(pos);

scripts/kconfig/menu.c

@@ -701,6 +701,11 @@ static void get_dep_str(struct gstr *r, struct expr *expr, const char *prefix)
 	}
 }
 
+int __attribute__((weak)) get_jump_key_char(void)
+{
+	return -1;
+}
+
 static void get_prompt_str(struct gstr *r, struct property *prop,
 			   struct list_head *head)
 {
@@ -743,11 +748,22 @@ static void get_prompt_str(struct gstr *r, struct property *prop,
 	}
 
 	str_printf(r, "  Location:\n");
-	for (j = 4; --i >= 0; j += 2) {
+	for (j = 0; --i >= 0; j++) {
+		int jk = -1;
+		int indent = 2 * j + 4;
+
 		menu = submenu[i];
-		if (jump && menu == location)
+		if (jump && menu == location) {
 			jump->offset = strlen(r->s);
-		str_printf(r, "%*c-> %s", j, ' ', menu_get_prompt(menu));
+			jk = get_jump_key_char();
+		}
+
+		if (jk >= 0) {
+			str_printf(r, "(%c)", jk);
+			indent -= 3;
+		}
+
+		str_printf(r, "%*c-> %s", indent, ' ', menu_get_prompt(menu));
 		if (menu->sym) {
 			str_printf(r, " (%s [=%s])", menu->sym->name ?
 				menu->sym->name : "<choice>",