menuconfig: Extend dialog_textbox so that it can return to a scrolled position

We can now display other UI elements (menus) "on top" of a textbox and then
seemingly come back to it in the same state it was left.
Signed-off-by: Benjamin Poirier <bpoirier@suse.de>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/kconfig/lxdialog/dialog.h

@@ -211,7 +211,7 @@ 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);
 int dialog_textbox(const char *title, const char *file, int height, int width,
-		   int *keys);
+		   int *keys, int *_vscroll, int *_hscroll);
 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

@@ -51,7 +51,7 @@ static void refresh_text_box(WINDOW *dialog, WINDOW *box, int boxh, int boxw,
  * keys is a null-terminated array
  */
 int dialog_textbox(const char *title, const char *tbuf, int initial_height,
-		   int initial_width, int *keys)
+		   int initial_width, int *keys, int *_vscroll, int *_hscroll)
 {
 	int i, x, y, cur_x, cur_y, key = 0;
 	int height, width, boxh, boxw;
@@ -65,6 +65,15 @@ int dialog_textbox(const char *title, const char *tbuf, int initial_height,
 	buf = tbuf;
 	page = buf;	/* page is pointer to start of page to be displayed */
 
+	if (_vscroll && *_vscroll) {
+		begin_reached = 0;
+
+		for (i = 0; i < *_vscroll; i++)
+			get_line();
+	}
+	if (_hscroll)
+		hscroll = *_hscroll;
+
 do_resize:
 	getmaxyx(stdscr, height, width);
 	if (height < 8 || width < 8)
@@ -275,6 +284,19 @@ int dialog_textbox(const char *title, const char *tbuf, int initial_height,
 	}
 	delwin(box);
 	delwin(dialog);
+	if (_vscroll) {
+		const char *s;
+
+		s = buf;
+		*_vscroll = 0;
+		back_lines(page_length);
+		while (s < page && (s = strchr(s, '\n'))) {
+			(*_vscroll)++;
+			s++;
+		}
+	}
+	if (_hscroll)
+		*_hscroll = hscroll;
 	return key;
 }
 

scripts/kconfig/mconf.c

@@ -280,7 +280,7 @@ static void conf_string(struct menu *menu);
 static void conf_load(void);
 static void conf_save(void);
 static int show_textbox_ext(const char *title, const char *text, int r, int c,
-			    int *keys);
+			    int *keys, int *vscroll, int *hscroll);
 static void show_textbox(const char *title, const char *text, int r, int c);
 static void show_helptext(const char *title, const char *text);
 static void show_help(struct menu *menu);
@@ -621,15 +621,15 @@ static void conf(struct menu *menu)
 }
 
 static int show_textbox_ext(const char *title, const char *text, int r, int c,
-			    int *keys)
+			    int *keys, int *vscroll, int *hscroll)
 {
 	dialog_clear();
-	return dialog_textbox(title, text, r, c, keys);
+	return dialog_textbox(title, text, r, c, keys, vscroll, hscroll);
 }
 
 static void show_textbox(const char *title, const char *text, int r, int c)
 {
-	show_textbox_ext(title, text, r, c, (int []) {0});
+	show_textbox_ext(title, text, r, c, (int []) {0}, NULL, NULL);
 }
 
 static void show_helptext(const char *title, const char *text)