scripts/kconfig/nconf: fix editing long strings

The original dialog_inputbox doesn't work with longer than prompt_width
strings, here fixed it in this way:
1) add variable cursor_form_win to record cursor of form_win,
   keep its value always between [0, prompt_width-1];
   reuse the original cursor_position as cursor of the string result,
   use (cursor_position-cursor_form_win) as begin offset to show part of
   the string in form_win;

Signed-off-by: Cheng Renquan <crquan@gmail.com>
Cc: Arnaud Lacombe <lacombar@gmail.com>
Cc: Nir Tzachar <nir.tzachar@gmail.com>

1 files changed, 23 insertions, 6 deletions

diff --git a/scripts/kconfig/nconf.gui.c b/scripts/kconfig/nconf.gui.c
index d64bc1c24c20..4b9d8b66087d 100644
--- a/scripts/kconfig/nconf.gui.c
+++ b/scripts/kconfig/nconf.gui.c
@@ -367,6 +367,7 @@ int dialog_inputbox(WINDOW *main_window,
         int i, x, y;
         int res = -1;
         int cursor_position = strlen(init);
+        int cursor_form_win;
         char *result = *resultp;
 
         if (strlen(init)+1 > *result_len) {
@@ -410,7 +411,9 @@ int dialog_inputbox(WINDOW *main_window,
         fill_window(prompt_win, prompt);
 
         mvwprintw(form_win, 0, 0, "%*s", prompt_width, " ");
-        mvwprintw(form_win, 0, 0, "%s", result);
+        cursor_form_win = min(cursor_position, prompt_width-1);
+        mvwprintw(form_win, 0, 0, "%s",
+                  result + cursor_position-cursor_form_win);
 
         /* create panels */
         panel = new_panel(win);
@@ -436,6 +439,8 @@ int dialog_inputbox(WINDOW *main_window,
                                                 &result[cursor_position],
                                                 len-cursor_position+1);
                                 cursor_position--;
+                                cursor_form_win--;
+                                len--;
                         }
                         break;
                 case KEY_DC:
@@ -443,18 +448,22 @@ int dialog_inputbox(WINDOW *main_window,
                                 memmove(&result[cursor_position],
                                                 &result[cursor_position+1],
                                                 len-cursor_position+1);
+                                len--;
                         }
                         break;
                 case KEY_UP:
                 case KEY_RIGHT:
-                        if (cursor_position < len &&
-                            cursor_position < min(*result_len, prompt_width))
+                        if (cursor_position < len) {
                                 cursor_position++;
+                                cursor_form_win++;
+                        }
                         break;
                 case KEY_DOWN:
                 case KEY_LEFT:
-                        if (cursor_position > 0)
+                        if (cursor_position > 0) {
                                 cursor_position--;
+                                cursor_form_win--;
+                        }
                         break;
                 default:
                         if ((isgraph(res) || isspace(res))) {
@@ -470,16 +479,24 @@ int dialog_inputbox(WINDOW *main_window,
                                                 len-cursor_position+1);
                                 result[cursor_position] = res;
                                 cursor_position++;
+                                cursor_form_win++;
+                                len++;
                         } else {
                                 mvprintw(0, 0, "unknown key: %d\n", res);
                         }
                         break;
                 }
+                if (cursor_form_win < 0)
+                        cursor_form_win = 0;
+                else if (cursor_form_win > prompt_width-1)
+                        cursor_form_win = prompt_width-1;
+
                 wmove(form_win, 0, 0);
                 wclrtoeol(form_win);
                 mvwprintw(form_win, 0, 0, "%*s", prompt_width, " ");
-                mvwprintw(form_win, 0, 0, "%s", result);
-                wmove(form_win, 0, cursor_position);
+                mvwprintw(form_win, 0, 0, "%s",
+                        result + cursor_position-cursor_form_win);
+                wmove(form_win, 0, cursor_form_win);
                 touchwin(win);
                 refresh_all_windows(main_window);