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>

diff --git a/scripts/kconfig/nconf.gui.c b/scripts/kconfig/nconf.gui.c
index d64bc1c24c2093a2eeb99f2ad0e32831785bee6e..4b9d8b66087d14610d95526b5bd08b472640fbda 100644 (file)
--- 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);