ait/key.c

/* key.c, Ait, BSD 3-Clause, Kevin Bloom, 2023,
   Derived from: Atto January 2017
   Derived from: Anthony's Editor January 93
*/

#include "header.h"
#include "termbox.h"
#include "util.h"

/* desc, keys, func */
keymap_t keymap[] = {
	{"C-a beginning-of-line    ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_A, -1}, lnbegin, UA_REPEAT },
	{"C-b backward-char        ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_B, -1}, left, UA_REPEAT },
	{"C-d delete               ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_D, -1}, delete, UA_REPEAT },
	{"C-e end-of-line          ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_E, -1}, lnend, UA_REPEAT },
	{"C-f foward-char          ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_F, -1}, right, UA_REPEAT },
	{"C-h backspace            ", TB_MOD_CTRL, (int[2]){TB_KEY_BACKSPACE, -1}, backsp, UA_REPEAT },
	{"C-h backspace            ", TB_MOD_CTRL, (int[2]){TB_KEY_BACKSPACE2, -1}, backsp, UA_REPEAT },
	{"C-i indent               ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_I, -1}, inserttabasspace, UA_REPEAT },
	{"C-k kill-to-eol          ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_K, -1}, killtoeol, UA_REPEAT },
	{"C-l refresh              ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_L, -1}, recenter, UA_NOTHING },
	{"C-x u undo               ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, 'u', -1}, undo, UA_NOTHING },
	{"C-/   undo               ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_SLASH, -1}, undo, UA_NOTHING },
	{"C-n next-line            ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_N, -1}, down, UA_REPEAT },
	{"C-m newline              ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_M, -1}, insertnewline, UA_REPEAT },
	{"C-p previous-line        ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_P, -1}, up, UA_REPEAT },
	{"C-r search               ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_R, -1}, search_rev, UA_NOTHING },
	{"C-o newline-below        ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_O, -1}, insertnewlinebelow, UA_REPEAT },
	{"C-s search               ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_S, -1}, search_fwd, UA_NOTHING },
	{"C-t transpose            ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_T, -1}, transpose, UA_REPEAT },
	{"C-u universal-argument   ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_U, -1}, universal_argument_load, UA_NOTHING },
	{"C-v forward-page         ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_V, -1}, pgdown, UA_REPEAT },
	{"C-w kill-region          ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_W, -1}, cut, UA_CUSTOM },
	{"C-y yank                 ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_Y, -1}, paste, UA_CUSTOM },
	{"C-z suspend              ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_Z, -1}, suspend, UA_NOTHING },
	{"C-space set-mark         ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_TILDE, -1}, iblock, UA_NOTHING },
	{"C-g remove-mark          ", TB_MOD_CTRL, (int[2]){TB_KEY_CTRL_G, -1}, unmark, UA_NOTHING },
	{"C-x 1 delete-other-window", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, '1', -1}, delete_other_windows, UA_NOTHING },
	{"C-x 2 split-window       ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, '2', -1}, split_window, UA_NOTHING },
	{"C-x 3 chop-window        ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, '3', -1}, chop_window, UA_NOTHING },
	{"C-x 0 close-window       ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, '0', -1}, close_window, UA_NOTHING },
	{"C-x o other-window       ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, 'o', -1}, next_window, UA_NOTHING },
	{"C-x = cursor-position    ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, '=', -1}, showpos, UA_NOTHING },
	{"C-x i insert-file        ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, 'i', -1}, insertfile, UA_NOTHING },
	{"C-x k kill-buffer        ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, 'k', -1}, killbuffer, UA_NOTHING },
	{"C-x C-n next-buffer      ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, TB_KEY_CTRL_N, -1}, next_buffer, UA_NOTHING },
	{"C-x n next-buffer        ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, 'n', -1}, next_buffer, UA_NOTHING },
	{"C-x b switch-to-buffer   ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, 'b', -1}, switch_buffer, UA_NOTHING },
	{"C-x ( start-kbd-macro    ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, '(', -1}, start_kbd_macro, UA_NOTHING },
	{"C-x ) start-kbd-macro    ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, ')', -1}, end_kbd_macro, UA_NOTHING },
    /* UA_PREVENT is misleading here, since it uses the numeric_argument in the get_key function */
	{"C-x e run-kbd-macro      ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, 'e', -1}, run_kbd_macro, UA_PREVENT },
	{"C-x C-f find-file        ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, TB_KEY_CTRL_F, -1}, readfile, UA_NOTHING },
	{"C-x C-s save-buffer      ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, TB_KEY_CTRL_S, -1}, savebuffer, UA_NOTHING },
	{"C-x C-g umark            ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, TB_KEY_CTRL_G, -1}, unmark, UA_NOTHING },
	{"C-x C-w write-file       ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, TB_KEY_CTRL_W, -1}, writefile, UA_NOTHING },
	{"C-x C-c exit             ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, TB_KEY_CTRL_C, -1}, quit_ask, UA_NOTHING },
	{"C-x C-x pop-to-mark      ", TB_MOD_CTRL, (int[3]){TB_KEY_CTRL_X, TB_KEY_CTRL_X, -1}, poptomark, UA_NOTHING },
	{"esc 0 numeric-arg-0      ", TB_MOD_ALT, (int[2]){'0', -1}, numeric_argument_load, UA_PREVENT },
	{"esc 1 numeric-arg-1      ", TB_MOD_ALT, (int[2]){'1', -1}, numeric_argument_load, UA_PREVENT },
	{"esc 2 numeric-arg-2      ", TB_MOD_ALT, (int[2]){'2', -1}, numeric_argument_load, UA_PREVENT },
	{"esc 3 numeric-arg-3      ", TB_MOD_ALT, (int[2]){'3', -1}, numeric_argument_load, UA_PREVENT },
	{"esc 4 numeric-arg-4      ", TB_MOD_ALT, (int[2]){'4', -1}, numeric_argument_load, UA_PREVENT },
	{"esc 5 numeric-arg-5      ", TB_MOD_ALT, (int[2]){'5', -1}, numeric_argument_load, UA_PREVENT },
	{"esc 6 numeric-arg-6      ", TB_MOD_ALT, (int[2]){'6', -1}, numeric_argument_load, UA_PREVENT },
	{"esc 7 numeric-arg-7      ", TB_MOD_ALT, (int[2]){'7', -1}, numeric_argument_load, UA_PREVENT },
	{"esc 8 numeric-arg-8      ", TB_MOD_ALT, (int[2]){'8', -1}, numeric_argument_load, UA_PREVENT },
	{"esc 9 numeric-arg-9      ", TB_MOD_ALT, (int[2]){'9', -1}, numeric_argument_load, UA_PREVENT },
	{"esc b back-word          ", TB_MOD_ALT, (int[2]){'b', -1}, wleft, UA_REPEAT },
	{"esc b back-word-delete   ", TB_MOD_CTRL | TB_MOD_ALT, (int[2]){TB_KEY_BACKSPACE2, -1}, wleftdelete, UA_REPEAT },
	{"esc b back-word-delete   ", TB_MOD_CTRL | TB_MOD_ALT, (int[2]){TB_KEY_BACKSPACE, -1}, wleftdelete, UA_REPEAT },
	{"esc f fwd-word           ", TB_MOD_ALT, (int[2]){'f', -1}, wright, UA_REPEAT },
	{"esc d fwd-word-delete    ", TB_MOD_ALT, (int[2]){'d', -1}, wrightdelete, UA_REPEAT },
	{"esc x execute-shell-cmd  ", TB_MOD_ALT, (int[2]){'x', -1}, insert_from_shell, UA_NOTHING },
	{"esc g gotoline           ", TB_MOD_ALT, (int[2]){'g', -1}, gotoline, UA_NOTHING },
	{"esc i indent             ", TB_MOD_ALT, (int[2]){'i', -1}, inserttab, UA_REPEAT },
	{"esc k kill-region        ", TB_MOD_ALT, (int[2]){'k', -1}, cut, UA_NOTHING },
	{"esc m back-to-indentation", TB_MOD_ALT, (int[2]){'m', -1}, back_to_indentation, UA_NOTHING },
	{"esc n negate             ", TB_MOD_ALT, (int[2]){'-', -1}, negate, UA_NOTHING },
	{"esc o open-shell-cmd     ", TB_MOD_ALT, (int[2]){'o', -1}, open_file_from_shell, UA_NOTHING },
	{"esc % query-replace      ", TB_MOD_ALT, (int[2]){'%', -1}, query_replace, UA_NOTHING },
	{"esc v backward-page      ", TB_MOD_ALT, (int[2]){'v', -1}, pgup, UA_REPEAT },
	{"esc w copy-region        ", TB_MOD_ALT, (int[2]){'w', -1}, copy, UA_NOTHING },
	{"esc @ set-mark           ", TB_MOD_ALT, (int[2]){'@', -1}, iblock, UA_NOTHING },
	{"esc < beg-of-buf         ", TB_MOD_ALT, (int[2]){'<', -1}, top, UA_NOTHING },
	{"esc > end-of-buf         ", TB_MOD_ALT, (int[2]){'>', -1}, bottom, UA_NOTHING },
	{"esc / delete-whitespace  ", TB_MOD_ALT, (int[2]){'\\', -1}, deletewhitespacebetween, UA_NOTHING },
	{"esc t query-replace      ", TB_MOD_ALT, (int[2]){'t', -1}, transposeword, UA_REPEAT },
	{"esc l lowercase-word     ", TB_MOD_ALT, (int[2]){'l', -1}, lowercaseword, UA_REPEAT },
	{"esc c capitalize-word    ", TB_MOD_ALT, (int[2]){'c', -1}, capitalizeword, UA_REPEAT },
	{"esc u uppercase-word     ", TB_MOD_ALT, (int[2]){'u', -1}, uppercaseword, UA_REPEAT },
	{"esc ; jump-to-char       ", TB_MOD_ALT, (int[2]){';', -1}, jumptochar, UA_REPEAT },
	{"esc : jump-to-char       ", TB_MOD_ALT, (int[2]){':', -1}, negated_jumptochar, UA_REPEAT },
	{"esc z zap-to-char        ", TB_MOD_ALT, (int[2]){'z', -1}, zaptochar, UA_REPEAT },
	{"esc Z zap-to-char        ", TB_MOD_ALT, (int[2]){'Z', -1}, negated_zaptochar, UA_REPEAT },
	{"esc home, beg-of-buf     ", 0, (int[2]){TB_KEY_HOME, -1}, top, UA_NOTHING },
	{"esc end, end-of-buf      ", 0, (int[2]){TB_KEY_END, -1}, bottom, UA_NOTHING },
	{"esc esc show-version     ", 0, (int[2]){TB_KEY_ESC, -1}, version, UA_NOTHING },
	{"ins toggle-overwrite-mode", 0, (int[2]){TB_KEY_INSERT, -1}, toggle_overwrite_mode , UA_NOTHING },
	{"del forward-delete-char  ", 0, (int[2]){TB_KEY_DELETE, -1}, delete, UA_REPEAT },
	{"backspace delete-left    ", 0, (int[2]){TB_KEY_BACKSPACE, -1}, backsp, UA_REPEAT },
	{"backspace delete-left    ", 0, (int[2]){TB_KEY_BACKSPACE2, -1}, backsp, UA_REPEAT },
	{"up previous-line         ", 0, (int[2]){TB_KEY_ARROW_UP, -1}, up, UA_REPEAT },
	{"down next-line           ", 0, (int[2]){TB_KEY_ARROW_DOWN, -1}, down, UA_REPEAT },
	{"left backward-character  ", 0, (int[2]){TB_KEY_ARROW_LEFT, -1}, left, UA_REPEAT },
	{"right forward-character  ", 0, (int[2]){TB_KEY_ARROW_RIGHT, -1}, right, UA_REPEAT },
	{"pgup backward-page       ", 0, (int[2]){TB_KEY_PGUP, -1}, pgup , UA_REPEAT },
	{"pgdn forward-page        ", 0, (int[2]){TB_KEY_PGDN, -1}, pgdown, UA_REPEAT },
  //	{"resize resize-terminal   ", 0, (int[2]){TB_KEY_},     resize_terminal , UA_NOTHING },
	{"C-M-f foward-bracket     ", TB_MOD_CTRL | TB_MOD_ALT, (int[2]){TB_KEY_CTRL_F, -1}, forward_bracket, UA_REPEAT },
	{"C-M-b backward-bracket   ", TB_MOD_CTRL | TB_MOD_ALT, (int[2]){TB_KEY_CTRL_B, -1}, backward_bracket, UA_REPEAT },
	{"K_ERROR                  ", 0, NULL, NULL, UA_NOTHING }
};

char_t *get_key(keymap_t *keys, keymap_t **key_return)
{
  keymap_t *k;
  int ret;
  static char_t buffer[K_BUFFER_LENGTH];
  static char_t *record = buffer;
  struct tb_event ev;

  *key_return = NULL;

  /* if recorded bytes remain, return next recorded byte. */
  if (*record != '\0') {
    *key_return = NULL;
    return record++;
  }
  /* reset record buffer. */
  record = buffer;

  if(execute_kbd_macro) {
    ev = record_buffer[run_buffer_index];
    ret = TB_OK;
    if(run_buffer_index > record_buffer_index) {
      if(numeric_argument > 0) {
        numeric_argument--;
      } else {
        execute_kbd_macro = FALSE;
      }
      run_buffer_index = 0;
    } else {
      run_buffer_index++;
    }
  } else {
    ret = tb_poll_event(&ev);
  }

  if(ret == TB_OK) {
    assert(K_BUFFER_LENGTH > record - buffer);

    if(ev.type == TB_EVENT_RESIZE) {
      resize_terminal();
      *key_return = NULL;
      return (record++);
    } else if(ev.type == TB_EVENT_MOUSE) {
      *key_return = NULL;
      return (record++);
    }
    *record++ = (unsigned)ev.ch;
    *record = '\0';

    if(record_input) {
      record_buffer[record_buffer_index] = ev;
      record_buffer_index++;
    }

    /* if recorded bytes match any multi-byte sequence... */
    for (k = keys; k->key_bytes != NULL; ++k) {
      if(k->key_mod == ev.mod &&
         (k->key_bytes[submatch] == ev.key ||
          (ev.ch != 0 && k->key_bytes[submatch] == (int)ev.ch))) {
        if(k->key_bytes[submatch+1] != -1) {
          submatch++;
          msg("C-x");
          break;
        } else {
          record = buffer;
          *record = '\0';
          *key_return = k;
          input_char = ev.ch;
          return record;
        }
      }
      if(submatch > 0 && k->key_bytes[submatch] == (int)ev.ch) {
        record = buffer;
        *record = '\0';
        *key_return = k;
        input_char = ev.ch;
        return record;
      }
    }
    unicode_buf[tb_utf8_unicode_to_char(unicode_buf, ev.ch)] = '\0';
    /* If no match is found, kill the loop. */
    if(key_return == NULL) {
      submatch = 0;
    }
  }
  /* nothing matched, return recorded bytes. */
  record = buffer;
  return (record++);
}

int getinput(char *prompt, char *buf, int nbuf, int flag, int allowblank)
{
  int cpos = 0;
  int c;
  int start_col = strlen(prompt);
  struct tb_event ev;

  print_to_msgline(prompt);
  clrtoeol(prompt, MSGLINE);

  if (flag == F_CLEAR) buf[0] = '\0';

  /* if we have a default value print it and go to end of it */
  if (buf[0] != '\0') {
    addstr(buf);
    cpos = strlen(buf);
  }

  for (;;) {
    tb_present();
    if(tb_poll_event(&ev) != TB_OK) return 0;

    if(msgline_editor(ev, prompt, buf, &cpos))
      continue;

    if(!ev.mod)
      c = ev.ch;
    else
      c = ev.key;

    /* ignore control keys other than backspace, cr, lf */
    if (c < 32 &&
        c != TB_KEY_CTRL_G &&
        c != TB_KEY_BACKSPACE &&
        c != TB_KEY_CTRL_J &&
        c != TB_KEY_ENTER)
      continue;

    switch(c) {
      case TB_KEY_CTRL_J: /* cr, lf */
      case TB_KEY_ENTER:
        buf[cpos] = '\0';
        return (cpos > 0 ? TRUE : allowblank);

      case TB_KEY_CTRL_G: /* ctrl-g */
        return FALSE;

      case TB_KEY_BACKSPACE2: /* del, erase */
      case TB_KEY_BACKSPACE: /* backspace */
        if (cpos == 0)
          continue;

        tb_set_cursor(start_col + cpos - 1, MSGLINE);
        addch(' ');
        tb_set_cursor(start_col + cpos - 1, MSGLINE);
        buf[--cpos] = '\0';
        break;

      default:
        if (cpos < nbuf -1) {
          for(int i = strlen(buf); i > cpos; i--) {
            buf[i] = buf[i - 1];
          }
          buf[cpos] = c;
          tb_set_cursor(start_col, MSGLINE);
          addstr(buf);
          cpos++;
          tb_set_cursor(start_col + cpos, MSGLINE);
        }
        break;
      }
    }
}

int msgline_editor(struct tb_event ev, char *prompt, char *buf, int *cpos)
{
  char full[NAME_MAX*2];
  int k = 0, i = 0, start_col = strlen(prompt);
  strcpy(full, prompt);
  if(ev.mod == TB_MOD_ALT || ev.mod == (TB_MOD_CTRL | TB_MOD_ALT)) {
      k = ev.ch;
      if(k == 'b') {
        if ((!isspace(buf[*cpos]) || !is_symbol(buf[*cpos])) && *cpos != 0)
          *cpos = *cpos -1;
        while ((isspace(buf[*cpos]) || is_symbol(buf[*cpos]))  && *cpos != 0)
          *cpos = *cpos -1;
        while (!isspace(buf[*cpos]) && !is_symbol(buf[*cpos]) && *cpos != 0)
          *cpos = *cpos -1;
        tb_set_cursor(start_col + *cpos, MSGLINE);
        return 1;
      } else if(k == 'f') {
        if ((!isspace(buf[*cpos]) || !is_symbol(buf[*cpos])) && *cpos != strlen(buf))
          *cpos = *cpos + 1;
        while ((isspace(buf[*cpos]) || is_symbol(buf[*cpos]))  && *cpos != strlen(buf))
          *cpos = *cpos + 1;
        while (!isspace(buf[*cpos]) && !is_symbol(buf[*cpos]) && *cpos != strlen(buf))
          *cpos = *cpos + 1;
        tb_set_cursor(start_col + *cpos, MSGLINE);
        return 1;
      } else if(k == 'd') {
        if ((!isspace(buf[*cpos]) || !is_symbol(buf[*cpos])) && *cpos != strlen(buf)) {
          for(i = *cpos; buf[i] != '\0'; i++) {
            buf[i] = buf[i+1];
          }
        }
        while ((isspace(buf[*cpos]) || is_symbol(buf[*cpos]))  && *cpos != strlen(buf)) {
          for(i = *cpos; buf[i] != '\0'; i++) {
            buf[i] = buf[i+1];
          }
        }
        while (!isspace(buf[*cpos]) && !is_symbol(buf[*cpos]) && *cpos != strlen(buf)) {
          for(i = *cpos; buf[i] != '\0'; i++) {
            buf[i] = buf[i+1];
          }
        }
        strcat(full, buf);
        tb_set_cursor(start_col, MSGLINE);
        addstr(buf);
        clrtoeol(full, MSGLINE);
        tb_set_cursor(start_col + *cpos, MSGLINE);
        full[strlen(prompt)] = '\0';
        return 1;
      } else if(ev.key == TB_KEY_BACKSPACE || ev.key == TB_KEY_BACKSPACE2) {
        if ((!isspace(buf[*cpos-1]) || !is_symbol(buf[*cpos-1])) && *cpos != 0) {
          *cpos = *cpos -1;
          for(i = *cpos; buf[i] != '\0'; i++) {
            buf[i] = buf[i+1];
          }
        }
        while ((isspace(buf[*cpos-1]) || is_symbol(buf[*cpos-1]))  && *cpos != 0) {
          *cpos = *cpos -1;
          for(i = *cpos; buf[i] != '\0'; i++) {
            buf[i] = buf[i+1];
          }
        }
        while (!isspace(buf[*cpos-1]) && !is_symbol(buf[*cpos-1]) && *cpos != 0) {
          *cpos = *cpos -1;
          for(i = *cpos; buf[i] != '\0'; i++) {
            buf[i] = buf[i+1];
          }
        }
        strcat(full, buf);
        tb_set_cursor(start_col, MSGLINE);
        addstr(buf);
        clrtoeol(full, MSGLINE);
        tb_set_cursor(start_col + *cpos, MSGLINE);
        full[strlen(prompt)] = '\0';
        return 1;
      }
    } else
      k = ev.key;
  switch(k) {
      case TB_KEY_CTRL_B:
      if(*cpos != 0)
        *cpos = *cpos - 1;
      tb_set_cursor(start_col + *cpos, MSGLINE);
      return 1;

    case TB_KEY_CTRL_F:
      if(*cpos != strlen(buf))
        *cpos = *cpos + 1;
      tb_set_cursor(start_col + *cpos, MSGLINE);
      return 1;

    case TB_KEY_HOME:
    case TB_KEY_CTRL_A:
      *cpos = 0;
      tb_set_cursor(start_col + *cpos, MSGLINE);
      return 1;

    case TB_KEY_END:
    case TB_KEY_CTRL_E:
      *cpos = strlen(buf);
      tb_set_cursor(start_col + *cpos, MSGLINE);
      return 1;

    case TB_KEY_CTRL_K:
      for(i = *cpos; buf[i] != '\0'; i++)
        buf[i] = '\0';
      strcat(full, buf);
      clrtoeol(full, MSGLINE);
      return 1;

    case TB_KEY_DELETE:
    case TB_KEY_CTRL_D:
      if(*cpos == strlen(buf))
        break;
      for(i = *cpos; buf[i] != '\0'; i++) {
        buf[i] = buf[i+1];
      }
      strcat(full, buf);
      tb_set_cursor(start_col, MSGLINE);
      addstr(buf);
      clrtoeol(full, MSGLINE);
      tb_set_cursor(start_col + *cpos, MSGLINE);
      full[strlen(prompt)] = '\0';
      return 1;
    case TB_KEY_BACKSPACE2: /* del, erase */
    case TB_KEY_BACKSPACE: /* backspace */
      if(*cpos == 0)
        return 1;
      *cpos = *cpos - 1;
      for(i = *cpos; buf[i] != '\0'; i++) {
        buf[i] = buf[i+1];
      }
      strcat(full, buf);
      tb_set_cursor(start_col, MSGLINE);
      addstr(buf);
      clrtoeol(full, MSGLINE);
      tb_set_cursor(start_col + *cpos, MSGLINE);
      full[strlen(prompt)] = '\0';
      return 1;

  default:
    return 0;
  }
  return 0;
}