creadline.c

/*************************************************************
 *
 * File:        creadline.c
 * Author:      David Kelley
 * Description: Functions for reading command line input,
 *              similar to gnu realine library but specific
 *              for ncurses
 *
 * Copyright (C) 2009 David Kelley
 *
 * This file is part of bviplus.
 *
 * Bviplus is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Bviplus is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with bviplus.  If not, see <http://www.gnu.org/licenses/>.
 *
 *************************************************************/

#include <string.h>
#include <stdlib.h>
#include "creadline.h"
#include "key_handler.h"

cmd_hist_t *new_history(void)
{
  cmd_hist_t *cmd_hist;
  cmd_item_t *cmd_item;
  cmd_hist = malloc(sizeof(cmd_hist_t));
  if (NULL == cmd_hist)
    return NULL;
  memset(cmd_hist, 0, sizeof(cmd_hist_t));

  cmd_item = malloc(sizeof(cmd_item_t) * MAX_CMD_HISTORY);
  if (NULL == cmd_item)
  {
    free(cmd_hist);
    return NULL;
  }
  memset(cmd_item, 0, sizeof(cmd_item_t) * MAX_CMD_HISTORY);

  cmd_hist->item = cmd_item;
  return cmd_hist;
}

void free_history(cmd_hist_t *history)
{
  if (NULL != history)
  {
    if (NULL != history->item)
      free(history->item);
    free(history);
  }
}

char *creadline(const char *prompt, WINDOW *w, int y, int x, cmd_hist_t *history)
{
  int i = 0, c = 0;
  int entry_hist_index, tmp_hist_index;
  cmd_item_t tmp_cmd;
  char *cmd;

  mvwprintw(w, y, x, "%s", prompt);
  x = x + strlen(prompt) - 1;

  entry_hist_index = history->hist_index;
  tmp_cmd.count = 0;
  tmp_cmd.position = 0;

  do
  {
    wrefresh(w);
    c = mgetch();
    switch(c)
    {
      case KEY_UP:
        if (NULL == history)
          continue;
        tmp_hist_index = history->hist_index-1;
        if (tmp_hist_index < 0)
          tmp_hist_index = MAX_CMD_HISTORY - 1;
        if (tmp_hist_index == entry_hist_index)
          continue;
        if (history->item[tmp_hist_index].count == 0)
          continue;

        history->hist_index = tmp_hist_index;

        strncpy(tmp_cmd.cbuff, history->item[history->hist_index].cbuff, MAX_CMD_BUF);
        tmp_cmd.count = history->item[history->hist_index].count;
        tmp_cmd.position = history->item[history->hist_index].position;

        wmove(w, y, x+1);
        wclrtoeol(w);

        for (i=0; i<tmp_cmd.count; i++)
          mvwaddch(w, y, x+i+1, tmp_cmd.cbuff[i]);
        tmp_cmd.position = tmp_cmd.count;
        break;
      case KEY_DOWN:
        if (NULL == history)
          continue;
        if (history->hist_index == entry_hist_index)
          continue;
        tmp_hist_index = history->hist_index+1;
        tmp_hist_index = tmp_hist_index % MAX_CMD_HISTORY;

        history->hist_index = tmp_hist_index;

        strncpy(tmp_cmd.cbuff, history->item[history->hist_index].cbuff, MAX_CMD_BUF);
        tmp_cmd.count = history->item[history->hist_index].count;
        tmp_cmd.position = history->item[history->hist_index].position;

        wmove(w, y, x+1);
        wclrtoeol(w);

        for (i=0; i<tmp_cmd.count; i++)
          mvwaddch(w, y, x+i+1, tmp_cmd.cbuff[i]);
        tmp_cmd.position = tmp_cmd.count;
        break;
      case BVICTRL('c'):
      case ESC:
        return NULL;
      case BVICTRL('?'):
      case BVICTRL('H'):
      case KEY_BACKSPACE:
      case BACKSPACE:
        if (tmp_cmd.position == 0)
          return NULL;
        for (i=tmp_cmd.position; i<tmp_cmd.count; i++)
        {
          tmp_cmd.cbuff[i-1] = tmp_cmd.cbuff[i];
          mvwaddch(w, y, x+i, tmp_cmd.cbuff[i]);
        }
        mvwaddch(w, y, x+tmp_cmd.count, ' ');
        wclrtoeol(w);
        tmp_cmd.position--;
        tmp_cmd.count--;
        break;
      case BVICTRL('u'):
        /* delete all to the left */
        memmove(tmp_cmd.cbuff, &tmp_cmd.cbuff[tmp_cmd.position], tmp_cmd.count - tmp_cmd.position);
        tmp_cmd.count -= tmp_cmd.position;
        tmp_cmd.position = 0;
        /* clear and re-draw */
        wmove(w, y, x+tmp_cmd.position+1);
        wclrtoeol(w);
        for (i=tmp_cmd.position; i<tmp_cmd.count; i++)
          mvwaddch(w, y, x+i+1, tmp_cmd.cbuff[i]);
        break;
      case DEL:
        /* delete one to the right */
        if (tmp_cmd.position < tmp_cmd.count)
        {
            memmove(&tmp_cmd.cbuff[tmp_cmd.position], &tmp_cmd.cbuff[tmp_cmd.position+1], tmp_cmd.count - tmp_cmd.position - 1);
            tmp_cmd.count -= 1;
            wclrtoeol(w);
            for (i=tmp_cmd.position; i<tmp_cmd.count; i++)
              mvwaddch(w, y, x+i+1, tmp_cmd.cbuff[i]);
        }
        break;
      case BVICTRL('a'):
        tmp_cmd.position=0;
        break;
      case BVICTRL('b'):
      case KEY_LEFT:
        if (--tmp_cmd.position < 0)
          tmp_cmd.position++;
        break;
      case BVICTRL('e'):
        tmp_cmd.position=tmp_cmd.count;
        break;
      case BVICTRL('f'):
      case KEY_RIGHT:
        if (++tmp_cmd.position > tmp_cmd.count)
          tmp_cmd.position--;
        break;
      case NL:
      case CR:
      case KEY_ENTER:
        break;
      default:
        if (tmp_cmd.count >= MAX_CMD_BUF)
          continue;
        for (i=tmp_cmd.count; i>=tmp_cmd.position; i--)
          tmp_cmd.cbuff[i+1] = tmp_cmd.cbuff[i];
        tmp_cmd.cbuff[tmp_cmd.position] = (char)c;
        tmp_cmd.count++;
        for (i=tmp_cmd.position; i<tmp_cmd.count; i++)
          mvwaddch(w, y, x+i+1, tmp_cmd.cbuff[i]);
        tmp_cmd.position++;
        break;
    }

    wmove(w, y, x+tmp_cmd.position+1);
  } while(c != NL && c != CR && c != KEY_ENTER);

  tmp_cmd.cbuff[tmp_cmd.count] = '\0';

  if (tmp_cmd.count)
  {
    cmd = malloc(MAX_CMD_BUF);
    if (cmd == NULL)
      return NULL;

    strncpy(cmd, tmp_cmd.cbuff, MAX_CMD_BUF);
    strncpy(history->item[entry_hist_index].cbuff, tmp_cmd.cbuff, MAX_CMD_BUF);
    history->item[entry_hist_index].count = tmp_cmd.count;
    history->item[entry_hist_index].position = tmp_cmd.position;
    history->hist_index = (entry_hist_index+1) % MAX_CMD_HISTORY;
    return cmd;
  }
  else
  {
    history->hist_index = entry_hist_index;
    return NULL;
  }
}