path: root/src/getstring.c

/*
 * Calcurse - text-based organizer
 *
 * Copyright (c) 2004-2011 calcurse Development Team <misc@calcurse.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the
 *        following disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the
 *        following disclaimer in the documentation and/or other
 *        materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Send your feedback or comments to : misc@calcurse.org
 * Calcurse home page : http://calcurse.org
 *
 */

#include "calcurse.h"

struct getstr_charinfo {
  unsigned int offset, dpyoff;
};

struct getstr_status {
  char *s;
  struct getstr_charinfo *ci;
  int pos, len;
  int scrpos;
};

/* Print the string at the desired position. */
static void
getstr_print (WINDOW *win, int x, int y, struct getstr_status *st)
{
  char c = 0;

  /* print string */
  mvwaddnstr (win, y, x, &st->s[st->ci[st->scrpos].offset], -1);
  wclrtoeol (win);

  /* print scrolling indicator */
  if (st->scrpos > 0 && st->ci[st->len].dpyoff -
      st->ci[st->scrpos].dpyoff > col - 2)
    c = '*';
  else if (st->scrpos > 0)
    c = '<';
  else if (st->ci[st->len].dpyoff - st->ci[st->scrpos].dpyoff > col - 2)
    c = '>';
  mvwprintw (win, y, col - 2, " %c", c);

  /* print cursor */
  wmove (win, y, st->ci[st->pos].dpyoff - st->ci[st->scrpos].dpyoff);
  wchgat (win, 1, A_REVERSE, COLR_CUSTOM, NULL);
}

/* Delete a character at the given position in string. */
static void
getstr_del_char (struct getstr_status *st)
{
  char *str = st->s + st->ci[st->pos].offset;
  int cl = st->ci[st->pos + 1].offset - st->ci[st->pos].offset;
  int cw = st->ci[st->pos + 1].dpyoff - st->ci[st->pos].dpyoff;
  int i;

  memmove (str, str + cl, strlen (str) + 1);

  st->len--;
  for (i = st->pos; i <= st->len; i++)
    {
      st->ci[i].offset = st->ci[i + 1].offset - cl;
      st->ci[i].dpyoff = st->ci[i + 1].dpyoff - cw;
    }
}

/* Add a character at the given position in string. */
static void
getstr_ins_char (struct getstr_status *st, char *c)
{
  char *str = st->s + st->ci[st->pos].offset;
  int cl = UTF8_LENGTH (c[0]);
  int cw = utf8_width (c);
  int i;

  memmove (str + cl, str, strlen (str) + 1);
  for (i = 0; i < cl; i++, str++)
    *str = c[i];

  for (i = st->len; i >= st->pos; i--)
    {
      st->ci[i + 1].offset = st->ci[i].offset + cl;
      st->ci[i + 1].dpyoff = st->ci[i].dpyoff + cw;
    }
  st->len++;
}

static void
bell (void)
{
  putchar ('\a');
}

/* Initialize getstring data structure. */
static void
getstr_init (struct getstr_status *st, char *str, struct getstr_charinfo *ci)
{
  int width;

  st->s = str;
  st->ci = ci;

  st->len = width = 0;
  while (*str)
    {
      st->ci[st->len].offset = str - st->s;
      st->ci[st->len].dpyoff = width;

      st->len++;
      width += utf8_width (str);
      str += UTF8_LENGTH (*str);
    }
  st->ci[st->len].offset = str - st->s;
  st->ci[st->len].dpyoff = width;

  st->pos = st->len;
  st->scrpos = 0;
}

/* Scroll left/right if the cursor moves outside the window range. */
static void
getstr_fixscr (struct getstr_status *st)
{
  const int pgsize = col / 3;
  int pgskip;

  while (st->pos < st->scrpos)
    {
      pgskip = 0;
      while (pgskip < pgsize && st->scrpos > 0)
        {
          st->scrpos--;
          pgskip += st->ci[st->scrpos + 1].dpyoff - st->ci[st->scrpos].dpyoff;
        }
    }
  while (st->ci[st->pos].dpyoff - st->ci[st->scrpos].dpyoff > col - 2)
    {
      pgskip = 0;
      while (pgskip < pgsize && st->scrpos < st->len)
        {
          pgskip += st->ci[st->scrpos + 1].dpyoff - st->ci[st->scrpos].dpyoff;
          st->scrpos++;
        }
    }
}

/*
 * Getstring allows to get user input and to print it on a window,
 * even if noecho() is on. This function is also used to modify an existing
 * text (the variable string can be non-NULL).
 * We need to do the echoing manually because of the multi-threading
 * environment, otherwise the cursor would move from place to place without
 * control.
 */
enum getstr
getstring (WINDOW *win, char *str, int l, int x, int y)
{
  struct getstr_status st;
  struct getstr_charinfo ci[l + 1];

  int ch, k;
  char c[UTF8_MAXLEN];

  getstr_init (&st, str, ci);
  custom_apply_attr (win, ATTR_HIGHEST);

  for (;;) {
    getstr_fixscr (&st);
    getstr_print (win, x, y, &st);
    wins_doupdate ();

    if ((ch = wgetch (win)) == '\n') break;
    switch (ch)
      {
        case KEY_BACKSPACE:     /* delete one character */
        case 330:
        case 127:
        case CTRL ('H'):
          if (st.pos > 0)
            {
              st.pos--;
              getstr_del_char (&st);
            }
          else
            bell ();
          break;
        case CTRL ('D'):        /* delete next character */
          if (st.pos < st.len)
            getstr_del_char (&st);
          else
            bell ();
          break;
        case CTRL ('W'):        /* delete a word */
          if (st.pos > 0) {
            while (st.pos && st.s[st.ci[st.pos - 1].offset] == ' ')
              {
                st.pos--;
                getstr_del_char (&st);
              }
            while (st.pos && st.s[st.ci[st.pos - 1].offset] != ' ')
              {
                st.pos--;
                getstr_del_char (&st);
              }
          }
          else
            bell ();
          break;
        case CTRL ('K'):        /* delete to end-of-line */
          st.s[st.ci[st.pos].offset] = 0;
          st.len = st.pos;
          break;
        case CTRL ('A'):        /* go to begginning of string */
          st.pos = 0;
          break;
        case CTRL ('E'):        /* go to end of string */
          st.pos = st.len;
          break;
        case KEY_LEFT:          /* move one char backward  */
        case CTRL ('B'):
          if (st.pos > 0) st.pos--;
          break;
        case KEY_RIGHT:         /* move one char forward */
        case CTRL ('F'):
          if (st.pos < st.len) st.pos++;
          break;
        case ESCAPE:            /* cancel editing */
          return (GETSTRING_ESC);
          break;
        default:                /* insert one character */
          c[0] = ch;
          for (k = 1; k < MIN (UTF8_LENGTH (c[0]), UTF8_MAXLEN); k++)
            c[k] = (unsigned char)wgetch (win);
          if (st.ci[st.len].offset + k < l)
            {
              getstr_ins_char (&st, c);
              st.pos++;
            }
      }
  }

  custom_remove_attr (win, ATTR_HIGHEST);

  return (st.len == 0 ? GETSTRING_RET : GETSTRING_VALID);
}

/* Update an already existing string. */
int
updatestring (WINDOW *win, char **str, int x, int y)
{
  int len = strlen (*str);
  char *buf;
  enum getstr ret;

  EXIT_IF (len + 1 > BUFSIZ, _("Internal error: line too long"));

  buf = mem_malloc (BUFSIZ);
  memcpy (buf, *str, len + 1);

  ret = getstring (win, buf, BUFSIZ, x, y);

  if (ret == GETSTRING_VALID)
    {
      len = strlen (buf);
      *str = mem_realloc (*str, len + 1, 1);
      EXIT_IF (*str == NULL, _("out of memory"));
      memcpy (*str, buf, len + 1);
    }

  mem_free (buf);
  return ret;
}