my homework was late :-)

[midnight-commander.git] / gtkedit / edit.c

/* editor low level data handling and cursor fundamentals.

   Copyright (C) 1996, 1997 the Free Software Foundation
   
   Authors: 1996, 1997 Paul Sheer

   $Id$

   This program 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 2 of the License, or
   (at your option) any later version.
   
   This program 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 this program; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
   02111-1307, USA.
*/

#define _EDIT_C THIS_IS

#include <config.h>
#if defined(NEEDS_IO_H)
#    include <io.h>
#    include <fcntl.h>
#    define CR_LF_TRANSLATION
#endif
#include "edit.h"

#ifdef SCO_FLAVOR
#       include <sys/timeb.h>
#endif /* SCO_FLAVOR */
#include <time.h>       /* for ctime() */
#if defined (HAVE_MAD) && ! defined (MIDNIGHT) && ! defined (GTK)
#include "mad.h"
#endif

#include <../src/dialog.h> /* MSG_ERROR */

extern char *edit_one_file;

/*
 *
 * here's a quick sketch of the layout: (don't run this through indent.)
 * 
 * (b1 is buffers1 and b2 is buffers2)
 * 
 *                                       |
 * \0\0\0\0\0m e _ f i l e . \nf i n . \n|T h i s _ i s _ s o\0\0\0\0\0\0\0\0\0
 * ______________________________________|______________________________________
 *                                       |
 * ...  |  b2[2]   |  b2[1]   |  b2[0]   |  b1[0]   |  b1[1]   |  b1[2]   | ...
 *      |->        |->        |->        |->        |->        |->        |
 *                                       |
 *           _<------------------------->|<----------------->_
 *                   WEdit->curs2        |   WEdit->curs1
 *           ^                           |                   ^
 *           |                          ^|^                  |
 *         cursor                       |||                cursor
 *                                      |||
 *                              file end|||file beginning
 *                                       |
 *                                       |
 * 
 *           _
 * This_is_some_file
 * fin.
 *
 *
 */

/*
   returns a byte from any location in the file.
   Returns '\n' if out of bounds.
 */

static int push_action_disabled = 0;

#ifndef NO_INLINE_GETBYTE

int edit_get_byte (WEdit * edit, long byte_index)
{
    unsigned long p;
    if (byte_index >= (edit->curs1 + edit->curs2) || byte_index < 0)
        return '\n';

    if (byte_index >= edit->curs1) {
        p = edit->curs1 + edit->curs2 - byte_index - 1;
        return edit->buffers2[p >> S_EDIT_BUF_SIZE][EDIT_BUF_SIZE - (p & M_EDIT_BUF_SIZE) - 1];
    } else {
        return edit->buffers1[byte_index >> S_EDIT_BUF_SIZE][byte_index & M_EDIT_BUF_SIZE];
    }
}

#endif

char *edit_get_buffer_as_text (WEdit * e)
{
    int l, i;
    char *t;
    l = e->curs1 + e->curs2;
    t = CMalloc (l + 1);
    for (i = 0; i < l; i++)
        t[i] = edit_get_byte (e, i);
    t[l] = 0;
    return t;
}


/* Note on CRLF->LF translation: */

#if MY_O_TEXT
#error MY_O_TEXT is depreciated. CR_LF_TRANSLATION must be defined which does CR-LF translation internally. See note in source.
#endif

/* 
   The edit_open_file (previously edit_load_file) function uses
   init_dynamic_edit_buffers to load a file. This is unnecessary
   since you can just as well fopen the file and insert the
   characters one by one. The real reason for
   init_dynamic_edit_buffers (besides allocating the buffers) is
   as an optimisation - it uses raw block reads and inserts large
   chunks at a time. It is hence extremely fast at loading files.
   Where we might not want to use it is if we were doing
   CRLF->LF translation or if we were reading from a pipe.
 */

/* Initialisation routines */

/* returns 1 on error */
/* loads file OR text into buffers. Only one must be none-NULL. */
/* cursor set to start of file */
int init_dynamic_edit_buffers (WEdit * edit, const char *filename, const char *text)
{
    long buf;
    int j, file = -1, buf2;

    for (j = 0; j <= MAXBUFF; j++) {
        edit->buffers1[j] = NULL;
        edit->buffers2[j] = NULL;
    }

    if (filename)
        if ((file = open ((char *) filename, O_RDONLY)) == -1) {
/* The file-name is printed after the ':' */
            edit_error_dialog (_ (" Error "), get_sys_error (catstrs (_ (" Failed trying to open file for reading: "), filename, " ", 0)));
            return 1;
        }
    edit->curs2 = edit->last_byte;

    buf2 = edit->curs2 >> S_EDIT_BUF_SIZE;

    edit->buffers2[buf2] = CMalloc (EDIT_BUF_SIZE);

    if (filename) {
        read (file, (char *) edit->buffers2[buf2] + EDIT_BUF_SIZE - (edit->curs2 & M_EDIT_BUF_SIZE), edit->curs2 & M_EDIT_BUF_SIZE);
    } else {
        memcpy (edit->buffers2[buf2] + EDIT_BUF_SIZE - (edit->curs2 & M_EDIT_BUF_SIZE), text, edit->curs2 & M_EDIT_BUF_SIZE);
        text += edit->curs2 & M_EDIT_BUF_SIZE;
    }

    for (buf = buf2 - 1; buf >= 0; buf--) {
        edit->buffers2[buf] = CMalloc (EDIT_BUF_SIZE);
        if (filename) {
            read (file, (char *) edit->buffers2[buf], EDIT_BUF_SIZE);
        } else {
            memcpy (edit->buffers2[buf], text, EDIT_BUF_SIZE);
            text += EDIT_BUF_SIZE;
        }
    }

    edit->curs1 = 0;
    if (file != -1)
        close (file);
    return 0;
}

/* detecting an error on save is easy: just check if every byte has been written. */
/* detecting an error on read, is not so easy 'cos there is not way to tell
   whether you read everything or not. */
/* FIXME: add proper `triple_pipe_open' to read, write and check errors. */
static const struct edit_filters {
    char *read, *write, *extension;
} all_filters[] = {

    {
        "bzip2 -cd %s 2>&1", "bzip2 > %s", ".bz2"
    },
    {
        "gzip -cd %s 2>&1", "gzip > %s", ".gz"
    },
    {
        "compress -cd %s 2>&1", "compress > %s", ".Z"
    }
};

static int edit_find_filter (const char *filename)
{
    int i, l;
    if (!filename)
        return -1;
    l = strlen (filename);
    for (i = 0; i < sizeof (all_filters) / sizeof (struct edit_filters); i++) {
        int e;
        e = strlen (all_filters[i].extension);
        if (l > e)
            if (!strcmp (all_filters[i].extension, filename + l - e))
                return i;
    }
    return -1;
}

char *edit_get_filter (const char *filename)
{
    int i, l;
    char *p;
    i = edit_find_filter (filename);
    if (i < 0)
        return 0;
    l = strlen (filename);
    p = malloc (strlen (all_filters[i].read) + l + 2);
    sprintf (p, all_filters[i].read, filename);
    return p;
}

char *edit_get_write_filter (char *writename, const char *filename)
{
    int i, l;
    char *p;
    i = edit_find_filter (filename);
    if (i < 0)
        return 0;
    l = strlen (writename);
    p = malloc (strlen (all_filters[i].write) + l + 2);
    sprintf (p, all_filters[i].write, writename);
    return p;
}

#ifdef CR_LF_TRANSLATION
/* reads into buffer, replace \r\n with \n */
long edit_insert_stream (WEdit * edit, FILE * f)
{
    int a = -1, b;
    long i;
    while ((b = fgetc (f))) {
        if (a == '\r' && b == '\n') {
            edit_insert (edit, '\n');
            i++;
            a = -1;
            continue;
        } else if (a >= 0) {
            edit_insert (edit, a);
            i++;
        }
        a = b;
    }
    if (a >= 0)
        edit_insert (edit, a);
    return i;
}
/* writes buffer, replaces, replace \n with \r\n */
long edit_write_stream (WEdit * edit, FILE * f)
{
    long i;
    int c;
    for (i = 0; i < edit->last_byte; i++) {
        c = edit_get_byte (edit, i);
        if (c == '\n') {
            if (fputc ('\r', f) < 0)
                break;
            if (fputc ('\n', f) < 0)
                break;
        } else {
            if (fputc (c, f) < 0)
                break;
        }
    }
    return i;
}
#else /* CR_LF_TRANSLATION */
long edit_insert_stream (WEdit * edit, FILE * f)
{
    int c;
    long i = 0;
    while ((c = fgetc (f)) >= 0) {
        edit_insert (edit, c);
        i++;
    }
    return i;
}
long edit_write_stream (WEdit * edit, FILE * f)
{
    long i;
    for (i = 0; i < edit->last_byte; i++)
        if (fputc (edit_get_byte (edit, i), f) < 0)
            break;
    return i;
}
#endif /* CR_LF_TRANSLATION */

#define TEMP_BUF_LEN 1024

/* inserts a file at the cursor, returns 1 on success */
int edit_insert_file (WEdit * edit, const char *filename)
{
    char *p;
    if ((p = edit_get_filter (filename))) {
        FILE *f;
        long current = edit->curs1;
        f = (FILE *) popen (p, "r");
        if (f) {
            edit_insert_stream (edit, f);
            edit_cursor_move (edit, current - edit->curs1);
            if (pclose (f) > 0) {
                edit_error_dialog (_ (" Error "), catstrs (_ (" Error reading from pipe: "), p, " ", 0));
                free (p);
                return 0;
            }
        } else {
            edit_error_dialog (_ (" Error "), get_sys_error (catstrs (_ (" Failed trying to open pipe for reading: "), p, " ", 0)));
            free (p);
            return 0;
        }
        free (p);
#ifdef CR_LF_TRANSLATION
    } else {
        FILE *f;
        long current = edit->curs1;
        f = fopen (filename, "r");
        if (f) {
            edit_insert_stream (edit, f);
            edit_cursor_move (edit, current - edit->curs1);
            if (fclose (f)) {
                edit_error_dialog (_ (" Error "), get_sys_error (catstrs (_ (" Error reading file: "), filename, " ", 0)));
                return 0;
            }
        } else {
            edit_error_dialog (_ (" Error "), get_sys_error (catstrs (_ (" Failed trying to open file for reading: "), filename, " ", 0)));
            return 0;
        }
#else
    } else {
        int i, file, blocklen;
        long current = edit->curs1;
        unsigned char *buf;
        if ((file = open ((char *) filename, O_RDONLY)) == -1)
            return 0;
        buf = malloc (TEMP_BUF_LEN);
        while ((blocklen = read (file, (char *) buf, TEMP_BUF_LEN)) > 0) {
            for (i = 0; i < blocklen; i++)
                edit_insert (edit, buf[i]);
        }
        edit_cursor_move (edit, current - edit->curs1);
        free (buf);
        close (file);
        if (blocklen)
            return 0;
#endif
    }
    return 1;
}

static int check_file_access (WEdit *edit, const char *filename, struct stat *st)
{
    int file;
#if defined(MIDNIGHT) || defined(GTK)
    if ((file = open ((char *) filename, O_RDONLY)) < 0) {
        close (creat ((char *) filename, 0666));
        if ((file = open ((char *) filename, O_RDONLY)) < 0) {
            edit_error_dialog (_ (" Error "), get_sys_error (catstrs (_ (" Failed trying to open file for reading: "), filename, " ", 0)));
            return 2;
        }
    }
#else
    if ((file = open ((char *) filename, O_RDONLY)) < 0) {
        edit_error_dialog (_ (" Error "), get_sys_error (catstrs (_ (" Failed trying to open file for reading: "), filename, " ", 0)));
        return 1;
    }
#endif
    if (stat ((char *) filename, st) < 0) {
        close (file);
/* The file-name is printed after the ':' */
        edit_error_dialog (_ (" Error "), get_sys_error (catstrs (_ (" Cannot get size/permissions info on file: "), filename, " ", 0)));
        return 1;
    }
    if (S_ISDIR (st->st_mode) || S_ISSOCK (st->st_mode)
        || S_ISFIFO (st->st_mode)) {
        close (file);
/* The file-name is printed after the ':' */
        edit_error_dialog (_ (" Error "), catstrs (_ (" Not an ordinary file: "), filename, " ", 0));
        return 1;
    }
    if (st->st_size >= SIZE_LIMIT) {
        close (file);
/* The file-name is printed after the ':' */
        edit_error_dialog (_ (" Error "), catstrs (_ (" File is too large: "), \
                                                   filename, _ (" \n Increase edit.h:MAXBUF and recompile the editor. "), 0));
        return 1;
    }
    close (file);
    return 0;
}

/* returns 1 on error */
int edit_open_file (WEdit * edit, const char *filename, const char *text, unsigned long text_size)
{
    struct stat st;
    if (text) {
        edit->last_byte = text_size;
        filename = 0;
    } else {
        int r;
        r = check_file_access (edit, filename, &st);
#if defined(MIDNIGHT) || defined(GTK)
        if (r == 2)
            return edit->delete_file = 1;
#endif
        if (r)
            return 1;
        edit->stat = st;
#ifndef CR_LF_TRANSLATION
        edit->last_byte = st.st_size;
#else
/* going to read the file into the buffer later byte by byte */
        edit->last_byte = 0;
        filename = 0;
        text = "";
#endif
    }
    return init_dynamic_edit_buffers (edit, filename, text);
}

#ifdef MIDNIGHT
#define space_width 1
#else
int space_width;
extern int option_long_whitespace;

void edit_set_space_width (int s)
{
    space_width = s;
}

int (*edit_file_is_open) (char *) = 0;

#endif

/* fills in the edit struct. returns 0 on fail. Pass edit as NULL for this */
WEdit *edit_init (WEdit * edit, int lines, int columns, const char *filename, const char *text, const char *dir, unsigned long text_size)
{
    char *f;
    int to_free = 0;
    int use_filter = 0;
#ifndef MIDNIGHT
    if (option_long_whitespace)
        edit_set_space_width (FONT_PER_CHAR[' '] * 2);
    else
        edit_set_space_width (FONT_PER_CHAR[' ']);
#endif
    if (!edit) {
#ifdef ENABLE_NLS
        /* 
         * Expand option_whole_chars_search by national letters using
         * current locale
         */

        static char option_whole_chars_search_buf [256];

        if (option_whole_chars_search_buf != option_whole_chars_search) {
            int i;
            int len = strlen (option_whole_chars_search);

            strcpy (option_whole_chars_search_buf, option_whole_chars_search);

            for (i = 1; i <= sizeof (option_whole_chars_search_buf); i++) {
                if (islower (i) && !strchr (option_whole_chars_search, i)) {
                    option_whole_chars_search_buf [len++] = i;
                }
            }

            option_whole_chars_search_buf [len] = 0;
            option_whole_chars_search = option_whole_chars_search_buf;
        }
#endif  /* ENABLE_NLS */
        edit = malloc (sizeof (WEdit));
        memset (edit, 0, sizeof (WEdit));
        to_free = 1;
    }
    memset (&(edit->from_here), 0, (unsigned long) &(edit->to_here) - (unsigned long) &(edit->from_here));
#ifndef MIDNIGHT
    edit->max_column = columns * FONT_MEAN_WIDTH;
#endif
    edit->num_widget_lines = lines;
    edit->num_widget_columns = columns;
    edit->stat.st_mode = S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH;
    edit->stat.st_uid = getuid ();
    edit->stat.st_gid = getgid ();
    edit->bracket = -1;
    if (!dir)
        dir = "";
    f = (char *) filename;
    if (filename) {
        f = catstrs (dir, filename, 0);
#ifndef MIDNIGHT
        if (edit_file_is_open)
            if ((*edit_file_is_open) (f)) {
                if (to_free)
                    free (edit);
                return 0;
            }
#endif
    }
    if (edit_find_filter (f) < 0) {
#ifdef CR_LF_TRANSLATION
        use_filter = 1;
#endif
        if (edit_open_file (edit, f, text, text_size)) {
/* edit_load_file already gives an error message */
            if (to_free)
                free (edit);
            return 0;
        }
    } else {
        use_filter = 1;
        if (edit_open_file (edit, 0, "", 0)) {
            if (to_free)
                free (edit);
            return 0;
        }
    }
    edit->force |= REDRAW_PAGE;
    if (filename) {
        filename = catstrs (dir, filename, 0);
        edit_split_filename (edit, (char *) filename);
    } else {
        edit->filename = (char *) strdup ("");
        edit->dir = (char *) strdup (dir);
    }
    edit->stack_size = START_STACK_SIZE;
    edit->stack_size_mask = START_STACK_SIZE - 1;
    edit->undo_stack = malloc ((edit->stack_size + 10) * sizeof (long));
    edit->total_lines = edit_count_lines (edit, 0, edit->last_byte);
    if (use_filter) {
        struct stat st;
        push_action_disabled = 1;
        if (check_file_access (edit, filename, &st)) {
            edit_clean (edit);
            if (to_free)
                free (edit);
            return 0;
        }
        edit->stat = st;
        if (!edit_insert_file (edit, f)) {
            edit_clean (edit);
            if (to_free)
                free (edit);
            return 0;
        }
/* FIXME: this should be an unmodification() function */
        push_action_disabled = 0;
    }
    edit->modified = 0;
    edit_load_syntax (edit, 0, 0);
    {
        int fg, bg;
        edit_get_syntax_color (edit, -1, &fg, &bg);
    }
    return edit;
}

/* clear the edit struct, freeing everything in it. returns 1 on success */
int edit_clean (WEdit * edit)
{
    if (edit) {
        int j = 0;
        edit_free_syntax_rules (edit);
        book_mark_flush (edit, -1);
        for (; j <= MAXBUFF; j++) {
            if (edit->buffers1[j] != NULL)
                free (edit->buffers1[j]);
            if (edit->buffers2[j] != NULL)
                free (edit->buffers2[j]);
        }

        if (edit->undo_stack)
            free (edit->undo_stack);
        if (edit->filename)
            free (edit->filename);
        if (edit->dir)
            free (edit->dir);
/* we don't want to clear the widget */
        memset (&(edit->from_here), 0, (unsigned long) &(edit->to_here) - (unsigned long) &(edit->from_here));
        return 1;
    }
    return 0;
}


/* returns 1 on success */
int edit_renew (WEdit * edit)
{
    int lines = edit->num_widget_lines;
    int columns = edit->num_widget_columns;
    char *dir;

    if (edit->dir)
        dir = (char *) strdup (edit->dir);
    else
        dir = 0;
    
    edit_clean (edit);
    if (!edit_init (edit, lines, columns, 0, "", dir, 0))
        return 0;
    return 1;
}

/* returns 1 on success, if returns 0, the edit struct would have been free'd */
int edit_reload (WEdit * edit, const char *filename, const char *text, const char *dir, unsigned long text_size)
{
    WEdit *e;
    int lines = edit->num_widget_lines;
    int columns = edit->num_widget_columns;
    e = malloc (sizeof (WEdit));
    memset (e, 0, sizeof (WEdit));
    e->widget = edit->widget;
    e->macro_i = -1;
    if (!edit_init (e, lines, columns, filename, text, dir, text_size)) {
        free (e);
        return 0;
    }
    edit_clean (edit);
    memcpy (edit, e, sizeof (WEdit));
    free (e);
    return 1;
}


/*
   Recording stack for undo:
   The following is an implementation of a compressed stack. Identical
   pushes are recorded by a negative prefix indicating the number of times the
   same char was pushed. This saves space for repeated curs-left or curs-right
   delete etc.

   eg:

  pushed:       stored:

   a
   b             a
   b            -3
   b             b
   c  -->       -4
   c             c
   c             d
   c
   d

   If the stack long int is 0-255 it represents a normal insert (from a backspace),
   256-512 is an insert ahead (from a delete), If it is betwen 600 and 700 it is one
   of the cursor functions #define'd in edit.h. 1000 through 700'000'000 is to
   set edit->mark1 position. 700'000'000 through 1400'000'000 is to set edit->mark2
   position.

   The only way the cursor moves or the buffer is changed is through the routines:
   insert, backspace, insert_ahead, delete, and cursor_move.
   These record the reverse undo movements onto the stack each time they are
   called.

   Each key press results in a set of actions (insert; delete ...). So each time
   a key is pressed the current position of start_display is pushed as
   KEY_PRESS + start_display. Then for undoing, we pop until we get to a number
   over KEY_PRESS. We then assign this number less KEY_PRESS to start_display. So undo
   tracks scrolling and key actions exactly. (KEY_PRESS is about (2^31) * (2/3) = 1400'000'000)

*/

void edit_push_action (WEdit * edit, long c,...)
{
    unsigned long sp = edit->stack_pointer;
    unsigned long spm1;
    long *t;
/* first enlarge the stack if necessary */
    if (sp > edit->stack_size - 10) {   /* say */
        if (option_max_undo < 256)
            option_max_undo = 256;
        if (edit->stack_size < option_max_undo) {
            t = malloc ((edit->stack_size * 2 + 10) * sizeof (long));
            if (t) {
                memcpy (t, edit->undo_stack, sizeof (long) * edit->stack_size);
                free (edit->undo_stack);
                edit->undo_stack = t;
                edit->stack_size <<= 1;
                edit->stack_size_mask = edit->stack_size - 1;
            }
        }
    }
    spm1 = (edit->stack_pointer - 1) & edit->stack_size_mask;
    if (push_action_disabled)
        return;

#ifdef FAST_MOVE_CURSOR
    if (c == CURS_LEFT_LOTS || c == CURS_RIGHT_LOTS) {
        va_list ap;
        edit->undo_stack[sp] = c == CURS_LEFT_LOTS ? CURS_LEFT : CURS_RIGHT;
        edit->stack_pointer = (edit->stack_pointer + 1) & edit->stack_size_mask;
        va_start (ap, c);
        c = -(va_arg (ap, int));
        va_end (ap);
    } else
#endif                          /* ! FAST_MOVE_CURSOR */
    if (spm1 != edit->stack_bottom && ((sp - 2) & edit->stack_size_mask) != edit->stack_bottom) {
        int d;
        if (edit->undo_stack[spm1] < 0) {
            d = edit->undo_stack[(sp - 2) & edit->stack_size_mask];
            if (d == c) {
                if (edit->undo_stack[spm1] > -1000000000) {
                    if (c < KEY_PRESS)  /* --> no need to push multiple do-nothings */
                        edit->undo_stack[spm1]--;
                    return;
                }
            }
/* #define NO_STACK_CURSMOVE_ANIHILATION */
#ifndef NO_STACK_CURSMOVE_ANIHILATION
            else if ((c == CURS_LEFT && d == CURS_RIGHT)
                     || (c == CURS_RIGHT && d == CURS_LEFT)) {  /* a left then a right anihilate each other */
                if (edit->undo_stack[spm1] == -2)
                    edit->stack_pointer = spm1;
                else
                    edit->undo_stack[spm1]++;
                return;
            }
#endif
        } else {
            d = edit->undo_stack[spm1];
            if (d == c) {
                if (c >= KEY_PRESS)
                    return;     /* --> no need to push multiple do-nothings */
                edit->undo_stack[sp] = -2;
                goto check_bottom;
            }
#ifndef NO_STACK_CURSMOVE_ANIHILATION
            else if ((c == CURS_LEFT && d == CURS_RIGHT)
                     || (c == CURS_RIGHT && d == CURS_LEFT)) {  /* a left then a right anihilate each other */
                edit->stack_pointer = spm1;
                return;
            }
#endif
        }
    }
    edit->undo_stack[sp] = c;
  check_bottom:

    edit->stack_pointer = (edit->stack_pointer + 1) & edit->stack_size_mask;

/*if the sp wraps round and catches the stack_bottom then erase the first set of actions on the stack to make space - by moving stack_bottom forward one "key press" */
    c = (edit->stack_pointer + 2) & edit->stack_size_mask;
    if (c == edit->stack_bottom || ((c + 1) & edit->stack_size_mask) == edit->stack_bottom)
        do {
            edit->stack_bottom = (edit->stack_bottom + 1) & edit->stack_size_mask;
        } while (edit->undo_stack[edit->stack_bottom] < KEY_PRESS && edit->stack_bottom != edit->stack_pointer);

/*If a single key produced enough pushes to wrap all the way round then we would notice that the [stack_bottom] does not contain KEY_PRESS. The stack is then initialised: */
    if (edit->stack_pointer != edit->stack_bottom && edit->undo_stack[edit->stack_bottom] < KEY_PRESS)
        edit->stack_bottom = edit->stack_pointer = 0;
}

/*
   TODO: if the user undos until the stack bottom, and the stack has not wrapped,
   then the file should be as it was when he loaded up. Then set edit->modified to 0.
 */
long pop_action (WEdit * edit)
{
    long c;
    unsigned long sp = edit->stack_pointer;
    if (sp == edit->stack_bottom) {
        return STACK_BOTTOM;
    }
    sp = (sp - 1) & edit->stack_size_mask;
    if ((c = edit->undo_stack[sp]) >= 0) {
/*      edit->undo_stack[sp] = '@'; */
        edit->stack_pointer = (edit->stack_pointer - 1) & edit->stack_size_mask;
        return c;
    }
    if (sp == edit->stack_bottom) {
        return STACK_BOTTOM;
    }
    c = edit->undo_stack[(sp - 1) & edit->stack_size_mask];
    if (edit->undo_stack[sp] == -2) {
/*      edit->undo_stack[sp] = '@'; */
        edit->stack_pointer = sp;
    } else
        edit->undo_stack[sp]++;

    return c;
}

/* is called whenever a modification is made by one of the four routines below */
static inline void edit_modification (WEdit * edit)
{
    edit->caches_valid = 0;
    edit->modified = 1;
    edit->screen_modified = 1;
}

/*
   Basic low level single character buffer alterations and movements at the cursor.
   Returns char passed over, inserted or removed.
 */

void edit_insert (WEdit * edit, int c)
{
/* check if file has grown to large */
    if (edit->last_byte >= SIZE_LIMIT)
        return;

/* first we must update the position of the display window */
    if (edit->curs1 < edit->start_display) {
        edit->start_display++;
        if (c == '\n')
            edit->start_line++;
    }
/* now we must update some info on the file and check if a redraw is required */
    if (c == '\n') {
        if (edit->book_mark)
            book_mark_inc (edit, edit->curs_line);
        edit->curs_line++;
        edit->total_lines++;
        edit->force |= REDRAW_LINE_ABOVE | REDRAW_AFTER_CURSOR;
    }
/* tell that we've modified the file */
    edit_modification (edit);

/* save the reverse command onto the undo stack */
    edit_push_action (edit, BACKSPACE);

/* update markers */
    edit->mark1 += (edit->mark1 > edit->curs1);
    edit->mark2 += (edit->mark2 > edit->curs1);
    edit->last_get_rule += (edit->last_get_rule > edit->curs1);

/* add a new buffer if we've reached the end of the last one */
    if (!(edit->curs1 & M_EDIT_BUF_SIZE))
        edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE] = malloc (EDIT_BUF_SIZE);

/* perfprm the insertion */
    edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE][edit->curs1 & M_EDIT_BUF_SIZE] = (unsigned char) c;

/* update file length */
    edit->last_byte++;

/* update cursor position */
    edit->curs1++;
}


/* same as edit_insert and move left */
void edit_insert_ahead (WEdit * edit, int c)
{
    if (edit->last_byte >= SIZE_LIMIT)
        return;
    if (edit->curs1 < edit->start_display) {
        edit->start_display++;
        if (c == '\n')
            edit->start_line++;
    }
    if (c == '\n') {
        if (edit->book_mark)
            book_mark_inc (edit, edit->curs_line);
        edit->total_lines++;
        edit->force |= REDRAW_AFTER_CURSOR;
    }
    edit_modification (edit);
    edit_push_action (edit, DELETE);

    edit->mark1 += (edit->mark1 >= edit->curs1);
    edit->mark2 += (edit->mark2 >= edit->curs1);
    edit->last_get_rule += (edit->last_get_rule >= edit->curs1);

    if (!((edit->curs2 + 1) & M_EDIT_BUF_SIZE))
        edit->buffers2[(edit->curs2 + 1) >> S_EDIT_BUF_SIZE] = malloc (EDIT_BUF_SIZE);
    edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE][EDIT_BUF_SIZE - (edit->curs2 & M_EDIT_BUF_SIZE) - 1] = c;

    edit->last_byte++;
    edit->curs2++;
}


int edit_delete (WEdit * edit)
{
    int p;
    if (!edit->curs2)
        return 0;

    edit->mark1 -= (edit->mark1 > edit->curs1);
    edit->mark2 -= (edit->mark2 > edit->curs1);
    edit->last_get_rule -= (edit->last_get_rule > edit->curs1);

    p = edit->buffers2[(edit->curs2 - 1) >> S_EDIT_BUF_SIZE][EDIT_BUF_SIZE - ((edit->curs2 - 1) & M_EDIT_BUF_SIZE) - 1];

    if (!(edit->curs2 & M_EDIT_BUF_SIZE)) {
        free (edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE]);
        edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE] = NULL;
    }
    edit->last_byte--;
    edit->curs2--;

    if (p == '\n') {
        if (edit->book_mark)
            book_mark_dec (edit, edit->curs_line);
        edit->total_lines--;
        edit->force |= REDRAW_AFTER_CURSOR;
    }
    edit_push_action (edit, p + 256);
    if (edit->curs1 < edit->start_display) {
        edit->start_display--;
        if (p == '\n')
            edit->start_line--;
    }
    edit_modification (edit);

    return p;
}


int edit_backspace (WEdit * edit)
{
    int p;
    if (!edit->curs1)
        return 0;

    edit->mark1 -= (edit->mark1 >= edit->curs1);
    edit->mark2 -= (edit->mark2 >= edit->curs1);
    edit->last_get_rule -= (edit->last_get_rule >= edit->curs1);

    p = *(edit->buffers1[(edit->curs1 - 1) >> S_EDIT_BUF_SIZE] + ((edit->curs1 - 1) & M_EDIT_BUF_SIZE));
    if (!((edit->curs1 - 1) & M_EDIT_BUF_SIZE)) {
        free (edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE]);
        edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE] = NULL;
    }
    edit->last_byte--;
    edit->curs1--;

    if (p == '\n') {
        if (edit->book_mark)
            book_mark_dec (edit, edit->curs_line);
        edit->curs_line--;
        edit->total_lines--;
        edit->force |= REDRAW_AFTER_CURSOR;
    }
    edit_push_action (edit, p);

    if (edit->curs1 < edit->start_display) {
        edit->start_display--;
        if (p == '\n')
            edit->start_line--;
    }
    edit_modification (edit);

    return p;
}

#ifdef FAST_MOVE_CURSOR

static void memqcpy (WEdit * edit, unsigned char *dest, unsigned char *src, int n)
{
    unsigned long next;
    while ((next = (unsigned long) memccpy (dest, src, '\n', n))) {
        edit->curs_line--;
        next -= (unsigned long) dest;
        n -= next;
        src += next;
        dest += next;
    }
}

int edit_move_backward_lots (WEdit * edit, long increment)
{
    int r, s, t;
    unsigned char *p;

    if (increment > edit->curs1)
        increment = edit->curs1;
    if (increment <= 0)
        return -1;
    edit_push_action (edit, CURS_RIGHT_LOTS, increment);

    t = r = EDIT_BUF_SIZE - (edit->curs2 & M_EDIT_BUF_SIZE);
    if (r > increment)
        r = increment;
    s = edit->curs1 & M_EDIT_BUF_SIZE;

    p = 0;
    if (s > r) {
        memqcpy (edit, edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE] + t - r,
              edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE] + s - r, r);
    } else {
        if (s) {
            memqcpy (edit, edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE] + t - s,
                     edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE], s);
            p = edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE];
            edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE] = 0;
        }
        memqcpy (edit, edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE] + t - r,
                 edit->buffers1[(edit->curs1 >> S_EDIT_BUF_SIZE) - 1] + EDIT_BUF_SIZE - (r - s), r - s);
    }
    increment -= r;
    edit->curs1 -= r;
    edit->curs2 += r;
    if (!(edit->curs2 & M_EDIT_BUF_SIZE)) {
        if (p)
            edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE] = p;
        else
            edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE] = malloc (EDIT_BUF_SIZE);
    } else {
        if (p)
            free (p);
    }

    s = edit->curs1 & M_EDIT_BUF_SIZE;
    while (increment) {
        p = 0;
        r = EDIT_BUF_SIZE;
        if (r > increment)
            r = increment;
        t = s;
        if (r < t)
            t = r;
        memqcpy (edit,
                 edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE] + EDIT_BUF_SIZE - t,
                 edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE] + s - t,
                 t);
        if (r >= s) {
            if (t) {
                p = edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE];
                edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE] = 0;
            }
            memqcpy (edit,
                     edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE] + EDIT_BUF_SIZE - r,
                     edit->buffers1[(edit->curs1 >> S_EDIT_BUF_SIZE) - 1] + EDIT_BUF_SIZE - (r - s),
                     r - s);
        }
        increment -= r;
        edit->curs1 -= r;
        edit->curs2 += r;
        if (!(edit->curs2 & M_EDIT_BUF_SIZE)) {
            if (p)
                edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE] = p;
            else
                edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE] = malloc (EDIT_BUF_SIZE);
        } else {
            if (p)
                free (p);
        }
    }
    return edit_get_byte (edit, edit->curs1);
}

#endif          /* ! FAST_MOVE_CURSOR */

/* moves the cursor right or left: increment positive or negative respectively */
int edit_cursor_move (WEdit * edit, long increment)
{
/* this is the same as a combination of two of the above routines, with only one push onto the undo stack */
    int c;

#ifdef FAST_MOVE_CURSOR
    if (increment < -256) {
        edit->force |= REDRAW_PAGE;
        return edit_move_backward_lots (edit, -increment);
    }
#endif          /* ! FAST_MOVE_CURSOR */

    if (increment < 0) {
        for (; increment < 0; increment++) {
            if (!edit->curs1)
                return -1;

            edit_push_action (edit, CURS_RIGHT);

            c = edit_get_byte (edit, edit->curs1 - 1);
            if (!((edit->curs2 + 1) & M_EDIT_BUF_SIZE))
                edit->buffers2[(edit->curs2 + 1) >> S_EDIT_BUF_SIZE] = malloc (EDIT_BUF_SIZE);
            edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE][EDIT_BUF_SIZE - (edit->curs2 & M_EDIT_BUF_SIZE) - 1] = c;
            edit->curs2++;
            c = edit->buffers1[(edit->curs1 - 1) >> S_EDIT_BUF_SIZE][(edit->curs1 - 1) & M_EDIT_BUF_SIZE];
            if (!((edit->curs1 - 1) & M_EDIT_BUF_SIZE)) {
                free (edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE]);
                edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE] = NULL;
            }
            edit->curs1--;
            if (c == '\n') {
                edit->curs_line--;
                edit->force |= REDRAW_LINE_BELOW;
            }
        }

        return c;
    } else if (increment > 0) {
        for (; increment > 0; increment--) {
            if (!edit->curs2)
                return -2;

            edit_push_action (edit, CURS_LEFT);

            c = edit_get_byte (edit, edit->curs1);
            if (!(edit->curs1 & M_EDIT_BUF_SIZE))
                edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE] = malloc (EDIT_BUF_SIZE);
            edit->buffers1[edit->curs1 >> S_EDIT_BUF_SIZE][edit->curs1 & M_EDIT_BUF_SIZE] = c;
            edit->curs1++;
            c = edit->buffers2[(edit->curs2 - 1) >> S_EDIT_BUF_SIZE][EDIT_BUF_SIZE - ((edit->curs2 - 1) & M_EDIT_BUF_SIZE) - 1];
            if (!(edit->curs2 & M_EDIT_BUF_SIZE)) {
                free (edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE]);
                edit->buffers2[edit->curs2 >> S_EDIT_BUF_SIZE] = 0;
            }
            edit->curs2--;
            if (c == '\n') {
                edit->curs_line++;
                edit->force |= REDRAW_LINE_ABOVE;
            }
        }
        return c;
    } else
        return -3;
}

/* These functions return positions relative to lines */

/* returns index of last char on line + 1 */
long edit_eol (WEdit * edit, long current)
{
    if (current < edit->last_byte) {
        for (;; current++)
            if (edit_get_byte (edit, current) == '\n')
                break;
    } else
        return edit->last_byte;
    return current;
}

/* returns index of first char on line */
long edit_bol (WEdit * edit, long current)
{
    if (current > 0) {
        for (;; current--)
            if (edit_get_byte (edit, current - 1) == '\n')
                break;
    } else
        return 0;
    return current;
}


int edit_count_lines (WEdit * edit, long current, int upto)
{
    int lines = 0;
    if (upto > edit->last_byte)
        upto = edit->last_byte;
    if (current < 0)
        current = 0;
    while (current < upto)
        if (edit_get_byte (edit, current++) == '\n')
            lines++;
    return lines;
}


/* If lines is zero this returns the count of lines from current to upto. */
/* If upto is zero returns index of lines forward current. */
long edit_move_forward (WEdit * edit, long current, int lines, long upto)
{
    if (upto) {
        return edit_count_lines (edit, current, upto);
    } else {
        int next;
        if (lines < 0)
            lines = 0;
        while (lines--) {
            next = edit_eol (edit, current) + 1;
            if (next > edit->last_byte)
                break;
            else
                current = next;
        }
        return current;
    }
}


/* Returns offset of 'lines' lines up from current */
long edit_move_backward (WEdit * edit, long current, int lines)
{
    if (lines < 0)
        lines = 0;
    current = edit_bol (edit, current);
    while((lines--) && current != 0)
        current = edit_bol (edit, current - 1);
    return current;
}

#ifdef MIDNIGHT
/* If cols is zero this returns the count of columns from current to upto. */
/* If upto is zero returns index of cols across from current. */
long edit_move_forward3 (WEdit * edit, long current, int cols, long upto)
{
    long p, q;
    int col = 0;

    if (upto) {
        q = upto;
        cols = -10;
    } else
        q = edit->last_byte + 2;

    for (col = 0, p = current; p < q; p++) {
        int c;
        if (cols != -10) {
            if (col == cols)
                return p;
            if (col > cols)
                return p - 1;
        }
        c = edit_get_byte (edit, p);
        if (c == '\r')
            continue;
        else
        if (c == '\t')
            col += TAB_SIZE - col % TAB_SIZE;
        else
            col++;
        /*if(edit->nroff ... */
        if (c == '\n') {
            if (upto)
                return col;
            else
                return p;
        }
    }
    return col;
}
#endif

/* returns the current column position of the cursor */
int edit_get_col (WEdit * edit)
{
    return edit_move_forward3 (edit, edit_bol (edit, edit->curs1), 0, edit->curs1);
}


/* Scrolling functions */

void edit_update_curs_row (WEdit * edit)
{
    edit->curs_row = edit->curs_line - edit->start_line;
}

void edit_update_curs_col (WEdit * edit)
{
    edit->curs_col = edit_move_forward3(edit, edit_bol(edit, edit->curs1), 0, edit->curs1);
}

/*moves the display start position up by i lines */
void edit_scroll_upward (WEdit * edit, unsigned long i)
{
    int lines_above = edit->start_line;
    if (i > lines_above)
        i = lines_above;
    if (i) {
        edit->start_line -= i;
        edit->start_display = edit_move_backward (edit, edit->start_display, i);
        edit->force |= REDRAW_PAGE;
        edit->force &= (0xfff - REDRAW_CHAR_ONLY);
#ifndef MIDNIGHT
#endif
    }
    edit_update_curs_row (edit);
}


/* returns 1 if could scroll, 0 otherwise */
void edit_scroll_downward (WEdit * edit, int i)
{
    int lines_below;
    lines_below = edit->total_lines - edit->start_line - (edit->num_widget_lines - 1);
    if (lines_below > 0) {
        if (i > lines_below)
            i = lines_below;
        edit->start_line += i;
        edit->start_display = edit_move_forward (edit, edit->start_display, i, 0);
        edit->force |= REDRAW_PAGE;
        edit->force &= (0xfff - REDRAW_CHAR_ONLY);
#ifndef MIDNIGHT
#endif
    }
    edit_update_curs_row (edit);
}

void edit_scroll_right (WEdit * edit, int i)
{
    edit->force |= REDRAW_PAGE;
    edit->force &= (0xfff - REDRAW_CHAR_ONLY);
    edit->start_col -= i;
}

void edit_scroll_left (WEdit * edit, int i)
{
    if (edit->start_col) {
        edit->start_col += i;
        if (edit->start_col > 0)
            edit->start_col = 0;
        edit->force |= REDRAW_PAGE;
        edit->force &= (0xfff - REDRAW_CHAR_ONLY);
    }
}

/* high level cursor movement commands */

static int is_in_indent (WEdit *edit)
{
    long p = edit_bol (edit, edit->curs1);
    while (p < edit->curs1)
        if (!strchr (" \t", edit_get_byte (edit, p++)))
            return 0;
    return 1;
}

static int left_of_four_spaces (WEdit *edit);

void edit_move_to_prev_col (WEdit * edit, long p)
{
    edit_cursor_move (edit, edit_move_forward3 (edit, p, edit->prev_col, 0) - edit->curs1);

    if (is_in_indent (edit) && option_fake_half_tabs) {
        edit_update_curs_col (edit);
        if (space_width)
        if (edit->curs_col % (HALF_TAB_SIZE * space_width)) {
            int q = edit->curs_col;
            edit->curs_col -= (edit->curs_col % (HALF_TAB_SIZE * space_width));
            p = edit_bol (edit, edit->curs1);
            edit_cursor_move (edit, edit_move_forward3 (edit, p, edit->curs_col, 0) - edit->curs1);
            if (!left_of_four_spaces (edit))
                edit_cursor_move (edit, edit_move_forward3 (edit, p, q, 0) - edit->curs1);
        }
    }
}


/* move i lines */
void edit_move_up (WEdit * edit, unsigned long i, int scroll)
{
    long p, l = edit->curs_line;

    if (i > l)
        i = l;
    if (i) {
        if (i > 1)
            edit->force |= REDRAW_PAGE;
        if (scroll)
            edit_scroll_upward (edit, i);

        p = edit_bol (edit, edit->curs1);
        edit_cursor_move (edit, (p = edit_move_backward (edit, p, i)) - edit->curs1);
        edit_move_to_prev_col (edit, p);

        edit->search_start = edit->curs1;
        edit->found_len = 0;
    }
}

int is_blank (WEdit * edit, long offset)
{
    long s, f;
    int c;
    s = edit_bol (edit, offset);
    f = edit_eol (edit, offset) - 1;
    while (s <= f) {
        c = edit_get_byte (edit, s++);
        if (!isspace (c))
            return 0;
    }
    return 1;
}


/* returns the offset of line i */
long edit_find_line (WEdit * edit, int line)
{
    int i, j = 0;
    int m = 2000000000;
    if (!edit->caches_valid) {
        for (i = 0; i < N_LINE_CACHES; i++)
            edit->line_numbers[i] = edit->line_offsets[i] = 0;
/* three offsets that we *know* are line 0 at 0 and these two: */
        edit->line_numbers[1] = edit->curs_line;
        edit->line_offsets[1] = edit_bol (edit, edit->curs1);
        edit->line_numbers[2] = edit->total_lines;
        edit->line_offsets[2] = edit_bol (edit, edit->last_byte);
        edit->caches_valid = 1;
    }
    if (line >= edit->total_lines)
        return edit->line_offsets[2];
    if (line <= 0)
        return 0;
/* find the closest known point */
    for (i = 0; i < N_LINE_CACHES; i++) {
        int n;
        n = abs (edit->line_numbers[i] - line);
        if (n < m) {
            m = n;
            j = i;
        }
    }
    if (m == 0)
        return edit->line_offsets[j];   /* know the offset exactly */
    if (m == 1 && j >= 3)
        i = j;                  /* one line different - caller might be looping, so stay in this cache */
    else
        i = 3 + (rand () % (N_LINE_CACHES - 3));
    if (line > edit->line_numbers[j])
        edit->line_offsets[i] = edit_move_forward (edit, edit->line_offsets[j], line - edit->line_numbers[j], 0);
    else
        edit->line_offsets[i] = edit_move_backward (edit, edit->line_offsets[j], edit->line_numbers[j] - line);
    edit->line_numbers[i] = line;
    return edit->line_offsets[i];
}

int line_is_blank (WEdit * edit, long line)
{
    return is_blank (edit, edit_find_line (edit, line));
}

/* moves up until a blank line is reached, or until just 
   before a non-blank line is reached */
static void edit_move_up_paragraph (WEdit * edit, int scroll)
{
    int i;
    if (edit->curs_line <= 1) {
        i = 0;
    } else {
        if (line_is_blank (edit, edit->curs_line)) {
            if (line_is_blank (edit, edit->curs_line - 1)) {
                for (i = edit->curs_line - 1; i; i--)
                    if (!line_is_blank (edit, i)) {
                        i++;
                        break;
                    }
            } else {
                for (i = edit->curs_line - 1; i; i--)
                    if (line_is_blank (edit, i))
                        break;
            }
        } else {
            for (i = edit->curs_line - 1; i; i--)
                if (line_is_blank (edit, i))
                    break;
        }
    }
    edit_move_up (edit, edit->curs_line - i, scroll);
}

/* move i lines */
void edit_move_down (WEdit * edit, int i, int scroll)
{
    long p, l = edit->total_lines - edit->curs_line;

    if (i > l)
        i = l;
    if (i) {
        if (i > 1)
            edit->force |= REDRAW_PAGE;
        if (scroll)
            edit_scroll_downward (edit, i);
        p = edit_bol (edit, edit->curs1);
        edit_cursor_move (edit, (p = edit_move_forward (edit, p, i, 0)) - edit->curs1);
        edit_move_to_prev_col (edit, p);

        edit->search_start = edit->curs1;
        edit->found_len = 0;
    }
}

/* moves down until a blank line is reached, or until just
   before a non-blank line is reached */
static void edit_move_down_paragraph (WEdit * edit, int scroll)
{
    int i;
    if (edit->curs_line >= edit->total_lines - 1) {
        i = edit->total_lines;
    } else {
        if (line_is_blank (edit, edit->curs_line)) {
            if (line_is_blank (edit, edit->curs_line + 1)) {
                for (i = edit->curs_line + 1; i; i++)
                    if (!line_is_blank (edit, i) || i > edit->total_lines) {
                        i--;
                        break;
                    }
            } else {
                for (i = edit->curs_line + 1; i; i++)
                    if (line_is_blank (edit, i) || i >= edit->total_lines)
                        break;
            }
        } else {
            for (i = edit->curs_line + 1; i; i++)
                if (line_is_blank (edit, i) || i >= edit->total_lines)
                    break;
        }
    }
    edit_move_down (edit, i - edit->curs_line, scroll);
}

static void edit_begin_page (WEdit *edit)
{
    edit_update_curs_row (edit);
    edit_move_up (edit, edit->curs_row, 0);
}

static void edit_end_page (WEdit *edit)
{
    edit_update_curs_row (edit);
    edit_move_down (edit, edit->num_widget_lines - edit->curs_row - 1, 0);
}


/* goto beginning of text */
static void edit_move_to_top (WEdit * edit)
{
    if (edit->curs_line) {
        edit_cursor_move (edit, -edit->curs1);
        edit_move_to_prev_col (edit, 0);
        edit->force |= REDRAW_PAGE;
        edit->search_start = 0;
        edit_update_curs_row(edit);
    }
}


/* goto end of text */
static void edit_move_to_bottom (WEdit * edit)
{
    if (edit->curs_line < edit->total_lines) {
        edit_cursor_move (edit, edit->curs2);
        edit->start_display = edit->last_byte;
        edit->start_line = edit->total_lines;
        edit_update_curs_row(edit);
        edit_scroll_upward (edit, edit->num_widget_lines - 1);
        edit->force |= REDRAW_PAGE;
    }
}

/* goto beginning of line */
static void edit_cursor_to_bol (WEdit * edit)
{
    edit_cursor_move (edit, edit_bol (edit, edit->curs1) - edit->curs1);
    edit->search_start = edit->curs1;
    edit->prev_col = edit_get_col (edit);
}

/* goto end of line */
static void edit_cursor_to_eol (WEdit * edit)
{
    edit_cursor_move (edit, edit_eol (edit, edit->curs1) - edit->curs1);
    edit->search_start = edit->curs1;
    edit->prev_col = edit_get_col (edit);
}

/* move cursor to line 'line' */
void edit_move_to_line (WEdit * e, long line)
{
    if(line < e->curs_line)
        edit_move_up (e, e->curs_line - line, 0);
    else
        edit_move_down (e, line - e->curs_line, 0);
    edit_scroll_screen_over_cursor (e);
}

/* scroll window so that first visible line is 'line' */
void edit_move_display (WEdit * e, long line)
{
    if(line < e->start_line)
        edit_scroll_upward (e, e->start_line - line);
    else
        edit_scroll_downward (e, line - e->start_line);
}

/* save markers onto undo stack */
void edit_push_markers (WEdit * edit)
{
    edit_push_action (edit, MARK_1 + edit->mark1);
    edit_push_action (edit, MARK_2 + edit->mark2);
}

void free_selections (void)
{
    int i;
    for (i = 0; i < NUM_SELECTION_HISTORY; i++)
        if (selection_history[i].text) {
            free (selection_history[i].text);
            selection_history[i].text = 0;
            selection_history[i].len = 0;
        }
    current_selection = 0;
}

/* return -1 on nothing to store or error, zero otherwise */
void edit_get_selection (WEdit * edit)
{
    long start_mark, end_mark;
    if (eval_marks (edit, &start_mark, &end_mark))
        return;
    if (selection_history[current_selection].len < 4096)        /* large selections should not be held -- to save memory */
        current_selection = (current_selection + 1) % NUM_SELECTION_HISTORY;
    selection_history[current_selection].len = end_mark - start_mark;
    if (selection_history[current_selection].text)
        free (selection_history[current_selection].text);
    selection_history[current_selection].text = malloc (selection_history[current_selection].len + 1);
    if (!selection_history[current_selection].text) {
        selection_history[current_selection].text = malloc (1);
        *selection_history[current_selection].text = 0;
        selection_history[current_selection].len = 0;
    } else {
        unsigned char *p = selection_history[current_selection].text;
        for (; start_mark < end_mark; start_mark++)
            *p++ = edit_get_byte (edit, start_mark);
        *p = 0;
    }
    selection.text = selection_history[current_selection].text;
    selection.len = selection_history[current_selection].len;
}

void edit_set_markers (WEdit * edit, long m1, long m2, int c1, int c2)
{
    edit->mark1 = m1;
    edit->mark2 = m2;
    edit->column1 = c1;
    edit->column2 = c2;
}


/* highlight marker toggle */
void edit_mark_cmd (WEdit * edit, int unmark)
{
    edit_push_markers (edit);
    if (unmark) {
        edit_set_markers (edit, 0, 0, 0, 0);
        edit->force |= REDRAW_PAGE;
    } else {
        if (edit->mark2 >= 0) {
            edit_set_markers (edit, edit->curs1, -1, edit->curs_col, edit->curs_col);
            edit->force |= REDRAW_PAGE;
        } else
            edit_set_markers (edit, edit->mark1, edit->curs1, edit->column1, edit->curs_col);
    }
}

static unsigned long my_type_of (int c)
{
    int x, r = 0;
    char *p, *q;
    if (!c)
        return 0;
    if (c == '!') {
        if (*option_chars_move_whole_word == '!')
            return 2;
        return 0x80000000UL;
    }
    if (isupper (c))
        c = 'A';
    else if (islower (c))
        c = 'a';
    else if (isalpha (c))
        c = 'a';
    else if (isdigit (c))
        c = '0';
    else if (isspace (c))
        c = ' ';
    q = strchr (option_chars_move_whole_word, c);
    if (!q)
        return 0xFFFFFFFFUL;
    do {
        for (x = 1, p = option_chars_move_whole_word; (unsigned long) p < (unsigned long) q; p++)
            if (*p == '!')
                x <<= 1;
        r |= x;
    } while ((q = strchr (q + 1, c)));
    return r;
}

void edit_left_word_move (WEdit * edit, int s)
{
    for (;;) {
        int c1, c2;
        edit_cursor_move (edit, -1);
        if (!edit->curs1)
            break;
        c1 = edit_get_byte (edit, edit->curs1 - 1);
        c2 = edit_get_byte (edit, edit->curs1);
        if (!(my_type_of (c1) & my_type_of (c2)))
            break;
        if (isspace (c1) && !isspace (c2))
            break;
        if (s)
            if (!isspace (c1) && isspace (c2))
                break;
    }
}

static void edit_left_word_move_cmd (WEdit * edit)
{
    edit_left_word_move (edit, 0);
    edit->force |= REDRAW_PAGE;
}

void edit_right_word_move (WEdit * edit, int s)
{
    for (;;) {
        int c1, c2;
        edit_cursor_move (edit, 1);
        if (edit->curs1 >= edit->last_byte)
            break;
        c1 = edit_get_byte (edit, edit->curs1 - 1);
        c2 = edit_get_byte (edit, edit->curs1);
        if (!(my_type_of (c1) & my_type_of (c2)))
            break;
        if (isspace (c1) && !isspace (c2))
            break;
        if (s)
            if (!isspace (c1) && isspace (c2))
                break;
    }
}

static void edit_right_word_move_cmd (WEdit * edit)
{
    edit_right_word_move (edit, 0);
    edit->force |= REDRAW_PAGE;
}


static void edit_right_delete_word (WEdit * edit)
{
    int c1, c2;
    for (;;) {
        if (edit->curs1 >= edit->last_byte)
            break;
        c1 = edit_delete (edit);
        c2 = edit_get_byte (edit, edit->curs1);
        if ((isspace (c1) == 0) != (isspace (c2) == 0))
            break;
        if (!(my_type_of (c1) & my_type_of (c2)))
            break;
    }
}

static void edit_left_delete_word (WEdit * edit)
{
    int c1, c2;
    for (;;) {
        if (edit->curs1 <= 0)
            break;
        c1 = edit_backspace (edit);
        c2 = edit_get_byte (edit, edit->curs1 - 1);
        if ((isspace (c1) == 0) != (isspace (c2) == 0))
            break;
        if (!(my_type_of (c1) & my_type_of (c2)))
            break;
    }
}

extern int column_highlighting;

/*
   the start column position is not recorded, and hence does not
   undo as it happed. But who would notice.
 */
void edit_do_undo (WEdit * edit)
{
    long ac;
    long count = 0;

    push_action_disabled = 1;   /* don't record undo's onto undo stack! */

    while ((ac = pop_action (edit)) < KEY_PRESS) {
        switch ((int) ac) {
        case STACK_BOTTOM:
            goto done_undo;
        case CURS_RIGHT:
            edit_cursor_move (edit, 1);
            break;
        case CURS_LEFT:
            edit_cursor_move (edit, -1);
            break;
        case BACKSPACE:
            edit_backspace (edit);
            break;
        case DELETE:
            edit_delete (edit);
            break;
        case COLUMN_ON:
            column_highlighting = 1;
            break;
        case COLUMN_OFF:
            column_highlighting = 0;
            break;
        }
        if (ac >= 256 && ac < 512)
            edit_insert_ahead (edit, ac - 256);
        if (ac >= 0 && ac < 256)
            edit_insert (edit, ac);

        if (ac >= MARK_1 - 2 && ac < MARK_2 - 2) {
            edit->mark1 = ac - MARK_1;
            edit->column1 = edit_move_forward3 (edit, edit_bol (edit, edit->mark1), 0, edit->mark1);
        } else if (ac >= MARK_2 - 2 && ac < KEY_PRESS) {
            edit->mark2 = ac - MARK_2;
            edit->column2 = edit_move_forward3 (edit, edit_bol (edit, edit->mark2), 0, edit->mark2);
        }
        if (count++)
            edit->force |= REDRAW_PAGE;         /* more than one pop usually means something big */
    }

    if (edit->start_display > ac - KEY_PRESS) {
        edit->start_line -= edit_count_lines (edit, ac - KEY_PRESS, edit->start_display);
        edit->force |= REDRAW_PAGE;
    } else if (edit->start_display < ac - KEY_PRESS) {
        edit->start_line += edit_count_lines (edit, edit->start_display, ac - KEY_PRESS);
        edit->force |= REDRAW_PAGE;
    }
    edit->start_display = ac - KEY_PRESS;       /* see push and pop above */
    edit_update_curs_row (edit);

  done_undo:;
    push_action_disabled = 0;
}

static void edit_delete_to_line_end (WEdit * edit)
{
    while (edit_get_byte (edit, edit->curs1) != '\n') {
        if (!edit->curs2)
            break;
        edit_delete (edit);
    }
}

static void edit_delete_to_line_begin (WEdit * edit)
{
    while (edit_get_byte (edit, edit->curs1 - 1) != '\n') {
        if (!edit->curs1)
            break;
        edit_backspace (edit);
    }
}

void edit_delete_line (WEdit * edit)
{
    int c;
    do {
        c = edit_delete (edit);
    } while (c != '\n' && c);
    do {
        c = edit_backspace (edit);
    } while (c != '\n' && c);
    if (c)
        edit_insert (edit, '\n');
}

static void insert_spaces_tab (WEdit * edit, int half)
{
    int i;
    edit_update_curs_col (edit);
    i = ((edit->curs_col / (option_tab_spacing * space_width / (half + 1))) + 1) * (option_tab_spacing * space_width / (half + 1)) - edit->curs_col;
    while (i > 0) {
        edit_insert (edit, ' ');
        i -= space_width;
    }
}

static int is_aligned_on_a_tab (WEdit * edit)
{
    edit_update_curs_col (edit);
    if ((edit->curs_col % (TAB_SIZE * space_width)) && edit->curs_col % (TAB_SIZE * space_width) != (HALF_TAB_SIZE * space_width))
        return 0;               /* not alligned on a tab */
    return 1;
}

static int right_of_four_spaces (WEdit *edit)
{
    int i, ch = 0;
    for (i = 1; i <= HALF_TAB_SIZE; i++)
        ch |= edit_get_byte (edit, edit->curs1 - i);
    if (ch == ' ')
        return is_aligned_on_a_tab (edit);
    return 0;
}

static int left_of_four_spaces (WEdit *edit)
{
    int i, ch = 0;
    for (i = 0; i < HALF_TAB_SIZE; i++)
        ch |= edit_get_byte (edit, edit->curs1 + i);
    if (ch == ' ')
        return is_aligned_on_a_tab (edit);
    return 0;
}

int edit_indent_width (WEdit * edit, long p)
{
    long q = p;
    while (strchr ("\t ", edit_get_byte (edit, q)) && q < edit->last_byte - 1)  /* move to the end of the leading whitespace of the line */
        q++;
    return edit_move_forward3 (edit, p, 0, q);  /* count the number of columns of indentation */
}

void edit_insert_indent (WEdit * edit, int indent)
{
#ifndef MIDNIGHT
    indent /= space_width;
#endif
    if (!option_fill_tabs_with_spaces) {
        while (indent >= TAB_SIZE) {
            edit_insert (edit, '\t');
            indent -= TAB_SIZE;
        }
    }
    while (indent-- > 0)
        edit_insert (edit, ' ');
}

void edit_auto_indent (WEdit * edit, int extra, int no_advance)
{
    long p;
    int indent;
    p = edit->curs1;
    while (isspace (edit_get_byte (edit, p - 1)) && p > 0)      /* move back/up to a line with text */
        p--;
    indent = edit_indent_width (edit, edit_bol (edit, p));
    if (edit->curs_col < indent && no_advance)
        indent = edit->curs_col;
    edit_insert_indent (edit, indent + (option_fake_half_tabs ? HALF_TAB_SIZE : TAB_SIZE) * space_width * extra);
}

static void edit_double_newline (WEdit * edit)
{
    edit_insert (edit, '\n');
    if (edit_get_byte (edit, edit->curs1) == '\n')
        return;
    if (edit_get_byte (edit, edit->curs1 - 2) == '\n')
        return;
    edit->force |= REDRAW_PAGE;
    edit_insert (edit, '\n');
}

static void edit_tab_cmd (WEdit * edit)
{
    int i;

    if (option_fake_half_tabs) {
        if (is_in_indent (edit)) {
            /*insert a half tab (usually four spaces) unless there is a
               half tab already behind, then delete it and insert a 
               full tab. */
            if (!option_fill_tabs_with_spaces && right_of_four_spaces (edit)) {
                for (i = 1; i <= HALF_TAB_SIZE; i++)
                    edit_backspace (edit);
                edit_insert (edit, '\t');
            } else {
                insert_spaces_tab (edit, 1);
            }
            return;
        }
    }
    if (option_fill_tabs_with_spaces) {
        insert_spaces_tab (edit, 0);
    } else {
        edit_insert (edit, '\t');
    }
    return;
}

void format_paragraph (WEdit * edit, int force);

static void check_and_wrap_line (WEdit * edit)
{
    int curs, c;
    if (!option_typewriter_wrap)
        return;
    edit_update_curs_col (edit);
#ifdef MIDNIGHT
    if (edit->curs_col < option_word_wrap_line_length)
        return;
#else
    CPushFont ("editor", 0);
    c = FONT_MEAN_WIDTH;
    CPopFont ();
    if (edit->curs_col < option_word_wrap_line_length * c)
        return;
#endif
    curs = edit->curs1;
    for (;;) {
        curs--;
        c = edit_get_byte (edit, curs);
        if (c == '\n' || curs <= 0) {
            edit_insert (edit, '\n');
            return;
        }
        if (c == ' ' || c == '\t') {
            int current = edit->curs1;
            edit_cursor_move (edit, curs - edit->curs1 + 1);
            edit_insert (edit, '\n');
            edit_cursor_move (edit, current - edit->curs1 + 1);
            return;
        }
    }
}

void edit_execute_macro (WEdit * edit, struct macro macro[], int n);

/* either command or char_for_insertion must be passed as -1 */
int edit_execute_cmd (WEdit * edit, int command, int char_for_insertion);

#ifdef MIDNIGHT
int edit_translate_key (WEdit * edit, unsigned int x_keycode, long x_key, int x_state, int *cmd, int *ch)
{
    int command = -1;
    int char_for_insertion = -1;

#include "edit_key_translator.c"

    *cmd = command;
    *ch = char_for_insertion;

    if((command == -1 || command == 0) && char_for_insertion == -1)  /* unchanged, key has no function here */
        return 0;
    return 1;
}
#endif

void edit_push_key_press (WEdit * edit)
{
    edit_push_action (edit, KEY_PRESS + edit->start_display);
    if (edit->mark2 == -1)
        edit_push_action (edit, MARK_1 + edit->mark1);
}

/* this find the matching bracket in either direction, and sets edit->bracket */
static long edit_get_bracket (WEdit * edit, int in_screen, unsigned long furthest_bracket_search)
{
    const char *b = "{}{[][()(", *p;
    int i = 1, a, inc = -1, c, d, n = 0;
    unsigned long j = 0;
    long q;
    edit_update_curs_row (edit);
    c = edit_get_byte (edit, edit->curs1);
    p = strchr (b, c);
/* no limit */
    if (!furthest_bracket_search)
        furthest_bracket_search--;
/* not on a bracket at all */
    if (!p)
        return -1;
/* the matching bracket */
    d = p[1];
/* going left or right? */
    if (strchr ("{[(", c))
        inc = 1;
    for (q = edit->curs1 + inc;; q += inc) {
/* out of buffer? */
        if (q >= edit->last_byte || q < 0)
            break;
        a = edit_get_byte (edit, q);
/* don't want to eat CPU */
        if (j++ > furthest_bracket_search)
            break;
/* out of screen? */
        if (in_screen) {
            if (q < edit->start_display)
                break;
/* count lines if searching downward */
            if (inc > 0 && a == '\n')
                if (n++ >= edit->num_widget_lines - edit->curs_row)     /* out of screen */
                    break;
        }
/* count bracket depth */
        i += (a == c) - (a == d);
/* return if bracket depth is zero */
        if (!i)
            return q;
    }
/* no match */
    return -1;
}

static long last_bracket = -1;

static void edit_find_bracket (WEdit * edit)
{
    if (option_find_bracket) {
        edit->bracket = edit_get_bracket (edit, 1, 10000);
        if (last_bracket != edit->bracket)
            edit->force |= REDRAW_PAGE;
        last_bracket = edit->bracket;
    }
}

static void edit_goto_matching_bracket (WEdit *edit)
{
    long q;
    q = edit_get_bracket (edit, 0, 0);
    if (q < 0)
        return;
    edit->bracket = edit->curs1;
    edit->force |= REDRAW_PAGE;
    edit_cursor_move (edit, q - edit->curs1);
}

/* this executes a command as though the user initiated it through a key press. */
/* callback with WIDGET_KEY as a message calls this after translating the key
   press */
/* this can be used to pass any command to the editor. Same as sendevent with
   msg = WIDGET_COMMAND and par = command  except the screen wouldn't update */
/* one of command or char_for_insertion must be passed as -1 */
/* commands are executed, and char_for_insertion is inserted at the cursor */
/* returns 0 if the command is a macro that was not found, 1 otherwise */
int edit_execute_key_command (WEdit * edit, int command, int char_for_insertion)
{
    int r;
    if (command == CK_Begin_Record_Macro) {
        edit->macro_i = 0;
        edit->force |= REDRAW_CHAR_ONLY | REDRAW_LINE;
        return command;
    }
    if (command == CK_End_Record_Macro && edit->macro_i != -1) {
        edit->force |= REDRAW_COMPLETELY;
        edit_save_macro_cmd (edit, edit->macro, edit->macro_i);
        edit->macro_i = -1;
        return command;
    }
    if (edit->macro_i >= 0 && edit->macro_i < MAX_MACRO_LENGTH - 1) {
        edit->macro[edit->macro_i].command = command;
        edit->macro[edit->macro_i++].ch = char_for_insertion;
    }
/* record the beginning of a set of editing actions initiated by a key press */
    if (command != CK_Undo)
        edit_push_key_press (edit);

    r = edit_execute_cmd (edit, command, char_for_insertion);
#ifdef GTK
    if (edit->stopped && edit->widget->destroy_me) {
        (*edit->widget->destroy_me) (edit->widget->destroy_me_user_data);
        return 0;
    }
#endif
    if (column_highlighting)
        edit->force |= REDRAW_PAGE;

    return r;
}

#ifdef MIDNIGHT
static const char *shell_cmd[] = SHELL_COMMANDS_i
void edit_mail_dialog (WEdit * edit);

#else
static void (*user_commamd) (WEdit *, int) = 0;
void edit_set_user_command (void (*func) (WEdit *, int))
{
    user_commamd = func;
}
#endif

/* 
   This executes a command at a lower level than macro recording.
   It also does not push a key_press onto the undo stack. This means
   that if it is called many times, a single undo command will undo
   all of them. It also does not check for the Undo command.
   Returns 0 if the command is a macro that was not found, 1
   otherwise.
 */
int edit_execute_cmd (WEdit * edit, int command, int char_for_insertion)
{
    int result = 1;
    edit->force |= REDRAW_LINE;
    if (edit->found_len || column_highlighting)
/* the next key press will unhighlight the found string, so update whole page */
        edit->force |= REDRAW_PAGE;

    if (command / 100 == 6) {   /* a highlight command like shift-arrow */
        column_highlighting = 0;
        if (!edit->highlight || (edit->mark2 != -1 && edit->mark1 != edit->mark2)) {
            edit_mark_cmd (edit, 1);    /* clear */
            edit_mark_cmd (edit, 0);    /* marking on */
        }
        edit->highlight = 1;
    } else {                    /* any other command */
        if (edit->highlight)
            edit_mark_cmd (edit, 0);    /* clear */
        edit->highlight = 0;
    }

/* first check for undo */
    if (command == CK_Undo) {
        edit_do_undo (edit);
        edit->found_len = 0;
        edit->prev_col = edit_get_col (edit);
        edit->search_start = edit->curs1;
        return 1;
    }
/* An ordinary key press */
    if (char_for_insertion >= 0) {
        if (edit->overwrite) {
            if (edit_get_byte (edit, edit->curs1) != '\n')
                edit_delete (edit);
        }
        edit_insert (edit, char_for_insertion);
        if (option_auto_para_formatting) {
            format_paragraph (edit, 0);
            edit->force |= REDRAW_PAGE;
        } else
            check_and_wrap_line (edit);
        edit->found_len = 0;
        edit->prev_col = edit_get_col (edit);
        edit->search_start = edit->curs1;
        edit_find_bracket (edit);
        edit_check_spelling (edit);
        return 1;
    }
    switch (command) {
    case CK_Begin_Page:
    case CK_End_Page:
    case CK_Begin_Page_Highlight:
    case CK_End_Page_Highlight:
    case CK_Word_Left:
    case CK_Word_Right:
    case CK_Up:
    case CK_Down:
    case CK_Word_Left_Highlight:
    case CK_Word_Right_Highlight:
    case CK_Up_Highlight:
    case CK_Down_Highlight:
        if (edit->mark2 == -1)
            break;              /*marking is following the cursor: may need to highlight a whole line */
    case CK_Left:
    case CK_Right:
    case CK_Left_Highlight:
    case CK_Right_Highlight:
        edit->force |= REDRAW_CHAR_ONLY;
    }

/* basic cursor key commands */
    switch (command) {
    case CK_BackSpace:
        if (option_backspace_through_tabs && is_in_indent (edit)) {
            while (edit_get_byte (edit, edit->curs1 - 1) != '\n'
                   && edit->curs1 > 0)
                edit_backspace (edit);
            break;
        } else {
            if (option_fake_half_tabs) {
                int i;
                if (is_in_indent (edit) && right_of_four_spaces (edit)) {
                    for (i = 0; i < HALF_TAB_SIZE; i++)
                        edit_backspace (edit);
                    break;
                }
            }
        }
        edit_backspace (edit);
        break;
    case CK_Delete:
        if (option_fake_half_tabs) {
            int i;
            if (is_in_indent (edit) && left_of_four_spaces (edit)) {
                for (i = 1; i <= HALF_TAB_SIZE; i++)
                    edit_delete (edit);
                break;
            }
        }
        edit_delete (edit);
        break;
    case CK_Delete_Word_Left:
        edit_left_delete_word (edit);
        break;
    case CK_Delete_Word_Right:
        edit_right_delete_word (edit);
        break;
    case CK_Delete_Line:
        edit_delete_line (edit);
        break;
    case CK_Delete_To_Line_End:
        edit_delete_to_line_end (edit);
        break;
    case CK_Delete_To_Line_Begin:
        edit_delete_to_line_begin (edit);
        break;
    case CK_Enter:
        if (option_auto_para_formatting) {
            edit_double_newline (edit);
            if (option_return_does_auto_indent)
                edit_auto_indent (edit, 0, 1);
            format_paragraph (edit, 0);
        } else {
            edit_insert (edit, '\n');
            if (option_return_does_auto_indent) {
                edit_auto_indent (edit, 0, 1);
            }
        }
        break;
    case CK_Return:
        edit_insert (edit, '\n');
        break;

    case CK_Page_Up:
    case CK_Page_Up_Highlight:
        edit_move_up (edit, edit->num_widget_lines - 1, 1);
        break;
    case CK_Page_Down:
    case CK_Page_Down_Highlight:
        edit_move_down (edit, edit->num_widget_lines - 1, 1);
        break;
    case CK_Left:
    case CK_Left_Highlight:
        if (option_fake_half_tabs) {
            if (is_in_indent (edit) && right_of_four_spaces (edit)) {
                edit_cursor_move (edit, -HALF_TAB_SIZE);
                edit->force &= (0xFFF - REDRAW_CHAR_ONLY);
                break;
            }
        }
        edit_cursor_move (edit, -1);
        break;
    case CK_Right:
    case CK_Right_Highlight:
        if (option_fake_half_tabs) {
            if (is_in_indent (edit) && left_of_four_spaces (edit)) {
                edit_cursor_move (edit, HALF_TAB_SIZE);
                edit->force &= (0xFFF - REDRAW_CHAR_ONLY);
                break;
            }
        }
        edit_cursor_move (edit, 1);
        break;
    case CK_Begin_Page:
    case CK_Begin_Page_Highlight:
        edit_begin_page (edit);
        break;
    case CK_End_Page:
    case CK_End_Page_Highlight:
        edit_end_page (edit);
        break;
    case CK_Word_Left:
    case CK_Word_Left_Highlight:
        edit_left_word_move_cmd (edit);
        break;
    case CK_Word_Right:
    case CK_Word_Right_Highlight:
        edit_right_word_move_cmd (edit);
        break;
    case CK_Up:
    case CK_Up_Highlight:
        edit_move_up (edit, 1, 0);
        break;
    case CK_Down:
    case CK_Down_Highlight:
        edit_move_down (edit, 1, 0);
        break;
    case CK_Paragraph_Up:
    case CK_Paragraph_Up_Highlight:
        edit_move_up_paragraph (edit, 0);
        break;
    case CK_Paragraph_Down:
    case CK_Paragraph_Down_Highlight:
        edit_move_down_paragraph (edit, 0);
        break;
    case CK_Scroll_Up:
    case CK_Scroll_Up_Highlight:
        edit_move_up (edit, 1, 1);
        break;
    case CK_Scroll_Down:
    case CK_Scroll_Down_Highlight:
        edit_move_down (edit, 1, 1);
        break;
    case CK_Home:
    case CK_Home_Highlight:
        edit_cursor_to_bol (edit);
        break;
    case CK_End:
    case CK_End_Highlight:
        edit_cursor_to_eol (edit);
        break;

    case CK_Tab:
        edit_tab_cmd (edit);
        if (option_auto_para_formatting) {
            format_paragraph (edit, 0);
            edit->force |= REDRAW_PAGE;
        } else
            check_and_wrap_line (edit);
        break;

    case CK_Toggle_Insert:
        edit->overwrite = (edit->overwrite == 0);
#ifndef MIDNIGHT
#ifdef GTK
/* *** */
#else
        CSetCursorColor (edit->overwrite ? color_palette (24) : color_palette (19));
#endif
#endif
        break;

    case CK_Mark:
        if (edit->mark2 >= 0) {
            if (column_highlighting)
                edit_push_action (edit, COLUMN_ON);
            column_highlighting = 0;
        }
        edit_mark_cmd (edit, 0);
        break;
    case CK_Column_Mark:
        if (!column_highlighting)
            edit_push_action (edit, COLUMN_OFF);
        column_highlighting = 1;
        edit_mark_cmd (edit, 0);
        break;
    case CK_Unmark:
        if (column_highlighting)
            edit_push_action (edit, COLUMN_ON);
        column_highlighting = 0;
        edit_mark_cmd (edit, 1);
        break;

    case CK_Toggle_Bookmark:
        book_mark_clear (edit, edit->curs_line, BOOK_MARK_FOUND_COLOR);
        if (book_mark_query_color (edit, edit->curs_line, BOOK_MARK_COLOR))
            book_mark_clear (edit, edit->curs_line, BOOK_MARK_COLOR);
        else
            book_mark_insert (edit, edit->curs_line, BOOK_MARK_COLOR);
        break;
    case CK_Flush_Bookmarks:
        book_mark_flush (edit, BOOK_MARK_COLOR);
        book_mark_flush (edit, BOOK_MARK_FOUND_COLOR);
        edit->force |= REDRAW_PAGE;
        break;
    case CK_Next_Bookmark:
        if (edit->book_mark) {
            struct _book_mark *p;
            p = (struct _book_mark *) book_mark_find (edit, edit->curs_line);
            if (p->next) {
                p = p->next;
                if (p->line >= edit->start_line + edit->num_widget_lines || p->line < edit->start_line)
                    edit_move_display (edit, p->line - edit->num_widget_lines / 2);
                edit_move_to_line (edit, p->line);
            }
        }
        break;
    case CK_Prev_Bookmark:
        if (edit->book_mark) {
            struct _book_mark *p;
            p = (struct _book_mark *) book_mark_find (edit, edit->curs_line);
            while (p->line == edit->curs_line)
                if (p->prev)
                    p = p->prev;
            if (p->line >= 0) {
                if (p->line >= edit->start_line + edit->num_widget_lines || p->line < edit->start_line)
                    edit_move_display (edit, p->line - edit->num_widget_lines / 2);
                edit_move_to_line (edit, p->line);
            }
        }
        break;

    case CK_Beginning_Of_Text:
    case CK_Beginning_Of_Text_Highlight:
        edit_move_to_top (edit);
        break;
    case CK_End_Of_Text:
    case CK_End_Of_Text_Highlight:
        edit_move_to_bottom (edit);
        break;

    case CK_Copy:
        edit_block_copy_cmd (edit);
        break;
    case CK_Remove:
        edit_block_delete_cmd (edit);
        break;
    case CK_Move:
        edit_block_move_cmd (edit);
        break;

    case CK_XStore:
        edit_copy_to_X_buf_cmd (edit);
        break;
    case CK_XCut:
        edit_cut_to_X_buf_cmd (edit);
        break;
    case CK_XPaste:
        edit_paste_from_X_buf_cmd (edit);
        break;
    case CK_Selection_History:
        edit_paste_from_history (edit);
        break;

    case CK_Save_As:
#ifndef MIDNIGHT
/*      if (COptionsOf (edit->widget) & EDITOR_NO_FILE) */
        if (edit->widget->options & EDITOR_NO_FILE)
            break;
#endif
        edit_save_as_cmd (edit);
        break;
    case CK_Save:
#ifndef MIDNIGHT
        if (COptionsOf (edit->widget) & EDITOR_NO_FILE)
            break;
#endif
        edit_save_confirm_cmd (edit);
        break;
    case CK_Load:
#ifndef MIDNIGHT
        if (COptionsOf (edit->widget) & EDITOR_NO_FILE)
            break;
#endif
        edit_load_cmd (edit);
        break;
    case CK_Save_Block:
        edit_save_block_cmd (edit);
        break;
    case CK_Insert_File:
        edit_insert_file_cmd (edit);
        break;

    case CK_Find:
        edit_search_cmd (edit, 0);
        break;
    case CK_Find_Again:
        edit_search_cmd (edit, 1);
        break;
    case CK_Replace:
        edit_replace_cmd (edit, 0);
        break;
    case CK_Replace_Again:
        edit_replace_cmd (edit, 1);
        break;

    case CK_Exit:
        edit_quit_cmd (edit);
        break;
    case CK_New:
        edit_new_cmd (edit);
        break;

    case CK_Help:
        edit_help_cmd (edit);
        break;

    case CK_Refresh:
        edit_refresh_cmd (edit);
        break;

    case CK_Date:{
            time_t t;
#ifdef HAVE_STRFTIME
            char s[1024];
#endif
            time (&t);
#ifdef HAVE_STRFTIME
            strftime (s, sizeof (s), "%c", localtime (&t));
            edit_printf (edit, s);
#else
            edit_printf (edit, ctime (&t));
#endif
            edit->force |= REDRAW_PAGE;
            break;
        }
    case CK_Goto:
        edit_goto_cmd (edit);
        break;
    case CK_Paragraph_Format:
        format_paragraph (edit, 1);
        edit->force |= REDRAW_PAGE;
        break;
    case CK_Delete_Macro:
        edit_delete_macro_cmd (edit);
        break;
    case CK_Match_Bracket:
        edit_goto_matching_bracket (edit);
        break;
    case CK_User_Menu:
        if (edit_one_file) {
            message (1, MSG_ERROR, _("User menu available only in mcedit invoked from mc"));
            break;
        }    
        else
            user_menu (edit);
        break;
#ifdef MIDNIGHT
    case CK_Sort:
        edit_sort_cmd (edit);
        break;
    case CK_Mail:
        edit_mail_dialog (edit);
        break;
#endif

/* These commands are not handled and must be handled by the user application */
#ifndef MIDNIGHT
    case CK_Sort:
    case CK_Mail:
    case CK_Find_File:
    case CK_Ctags:
    case CK_Terminal:
    case CK_Terminal_App:
#endif
    case CK_Complete:
    case CK_Cancel:
    case CK_Save_Desktop:
    case CK_New_Window:
    case CK_Cycle:
    case CK_Save_And_Quit:
    case CK_Check_Save_And_Quit:
    case CK_Run_Another:
    case CK_Debug_Start:
    case CK_Debug_Stop:
    case CK_Debug_Toggle_Break:
    case CK_Debug_Clear:
    case CK_Debug_Next:
    case CK_Debug_Step:
    case CK_Debug_Back_Trace:
    case CK_Debug_Continue:
    case CK_Debug_Enter_Command:
    case CK_Debug_Until_Curser:
        result = 0;
        break;
    case CK_Menu:
#ifdef GTK
        if (edit->widget->menubar)
            gtk_menu_popup (GTK_MENU(
                (GTK_MENU_ITEM (g_list_nth_data (GTK_MENU_BAR (edit->widget->menubar)->menu_shell.children, 0)))->submenu
            ), 0, 0, 0, 0, 1, 0);
        result = 1;
#else
        result = 0;
#endif
        break;
    }

#ifdef MIDNIGHT
/* CK_Pipe_Block */
    if ((command / 1000) == 1)  /* a shell command */
        edit_block_process_cmd (edit, shell_cmd[command - 1000], 1);
    if (command > CK_Macro (0) && command <= CK_Last_Macro) {   /* a macro command */
        struct macro m[MAX_MACRO_LENGTH];
        int nm;
        if ((result = edit_load_macro_cmd (edit, m, &nm, command - 2000)))
            edit_execute_macro (edit, m, nm);
    }
#else
    if (IS_USER_COMMAND (command))      /* a user defined command */
        if (user_commamd)
            (*user_commamd) (edit, command & 0xFFFF);
    if (IS_MACRO_COMMAND (command)) {   /* a macro command */
        struct macro m[MAX_MACRO_LENGTH];
        int nm;
        if ((result = edit_load_macro_cmd (edit, m, &nm, command & 0xFFFF)))
            edit_execute_macro (edit, m, nm);
    }
#endif

/* keys which must set the col position, and the search vars */
    switch (command) {
    case CK_Find:
    case CK_Find_Again:
    case CK_Replace:
    case CK_Replace_Again:
        edit->prev_col = edit_get_col (edit);
        return 1;
        break;
    case CK_Up:
    case CK_Up_Highlight:
    case CK_Down:
    case CK_Down_Highlight:
    case CK_Page_Up:
    case CK_Page_Up_Highlight:
    case CK_Page_Down:
    case CK_Page_Down_Highlight:
    case CK_Beginning_Of_Text:
    case CK_Beginning_Of_Text_Highlight:
    case CK_End_Of_Text:
    case CK_End_Of_Text_Highlight:
    case CK_Paragraph_Up:
    case CK_Paragraph_Up_Highlight:
    case CK_Paragraph_Down:
    case CK_Paragraph_Down_Highlight:
    case CK_Scroll_Up:
    case CK_Scroll_Up_Highlight:
    case CK_Scroll_Down:
    case CK_Scroll_Down_Highlight:
        edit->search_start = edit->curs1;
        edit->found_len = 0;
        edit_find_bracket (edit);
        edit_check_spelling (edit);
        return 1;
        break;
    default:
        edit->found_len = 0;
        edit->prev_col = edit_get_col (edit);
        edit->search_start = edit->curs1;
    }
    edit_find_bracket (edit);
    edit_check_spelling (edit);

    if (option_auto_para_formatting) {
        switch (command) {
        case CK_BackSpace:
        case CK_Delete:
        case CK_Delete_Word_Left:
        case CK_Delete_Word_Right:
        case CK_Delete_To_Line_End:
        case CK_Delete_To_Line_Begin:
            format_paragraph (edit, 0);
            edit->force |= REDRAW_PAGE;
        }
    }
    return result;
}


/* either command or char_for_insertion must be passed as -1 */
/* returns 0 if command is a macro that was not found, 1 otherwise */
int edit_execute_command (WEdit * edit, int command, int char_for_insertion)
{
    int r;
    r = edit_execute_cmd (edit, command, char_for_insertion);
    edit_update_screen (edit);
    return r;
}

void edit_execute_macro (WEdit * edit, struct macro macro[], int n)
{
    int i = 0;
    edit->force |= REDRAW_PAGE;
    for (; i < n; i++) {
        edit_execute_cmd (edit, macro[i].command, macro[i].ch);
    }
    edit_update_screen (edit);
}

/* User edit menu, like user menu (F2) but only in editor. */
void user_menu (WEdit *edit)
{
    FILE *fd;
    int nomark;
    struct stat status;
    long start_mark, end_mark;
    char *block_file = catstrs (home_dir, BLOCK_FILE, 0);
    char *error_file = catstrs (home_dir, ERROR_FILE, 0);
    int rc = 0;

    nomark = eval_marks (edit, &start_mark, &end_mark); 
    if (! nomark) /* remember marked or not */
        edit_save_block (edit, block_file = catstrs (home_dir, BLOCK_FILE, 0),
                                                        start_mark, end_mark);

    /* run shell scripts from menu */     
    user_menu_cmd (edit);
    
    if (stat (error_file, &status) == 0) {
        if (!status.st_size) {  /* no error messages */
            if (stat (block_file, &status) == 0)
                if (!status.st_size)
                    return;  /* no block messages */
            if (! nomark) /* i.e. we have marked block */
                rc = edit_block_delete_cmd(edit);
            if (!rc) {
                edit_cursor_to_bol (edit);
                edit_insert_file (edit, block_file);
                edit_cursor_to_eol (edit);
                if ((fd = fopen (block_file, "w"))) fclose(fd);
            }
        } else { /* it is error */
                edit_cursor_to_bol (edit);
                edit_insert_file (edit, error_file);
                if ((fd = fopen (error_file, "w"))) fclose(fd);
                if ((fd = fopen (block_file, "w"))) fclose(fd);
        }
    } else {
        edit_error_dialog ("",
        get_sys_error (catstrs (_ ("Error trying to stat file:"),
                                                            error_file, 0)));
        return;
    }
    edit_refresh_cmd (edit);
    edit->force |= REDRAW_COMPLETELY;
    return;
}