reactos/rosapps/mc/edit/edit.c

/* editor low level data handling and cursor fundamentals.

   Copyright (C) 1996, 1997 the Free Software Foundation

   Authors: 1996, 1997 Paul Sheer

   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., 675 Mass Ave, Cambridge, MA 02139, USA. */

#define _EDIT_C THIS_IS

#include <config.h>
#if defined(OS2_NT)
#    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() */

/*
 *
 * 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.
 */
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];
    }
}

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;
}

/* 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)
{

#if defined CR_LF_TRANSLATION
    /* Variables needed for safe handling of Translation from Microsoft CR/LF EOL to
       Unix Style LF EOL - Franco */
    long bytes_wanted,bytes_read,bytes_missing;
    char *p;
#endif

    long buf;
    int j, file = 0, buf2;

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

    if (filename)
	if ((file = open ((char *) filename, O_RDONLY | MY_O_TEXT)) == -1) {
/* The file-name is printed after the ':' */
	    edit_error_dialog (_(" Error "), get_sys_error (catstrs (_(" Fail 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);

/*
_read returns the number of bytes read,
which may be less than count if there are fewer than count bytes left in the file
or if the file was opened in text mode,
in which case each carriage return<72>linefeed (CR-LF) pair is replaced
with a single linefeed character. Only the single linefeed character is counted
in the return value. The replacement does not affect the file pointer.

_eof returns 1 if the current position is end of file, or 0 if it is not.
A return value of -1 indicates an error; in this case, errno is set to EBADF,
which indicates an invalid file handle.
*/
    if (filename){

#if defined CR_LF_TRANSLATION
	bytes_wanted=edit->curs2 & M_EDIT_BUF_SIZE;
	p = (char *) edit->buffers2[buf2] + EDIT_BUF_SIZE - (edit->curs2 & M_EDIT_BUF_SIZE);
	bytes_read = read (file, p , edit->curs2 & M_EDIT_BUF_SIZE);
	bytes_missing = bytes_wanted - bytes_read ;
	while(bytes_missing ){
		p += bytes_read;
		bytes_read = read(file,p,bytes_missing);
		if(bytes_read <= 0) break;
		bytes_missing -= bytes_read ;
	}
#else
	read (file, (char *) edit->buffers2[buf2] + EDIT_BUF_SIZE - (edit->curs2 & M_EDIT_BUF_SIZE), edit->curs2 & M_EDIT_BUF_SIZE);
#endif
    }
    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){
#if defined CR_LF_TRANSLATION
		bytes_wanted = EDIT_BUF_SIZE;
		p = (char *) edit->buffers2[buf];
		bytes_read = read (file, p, EDIT_BUF_SIZE);
		bytes_missing = bytes_wanted - bytes_read ;
		while(bytes_missing ){
			p += bytes_read;
			bytes_read = read(file,p,bytes_missing);
			if(bytes_read <= 0) break;
			bytes_missing -= bytes_read ;
		}
#else
	    read (file, (char *) edit->buffers2[buf], EDIT_BUF_SIZE);
#endif
 	}
	else {
	    memcpy (edit->buffers2[buf], text, EDIT_BUF_SIZE);
	    text += EDIT_BUF_SIZE;
	}
    }

    edit->curs1 = 0;
    if (filename)
	close (file);

    return 0;
}

/* returns 1 on error */
int edit_load_file (WEdit * edit, const char *filename, const char *text, unsigned long text_size)
{
    struct stat s;
    int file;

/* VARS for Lastbyte calculation in TEXT mode FRANCO */
#if defined CR_LF_TRANSLATION
 char tmp_buf[1024];
 long real_size,bytes_read;
#endif

    if (text) {
	edit->last_byte = text_size;
	filename = NULL;
    } else {
#if defined(MIDNIGHT) || defined(GTK)
    if ((file = open ((char *) filename, O_RDONLY | MY_O_TEXT )) < 0)
	{
		close(creat((char *) filename, 0666));
		if ((file = open ((char *) filename, O_RDONLY | MY_O_TEXT )) < 0) {
			edit_error_dialog (_(" Error "), get_sys_error (catstrs (" Fail trying to open the file, ", filename, ", for reading ", 0)));
			return 1;
		}
		edit->delete_file = 1;
	}
#else
	if ((file = open ((char *) filename, O_RDONLY)) < 0) {
	    edit_error_dialog (_(" Error "), get_sys_error (catstrs (_(" Fail trying to open file for reading: "), filename, " ", 0)));
	    return 1;
	}
#endif
	if (stat ((char *) filename, &s) < 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 (s.st_mode) || S_ISSOCK (s.st_mode)
	    || S_ISFIFO (s.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 (s.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;
	}

/* Lastbyte calculation in TEXT mode FRANCO */
#if defined CR_LF_TRANSLATION
	if(file && (!text)){
		real_size=0;
		tmp_buf[1024]=0;
		while((bytes_read = read(file,tmp_buf,1024)) > 0){
			real_size += bytes_read;
		}
		s.st_size = real_size;
	}

#endif

	close (file);
	edit->last_byte = s.st_size;
	edit->stat = s;
    }

    return init_dynamic_edit_buffers (edit, filename, text);
}

#ifdef MIDNIGHT
#define space_width 1
#else
int space_width;
extern int option_long_whitespace;
extern unsigned char per_char[256];

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

#endif

/* fills in the edit struct. returns 0 on fail. Pass edit as NULL for this function to do an malloc for you */
WEdit *edit_init (WEdit * edit, int lines, int columns, const char *filename, const char *text, const char *dir, unsigned long text_size)
{
    char *f;
#ifndef MIDNIGHT
    if (option_long_whitespace)
	edit_set_space_width (per_char[' '] * 2);
    else
	edit_set_space_width (per_char[' ']);
#endif
    if (!edit)
	edit = malloc (sizeof (WEdit));
    if (!edit) {
	edit_error_dialog (_(" Error "), _(" Error allocating memory "));
	return 0;
    }
    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);
    if (edit_load_file (edit, f, text, text_size)) {
/* edit_load_file already gives an error message */
	free (edit);
	return 0;
    }
    edit->force |= REDRAW_PAGE;
    if (filename) {
	filename = catstrs (dir, filename, 0);
	edit_split_filename (edit, (char *) filename);
    } else {
	edit->filename = strdup ("");
	edit->dir = 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));
    if (!edit->undo_stack) {
	edit_error_dialog (_(" Error "), _(" Error allocating memory "));
	free (edit);
	return 0;
    }
    edit->total_lines = edit_count_lines (edit, 0, edit->last_byte);
    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);
	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 = 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 */
int edit_reload (WEdit * edit, const char *filename, const char *text, const char *dir, unsigned long text_size)
{
    int lines = edit->num_widget_lines;
    int columns = edit->num_widget_columns;
    edit_clean (edit);
    if (!edit_init (edit, lines, columns, filename, text, dir, text_size)) {
	return 0;
    }
    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 curser 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)

*/

static int push_action_disabled = 0;

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->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') {
	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') {
	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') {
	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') {
	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

#define memqcpy(edit,d,s,i)						\
	{								\
	    unsigned long next;						\
	    char *dest = d;						\
	    char *src = s;						\
	    int n = i;							\
	    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;
    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 curser 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 0
	    if (current == edit->last_byte || edit_get_byte (edit, current) == '\n')
#else
	    if (edit_get_byte (edit, current) == '\n')
#endif
		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 0
	    if (current == 0 || edit_get_byte (edit, current - 1) == '\n')
#else
	    if (edit_get_byte (edit, current - 1) == '\n')
#endif
		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 (float) 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);
    }
    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);
    }
    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);

static 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 (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 */
static 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 ((c > ' ' && c <= '~') || c >= 160)	/* non-printables on a line are considered "blank" */
	    return 0;
    }
    return 1;
}

int line_is_blank (WEdit * edit, long line)
{
    static long p = -1, l = 0;
    if (p == -1 || abs (l - line) > abs (edit->curs_line - line)) {
	l = edit->curs_line;
	p = edit->curs1;
    }
    if (line < l)
	p = edit_move_backward (edit, p, l - line);
    else if (line > l)
	p = edit_move_forward (edit, p, line - l, 0);
    l = line;
    return is_blank (edit, p);
}

/* 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 */
static 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);
    }
}

int my_type_of (int c)
{
    if (c < ' ' && c > 0)
	return 1;
    if (strchr ("+_-.", c))
	if (strchr (option_whole_chars_move, c))
	    return 3;
    if (!strcasechr (option_whole_chars_move, c))
	return 2;
    if ((c >= '0' && c <= '9') || (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c >= 160)
	return 3;
    return c;
}

void edit_left_word_move (WEdit * edit)
{
    do {
	edit_cursor_move (edit, -1);
	if (!edit->curs1)
	    break;
    } while (my_type_of (edit_get_byte (edit, edit->curs1))
	     ==
	     my_type_of (edit_get_byte (edit, edit->curs1 - 1)));
}

static void edit_left_word_move_cmd (WEdit * edit)
{
    edit_left_word_move (edit);
    if (strchr (option_whole_chars_move, ' '))
	if (strchr ("\t ", edit_get_byte (edit, edit->curs1)))
	    edit_left_word_move (edit);
    edit->force |= REDRAW_PAGE;
}

void edit_right_word_move (WEdit * edit)
{
    do {
	edit_cursor_move (edit, 1);
	if (edit->curs1 >= edit->last_byte)
	    break;
    } while (my_type_of (edit_get_byte (edit, edit->curs1 - 1))
	     ==
	     my_type_of (edit_get_byte (edit, edit->curs1)));
}

static void edit_right_word_move_cmd (WEdit * edit)
{
    edit_right_word_move (edit);
    if (strchr (option_whole_chars_move, ' '))
	if (strchr ("\t ", edit_get_byte (edit, edit->curs1)))
	    edit_right_word_move (edit);
    edit->force |= REDRAW_PAGE;
}


static void edit_right_delete_word (WEdit * edit)
{
    int c;
    do {
	c = edit_delete (edit);
    } while (my_type_of (c) == my_type_of (edit_get_byte (edit, edit->curs1)));
}

static void edit_left_delete_word (WEdit * edit)
{
    int c;
    do {
	c = edit_backspace (edit);
    } while (my_type_of (c) == my_type_of (edit_get_byte (edit, edit->curs1 - 1)));
}


/*
   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;
	}
	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;
	} else if (ac >= MARK_2 - 2 && ac < KEY_PRESS) {
	    edit->mark2 = ac - MARK_2;
	}
	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)
{
    for (;;) {
	if (edit_get_byte (edit, edit->curs1) == '\n')
	    break;
	if (!edit->curs2)
	    break;
	edit_delete (edit);
    }
}

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

static 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 i = option_tab_spacing;
    while (i--)
	edit_insert (edit, ' ');
}

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--)
	edit_insert (edit, ' ');
}

static void edit_auto_indent (WEdit * edit, int always)
{
    long p;
    int indent;
    p = edit->curs1;
    while (strchr ("\t\n\r ", 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)
	indent = edit->curs_col;
    edit_insert_indent (edit, indent);
}

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 (right_of_four_spaces (edit)) {
		for (i = 1; i <= HALF_TAB_SIZE; i++)
		    edit_backspace (edit);
		if (option_fill_tabs_with_spaces) {
		    insert_spaces_tab (edit);
		} else {
		    edit_insert (edit, '\t');
		}
	    } else {
		for (i = 1; i <= HALF_TAB_SIZE; i++)
		    edit_insert (edit, ' ');
	    }
	    return;
	}
    }
    if (option_fill_tabs_with_spaces) {
	insert_spaces_tab (edit);
    } 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)
#else
    if (edit->curs_col < option_word_wrap_line_length * FONT_MEAN_WIDTH)
#endif
	return;
    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 */
void edit_find_bracket (WEdit * edit)
{
    if (option_find_bracket) {
	const char *b = "{}{[][()(", *p;
	static int last_bracket = -1;
	int i = 1, a, inc = -1, c, d, n = 0, j = 0;
	long q;

	edit->bracket = -1;
	c = edit_get_byte (edit, edit->curs1);
	p = strchr (b, c);
	edit_update_curs_row (edit);
	if (p) {
	    d = p[1];
	    if (strchr ("{[(", c))
		inc = 1;
	    for (q = edit->curs1 + inc;; q += inc) {
		if (q >= edit->last_byte || q < edit->start_display || j++ > 10000)
		    break;
		a = edit_get_byte (edit, q);
		if (inc > 0 && a == '\n')
		    n++;
		if (n >= edit->num_widget_lines - edit->curs_row)	/* out of screen */
		    break;
		i += (a == c) - (a == d);
		if (!i) {
		    edit->bracket = q;
		    break;
		}
	    }
	}
	if (last_bracket != edit->bracket)
	    edit->force |= REDRAW_PAGE;
	last_bracket = edit->bracket;
    }
}


/* 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);

    return r;
}

#ifdef MIDNIGHT
static const char *shell_cmd[] = SHELL_COMMANDS_i
#else
static void (*user_commamd) (WEdit *, int) = 0;
void edit_set_user_command (void (*func) (WEdit *, int))
{
    user_commamd = func;
}

#endif

void edit_mail_dialog (WEdit * edit);

/*
   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)
/* 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 */
	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);
	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);
	    format_paragraph (edit, 0);
	} else if (option_return_does_auto_indent) {
	    edit_insert (edit, '\n');
	    edit_auto_indent (edit, 0);
	} else {
	    edit_insert (edit, '\n');
	}
	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
	CSetCursorColor (edit->overwrite ? color_palette (24) : color_palette (19));
#endif
	break;

    case CK_Mark:
	edit_mark_cmd (edit, 0);
	break;
    case CK_Unmark:
	edit_mark_cmd (edit, 1);
	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 (edit->widget->options & EDITOR_NO_FILE)
	    break;
#endif
	edit_save_as_cmd (edit);
	break;
    case CK_Save:
#ifndef MIDNIGHT
	if (edit->widget->options & EDITOR_NO_FILE)
	    break;
#endif
	edit_save_confirm_cmd (edit);
	break;
    case CK_Load:
#ifndef MIDNIGHT
	if (edit->widget->options & 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;
	    time (&t);
	    edit_printf (edit, ctime (&t));
	    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;
#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:
#endif
    case CK_Complete:
    case CK_Cancel:
    case CK_Save_Desktop:
    case CK_New_Window:
    case CK_Cycle:
    case CK_Menu:
    case CK_Save_And_Quit:
    case CK_Check_Save_And_Quit:
    case CK_Run_Another:
	result = 0;
	break;
    }

#ifdef MIDNIGHT
/* CK_Pipe_Block */
    if ((command / 1000) == 1)	/* a shell command */
	edit_block_process_cmd (edit, shell_cmd[command - 1000], 1);
#else
    if ((command / 1000) == 1)	/* a user defined command */
	if (user_commamd)
	    (*user_commamd) (edit, command - 1000);
#endif

    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);
    }
/* 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);
	return 1;
	break;
    default:
	edit->found_len = 0;
	edit->prev_col = edit_get_col (edit);
	edit->search_start = edit->curs1;
    }
    edit_find_bracket (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);
}