edit.c

具有IDE功能的编辑器

    } else {
	for (; *c; c++)
	    edit_insert (edit, *c);
    }
}

long edit_backspace_wide (WEdit * edit)
{
    int i;
    long c = 0;
    if (!edit->curs1)
	return 0;
    for (i = edit->curs1 - 1; i >= 0; i--)
	if ((c = edit_get_wide_byte (edit, i)) != -1)
	    break;
    while (edit->curs1 > i)
	edit_backspace (edit);
    return c;
}

static int right_of_four_spaces (WEdit *edit);
void edit_tab_cmd (WEdit * edit);

void edit_backspace_tab (WEdit * edit, int whole_tabs_only)
{
    int i;
    if (whole_tabs_only) {
	int indent;
	/* count the number of columns of indentation */
	indent = edit_move_forward3 (edit, edit_bol (edit, edit->curs1), 0, edit->curs1);
	for (;;) {
	    int c;
	    c = edit_get_byte (edit, edit->curs1 - 1);
	    if (!isspace (c) || c == '\n')
		break;
	    edit_backspace (edit);
	}
	while (edit_move_forward3 (edit, edit_bol (edit, edit->curs1), 0, edit->curs1) <
	       (indent - space_width * (option_fake_half_tabs ? HALF_TAB_SIZE : TAB_SIZE)))
	    edit_tab_cmd (edit);
	return;
    }
    if (option_fake_half_tabs && right_of_four_spaces (edit)) {
	for (i = 0; i < HALF_TAB_SIZE; i++)
	    edit_backspace (edit);
	return;
    }
    edit_backspace (edit);
}

void edit_wide_char_align (WEdit * edit)
{
    while (edit_get_wide_byte (edit, edit->curs1) == -1)
	edit_cursor_move (edit, 1);
}

void edit_wide_char_align_left (WEdit * edit)
{
    while (edit_get_wide_byte (edit, edit->curs1) == -1)
	edit_cursor_move (edit, -1);
}

#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 (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);
#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;