www.pudn.com > vim53src.zip > multbyte.c

/* vi:set ts=8 sts=4 sw=4: 
 * 
 * VIM - Vi IMproved	by Bram Moolenaar 
 * Multibyte extensions by Sung-Hoon Baek 
 * 
 * Do ":help uganda"  in Vim to read copying and usage conditions. 
 * Do ":help credits" in Vim to see a list of people who contributed. 
 */ 
/* 
 *	file : multbyte.c 
 */ 
 
#include "vim.h" 
#include "globals.h" 
#include "proto.h" 
#include "option.h" 
#ifdef WIN32 
# include  
# include  
#endif 
 
#if defined(MULTI_BYTE) || defined(PROTO) 
 
/* 
 * Is 'c' a lead byte of multi-byte character? 
 */ 
    int 
IsLeadByte(c) 
    int		c; 
{ 
#ifdef WIN32 
    /* is_dbcs is set by setting 'fileencoding'.  It becomes a Windows 
     * CodePage identifier, which we can pass directly in to Windows API*/ 
    return IsDBCSLeadByteEx(is_dbcs, (BYTE)c); 
#else 
    return (c & 0x80); 
#endif 
} 
 
/* 
 * Is *p a trail byte of multi-byte character?  base : string pointer to line 
 */ 
    int 
IsTrailByte(base, p) 
    char_u *base; 
    char_u *p; 
{ 
    int lbc = 0;    /* lead byte count*/ 
 
    if (base >= p) 
	return 0; 
 
    while (p > base) 
    { 
	if (!IsLeadByte(*(--p))) 
	    break; 
	lbc++; 
    } 
 
    return (lbc & 1); 
} 
 
/* 
 * if the cursor moves on an trail byte, set the cursor on the lead byte. 
 */ 
    int 
AdjustCursorForMultiByteCharacter() 
{ 
    char_u *p; 
 
    if (curwin->w_cursor.col > 0 ) 
    { 
	p = ml_get(curwin->w_cursor.lnum); 
	if (IsTrailByte(p, p + curwin->w_cursor.col)) 
	{ 
	    --curwin->w_cursor.col; 
	    return 1; 
	} 
    } 
    return 0; 
} 
 
/* 
 * count the length of the str which has multi-byte characters.  two-byte 
 * character counts as one character. 
 */ 
    int 
MultiStrLen(str) 
    char_u	*str; 
{ 
    int count; 
 
    if (str == NULL) 
	return 0; 
    for (count = 0; *str != NUL; count++) 
    { 
	if (IsLeadByte(*str)) 
	{ 
	    str++; 
	    if (*str != NUL) 
		str++; 
	} 
	else 
	    str++; 
    } 
    return count; 
} 
 
    int 
han_dec(lp) 
    FPOS  *lp; 
{ 
    char_u *p = ml_get(lp->lnum); 
 
    if (lp->col > 0) 
    {		/* still within line */ 
	lp->col--; 
	if ( lp->col > 0 && IsTrailByte(p, p + lp->col)) 
	    lp->col--; 
	return 0; 
    } 
    if (lp->lnum > 1) 
    {		/* there is a prior line */ 
	lp->lnum--; 
	lp->col = STRLEN(ml_get(lp->lnum)); 
	if ( lp->col > 0 && IsTrailByte(p, p + lp->col)) 
	    lp->col--; 
	return 1; 
    } 
    return -1;			/* at start of file */ 
} 
 
#endif /* MULTI_BYTE */