/*
 * STEVIE - Simply Try this Editor for VI Enthusiasts
 *
 * Code Contributions By : Tim Thompson           twitch!tjt
 *                         Tony Andrews           onecom!wldrdg!tony 
 *                         G. R. (Fred) Walter    watmath!watcgl!grwalter 
 */

#include "stevie.h"

#ifdef	MEGAMAX
overlay "mark"
#endif

/*
 * This file contains routines to maintain and manipulate marks. 
 */

#define	NMARKS	10		/* max. # of marks that can be saved */

struct mark {
    char            name;
    LPTR            pos;
};

static struct mark mlist[NMARKS];
static struct mark pcmark;	/* previous context mark */
static bool_t   pcvalid = FALSE;/* true if pcmark is valid */

/*
 * setmark(c) - set mark 'c' at current cursor position 
 *
 * Returns TRUE on success, FALSE if no room for mark or bad name given. 
 */
bool_t
setmark(c)
    char            c;
{
    int             i;

    if (!isalpha(c))
	return FALSE;

    /*
     * If there is already a mark of this name, then just use the existing
     * mark entry. 
     */
    for (i = 0; i < NMARKS; i++) {
	if (mlist[i].name == c) {
	    mlist[i].pos = *Curschar;
	    return TRUE;
	}
    }

    /*
     * There wasn't a mark of the given name, so find a free slot 
     */
    for (i = 0; i < NMARKS; i++) {
	if (mlist[i].name == NUL) {	/* got a free one */
	    mlist[i].name = c;
	    mlist[i].pos = *Curschar;
	    return TRUE;
	}
    }
    return FALSE;
}

/*
 * setpcmark() - set the previous context mark to the current position 
 */
void
setpcmark()
{
    pcmark.pos = *Curschar;
    pcvalid = TRUE;
}

/*
 * getmark(c) - find mark for char 'c' 
 *
 * Return pointer to LPTR or NULL if no such mark. 
 */
LPTR           *
getmark(c)
    char            c;
{
    int             i;

    if (c == '\'' || c == '`')	/* previous context mark */
	return pcvalid ? &(pcmark.pos) : (LPTR *) NULL;

    for (i = 0; i < NMARKS; i++) {
	if (mlist[i].name == c)
	    return &(mlist[i].pos);
    }
    return (LPTR *) NULL;
}

/*
 * clrall() - clear all marks 
 *
 * Used mainly when trashing the entire buffer during ":e" type commands 
 */
void
clrall()
{
    int             i;

    for (i = 0; i < NMARKS; i++)
	mlist[i].name = NUL;
    pcvalid = FALSE;
}

/*
 * clrmark(line) - clear any marks for 'line' 
 *
 * Used any time a line is deleted so we don't have marks pointing to
 * non-existent lines. 
 */
void
clrmark(line)
    LINE           *line;
{
    int             i;

    for (i = 0; i < NMARKS; i++) {
	if (mlist[i].pos.linep == line)
	    mlist[i].name = NUL;
    }
    if (pcvalid && (pcmark.pos.linep == line))
	pcvalid = FALSE;
}