/*
 * Copyright 1989 Massachusetts Institute of Technology
 *
 * Permission to use, copy, modify, and distribute this software and its
 * documentation for any purpose and without fee is hereby granted, provided
 * that the above copyright notice appear in all copies and that both that
 * copyright notice and this permission notice appear in supporting
 * documentation, and that the name of M.I.T. not be used in advertising
 * or publicity pertaining to distribution of the software without specific,
 * written prior permission.  M.I.T. makes no representations about the
 * suitability of this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 *
 * M.I.T. DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL M.I.T.
 * BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN 
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

/**********************************************************************
 *
 * regions.c
 *
 * Region related routines
 *
 * 4/26/99 D. J. Hawkey Jr.
 *
 **********************************************************************/

#include <stdio.h>
#include <string.h>
#include "twm.h"
#include "screen.h"
#include "list.h"
#include "regions.h"
#include "gram.h"
#include "parse.h"
#include "util.h"

void
splitRegionEntry (re, grav1, grav2, w, h)
    RegionEntry	*re;
    int		grav1, grav2;
    int		w, h;
{
    RegionEntry	*new;

    switch (grav1) {
    case D_NORTH:
    case D_SOUTH:
	if (w != re->w)
	    splitRegionEntry (re, grav2, grav1, w, re->h);
	if (h != re->h) {
	    new = (RegionEntry *)malloc (sizeof (RegionEntry));
	    new->u.twm_win = 0;
	    /* djhjr - 10/20/01 */
	    new->type = LTYPE_EXACT_NAME;
	    new->usedby = 0;
	    new->next = re->next;
	    re->next = new;
	    new->x = re->x;
	    new->h = (re->h - h);
	    new->w = re->w;
	    re->h = h;
	    if (grav1 == D_SOUTH) {
		new->y = re->y;
		re->y = new->y + new->h;
	    } else
		new->y = re->y + re->h;
	}
	break;
    case D_EAST:
    case D_WEST:
	if (h != re->h)
	    splitRegionEntry (re, grav2, grav1, re->w, h);
	if (w != re->w) {
	    new = (RegionEntry *)malloc (sizeof (RegionEntry));
	    new->u.twm_win = 0;
	    /* djhjr - 10/20/01 */
	    new->type = LTYPE_EXACT_NAME;
	    new->usedby = 0;
	    new->next = re->next;
	    re->next = new;
	    new->y = re->y;
	    new->w = (re->w - w);
	    new->h = re->h;
	    re->w = w;
	    if (grav1 == D_EAST) {
		new->x = re->x;
		re->x = new->x + new->w;
	    } else
		new->x = re->x + re->w;
	}
	break;
    }
}

int
roundEntryUp (v, multiple)
{
    return ((v + multiple - 1) / multiple) * multiple;
}

RegionEntry *
prevRegionEntry (re, rr)
    RegionEntry	*re;
    RootRegion	*rr;
{
    RegionEntry	*ep;

    if (re == rr->entries)
	return 0;
    for (ep = rr->entries; ep->next != re; ep=ep->next)
	;
    return ep;
}

/*
 * old is being freed; and is adjacent to re.  Merge regions together.
 */
void
mergeRegionEntries (old, re)
    RegionEntry	*old, *re;
{
    if (old->y == re->y) {
	re->w = old->w + re->w;
	if (old->x < re->x)
	    re->x = old->x;
    } else {
	re->h = old->h + re->h;
	if (old->y < re->y)
	    re->y = old->y;
    }
}

void
downRegionEntry(rr, re)
RootRegion	*rr;
RegionEntry	*re;
{
	RegionEntry	*ep, *en;

	re->u.twm_win = 0;
	re->usedby = 0;
	ep = prevRegionEntry (re, rr);
	en = re->next;
	for (;;) {
		if (ep && ep->usedby == 0 &&
				((ep->x == re->x && ep->w == re->w) ||
				(ep->y == re->y && ep->h == re->h)))
		{
			ep->next = re->next;
			mergeRegionEntries (re, ep);
			if (re->usedby == USEDBY_NAME)
				free(re->u.name);
/* djhjr - 10/20/01 */
#ifndef NO_REGEX_SUPPORT
			if (re->type & LTYPE_C_REGEXP)
				regfree(&re->re);
#endif
			free ((char *) re);
			re = ep;
			ep = prevRegionEntry (ep, rr);
		} else if (en && en->usedby == 0 &&
				((en->x == re->x && en->w == re->w) ||
				(en->y == re->y && en->h == re->h)))
		{
			re->next = en->next;
			mergeRegionEntries (en, re);
			if (en->usedby == USEDBY_NAME)
				free(en->u.name);
/* djhjr - 10/20/01 */
#ifndef NO_REGEX_SUPPORT
			if (en->type & LTYPE_C_REGEXP)
				regfree(&en->re);
#endif
			free ((char *) en);
			en = re->next;
		} else
			break;
	}
}

RootRegion *
AddRegion(geom, grav1, grav2, stepx, stepy)
char *geom;
int grav1, grav2, stepx, stepy;
{
    RootRegion *rr;
    int mask;

    rr = (RootRegion *)malloc(sizeof(RootRegion));
    rr->next = NULL;
    rr->grav1 = grav1;
    rr->grav2 = grav2;
    rr->stepx = (stepx <= 0) ? 2 : stepx; /* hard-coded value was '1' - djhjr - 9/26/99 */
    rr->stepy = (stepy <= 0) ? 1 : stepy;
    rr->x = rr->y = rr->w = rr->h = 0;

    mask = XParseGeometry(geom, &rr->x, &rr->y, (unsigned int *)&rr->w, (unsigned int *)&rr->h);
    if (mask & XNegative)
        rr->x += Scr->MyDisplayWidth - rr->w;
    if (mask & YNegative)
        rr->y += Scr->MyDisplayHeight - rr->h;

    rr->entries = (RegionEntry *)malloc(sizeof(RegionEntry));
    rr->entries->next = 0;
    rr->entries->x = rr->x;
    rr->entries->y = rr->y;
    rr->entries->w = rr->w;
    rr->entries->h = rr->h;
    rr->entries->u.twm_win = 0;
    /* djhjr - 10/20/01 */
    rr->entries->type = LTYPE_EXACT_NAME;
    rr->entries->usedby = 0;

    return rr;
}

void
FreeRegionEntries (rr)
    RootRegion	*rr;
{
    RegionEntry	*re, *tmp;

    for (re = rr->entries; re; re=tmp)
    {
	tmp = re->next;
	if (re->usedby == USEDBY_NAME)
		free(re->u.name);
/* djhjr - 10/20/01 */
#ifndef NO_REGEX_SUPPORT
	if (re->type & LTYPE_C_REGEXP)
		regfree(&re->re);
#endif
	free ((char *) re);
    }
}

void
FreeRegions (first, last)
    RootRegion	*first, *last;
{
    RootRegion *rr, *tmp;

    for (rr = first; rr != NULL;)
    {
	tmp = rr;
	FreeRegionEntries (rr);
	rr = rr->next;
	free((char *) tmp);
    }
    first = NULL;
    last = NULL;
}