20060303a

1 files changed, 1165 insertions, 0 deletions

diff --git a/libtk/parse.c b/libtk/parse.c
new file mode 100644
index 00000000..d2a31dd3
--- /dev/null
+++ b/libtk/parse.c
@@ -0,0 +1,1165 @@
+#include "lib9.h"
+#include "kernel.h"
+#include "draw.h"
+#include "tk.h"
+
+#define	O(t, e)		((long)(&((t*)0)->e))
+
+static char* pdist(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pstab(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* ptext(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pwinp(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pbmap(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pbool(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pfont(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pfrac(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pnnfrac(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pctag(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* ptabs(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pcolr(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pimag(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* psize(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pnndist(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pact(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* pignore(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* psticky(TkTop*, TkOption*, void*, char**, char*, char*);
+static char* plist(TkTop*, TkOption*, void*, char**, char*, char*);
+
+static char* (*oparse[])(TkTop*, TkOption*, void*, char**, char*, char*) =
+{
+	/* OPTdist */	pdist,
+	/* OPTstab */	pstab,
+	/* OPTtext */	ptext,
+	/* OPTwinp */	pwinp,
+	/* OPTflag */	pstab,
+	/* OPTbmap */	pbmap,
+	/* OPTbool */	pbool,
+	/* OPTfont */	pfont,
+	/* OPTfrac */	pfrac,
+	/* OPTnnfrac */	pnnfrac,
+	/* OPTctag */	pctag,
+	/* OPTtabs */	ptabs,
+	/* OPTcolr */	pcolr,
+	/* OPTimag */	pimag,
+	/* OPTsize */	psize,
+	/* OPTnndist */	pnndist,
+	/* OPTact */	pact,
+	/* OPTignore */	pignore,
+	/* OPTsticky */	psticky,
+	/* OPTlist */ plist,
+};
+
+char*
+tkskip(char *s, char *bl)
+{
+	char *p;
+
+	while(*s) {
+		for(p = bl; *p; p++)
+			if(*p == *s)
+				break;
+		if(*p == '\0')
+			return s;	
+		s++;
+	}
+	return s;
+}
+
+/* XXX - Tad: error propagation? */
+char*
+tkword(TkTop *t, char *str, char *buf, char *ebuf, int *gotarg)
+{
+	int c, lev, tmp;
+	char *val, *e, *p, *cmd;
+	if (gotarg == nil)
+		gotarg = &tmp;
+
+	/*
+	 * ebuf is one beyond last byte in buf; leave room for nul byte in
+	 * all cases.
+	 */
+	--ebuf;
+
+	str = tkskip(str, " \t");
+	*gotarg = 1;
+	lev = 1;
+	switch(*str) {
+	case '{':
+		/* XXX - DBK: According to Ousterhout (p.37), while back=
+		 * slashed braces don't count toward finding the matching
+		 * closing braces, the backslashes should not be removed.
+		 * Presumably this also applies to other backslashed
+		 * characters: the backslash should not be removed.
+		 */
+		str++;
+		while(*str && buf < ebuf) {
+			c = *str++;
+			if(c == '\\') {
+				if(*str == '}' || *str == '{' || *str == '\\')
+					c = *str++;
+			}
+			else
+			if(c == '}') {
+				lev--;
+				if(lev == 0)
+					break;
+			}
+			else
+			if(c == '{')
+				lev++;
+			*buf++ = c;
+		}
+		break;
+	case '[':
+		/* XXX - DBK: According to Ousterhout (p. 33) command
+		 * substitution may occur anywhere within a word, not
+		 * only (as here) at the beginning.
+		 */
+		cmd = malloc(strlen(str));	/* not strlen+1 because the first character is skipped */
+		if ( cmd == nil ) {
+			buf[0] = '\0';	/* DBK - Why not an error message? */
+			return str;
+		}
+		p = cmd;
+		str++;
+		while(*str) {
+			c = *str++;
+			if(c == '\\') {
+				if(*str == ']' || *str == '[' || *str == '\\')
+					c = *str++;
+			}
+			else
+			if(c == ']') {
+				lev--;
+				if(lev == 0)
+					break;
+			}
+			else
+			if(c == '[')
+				lev++;
+			*p++ = c;
+		}
+		*p = '\0';
+		val = nil;
+		e = tkexec(t, cmd, &val);
+		free(cmd);
+		 /* XXX - Tad: is this appropriate behavior?
+		  *	      Am I sure that the error doesn't need to be
+		  *	      propagated back to the caller?
+		  */
+		if(e == nil && val != nil) {
+			strncpy(buf, val, ebuf-buf);
+			buf = ebuf;
+			free(val);
+		}
+		break;
+	case '\'':
+		str++;
+		while(*str && buf < ebuf)
+			*buf++ = *str++;
+		break;
+	case '\0':
+		*gotarg = 0;
+		break;
+	default:
+		/* XXX - DBK: See comment above about command substitution.
+		 * Also, any backslashed character should be replaced by
+		 * itself (e.g. to put a space, tab, or [ into a word.
+		 * We assume that the C compiler has already done the
+		 * standard ANSI C substitutions.  (But should we?)
+		 */
+		while(*str && *str != ' ' && *str != '\t' && buf < ebuf)
+			*buf++ = *str++;
+	}
+	*buf = '\0';
+	return str;
+}
+
+static TkOption*
+Getopt(TkOption *o, char *buf)
+{
+	while(o->o != nil) {
+		if(strcmp(buf, o->o) == 0)
+			return o;
+		o++;
+	}
+	return nil;
+}
+
+TkName*
+tkmkname(char *name)
+{
+	TkName *n;
+
+	n = malloc(sizeof(struct TkName)+strlen(name));
+	if(n == nil)
+		return nil;
+	strcpy(n->name, name);
+	n->link = nil;
+	n->obj = nil;
+	return n;
+}
+
+char*
+tkparse(TkTop *t, char *str, TkOptab *ot, TkName **nl)
+{
+	int l;
+	TkOptab *ft;
+	TkOption *o;
+	TkName *f, *n;
+	char *e, *buf, *ebuf;
+
+	l = strlen(str);
+	if (l < Tkmaxitem)
+		l = Tkmaxitem;
+	buf = malloc(l + 1);
+	if(buf == 0)
+		return TkNomem;
+	ebuf = buf + l + 1;
+
+	e = nil;
+	while(e == nil) {
+		str = tkword(t, str, buf, ebuf, nil);
+		switch(*buf) {
+		case '\0':
+			goto done;
+		case '-':
+			if (buf[1] != '\0') {
+				for(ft = ot; ft->ptr; ft++) {
+					o = Getopt(ft->optab, buf+1);
+					if(o != nil) {
+						e = oparse[o->type](t, o, ft->ptr, &str, buf, ebuf);
+						break;
+					}
+				}
+				if(ft->ptr == nil){
+					e = TkBadop;
+					tkerr(t, buf);
+				}
+				break;
+			}
+			/* fall through if we've got a singleton '-' */
+		default:
+			if(nl == nil) {
+				e = TkBadop;
+				tkerr(t, buf);
+				break;
+			}
+			n = tkmkname(buf);
+			if(n == nil) {
+				e = TkNomem;
+				break;
+			}
+			if(*nl == nil)
+				*nl = n;
+			else {
+				for(f = *nl; f->link; f = f->link)
+					;
+				f->link = n;
+			}
+		}		
+	}
+
+	if(e != nil && nl != nil)
+		tkfreename(*nl);
+done:
+	free(buf);
+	return e;
+}
+
+char*
+tkconflist(TkOptab *ot, char **val)
+{
+	TkOption *o;
+	char *f, *e;
+
+	f = "-%s";
+	while(ot->ptr != nil) {
+		o = ot->optab;
+		while(o->o != nil) {
+			e = tkvalue(val, f, o->o);
+			if(e != nil)
+				return e;
+			f = " -%s";
+			o++;
+		}
+		ot++;
+	}
+	return nil;
+}
+
+char*
+tkgencget(TkOptab *ft, char *arg, char **val, TkTop *t)
+{
+	Tk *w;
+	char *c;
+	Point g;
+	TkEnv *e;
+	TkStab *s;
+	TkOption *o;
+	int wh, con, i, n, flag, *v;
+	char *r, *buf, *fmt;
+
+	buf = mallocz(Tkmaxitem, 0);
+	if(buf == nil)
+		return TkNomem;
+
+	tkitem(buf, arg);
+	r = buf;
+	if(*r == '-')
+		r++;
+	o = nil;
+	while(ft->ptr) {
+		o = Getopt(ft->optab, r);
+		if(o != nil)
+			break;
+		ft++;
+	}
+	if(o == nil) {
+		tkerr(t, r);
+		free(buf);
+		return TkBadop;
+	}
+
+	switch(o->type) {
+	default:
+		tkerr(t, r);
+		free(buf);
+		return TkBadop;
+	case OPTignore:
+		return nil;
+	case OPTact:
+		w = ft->ptr;
+		g = tkposn(w);
+		n = g.y;
+		if(o->aux == 0)
+			n = g.x;
+		free(buf);
+		return tkvalue(val, "%d", n);
+	case OPTdist:
+	case OPTnndist:
+		free(buf);
+		return tkvalue(val, "%d", OPTION(ft->ptr, int, o->offset));
+	case OPTsize:
+		w = ft->ptr;
+		if(strcmp(r, "width") == 0)
+			wh = w->req.width;
+		else
+			wh = w->req.height;
+		free(buf);
+		return tkvalue(val, "%d", wh);
+	case OPTtext:
+		c = OPTION(ft->ptr, char*, o->offset);
+		if(c == nil)
+			c = "";
+		free(buf);
+		return tkvalue(val, "%s", c);
+	case OPTwinp:
+		w = OPTION(ft->ptr, Tk*, o->offset);
+		if(w == nil || w->name == nil)
+			c = "";
+		else
+			c = w->name->name;
+		free(buf);
+		return tkvalue(val, "%s", c);
+	case OPTstab:
+		s = o->aux;
+		c = "";
+		con = OPTION(ft->ptr, int, o->offset);
+		while(s->val) {
+			if(con == s->con) {
+				c = s->val;
+				break;
+			}
+			s++;
+		}
+		free(buf);
+		return tkvalue(val, "%s", c);
+	case OPTflag:
+		con = OPTION(ft->ptr, int, o->offset);
+		flag = 0;
+		for (s = o->aux; s->val != nil; s++)
+			flag |= s->con;
+		c = "";
+		for (s = o->aux; s->val != nil; s++) {
+			if ((con & flag) == s->con) {
+				c = s->val;
+				break;
+			}
+		}
+		free(buf);
+		return tkvalue(val, "%s", c);
+	case OPTfont:
+		e = OPTION(ft->ptr, TkEnv*, o->offset);
+		free(buf);
+		if (e->font != nil)
+			return tkvalue(val, "%s", e->font->name);
+		return nil;
+	case OPTcolr:
+		e = OPTION(ft->ptr, TkEnv*, o->offset);
+		i = AUXI(o->aux);
+		free(buf);
+		return tkvalue(val, "#%.8lux", e->colors[i]);
+	case OPTfrac:
+	case OPTnnfrac:
+		v = &OPTION(ft->ptr, int, o->offset);
+		n = (int)o->aux;
+		if(n == 0)
+			n = 1;
+		fmt = "%s";
+		for(i = 0; i < n; i++) {
+			tkfprint(buf, *v++);
+			r = tkvalue(val, fmt, buf);
+			if(r != nil) {
+				free(buf);
+				return r;
+			}
+			fmt = " %s";
+		}
+		free(buf);
+		return nil;
+	case OPTbmap:
+		return tkvalue(val, "%d", OPTION(ft->ptr, Image*, o->offset) != nil);
+	case OPTimag:
+		return tkvalue(val, "%d", OPTION(ft->ptr, TkImg*, o->offset) != nil);
+	}
+}
+
+static char*
+pact(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	USED(buf);
+	USED(ebuf);
+	USED(str);
+	USED(place);
+	tkerr(t, o->o);
+	return TkBadop;
+}
+
+static char*
+pignore(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	char *p;
+	USED(t);
+	USED(o);
+	USED(place);
+
+	p = tkword(t, *str, buf, ebuf, nil);
+	if(*buf == '\0')
+		return TkOparg;
+	*str = p;
+	return nil;
+}
+
+static char*
+pdist(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	int d;
+	char *e;
+	TkEnv *env;
+
+	USED(buf);
+	USED(ebuf);
+
+	/*
+	 * this is a bit of a hack, as 0 is a valid option offset,
+	 * but a nil aux is commonly used when 'w' and 'h' suffixes
+	 * aren't appropriate.
+	 * just make sure that no structure placed in TkOptab->ptr
+	 * with an OPTdist element has a TkEnv as its first member.
+	 */
+
+	if (o->aux == nil)
+		env = nil;
+	else
+		env = OPTION(place, TkEnv*, AUXI(o->aux));
+	e = tkfracword(t, str, &d, env);
+	if(e != nil)
+		return e;
+	OPTION(place, int, o->offset) = TKF2I(d);
+	return nil;
+}
+
+static char*
+pnndist(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	char* e;
+	int oldv;
+
+	oldv = OPTION(place, int, o->offset);
+	e = pdist(t, o, place, str, buf, ebuf);
+	if(e == nil && OPTION(place, int, o->offset) < 0) {
+		OPTION(place, int, o->offset) = oldv;
+		return TkBadvl;
+	}
+	return e;	
+}
+
+static char*
+psize(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	Tk *tk;
+	char *e;
+	int d, off;
+
+	USED(ebuf);
+	e = tkfracword(t, str, &d, OPTION(place, TkEnv*, AUXI(o->aux)));
+	if (e != nil)
+		return e;
+	if(d < 0)
+		return TkBadvl;
+
+	tk = place;
+	/*
+	 * XXX there's no way of resetting Tksetwidth or Tksetheight.
+	 * could perhaps allow it by setting width/height to {}
+	 */
+	if(strcmp(buf+1, "width") == 0) {
+		tk->flag |= Tksetwidth;
+		off = O(Tk, req.width);
+	}
+	else {
+		tk->flag |= Tksetheight;
+		off = O(Tk, req.height);
+	}
+	OPTION(place, int, off) = TKF2I(d);
+	return nil;
+}
+
+static char*
+pstab(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	char *p;
+	int mask;
+	TkStab *s, *c;
+
+	p = tkword(t, *str, buf, ebuf, nil);
+	if(*buf == '\0')
+		return TkOparg;
+
+	for(s = o->aux; s->val; s++)
+		if(strcmp(s->val, buf) == 0)
+			break;
+	if(s->val == nil)
+		return TkBadvl;
+
+	*str = p;
+	if(o->type == OPTstab) {
+		OPTION(place, int, o->offset) = s->con;
+		return nil;
+	}
+
+	mask = 0;
+	for(c = o->aux; c->val; c++)
+		mask |= c->con;
+
+	OPTION(place, int, o->offset) &= ~mask;
+	OPTION(place, int, o->offset) |= s->con;
+
+	/*
+	 * a hack, but otherwise we have to dirty the focus order
+	 * every time any command is executed on a widget
+	 */
+	if (!strcmp(o->o, "takefocus"))
+		tkdirtyfocusorder(t);
+	return nil;
+}
+
+enum {
+	Stickyn = (1<<0),
+	Stickye = (1<<1),
+	Stickys = (1<<2),
+	Stickyw = (1<<3)
+};
+
+static int stickymap[16] =
+{
+	0,
+	Tknorth,
+	Tkeast,
+	Tknorth|Tkeast,
+	Tksouth,
+	Tkfilly,
+	Tksouth|Tkeast,
+	Tkeast|Tkfilly,
+	Tkwest,
+	Tknorth|Tkwest,
+	Tkfillx,
+	Tknorth|Tkfillx,
+	Tksouth|Tkwest,
+	Tkwest|Tkfilly,
+	Tksouth|Tkfillx,
+	Tkfillx|Tkfilly,
+};
+
+static char*
+psticky(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	char *p, *s;
+	int flag, sflag;
+
+	p = tkword(t, *str, buf, ebuf, nil);
+	*str = p;
+
+	flag = 0;
+	for (s = buf; *s; s++) {
+		switch (*s) {
+		case 'n':
+			flag |= Stickyn;
+			break;
+		case 's':
+			flag |= Stickys;
+			break;
+		case 'e':
+			flag |= Stickye;
+			break;
+		case 'w':
+			flag |= Stickyw;
+			break;
+		case ' ':
+		case ',':
+			break;
+		default:
+			return TkBadvl;
+		}
+	}
+	sflag =  OPTION(place, int, o->offset) & ~(Tkanchor|Tkfill);
+	OPTION(place, int, o->offset) = sflag | stickymap[flag];
+	return nil;
+}
+
+static char*
+ptext(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	char **p;
+
+	*str = tkword(t, *str, buf, ebuf, nil);
+
+	p = &OPTION(place, char*, o->offset);
+	if(*p != nil)
+		free(*p);
+	if(buf[0] == '\0')
+		*p = nil;
+	else {
+		*p = strdup(buf);
+		if(*p == nil)
+			return TkNomem;
+	}
+	return nil;
+}
+
+static char*
+pimag(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	int locked;
+	Display *d;
+	TkImg **p, *i;
+
+	i = nil;
+	p = &OPTION(place, TkImg*, o->offset);
+	*str = tkword(t, *str, buf, ebuf, nil);
+	if(*buf != '\0') {
+		i = tkname2img(t, buf);
+		if(i == nil)
+			return TkBadvl;
+		i->ref++;
+	}
+
+	if(*p != nil) {
+		d = t->display;
+		locked = lockdisplay(d);
+		tkimgput(*p);
+		if(locked)
+			unlockdisplay(d);
+	}
+	*p = i;
+	return nil;
+}
+
+static char*
+pbmap(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	Display *d;
+	Image *i, **p;
+	int locked, fd;
+	char *c;
+
+	p = &OPTION(place, Image*, o->offset);
+
+	d = t->display;
+	*str = tkword(t, *str, buf, ebuf, nil);
+	if(*buf == '\0' || *buf == '-') {
+		if(*p != nil) {
+			locked = lockdisplay(d);
+			freeimage(*p);
+			if(locked)
+				unlockdisplay(d);
+			*p = nil;
+		}
+		return nil;
+	}
+
+	if(buf[0] == '@')
+		i = display_open(d, buf+1);
+	else
+	if(buf[0] == '<') {
+		buf++;
+		fd = strtoul(buf, &c, 0);
+		if(c == buf) {
+			return TkBadvl;
+		}
+		i = readimage(d, fd, 1);
+	}
+	else {
+		char *file;
+
+		file = mallocz(Tkmaxitem, 0);
+		if(file == nil)
+			return TkNomem;
+
+		snprint(file, Tkmaxitem, "/icons/tk/%s", buf);
+		i = display_open(d, file);
+		free(file);
+	}
+	if(i == nil)
+		return TkBadbm;
+
+	if(*p != nil) {
+		locked = lockdisplay(d);
+		freeimage(*p);
+		if(locked)
+			unlockdisplay(d);
+	}
+	*p = i;
+	return nil;
+}
+
+static char*
+pfont(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	TkEnv *e;
+	Display *d;
+	int locked;
+	Font *font;
+
+	*str = tkword(t, *str, buf, ebuf, nil);
+	if(*buf == '\0')
+		return TkOparg;
+
+	d = t->display;
+	font = font_open(d, buf);
+	if(font == nil)
+		return TkBadft;
+
+	e = tkdupenv(&OPTION(place, TkEnv*, o->offset));
+	if(e == nil) {
+		freefont(font);		/* XXX lockdisplay around this? */
+		return TkNomem;
+	}
+	if(e->font)
+		font_close(e->font);
+	e->font = font;
+
+	locked = lockdisplay(d);
+	e->wzero = stringwidth(font, "0");
+	if ( e->wzero <= 0 )
+		e->wzero = e->font->height / 2;
+	if(locked)
+		unlockdisplay(d);
+
+	return nil;
+}
+
+static int
+hex(int c)
+{
+	if(c >= 'a')
+		c -= 'a'-'A';
+	if(c >= 'A')
+		c = 10 + (c - 'A');
+	else
+		c -= '0';
+	return c;
+}
+
+static ulong
+changecol(TkEnv *e, int setcol, int col, ulong rgba)
+{
+	if (setcol) {
+		e->set |= (1<<col);
+	} else {
+		rgba = 0;
+		e->set &= ~(1<<col);
+	}
+	e->colors[col] = rgba;
+	return rgba;
+}
+
+char*
+tkparsecolor(char *buf, ulong *rgba)
+{
+	char *p, *q, *e;
+	int R, G, B, A;
+	int i, alpha, len, alen;
+	/*
+	 * look for alpha modifier in *#AA or *0.5 format
+	 */
+	len = strlen(buf);
+	p = strchr(buf, '*');
+	if(p != nil) {
+		alen = len - (p - buf);
+		if(p[1] == '#') {
+			if(alen != 4)
+				return TkBadvl;
+			alpha = (hex(p[2])<<4) | (hex(p[3]));
+		} else {
+			q = p+1;
+			e = tkfrac(&q, &alpha, nil);
+			if (e != nil)
+				return e;
+			alpha = TKF2I(alpha * 0xff);
+		}
+		*p = '\0';
+		len -= alen;
+	} else
+		alpha = 0xff;
+	
+	if (*buf == '#') {
+		switch(len) {
+		case 4:			/* #RGB */
+			R = hex(buf[1]);
+			G = hex(buf[2]);
+			B = hex(buf[3]);
+			*rgba = (R<<28) | (G<<20) | (B<<12) | 0xff;
+			break;
+		case 7:			/* #RRGGBB */
+			R = (hex(buf[1])<<4)|(hex(buf[2]));
+			G = (hex(buf[3])<<4)|(hex(buf[4]));
+			B = (hex(buf[5])<<4)|(hex(buf[6]));
+			*rgba = (R<<24) | (G<<16) | (B<<8) | 0xff;
+			break;
+		case 9:			/* #RRGGBBAA */
+			R = (hex(buf[1])<<4)|(hex(buf[2]));
+			G = (hex(buf[3])<<4)|(hex(buf[4]));
+			B = (hex(buf[5])<<4)|(hex(buf[6]));
+			A = (hex(buf[7])<<4)|(hex(buf[8]));
+			*rgba = (R<<24) | (G<<16) | (B<<8) | A;
+			break;
+		default:
+			return TkBadvl;
+		}
+	} else {
+		for(i = 0; tkcolortab[i].val != nil; i++)
+			if (!strcmp(tkcolortab[i].val, buf))
+				break;
+		if (tkcolortab[i].val == nil)
+			return TkBadvl;
+		*rgba = tkcolortab[i].con;
+	}
+	if (alpha != 0xff) {
+		tkrgbavals(*rgba, &R, &G, &B, &A);
+		A = (A * alpha) / 255;
+		*rgba = tkrgba(R, G, B, A);
+	}
+	return nil;
+}
+
+static char*
+pcolr(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	TkEnv *env;
+	char *e;
+	ulong rgba, dark, light;
+	int color, setcol;
+
+	*str = tkword(t, *str, buf, ebuf, nil);
+	rgba = 0;
+	if(*buf == '\0') {
+		setcol = 0;
+	} else {
+		setcol = 1;
+		e = tkparsecolor(buf, &rgba);
+		if(e != nil)
+			return e;
+	}
+		
+	env = tkdupenv(&OPTION(place, TkEnv*, o->offset));
+	if(env == nil)
+		return TkNomem;
+
+	color = AUXI(o->aux);
+	rgba = changecol(env, setcol, color, rgba);
+	if(color == TkCbackgnd || color == TkCselectbgnd || color == TkCactivebgnd) {
+		if (setcol) {
+			light = tkrgbashade(rgba, TkLightshade);
+			dark = tkrgbashade(rgba, TkDarkshade);
+		} else
+			light = dark = 0;
+		changecol(env, setcol, color+1, light);
+		changecol(env, setcol, color+2, dark);
+	}
+	return nil;
+}
+
+static char*
+pbool(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	USED(buf);
+	USED(ebuf);
+	USED(str);
+	USED(t);
+	OPTION(place, int, o->offset) = 1;
+	return nil;
+}
+
+static char*
+pwinp(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	Tk *f;
+	char *p;
+
+	p = tkword(t, *str, buf, ebuf, nil);
+	if(*buf == '\0')
+		return TkOparg;
+	*str = p;
+	
+	f = tklook(t, buf, 0);
+	if(f == nil){
+		tkerr(t, buf);
+		return TkBadwp;
+	}
+
+	OPTION(place, Tk*, o->offset) = f;
+	return nil;
+}
+
+static char*
+pctag(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	char *p;
+	TkName *n, *l;
+
+	*str = tkword(t, *str, buf, ebuf, nil);
+
+	l = nil;
+	p = buf;
+	while(*p) {
+		p = tkskip(p, " \t");
+		buf = p;
+		while(*p && *p != ' ' && *p != '\t')
+			p++;
+		if(*p != '\0')
+			*p++ = '\0';
+
+		if(p == buf || buf[0] >= '0' && buf[0] <= '9') {
+			tkfreename(l);
+			return TkBadtg;
+		}
+		n = tkmkname(buf);
+		if(n == nil) {
+			tkfreename(l);
+			return TkNomem;
+		}
+		n->link = l;
+		l = n;
+	}
+	tkfreename(OPTION(place, TkName*, o->offset));
+	OPTION(place, TkName*, o->offset) = l;
+	return nil;
+}
+
+static char*
+pfrac(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	char *p, *e;
+	int i, n, d, *v;
+
+	*str = tkword(t, *str, buf, ebuf, nil);
+
+	v = &OPTION(place, int, o->offset);
+	n = (int)o->aux;
+	if(n == 0)
+		n = 1;
+	p = buf;
+	for(i = 0; i < n; i++) {
+		p = tkskip(p, " \t");
+		if(*p == '\0')
+			return TkOparg;
+		e = tkfracword(t, &p, &d, nil);
+		if (e != nil)
+			return e;
+		*v++ = d;
+	}
+	return nil;
+}
+
+/*
+ * N.B. nnfrac only accepts aux==nil (can't deal with several items)
+ */
+static char*
+pnnfrac(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	int oldv;
+	char *e;
+
+	oldv = OPTION(place, int, o->offset);
+
+	e = pfrac(t, o, place, str, buf, ebuf);
+	if(e == nil && OPTION(place, int, o->offset) < 0) {
+		OPTION(place, int, o->offset) = oldv;
+		return TkBadvl;
+	}
+	return e;	
+
+}
+
+typedef struct Tabspec {
+	int	dist;
+	int	just;
+	TkEnv	*env;
+} Tabspec;
+
+static char*
+ptabs(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	char *e, *p, *eibuf;
+	TkOption opd, opj;
+	Tabspec tspec;
+	TkTtabstop *tabfirst, *tab, *tabprev;
+	char *ibuf;
+
+	ibuf = mallocz(Tkmaxitem, 0);
+	if(ibuf == nil)
+		return TkNomem;
+	eibuf = ibuf + Tkmaxitem;
+	tspec.env = OPTION(place, TkEnv*, AUXI(o->aux));
+	opd.offset = O(Tabspec, dist);
+	opd.aux = IAUX(O(Tabspec, env));
+	opj.offset = O(Tabspec, dist);
+	opj.aux = tktabjust;
+	tabprev = nil;
+	tabfirst = nil;
+
+	p = tkword(t, *str, buf, ebuf, nil);
+	if(*buf == '\0') {
+		free(ibuf);
+		return TkOparg;
+	}
+	*str = p;
+
+	p = buf;
+	while(*p != '\0') {
+		e = pdist(t, &opd, &tspec, &p, ibuf, eibuf);
+		if(e != nil) {
+			free(ibuf);
+			return e;
+		}
+
+		e = pstab(t, &opj, &tspec, &p, ibuf, eibuf);
+		if(e != nil)
+			tspec.just = Tkleft;
+
+		tab = malloc(sizeof(TkTtabstop));
+		if(tab == nil) {
+			free(ibuf);
+			return TkNomem;
+		}
+
+		tab->pos = tspec.dist;
+		tab->justify = tspec.just;
+		tab->next = nil;
+		if(tabfirst == nil)
+			tabfirst = tab;
+		else
+			tabprev->next = tab;
+		tabprev = tab;
+	}
+	free(ibuf);
+
+	tab = OPTION(place, TkTtabstop*, o->offset);
+	if(tab != nil)
+		free(tab);
+	OPTION(place, TkTtabstop*, o->offset) = tabfirst;
+	return nil;
+}
+
+char*
+tkxyparse(Tk* tk, char **parg, Point *p)
+{
+	char *buf;
+
+	buf = mallocz(Tkmaxitem, 0);
+	if(buf == nil)
+		return TkNomem;
+
+	*parg = tkword(tk->env->top, *parg, buf, buf+Tkmaxitem, nil);
+	if(*buf == '\0') {
+		free(buf);
+		return TkOparg;
+	}
+	p->x = atoi(buf);
+
+	*parg = tkword(tk->env->top, *parg, buf, buf+Tkmaxitem, nil);
+	if(*buf == '\0') {
+		free(buf);
+		return TkOparg;
+	}
+	p->y = atoi(buf);
+
+	free(buf);
+	return nil;
+}
+
+static char*
+plist(TkTop *t, TkOption *o, void *place, char **str, char *buf, char *ebuf)
+{
+	char *w, ***p, *wbuf, *ewbuf, **v, **nv;
+	int n, m, i, found;
+
+	*str = tkword(t, *str, buf, ebuf, nil);
+	n = strlen(buf) + 1;
+	wbuf = mallocz(n, 0);
+	if (wbuf == nil)
+		return TkNomem;		/* XXX should we free old values too? */
+	ewbuf = &wbuf[n];
+
+	p = &OPTION(place, char**, o->offset);
+	if (*p != nil){
+		for (v = *p; *v; v++)
+			free(*v);
+		free(*p);
+	}
+	n = 0;
+	m = 4;
+	w = buf;
+	v = malloc(m * sizeof(char*));
+	if (v == nil)
+		goto Error;
+	for (;;) {
+		w = tkword(t, w, wbuf, ewbuf, &found);
+		if (!found)
+			break;
+		if (n == m - 1) {
+			m += m/2;
+			nv = realloc(v, m * sizeof(char*));
+			if (nv == nil)
+				goto Error;
+			v = nv;
+		}
+		v[n] = strdup(wbuf);
+		if (v[n] == nil)
+			goto Error;
+		n++;
+	}
+	v[n++] = nil;
+	*p = realloc(v, n * sizeof(char*));
+	free(wbuf);
+	return nil;
+Error:
+	free(buf);
+	for (i = 0; i < n; i++)
+		free(v[i]);
+	free(v);
+	*p = nil;
+	return TkNomem;
+}