Initial import.

7 files changed, 885 insertions, 0 deletions

diff --git a/src/libframe/frdelete.c b/src/libframe/frdelete.c
new file mode 100644
index 00000000..04ef6a09
--- /dev/null
+++ b/src/libframe/frdelete.c
@@ -0,0 +1,122 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <mouse.h>
+#include <frame.h>
+
+int
+frdelete(Frame *f, ulong p0, ulong p1)
+{
+	Point pt0, pt1, ppt0;
+	Frbox *b;
+	int n0, n1, n;
+	ulong cn1;
+	Rectangle r;
+	int nn0;
+	Image *col;
+
+	if(p0>=f->nchars || p0==p1 || f->b==nil)
+		return 0;
+	if(p1 > f->nchars)
+		p1 = f->nchars;
+	n0 = _frfindbox(f, 0, 0, p0);
+	if(n0 == f->nbox)
+		drawerror(f->display, "off end in frdelete");
+	n1 = _frfindbox(f, n0, p0, p1);
+	pt0 = _frptofcharnb(f, p0, n0);
+	pt1 = frptofchar(f, p1);
+	if(f->p0 == f->p1)
+		frtick(f, frptofchar(f, f->p0), 0);
+	nn0 = n0;
+	ppt0 = pt0;
+	_frfreebox(f, n0, n1-1);
+	f->modified = 1;
+
+	/*
+	 * Invariants:
+	 *  - pt0 points to beginning, pt1 points to end
+	 *  - n0 is box containing beginning of stuff being deleted
+	 *  - n1, b are box containing beginning of stuff to be kept after deletion
+	 *  - cn1 is char position of n1
+	 *  - f->p0 and f->p1 are not adjusted until after all deletion is done
+	 */
+	b = &f->box[n1];
+	cn1 = p1;
+	while(pt1.x!=pt0.x && n1<f->nbox){
+		_frcklinewrap0(f, &pt0, b);
+		_frcklinewrap(f, &pt1, b);
+		n = _frcanfit(f, pt0, b);
+		if(n==0)
+			drawerror(f->display, "_frcanfit==0");
+		r.min = pt0;
+		r.max = pt0;
+		r.max.y += f->font->height;
+		if(b->nrune > 0){
+			if(n != b->nrune){
+				_frsplitbox(f, n1, n);
+				b = &f->box[n1];
+			}
+			r.max.x += b->wid;
+			draw(f->b, r, f->b, nil, pt1);
+			cn1 += b->nrune;
+		}else{
+			r.max.x += _frnewwid0(f, pt0, b);
+			if(r.max.x > f->r.max.x)
+				r.max.x = f->r.max.x;
+			col = f->cols[BACK];
+			if(f->p0<=cn1 && cn1<f->p1)
+				col = f->cols[HIGH];
+			draw(f->b, r, col, nil, pt0);
+			cn1++;
+		}
+		_fradvance(f, &pt1, b);
+		pt0.x += _frnewwid(f, pt0, b);
+		f->box[n0++] = f->box[n1++];
+		b++;
+	}
+	if(n1==f->nbox && pt0.x!=pt1.x)	/* deleting last thing in window; must clean up */
+		frselectpaint(f, pt0, pt1, f->cols[BACK]);
+	if(pt1.y != pt0.y){
+		Point pt2;
+
+		pt2 = _frptofcharptb(f, 32767, pt1, n1);
+		if(pt2.y > f->r.max.y)
+			drawerror(f->display, "frptofchar in frdelete");
+		if(n1 < f->nbox){
+			int q0, q1, q2;
+
+			q0 = pt0.y+f->font->height;
+			q1 = pt1.y+f->font->height;
+			q2 = pt2.y+f->font->height;
+			if(q2 > f->r.max.y)
+				q2 = f->r.max.y;
+			draw(f->b, Rect(pt0.x, pt0.y, pt0.x+(f->r.max.x-pt1.x), q0),
+				f->b, nil, pt1);
+			draw(f->b, Rect(f->r.min.x, q0, f->r.max.x, q0+(q2-q1)),
+				f->b, nil, Pt(f->r.min.x, q1));
+			frselectpaint(f, Pt(pt2.x, pt2.y-(pt1.y-pt0.y)), pt2, f->cols[BACK]);
+		}else
+			frselectpaint(f, pt0, pt2, f->cols[BACK]);
+	}
+	_frclosebox(f, n0, n1-1);
+	if(nn0>0 && f->box[nn0-1].nrune>=0 && ppt0.x-f->box[nn0-1].wid>=(int)f->r.min.x){
+		--nn0;
+		ppt0.x -= f->box[nn0].wid;
+	}
+	_frclean(f, ppt0, nn0, n0<f->nbox-1? n0+1 : n0);
+	if(f->p1 > p1)
+		f->p1 -= p1-p0;
+	else if(f->p1 > p0)
+		f->p1 = p0;
+	if(f->p0 > p1)
+		f->p0 -= p1-p0;
+	else if(f->p0 > p0)
+		f->p0 = p0;
+	f->nchars -= p1-p0;
+	if(f->p0 == f->p1)
+		frtick(f, frptofchar(f, f->p0), 1);
+	pt0 = frptofchar(f, f->nchars);
+	n = f->nlines;
+	f->nlines = (pt0.y-f->r.min.y)/f->font->height+(pt0.x>f->r.min.x);
+	return n - f->nlines;
+}
diff --git a/src/libframe/frinit.c b/src/libframe/frinit.c
new file mode 100644
index 00000000..c178ede1
--- /dev/null
+++ b/src/libframe/frinit.c
@@ -0,0 +1,83 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <mouse.h>
+#include <frame.h>
+
+void
+frinit(Frame *f, Rectangle r, Font *ft, Image *b, Image *cols[NCOL])
+{
+	f->font = ft;
+	f->display = b->display;
+	f->maxtab = 8*stringwidth(ft, "0");
+	f->nbox = 0;
+	f->nalloc = 0;
+	f->nchars = 0;
+	f->nlines = 0;
+	f->p0 = 0;
+	f->p1 = 0;
+	f->box = 0;
+	f->lastlinefull = 0;
+	if(cols != 0)
+		memmove(f->cols, cols, sizeof f->cols);
+	frsetrects(f, r, b);
+	if(f->tick==nil && f->cols[BACK]!=0)
+		frinittick(f);
+}
+
+void
+frinittick(Frame *f)
+{
+	Image *b;
+	Font *ft;
+
+	b = f->display->screenimage;
+	ft = f->font;
+	if(f->tick)
+		freeimage(f->tick);
+	f->tick = allocimage(f->display, Rect(0, 0, FRTICKW, ft->height), b->chan, 0, DWhite);
+	if(f->tick == nil)
+		return;
+	if(f->tickback)
+		freeimage(f->tickback);
+	f->tickback = allocimage(f->display, f->tick->r, b->chan, 0, DWhite);
+	if(f->tickback == 0){
+		freeimage(f->tick);
+		f->tick = 0;
+		return;
+	}
+	/* background color */
+	draw(f->tick, f->tick->r, f->cols[BACK], nil, ZP);
+	/* vertical line */
+	draw(f->tick, Rect(FRTICKW/2, 0, FRTICKW/2+1, ft->height), f->display->black, nil, ZP);
+	/* box on each end */
+	draw(f->tick, Rect(0, 0, FRTICKW, FRTICKW), f->cols[TEXT], nil, ZP);
+	draw(f->tick, Rect(0, ft->height-FRTICKW, FRTICKW, ft->height), f->cols[TEXT], nil, ZP);
+}
+
+void
+frsetrects(Frame *f, Rectangle r, Image *b)
+{
+	f->b = b;
+	f->entire = r;
+	f->r = r;
+	f->r.max.y -= (r.max.y-r.min.y)%f->font->height;
+	f->maxlines = (r.max.y-r.min.y)/f->font->height;
+}
+
+void
+frclear(Frame *f, int freeall)
+{
+	if(f->nbox)
+		_frdelbox(f, 0, f->nbox-1);
+	if(f->box)
+		free(f->box);
+	if(freeall){
+		freeimage(f->tick);
+		freeimage(f->tickback);
+		f->tick = 0;
+		f->tickback = 0;
+	}
+	f->box = 0;
+	f->ticked = 0;
+}
diff --git a/src/libframe/frinsert.c b/src/libframe/frinsert.c
new file mode 100644
index 00000000..8ca39fcf
--- /dev/null
+++ b/src/libframe/frinsert.c
@@ -0,0 +1,285 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <mouse.h>
+#include <frame.h>
+
+#define	DELTA	25
+#define	TMPSIZE	256
+static Frame		frame;
+
+static
+Point
+bxscan(Frame *f, Rune *sp, Rune *ep, Point *ppt)
+{
+	int w, c, nb, delta, nl, nr, rw;
+	Frbox *b;
+	char *s, tmp[TMPSIZE+3];	/* +3 for rune overflow */
+	uchar *p;
+
+	frame.r = f->r;
+	frame.b = f->b;
+	frame.font = f->font;
+	frame.maxtab = f->maxtab;
+	frame.nbox = 0;
+	frame.nchars = 0;
+	memmove(frame.cols, f->cols, sizeof frame.cols);
+	delta = DELTA;
+	nl = 0;
+	for(nb=0; sp<ep && nl<=f->maxlines; nb++,frame.nbox++){
+		if(nb == frame.nalloc){
+			_frgrowbox(&frame, delta);
+			if(delta < 10000)
+				delta *= 2;
+		}
+		b = &frame.box[nb];
+		c = *sp;
+		if(c=='\t' || c=='\n'){
+			b->bc = c;
+			b->wid = 5000;
+			b->minwid = (c=='\n')? 0 : stringwidth(frame.font, " ");
+			b->nrune = -1;
+			if(c=='\n')
+				nl++;
+			frame.nchars++;
+			sp++;
+		}else{
+			s = tmp;
+			nr = 0;
+			w = 0;
+			while(sp < ep){
+				c = *sp;
+				if(c=='\t' || c=='\n')
+					break;
+				rw = runetochar(s, sp);
+				if(s+rw >= tmp+TMPSIZE)
+					break;
+				w += runestringnwidth(frame.font, sp, 1);
+				sp++;
+				s += rw;
+				nr++;
+			}
+			*s++ = 0;
+			p = _frallocstr(f, s-tmp);
+			b = &frame.box[nb];
+			b->ptr = p;
+			memmove(p, tmp, s-tmp);
+			b->wid = w;
+			b->nrune = nr;
+			frame.nchars += nr;
+		}
+	}
+	_frcklinewrap0(f, ppt, &frame.box[0]);
+	return _frdraw(&frame, *ppt);
+}
+
+static
+void
+chopframe(Frame *f, Point pt, ulong p, int bn)
+{
+	Frbox *b;
+
+	for(b = &f->box[bn]; ; b++){
+		if(b >= &f->box[f->nbox])
+			drawerror(f->display, "endofframe");
+		_frcklinewrap(f, &pt, b);
+		if(pt.y >= f->r.max.y)
+			break;
+		p += NRUNE(b);
+		_fradvance(f, &pt, b);
+	}
+	f->nchars = p;
+	f->nlines = f->maxlines;
+	if(b<&f->box[f->nbox])				/* BUG */
+		_frdelbox(f, (int)(b-f->box), f->nbox-1);
+}
+
+void
+frinsert(Frame *f, Rune *sp, Rune *ep, ulong p0)
+{
+	Point pt0, pt1, opt0, ppt0, ppt1, pt;
+	Frbox *b;
+	int n, n0, nn0, y;
+	ulong cn0;
+	Image *col;
+	Rectangle r;
+	static struct{
+		Point pt0, pt1;
+	}*pts;
+	static int nalloc=0;
+	int npts;
+
+	if(p0>f->nchars || sp==ep || f->b==nil)
+		return;
+	n0 = _frfindbox(f, 0, 0, p0);
+	cn0 = p0;
+	nn0 = n0;
+	pt0 = _frptofcharnb(f, p0, n0);
+	ppt0 = pt0;
+	opt0 = pt0;
+	pt1 = bxscan(f, sp, ep, &ppt0);
+	ppt1 = pt1;
+	if(n0 < f->nbox){
+		_frcklinewrap(f, &pt0, b = &f->box[n0]);	/* for frdrawsel() */
+		_frcklinewrap0(f, &ppt1, b);
+	}
+	f->modified = 1;
+	/*
+	 * ppt0 and ppt1 are start and end of insertion as they will appear when
+	 * insertion is complete. pt0 is current location of insertion position
+	 * (p0); pt1 is terminal point (without line wrap) of insertion.
+	 */
+	if(f->p0 == f->p1)
+		frtick(f, frptofchar(f, f->p0), 0);
+
+	/*
+	 * Find point where old and new x's line up
+	 * Invariants:
+	 *	pt0 is where the next box (b, n0) is now
+	 *	pt1 is where it will be after the insertion
+	 * If pt1 goes off the rectangle, we can toss everything from there on
+	 */
+	for(b = &f->box[n0],npts=0;
+	     pt1.x!=pt0.x && pt1.y!=f->r.max.y && n0<f->nbox; b++,n0++,npts++){
+		_frcklinewrap(f, &pt0, b);
+		_frcklinewrap0(f, &pt1, b);
+		if(b->nrune > 0){
+			n = _frcanfit(f, pt1, b);
+			if(n == 0)
+				drawerror(f->display, "_frcanfit==0");
+			if(n != b->nrune){
+				_frsplitbox(f, n0, n);
+				b = &f->box[n0];
+			}
+		}
+		if(npts == nalloc){
+			pts = realloc(pts, (npts+DELTA)*sizeof(pts[0]));
+			nalloc += DELTA;
+			b = &f->box[n0];
+		}
+		pts[npts].pt0 = pt0;
+		pts[npts].pt1 = pt1;
+		/* has a text box overflowed off the frame? */
+		if(pt1.y == f->r.max.y)
+			break;
+		_fradvance(f, &pt0, b);
+		pt1.x += _frnewwid(f, pt1, b);
+		cn0 += NRUNE(b);
+	}
+	if(pt1.y > f->r.max.y)
+		drawerror(f->display, "frinsert pt1 too far");
+	if(pt1.y==f->r.max.y && n0<f->nbox){
+		f->nchars -= _frstrlen(f, n0);
+		_frdelbox(f, n0, f->nbox-1);
+	}
+	if(n0 == f->nbox)
+		f->nlines = (pt1.y-f->r.min.y)/f->font->height+(pt1.x>f->r.min.x);
+	else if(pt1.y!=pt0.y){
+		int q0, q1;
+
+		y = f->r.max.y;
+		q0 = pt0.y+f->font->height;
+		q1 = pt1.y+f->font->height;
+		f->nlines += (q1-q0)/f->font->height;
+		if(f->nlines > f->maxlines)
+			chopframe(f, ppt1, p0, nn0);
+		if(pt1.y < y){
+			r = f->r;
+			r.min.y = q1;
+			r.max.y = y;
+			if(q1 < y)
+				draw(f->b, r, f->b, nil, Pt(f->r.min.x, q0));
+			r.min = pt1;
+			r.max.x = pt1.x+(f->r.max.x-pt0.x);
+			r.max.y = q1;
+			draw(f->b, r, f->b, nil, pt0);
+		}
+	}
+	/*
+	 * Move the old stuff down to make room.  The loop will move the stuff
+	 * between the insertion and the point where the x's lined up.
+	 * The draw()s above moved everything down after the point they lined up.
+	 */
+	for((y=pt1.y==f->r.max.y?pt1.y:0),b = &f->box[n0-1]; --npts>=0; --b){
+		pt = pts[npts].pt1;
+		if(b->nrune > 0){
+			r.min = pt;
+			r.max = r.min;
+			r.max.x += b->wid;
+			r.max.y += f->font->height;
+			draw(f->b, r, f->b, nil, pts[npts].pt0);
+			/* clear bit hanging off right */
+			if(npts==0 && pt.y>pt0.y){
+				/*
+				 * first new char is bigger than first char we're
+				 * displacing, causing line wrap. ugly special case.
+				 */
+				r.min = opt0;
+				r.max = opt0;
+				r.max.x = f->r.max.x;
+				r.max.y += f->font->height;
+				if(f->p0<=cn0 && cn0<f->p1)	/* b+1 is inside selection */
+					col = f->cols[HIGH];
+				else
+					col = f->cols[BACK];
+				draw(f->b, r, col, nil, r.min);
+			}else if(pt.y < y){
+				r.min = pt;
+				r.max = pt;
+				r.min.x += b->wid;
+				r.max.x = f->r.max.x;
+				r.max.y += f->font->height;
+				if(f->p0<=cn0 && cn0<f->p1)	/* b+1 is inside selection */
+					col = f->cols[HIGH];
+				else
+					col = f->cols[BACK];
+				draw(f->b, r, col, nil, r.min);
+			}
+			y = pt.y;
+			cn0 -= b->nrune;
+		}else{
+			r.min = pt;
+			r.max = pt;
+			r.max.x += b->wid;
+			r.max.y += f->font->height;
+			if(r.max.x >= f->r.max.x)
+				r.max.x = f->r.max.x;
+			cn0--;
+			if(f->p0<=cn0 && cn0<f->p1)	/* b is inside selection */
+				col = f->cols[HIGH];
+			else
+				col = f->cols[BACK];
+			draw(f->b, r, col, nil, r.min);
+			y = 0;
+			if(pt.x == f->r.min.x)
+				y = pt.y;
+		}
+	}
+	/* insertion can extend the selection, so the condition here is different */
+	if(f->p0<p0 && p0<=f->p1)
+		col = f->cols[HIGH];
+	else
+		col = f->cols[BACK];
+	frselectpaint(f, ppt0, ppt1, col);
+	_frredraw(&frame, ppt0);
+	_fraddbox(f, nn0, frame.nbox);
+	for(n=0; n<frame.nbox; n++)
+		f->box[nn0+n] = frame.box[n];
+	if(nn0>0 && f->box[nn0-1].nrune>=0 && ppt0.x-f->box[nn0-1].wid>=f->r.min.x){
+		--nn0;
+		ppt0.x -= f->box[nn0].wid;
+	}
+	n0 += frame.nbox;
+	_frclean(f, ppt0, nn0, n0<f->nbox-1? n0+1 : n0);
+	f->nchars += frame.nchars;
+	if(f->p0 >= p0)
+		f->p0 += frame.nchars;
+	if(f->p0 > f->nchars)
+		f->p0 = f->nchars;
+	if(f->p1 >= p0)
+		f->p1 += frame.nchars;
+	if(f->p1 > f->nchars)
+		f->p1 = f->nchars;
+	if(f->p0 == f->p1)
+		frtick(f, frptofchar(f, f->p0), 1);
+}
diff --git a/src/libframe/frptofchar.c b/src/libframe/frptofchar.c
new file mode 100644
index 00000000..58536ed9
--- /dev/null
+++ b/src/libframe/frptofchar.c
@@ -0,0 +1,115 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <mouse.h>
+#include <frame.h>
+
+Point
+_frptofcharptb(Frame *f, ulong p, Point pt, int bn)
+{
+	uchar *s;
+	Frbox *b;
+	int w, l;
+	Rune r;
+
+	for(b = &f->box[bn]; bn<f->nbox; bn++,b++){
+		_frcklinewrap(f, &pt, b);
+		if(p < (l=NRUNE(b))){
+			if(b->nrune > 0)
+				for(s=b->ptr; p>0; s+=w, p--){
+					if((r = *s) < Runeself)
+						w = 1;
+					else
+						w = chartorune(&r, (char*)s);
+					pt.x += stringnwidth(f->font, (char*)s, 1);
+					if(r==0 || pt.x>f->r.max.x)
+						drawerror(f->display, "frptofchar");
+				}
+			break;
+		}
+		p -= l;
+		_fradvance(f, &pt, b);
+	}
+	return pt;
+}
+
+Point
+frptofchar(Frame *f, ulong p)
+{
+	return _frptofcharptb(f, p, f->r.min, 0);
+}
+
+Point
+_frptofcharnb(Frame *f, ulong p, int nb)	/* doesn't do final _fradvance to next line */
+{
+	Point pt;
+	int nbox;
+
+	nbox = f->nbox;
+	f->nbox = nb;
+	pt = _frptofcharptb(f, p, f->r.min, 0);
+	f->nbox = nbox;
+	return pt;
+}
+
+static
+Point
+_frgrid(Frame *f, Point p)
+{
+	p.y -= f->r.min.y;
+	p.y -= p.y%f->font->height;
+	p.y += f->r.min.y;
+	if(p.x > f->r.max.x)
+		p.x = f->r.max.x;
+	return p;
+}
+
+ulong
+frcharofpt(Frame *f, Point pt)
+{
+	Point qt;
+	int w, bn;
+	uchar *s;
+	Frbox *b;
+	ulong p;
+	Rune r;
+
+	pt = _frgrid(f, pt);
+	qt = f->r.min;
+	for(b=f->box,bn=0,p=0; bn<f->nbox && qt.y<pt.y; bn++,b++){
+		_frcklinewrap(f, &qt, b);
+		if(qt.y >= pt.y)
+			break;
+		_fradvance(f, &qt, b);
+		p += NRUNE(b);
+	}
+	for(; bn<f->nbox && qt.x<=pt.x; bn++,b++){
+		_frcklinewrap(f, &qt, b);
+		if(qt.y > pt.y)
+			break;
+		if(qt.x+b->wid > pt.x){
+			if(b->nrune < 0)
+				_fradvance(f, &qt, b);
+			else{
+				s = b->ptr;
+				for(;;){
+					if((r = *s) < Runeself)
+						w = 1;
+					else
+						w = chartorune(&r, (char*)s);
+					if(r == 0)
+						drawerror(f->display, "end of string in frcharofpt");
+					qt.x += stringnwidth(f->font, (char*)s, 1);
+					s += w;
+					if(qt.x > pt.x)
+						break;
+					p++;
+				}
+			}
+		}else{
+			p += NRUNE(b);
+			_fradvance(f, &qt, b);
+		}
+	}
+	return p;
+}
diff --git a/src/libframe/frselect.c b/src/libframe/frselect.c
new file mode 100644
index 00000000..b319c576
--- /dev/null
+++ b/src/libframe/frselect.c
@@ -0,0 +1,132 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <mouse.h>
+#include <frame.h>
+
+static
+int
+region(int a, int b)
+{
+	if(a < b)
+		return -1;
+	if(a == b)
+		return 0;
+	return 1;
+}
+
+void
+frselect(Frame *f, Mousectl *mc)	/* when called, button 1 is down */
+{
+	ulong p0, p1, q;
+	Point mp, pt0, pt1, qt;
+	int reg, b, scrled;
+
+	mp = mc->m.xy;
+	b = mc->m.buttons;
+
+	f->modified = 0;
+	frdrawsel(f, frptofchar(f, f->p0), f->p0, f->p1, 0);
+	p0 = p1 = frcharofpt(f, mp);
+	f->p0 = p0;
+	f->p1 = p1;
+	pt0 = frptofchar(f, p0);
+	pt1 = frptofchar(f, p1);
+	frdrawsel(f, pt0, p0, p1, 1);
+	reg = 0;
+	do{
+		scrled = 0;
+		if(f->scroll){
+			if(mp.y < f->r.min.y){
+				(*f->scroll)(f, -(f->r.min.y-mp.y)/(int)f->font->height-1);
+				p0 = f->p1;
+				p1 = f->p0;
+				scrled = 1;
+			}else if(mp.y > f->r.max.y){
+				(*f->scroll)(f, (mp.y-f->r.max.y)/(int)f->font->height+1);
+				p0 = f->p0;
+				p1 = f->p1;
+				scrled = 1;
+			}
+			if(scrled){
+				if(reg != region(p1, p0))
+					q = p0, p0 = p1, p1 = q;	/* undo the swap that will happen below */
+				pt0 = frptofchar(f, p0);
+				pt1 = frptofchar(f, p1);
+				reg = region(p1, p0);
+			}
+		}
+		q = frcharofpt(f, mp);
+		if(p1 != q){
+			if(reg != region(q, p0)){	/* crossed starting point; reset */
+				if(reg > 0)
+					frdrawsel(f, pt0, p0, p1, 0);
+				else if(reg < 0)
+					frdrawsel(f, pt1, p1, p0, 0);
+				p1 = p0;
+				pt1 = pt0;
+				reg = region(q, p0);
+				if(reg == 0)
+					frdrawsel(f, pt0, p0, p1, 1);
+			}
+			qt = frptofchar(f, q);
+			if(reg > 0){
+				if(q > p1)
+					frdrawsel(f, pt1, p1, q, 1);
+				else if(q < p1)
+					frdrawsel(f, qt, q, p1, 0);
+			}else if(reg < 0){
+				if(q > p1)
+					frdrawsel(f, pt1, p1, q, 0);
+				else
+					frdrawsel(f, qt, q, p1, 1);
+			}
+			p1 = q;
+			pt1 = qt;
+		}
+		f->modified = 0;
+		if(p0 < p1) {
+			f->p0 = p0;
+			f->p1 = p1;
+		}
+		else {
+			f->p0 = p1;
+			f->p1 = p0;
+		}
+		if(scrled)
+			(*f->scroll)(f, 0);
+		flushimage(f->display, 1);
+		if(!scrled)
+			readmouse(mc);
+		mp = mc->m.xy;
+	}while(mc->m.buttons == b);
+}
+
+void
+frselectpaint(Frame *f, Point p0, Point p1, Image *col)
+{
+	int n;
+	Point q0, q1;
+
+	q0 = p0;
+	q1 = p1;
+	q0.y += f->font->height;
+	q1.y += f->font->height;
+	n = (p1.y-p0.y)/f->font->height;
+	if(f->b == nil)
+		drawerror(f->display, "frselectpaint b==0");
+	if(p0.y == f->r.max.y)
+		return;
+	if(n == 0)
+		draw(f->b, Rpt(p0, q1), col, nil, ZP);
+	else{
+		if(p0.x >= f->r.max.x)
+			p0.x = f->r.max.x-1;
+		draw(f->b, Rect(p0.x, p0.y, f->r.max.x, q0.y), col, nil, ZP);
+		if(n > 1)
+			draw(f->b, Rect(f->r.min.x, q0.y, f->r.max.x, p1.y),
+				col, nil, ZP);
+		draw(f->b, Rect(f->r.min.x, p1.y, q1.x, q1.y),
+			col, nil, ZP);
+	}
+}
diff --git a/src/libframe/frstr.c b/src/libframe/frstr.c
new file mode 100644
index 00000000..950b3e21
--- /dev/null
+++ b/src/libframe/frstr.c
@@ -0,0 +1,37 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <mouse.h>
+#include <frame.h>
+
+#define	CHUNK	16
+#define	ROUNDUP(n)	((n+CHUNK)&~(CHUNK-1))
+
+uchar *
+_frallocstr(Frame *f, unsigned n)
+{
+	uchar *p;
+
+	p = malloc(ROUNDUP(n));
+	if(p == 0)
+		drawerror(f->display, "out of memory");
+	return p;
+}
+
+void
+_frinsure(Frame *f, int bn, unsigned n)
+{
+	Frbox *b;
+	uchar *p;
+
+	b = &f->box[bn];
+	if(b->nrune < 0)
+		drawerror(f->display, "_frinsure");
+	if(ROUNDUP(b->nrune) > n)	/* > guarantees room for terminal NUL */
+		return;
+	p = _frallocstr(f, n);
+	b = &f->box[bn];
+	memmove(p, b->ptr, NBYTE(b)+1);
+	free(b->ptr);
+	b->ptr = p;
+}
diff --git a/src/libframe/frutil.c b/src/libframe/frutil.c
new file mode 100644
index 00000000..c8e3c043
--- /dev/null
+++ b/src/libframe/frutil.c
@@ -0,0 +1,111 @@
+#include <u.h>
+#include <libc.h>
+#include <draw.h>
+#include <mouse.h>
+#include <frame.h>
+
+int
+_frcanfit(Frame *f, Point pt, Frbox *b)
+{
+	int left, w, nr;
+	uchar *p;
+	Rune r;
+
+	left = f->r.max.x-pt.x;
+	if(b->nrune < 0)
+		return b->minwid <= left;
+	if(left >= b->wid)
+		return b->nrune;
+	for(nr=0,p=b->ptr; *p; p+=w,nr++){
+		r = *p;
+		if(r < Runeself)
+			w = 1;
+		else
+			w = chartorune(&r, (char*)p);
+		left -= stringnwidth(f->font, (char*)p, 1);
+		if(left < 0)
+			return nr;
+	}
+	drawerror(f->display, "_frcanfit can't");
+	return 0;
+}
+
+void
+_frcklinewrap(Frame *f, Point *p, Frbox *b)
+{
+	if((b->nrune<0? b->minwid : b->wid) > f->r.max.x-p->x){
+		p->x = f->r.min.x;
+		p->y += f->font->height;
+	}
+}
+
+void
+_frcklinewrap0(Frame *f, Point *p, Frbox *b)
+{
+	if(_frcanfit(f, *p, b) == 0){
+		p->x = f->r.min.x;
+		p->y += f->font->height;
+	}
+}
+
+void
+_fradvance(Frame *f, Point *p, Frbox *b)
+{
+	if(b->nrune<0 && b->bc=='\n'){
+		p->x = f->r.min.x;
+		p->y += f->font->height;
+	}else
+		p->x += b->wid;
+}
+
+int
+_frnewwid(Frame *f, Point pt, Frbox *b)
+{
+	b->wid = _frnewwid0(f, pt, b);
+	return b->wid;
+}
+
+int
+_frnewwid0(Frame *f, Point pt, Frbox *b)
+{
+	int c, x;
+
+	c = f->r.max.x;
+	x = pt.x;
+	if(b->nrune>=0 || b->bc!='\t')
+		return b->wid;
+	if(x+b->minwid > c)
+		x = pt.x = f->r.min.x;
+	x += f->maxtab;
+	x -= (x-f->r.min.x)%f->maxtab;
+	if(x-pt.x<b->minwid || x>c)
+		x = pt.x+b->minwid;
+	return x-pt.x;
+}
+
+void
+_frclean(Frame *f, Point pt, int n0, int n1)	/* look for mergeable boxes */
+{
+	Frbox *b;
+	int nb, c;
+
+	c = f->r.max.x;
+	for(nb=n0; nb<n1-1; nb++){
+		b = &f->box[nb];
+		_frcklinewrap(f, &pt, b);
+		while(b[0].nrune>=0 && nb<n1-1 && b[1].nrune>=0 && pt.x+b[0].wid+b[1].wid<c){
+			_frmergebox(f, nb);
+			n1--;
+			b = &f->box[nb];
+		}
+		_fradvance(f, &pt, &f->box[nb]);
+	}
+	for(; nb<f->nbox; nb++){
+		b = &f->box[nb];
+		_frcklinewrap(f, &pt, b);
+		_fradvance(f, &pt, &f->box[nb]);
+	}
+	f->lastlinefull = 0;
+	if(pt.y >= f->r.max.y)
+		f->lastlinefull = 1;
+}