#include <u.h>#include <libc.h>#include <draw.h>#include <thread.h>#include <mouse.h>#include <frame.h> intfrdelete(Frame *f, ulong p0, ulong p1){	Point pt0, pt1, ppt0;	Frbox *b;	int n0, n1, n, w0;	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){			w0 = b->wid;			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; 			/* blank remainder of line */			r.min.x = r.max.x;			r.max.x += w0 - b->wid;			if(r.max.x > f->r.max.x)				r.max.x = f->r.max.x;			if(r.max.x != r.min.x)				draw(f->b, r, f->cols[BACK], nil, r.min);		}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;}