1 files changed, 122 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;
+}