1 files changed, 132 insertions, 0 deletions
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);
+	}
+}