diff -r 3b8b1da2ff29 -r 12b1f4649ab1 src/Tools/GraphBrowser/awt/Border.java
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/Tools/GraphBrowser/awt/Border.java	Fri Jul 16 12:55:02 2021 +0200
@@ -0,0 +1,39 @@
+/***************************************************************************
+  Title:      awt/Border.java
+  Author:     Stefan Berghofer, TU Muenchen
+
+  This class defines a nice 3D border.
+***************************************************************************/
+
+package isabelle.awt;
+
+import java.awt.*;
+
+public class Border extends Panel {
+	int bs;
+
+	public Insets getInsets() {
+		return new Insets(bs*3/2,bs*3/2,bs*3/2,bs*3/2);
+	}
+
+	public Border(Component comp,int s) {
+		setLayout(new GridLayout(1,1));
+		add(comp);
+		bs=s;
+	}
+
+	public void paint(Graphics g) {
+		int w = getSize().width;
+		int h = getSize().height;
+		int x1[]={0,bs,w-bs,w}, y1[]={0,bs,bs,0};
+		int x2[]={w,w-bs,w-bs,w}, y2[]={0,bs,h-bs,h};
+		int y3[]={h,h-bs,h-bs,h};
+
+		g.setColor(new Color(224,224,224));
+		g.fillPolygon(y1,y2,4);
+		g.fillPolygon(x1,y1,4);
+		g.setColor(Color.gray);
+		g.fillPolygon(x2,y2,4);
+		g.fillPolygon(x1,y3,4);
+	}
+}