Implement copy action

src/main/java/ovh/gasser/newshapes/shapes/SCollection.java

@@ -12,6 +12,7 @@ import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 import java.util.Spliterator;
+import java.util.stream.Collectors;
 
 public class SCollection extends AbstractShape implements Streamable<Shape> {
     private final static Logger logger = LoggerFactory.getLogger(SCollection.class);
@@ -43,6 +44,14 @@ public class SCollection extends AbstractShape implements Streamable<Shape> {
         }
     }
 
+    @Override
+    public Shape clone() {
+        var clonedChildren = children.stream().map(Shape::clone).toArray(Shape[]::new);
+        var collection = new SCollection(clonedChildren);
+        collection.addAttributes(new SelectionAttributes());
+        return collection;
+    }
+
     @Override
     public void setLoc(Point newLoc) {
         final Point loc = getBounds().getLocation();
@@ -59,6 +68,10 @@ public class SCollection extends AbstractShape implements Streamable<Shape> {
         return children.spliterator();
     }
 
+    public void add(Shape s) {
+        children.add(s);
+    }
+
     public void remove(Shape s) {
         if (!children.remove(s)) {
             logger.error("Unable to delete shape: {}", s);