source: josm/src/org/openstreetmap/josm/command/AddCommand.java@ 21

package org.openstreetmap.josm.command;

import java.awt.Component;
import java.util.Iterator;

import javax.swing.JLabel;

import org.openstreetmap.josm.data.osm.Key;
import org.openstreetmap.josm.data.osm.LineSegment;
import org.openstreetmap.josm.data.osm.Node;
import org.openstreetmap.josm.data.osm.OsmPrimitive;
import org.openstreetmap.josm.data.osm.Track;
import org.openstreetmap.josm.data.osm.visitor.SelectionComponentVisitor;
import org.openstreetmap.josm.data.osm.visitor.Visitor;

/**
 * A command that adds an osm primitive to a dataset. Keys cannot be added this
 * way. Use ChangeKeyValueCommand instead.
 * 
 * @author imi
 */
public class AddCommand implements Command, Visitor {

        /**
         * The primitive to add to the dataset.
         */
        private final OsmPrimitive osm;
        /**
         * The dataset to add the primitive to.
         */
        private final DataSet ds;

        /**
         * Create the command and specify the element to add.
         */
        public AddCommand(OsmPrimitive osm, DataSet dataSet) {
                this.osm = osm;
                this.ds = dataSet;
        }

        public void executeCommand() {
                osm.visit(this);
        }

        public Component commandDescription() {
                SelectionComponentVisitor v = new SelectionComponentVisitor();
                osm.visit(v);
                return new JLabel(v.name, v.icon, JLabel.LEADING);
        }

        /**
         * Add the node to the nodes - list only.
         * @param n The node to add.
         */
        public void visit(Node n) {
                ds.nodes.add(n);
        }

        /**
         * Add the line segment to the list of pending line segments.
         * @param ls The line segment to add.
         */
        public void visit(LineSegment ls) {
                ds.pendingLineSegments.add(ls);
        }

        /**
         * Add the track to the dataset. Remove all line segments that were pending
         * from the dataset.
         */
        public void visit(Track t) {
                ds.addTrack(t);
                for (Iterator<LineSegment> it =  ds.pendingLineSegments.iterator(); it.hasNext();)
                        if (t.segments().contains(it.next()))
                                it.remove();
        }

        /**
         * Add the key to the parent specified by the constructor
         */
        public void visit(Key k) {
                throw new IllegalStateException("Keys are added by using ChangeKeyValueCommand");
        }
}