source: josm/src/org/openstreetmap/josm/actions/mapmode/MapMode.java@ 68

package org.openstreetmap.josm.actions.mapmode;

import java.awt.event.ActionEvent;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.KeyStroke;

import org.openstreetmap.josm.actions.JosmAction;
import org.openstreetmap.josm.gui.MapFrame;
import org.openstreetmap.josm.gui.MapView;

/**
 * A class implementing MapMode is able to be selected as an mode for map editing.
 * As example scrolling the map is a MapMode, connecting Nodes to new LineSegments
 * is another.
 * 
 * MapModes should register/deregister all necessary listener on the map's view
 * control. 
 */
abstract public class MapMode extends JosmAction implements MouseListener, MouseMotionListener {

        /**
         * The parent mapframe this mode belongs to.
         */
        protected final MapFrame mapFrame;
        /**
         * Shortcut to the MapView.
         */
        protected final MapView mv;

        /**
         * Construct a mapMode with the given icon and the given MapFrame
         */
        public MapMode(String name, String iconName, String tooltip, String keyname, int keystroke, MapFrame mapFrame) {
                super(name, "mapmode/"+iconName, tooltip, keyname, KeyStroke.getKeyStroke(keystroke, 0));
                this.mapFrame = mapFrame;
                mv = mapFrame.mapView;
        }

        /**
         * Register all listener to the mapView
         * @param mapView       The view, where the listener should be registered.
         */
        public void registerListener() {
                firePropertyChange("active", false, true);
        }
        
        /**
         * Unregister all listener previously registered. 
         * @param mapView       The view from which the listener should be deregistered.
         */
        public void unregisterListener() {
                firePropertyChange("active", true, false);
        }

        /**
         * Call selectMapMode(this) on the parent mapFrame.
         */
        public void actionPerformed(ActionEvent e) {
                mapFrame.selectMapMode(this);
        }

        /**
         * Does nothing. Only to subclass.
         */
        public void mouseClicked(MouseEvent e) {}
        /**
         * Does nothing. Only to subclass.
         */
        public void mousePressed(MouseEvent e) {}
        /**
         * Does nothing. Only to subclass.
         */
        public void mouseReleased(MouseEvent e) {}
        /**
         * Does nothing. Only to subclass.
         */
        public void mouseEntered(MouseEvent e) {}
        /**
         * Does nothing. Only to subclass.
         */
        public void mouseExited(MouseEvent e) {}
        /**
         * Does nothing. Only to subclass.
         */
        public void mouseMoved(MouseEvent e) {}
        /**
         * Does nothing. Only to subclass.
         */
        public void mouseDragged(MouseEvent e) {}
}