source: josm/src/org/openstreetmap/josm/gui/engine/Engine.java@ 17

package org.openstreetmap.josm.gui.engine;

import java.awt.Graphics;

import org.openstreetmap.josm.data.osm.LineSegment;
import org.openstreetmap.josm.data.osm.Node;
import org.openstreetmap.josm.data.osm.Track;
import org.openstreetmap.josm.gui.MapView;

/**
 * Subclasses of Engine are able to draw map data on the screen. The layout and
 * colors depend only on the engine used, but it may have an configuration panel.
 *
 * @author imi
 */
abstract public class Engine {

        /**
         * The Graphics surface to draw on. This should be set before each painting
         * sequence.
         */
        protected Graphics g;
        /**
         * The mapView, this engine was created for.
         */
        protected MapView mv;

        
        /**
         * Called to initialize the Engine for a new drawing sequence.
         * @param g
         */
        public void init(Graphics g, MapView mv) {
                this.g = g;
                this.mv = mv;
        }

        /**
         * Draw the node.
         */
        abstract public void drawNode(Node n);
        
        /**
         * Draw the track.
         */
        abstract public void drawTrack(Track t);
        
        /**
         * Draw the pending line segment. Non-pending line segments must be drawn
         * within drawTrack.
         */
        abstract public void drawPendingLineSegment(LineSegment ls);
}