linklayer.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

// **********************************************************************
// 
// <copyright>
// 
//  BBN Technologies
//  10 Moulton Street
//  Cambridge, MA 02138
//  [phone]
// 
//  Copyright (C) BBNT Solutions LLC. All rights reserved.
// 
// </copyright>
// **********************************************************************
// 
// $Source: /cvs/distapps/openmap/src/openmap/com/bbn/openmap/layer/link/LinkLayer.java,v $
// $RCSfile: LinkLayer.java,v $
// $Revision: 1.12.2.2 $
// $Date: 2005/08/09 18:10:45 $
// $Author: dietrick $
// 
// **********************************************************************

package com.bbn.openmap.layer.link;

/*  Java Core  */
import java.awt.Container;
import java.awt.event.MouseEvent;
import java.io.IOException;
import java.net.URL;
import java.net.UnknownHostException;
import java.util.Enumeration;
import java.util.Properties;
import java.util.Vector;

/*  OpenMap  */
import com.bbn.openmap.LatLonPoint;
import com.bbn.openmap.MapBean;
import com.bbn.openmap.MapHandler;
import com.bbn.openmap.MoreMath;
import com.bbn.openmap.util.Debug;
import com.bbn.openmap.util.PropUtils;
import com.bbn.openmap.event.MapMouseListener;
import com.bbn.openmap.event.SelectMouseMode;
import com.bbn.openmap.layer.OMGraphicHandlerLayer;
import com.bbn.openmap.omGraphics.OMAction;
import com.bbn.openmap.omGraphics.OMGraphic;
import com.bbn.openmap.omGraphics.OMGraphicList;
import com.bbn.openmap.omGraphics.grid.OMGridGenerator;
import com.bbn.openmap.proj.GreatCircle;
import com.bbn.openmap.proj.Mercator;
import com.bbn.openmap.proj.Proj;
import com.bbn.openmap.proj.ProjMath;
import com.bbn.openmap.proj.Projection;
import com.bbn.openmap.proj.ProjectionFactory;
import com.bbn.openmap.tools.drawing.DrawingToolRequestor;

/**
 * The LinkLayer is a Swing component, and an OpenMap layer, that
 * communicates with a server via the Link protocol. It transmits
 * graphics requests and gesture information, and handles the
 * responses to those queries. The entry in the openmap.properties
 * file looks like this:
 * <P>
 * 
 * <pre>
 * 
 *  
 *   
 *   
 *    # port number of server
 *    link.port=3031
 *   
 *    # host name of server
 *    link.host=host.com
 *   
 *    # URL of properties file for server attributes.  Properties
 *    # contained in this file are passed directly to the server to provide
 *    # additional information to the server about how to provide the
 *    # graphics.  Some standard properties are listed in the
 *    # LinkPropertiesConstants file, but any property can be passed to the
 *    # server.  How the server handles the property depends on the server,
 *    # but non-applicable properties are ignored.
 *    link.propertiesURL=http://location.of.properties.file.com
 *   
 *    
 *   
 *  
 * </pre>
 * 
 * You have to call setProperties() on this layer to set its
 * parameters, and to start the thread that listens to updates from
 * the server.
 */
public class LinkLayer extends OMGraphicHandlerLayer implements
        MapMouseListener, LinkPropertiesConstants, LinkActionConstants,
        DrawingToolRequestor {

    /**
     * The thread listener used to communicate asynchronously. The
     * LinkLayer sends out requsts and notifications to the server,
     * and the LinkListener reads any input from the server, making
     * calls on the LinkLayer as appropriate.
     */
    protected LinkListener listener;
    /**
     * A masked integer describing which gestures should be sent to
     * the server.
     */
    protected int gestureDescriptor = 0;
    /** The port to connect to the server on. */
    protected int port;
    /** The host where the server is running. */
    protected String host;
    /**
     * The special parameters (attributes) transmitted to the server
     * with every query.
     */
    protected LinkProperties args;
    /**
     * The object that provides a link to the layer (and its various
     * threads) on a coordinateed basis.
     */
    protected LinkManager linkManager = null;
    /** The flag to supress pop-up messages. */
    protected boolean quiet = false;
    /** The generator to use with LinkGrid objects. */
    protected OMGridGenerator currentGenerator = null;

    /**
     * The property name to specify what port the server is running
     * on. "port"
     */
    public final static String PortProperty = "port";
    /**
     * The property name to specify the hostname the server is running
     * on. "host"
     */
    public final static String HostProperty = "host";
    /**
     * The property name to specify a URL of a properties file
     * containing properties that will be sent to the server within
     * requests to it. The contents of this file depends on the
     * server. "propertiesURL"
     */
    public final static String ArgsProperty = "propertiesURL";
    public final static String ServerLocationProperty = "isl";
    /**
     * The property to make the layer quiet. "quiet"
     */
    public final static String QuietProperty = "quiet";
    /**
     * The property to specify which grid generator to use for grid
     * objects. "gridGenerator"
     */
    public final static String GridGeneratorProperty = "gridGenerator";
    /**
     * The property to set a pixel distance limit for gestures.
     * "distanceLimit"
     */
    public final static String DistanceLimitProperty = "distanceLimit";

    public final static int DEFAULT_DISTANCE_LIMIT = 4;

    /**
     * The maximum distance away a mouse event can happen away from a
     * graphic in order for it to be considered to have touched.
     */
    protected int distanceLimit = DEFAULT_DISTANCE_LIMIT;

    /**
     * The property to set to true if the server should be able to
     * decide when to kill the client, the overall application. False
     * by default, only modified in setProperties. "exitOnCommand"
     */
    public final static String ExitOnCommandProperty = "exitOnCommand";

    /**
     * The default constructor for the Layer. All of the attributes
     * are set to their default values.
     */
    public LinkLayer() {
        // We don't want to reset the OMGraphicsList automatically
        // when the projection changes, now. With ansynchronous
        // behavior, the current list should be reprojected and the
        // server notified, and the server will update itself if
        // needed.
        setProjectionChangePolicy(new com.bbn.openmap.layer.policy.ListResetPCPolicy(
                this) {
            // Modified so it doesn't reset the OMGraphicList when
            // the SwingWorker thread returns. The list has
            // already been nulled out, will be reset when the
            // asynchronous thread decides it is.
            public void workerComplete(OMGraphicList list) {}
        });
    }

    /**
     * Constructor to use when LinkLayer is not being used with
     * OpenMap application.
     * 
     * @param host the hostname of the server's computer.
     * @param port the port number of the server.
     * @param propertiesURL the URL of a properties file that contains
     *        parameters for the server.
     */
    public LinkLayer(String host, int port, String propertiesURL) {
        this();
        this.host = host;
        this.port = port;
        linkManager = new LinkManager(host, port);

        args = new LinkProperties();

        if (propertiesURL != null) {
            try {
                URL propertiesFile = new URL(propertiesURL);
                args.load(propertiesFile.openStream());
            } catch (java.net.MalformedURLException mue) {
                System.err.println("LinkLayer:  Properties URL isn't valid: "
                        + propertiesURL);
                System.err.println(mue);
            } catch (IOException ioe) {
                System.err.println("LinkLayer: IOException reading properties file:");
                System.err.println(ioe);
            }
        }
    }

    /**
     * Sets the current graphics list to the given list.
     * 
     * @param aList a list of OMGraphics
     */
    public synchronized void setGraphicList(LinkOMGraphicList aList) {
        super.setList(aList);
    }

    /**
     * Retrieves the current graphics list.
     */
    public synchronized LinkOMGraphicList getGraphicList() {
        return (LinkOMGraphicList) getList();
    }

    /**
     * Called when the layer is no longer part of the map. In this
     * case, we should disconnect from the server if we have a link.
     */
    public void removed(Container cont) {
        linkManager.resetLink();
    }

    /**
     * Sets the masked integer which indicates what types of events
     * get sent to the server.
     * 
     * @param descriptor masked int
     * @see LinkActionRequest
     */
    public synchronized void setGestureDescriptor(int descriptor) {
        gestureDescriptor = descriptor;
    }

    /**
     * Gets the masked integer which indicates what types of events
     * get sent to the server.
     * 
     * @return descriptor masked int
     * @see LinkActionRequest
     */
    public synchronized int getGestureDescriptor() {
        return gestureDescriptor;
    }

    /**
     * Set all the Link properties from a properties object.
     * 
     * @param prefix the prefix to the properties tha might
     *        individualize it to a particular layer.
     * @param properties the properties for the layer.
     */
    public void setProperties(String prefix, Properties properties) {

        super.setProperties(prefix, properties);

        String realPrefix = PropUtils.getScopedPropertyPrefix(prefix);

        String quietString = properties.getProperty(realPrefix + QuietProperty);
        if (quietString != null && quietString.intern() == "true") {
            quiet = true;
        }

        host = properties.getProperty(realPrefix + HostProperty);

        port = PropUtils.intFromProperties(properties, realPrefix
                + PortProperty, LinkServerStarter.DEFAULT_PORT);

        linkManager = new LinkManager(host, port);

        linkManager.setObeyCommandToExit(PropUtils.booleanFromProperties(properties,
                realPrefix + ExitOnCommandProperty,
                false));

        String propertiesURL = properties.getProperty(realPrefix + ArgsProperty);

        args = new LinkProperties(); // Empty if not filled.
        if (propertiesURL != null) {
            try {
                URL propertiesFile = new URL(propertiesURL);
                args.load(propertiesFile.openStream());
            } catch (java.net.MalformedURLException mue) {
                System.err.println("LinkLayer:  Properties URL isn't valid: "
                        + realPrefix + ArgsProperty);
                System.err.println(mue);
            } catch (IOException ioe) {
                System.err.println("LinkLayer: IOException reading properties file:");
                System.err.println(ioe);
            }
        }