// **********************************************************************
//
// <copyright>
//
// BBN Technologies
// 10 Moulton Street
// Cambridge, MA 02138
// (617) 873-8000
//
// Copyright (C) BBNT Solutions LLC. All rights reserved.
//
// </copyright>
// **********************************************************************
//
// $Source: /cvs/distapps/openmap/src/openmap/com/bbn/openmap/layer/link/BufferedLinkLayer.java,v $
// $RCSfile: BufferedLinkLayer.java,v $
// $Revision: 1.4.2.1 $
// $Date: 2004/10/14 18:27:06 $
// $Author: dietrick $
//
// **********************************************************************
package com.bbn.openmap.layer.link;
/* Java Core */
import java.io.IOException;
import java.net.UnknownHostException;
/* OpenMap */
import com.bbn.openmap.omGraphics.OMGraphicList;
import com.bbn.openmap.proj.Projection;
import com.bbn.openmap.util.Debug;
/**
* The BufferedLinkLayer 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>
* <code>
* # port number of server
* link.port=3031
* # host name of server
* link.host=host.com
* # URL of proerties file for server attributes
* link.propertiesURL=http://location.of.properties.file.com
* </code>
*/
public class BufferedLinkLayer extends LinkLayer {
/**
* The default constructor for the Layer. All of the attributes
* are set to their default values.
*/
public BufferedLinkLayer() {
super();
setProjectionChangePolicy(new com.bbn.openmap.layer.policy.StandardPCPolicy(this));
}
/**
* 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 BufferedLinkLayer(String host, int port, String propertiesURL) {
super(host, port, propertiesURL);
setProjectionChangePolicy(new com.bbn.openmap.layer.policy.StandardPCPolicy(this));
}
/**
* Prepares the graphics for the layer. This is where the
* getRectangle() method call is made on the link.
* <p>
* Occasionally it is necessary to abort a prepare call. When this
* happens, the map will set the cancel bit in the LayerThread,
* (the thread that is running the prepare). If this Layer needs
* to do any cleanups during the abort, it should do so, but
* return out of the prepare asap.
*
* @return a list of graphics.
*/
public synchronized OMGraphicList prepare() {
if (isCancelled()) {
Debug.message("link", getName()
+ "|BufferedLinkLayer.prepare(): aborted.");
return null;
}
Projection projection = getProjection();
if (projection == null) {
System.err.println("Link Layer needs to be added to the MapBean before it can get graphics!");
return new LinkOMGraphicList();
}
Debug.message("basic", getName()
+ "|BufferedLinkLayer.prepare(): doing it");
// Setting the OMGraphicsList for this layer. Remember, the
// LinkOMGraphicList is made up of OMGraphics, which are
// generated
// (projected) when the graphics are added to the list. So,
// after this call, the list is ready for painting.
OMGraphicList omGraphics = getList();
if (omGraphics == null || omGraphics.size() == 0) {
////////////// Call getRectangle for server....
try {
// We do want the link object here... If another
// thread is
// using the link, wait.
ClientLink l = linkManager.getLink(true);
if (l == null) {
System.err.println("BufferedLinkLayer: unable to get link in prepare().");
return new LinkOMGraphicList();
}
synchronized (l) {
omGraphics = getAllGraphics(l, projection);
}
linkManager.finLink();
} catch (UnknownHostException uhe) {
System.err.println("BufferedLinkLayer: unknown host!");
omGraphics = new LinkOMGraphicList();
} catch (java.io.IOException ioe) {
System.err.println("BufferedLinkLayer: IOException contacting server for map request!");
System.err.println(ioe);
linkManager.resetLink();
if (!quiet) {
fireRequestMessage("Communication error between "
+ getName() + " layer\nand Link Server: Host: "
+ host + ", Port: " + port);
}
System.err.println("BufferedLinkLayer: Communication error between "
+ getName()
+ " layer\nand Link Server: Host: "
+ host
+ ", Port: " + port);
omGraphics = new LinkOMGraphicList();
}
} else {
omGraphics.project(projection);
}
/////////////////////
// safe quit
int size = 0;
if (omGraphics != null) {
size = omGraphics.size();
if (Debug.debugging("basic")) {
System.out.println(getName()
+ "|BufferedLinkLayer.prepare(): finished with " + size
+ " graphics");
}
} else {
Debug.message("basic",
getName()
+ "|BufferedLinkLayer.prepare(): finished with null graphics list");
}
return omGraphics;
}
/**
* Creates the LinkMapRequest, and gets the results.
*
* @param link the link to communicate over.
* @param proj the projection to give to the graphics.
* @return LinkOMGraphicList containing graphics from the server.
* @throws IOException
*/
protected LinkOMGraphicList getAllGraphics(ClientLink link, Projection proj)
throws IOException {
LinkBoundingPoly[] boundingPolys = new LinkBoundingPoly[1];
boundingPolys[0] = new LinkBoundingPoly(-180.0f, -90f, 180f, 90);
LinkMapRequest.write(proj.getCenter().getLatitude(),
proj.getCenter().getLongitude(),
proj.getScale(),
proj.getHeight(),
proj.getWidth(),
boundingPolys,
args,
link);
link.readAndParse(proj, currentGenerator);
// While we are here, check for any change in gesture query
// requests.
LinkActionRequest lar = link.getActionRequest();
if (lar != null) {
setGestureDescriptor(lar.getDescriptor());
}
LinkGraphicList lgl = link.getGraphicList();
if (lgl != null) {
//Deal with all the messaging....
handleMessages(lgl.getProperties());
return lgl.getGraphics();
} else {
Debug.message("link",
"BufferedLinkLayer: getAllGraphics(): no graphic response.");
return new LinkOMGraphicList();
}
}
}