projectionfactoryloader.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/proj/ProjectionFactoryLoader.java,v $
// $RCSfile: ProjectionFactoryLoader.java,v $
// $Revision: 1.1.2.2 $
// $Date: 2004/10/14 18:27:38 $
// $Author: dietrick $
// 
// **********************************************************************

package com.bbn.openmap.proj;

import com.bbn.openmap.PropertyConsumer;
import com.bbn.openmap.OMComponent;
import com.bbn.openmap.util.ComponentFactory;
import com.bbn.openmap.util.PropUtils;

import java.beans.beancontext.BeanContext;
import java.beans.PropertyVetoException;
import java.util.Iterator;
import java.util.Properties;
import java.util.Vector;

/**
 * All this class does is add the instance of the ProjectionFactory to
 * the MapHandler. This class needs to be added to the MapHandler in
 * order for a ProjectionFactory to be created and the
 * ProjectionLoaders to be recognized by the application. To keep
 * multiple ProjectionLoaders out of the openmap.components property
 * for readability, this class has a property that lets you set which
 * ProjectionLoaders are created and added to the application:
 * 
 * <pre>
 * 
 * 
 *  # For a projFactoryLoader marker name added to the openmap.components property.
 *  projFactoryLoader.class=com.bbn.openmap.proj.ProjectionFactoryLoader
 *  projFactoryLoader.class=com.bbn.openmap.proj.ProjectionFactoryLoader
 *  projFactoryLoader.projectionLoaders=mercatorloader cadrgloader ortholoader llxyloader gnomonicloader
 *  projFactoryLoader.mercatorloader.class=com.bbn.openmap.proj.MercatorLoader
 *  projFactoryLoader.cadrgloader.class=com.bbn.openmap.proj.CADRGLoader
 *  projFactoryLoader.ortholoader.class=com.bbn.openmap.proj.OrthographicLoader
 *  projFactoryLoader.llxyloader.class=com.bbn.openmap.proj.LLXYLoader
 *  projFactoryLoader.gnomonicloader.class=com.bbn.openmap.proj.GnomonicLoader
 * 
 *  
 * </pre>
 * 
 * The above properties create 5 ProjectionLoaders which are added to
 * the MapHandler, along with the ProjectionFactory singleton
 * instance. The ProjectionLoader may have additional properties which
 * can be set as well, like their pretty GUI name and description.
 */
public class ProjectionFactoryLoader extends OMComponent {

    protected Vector loaders;

    public final static String ProjectionLoadersProperty = "projectionLoaders";

    public ProjectionFactoryLoader() {
        super();
    }

    /**
     * When the BeanContext (MapHandler) gets set, the singleton
     * instance of the ProjectionFactory is created (asked for) and
     * added to the BeanContext.
     */
    public void setBeanContext(BeanContext in_bc) throws PropertyVetoException {

        if (in_bc != null) {
            in_bc.add(ProjectionFactory.getInstance());

            if (loaders != null && loaders.size() > 0) {
                for (Iterator it = loaders.iterator(); it.hasNext(); in_bc.add(it.next())) {
                }
            }
        }
    }

    /**
     * Check the properties for those to create ProjectionLoaders.
     */
    public void setProperties(String prefix, Properties props) {
        super.setProperties(prefix, props);
        prefix = PropUtils.getScopedPropertyPrefix(prefix);

        String loaderPrefixesString = props.getProperty(prefix
                + ProjectionLoadersProperty);
        if (loaderPrefixesString != null) {
            Vector loaderPrefixes = PropUtils.parseSpacedMarkers(loaderPrefixesString);
            loaders = ComponentFactory.create(loaderPrefixes, prefix, props);
        }
    }

    /**
     * Create the properties to create ProjectionLoaders that this
     * loader created.
     */
    public Properties getProperties(Properties props) {
        props = super.getProperties(props);
        String prefix = PropUtils.getScopedPropertyPrefix(this);

        if (loaders != null) {
            StringBuffer markerlist = new StringBuffer();
            int count = 0;
            for (Iterator it = loaders.iterator(); it.hasNext();) {

                ProjectionLoader pl = (ProjectionLoader) it.next();
                String markerName;
                if (pl instanceof PropertyConsumer) {

                    PropertyConsumer pc = (PropertyConsumer) pl;
                    markerName = pc.getPropertyPrefix();

                    // Need to do this here before the marker name
                    // potentially changes
                    props.put(markerName + ".class", pl.getClass().getName());

                    if (markerName.startsWith(prefix)) {
                        markerName = markerName.substring(prefix.length());
                    }
                    pc.getProperties(props);

                } else {

                    markerName = "projectionLoader" + (count++);
                    // Need to do this here for any projection loaders
                    // that aren't property consumers.
                    props.put(markerName + ".class", pl.getClass().getName());

                }

                markerlist.append(" " + markerName);
            }

            props.put(prefix + ProjectionLoadersProperty, markerlist.toString());
        }

        return props;
    }

    /**
     * Create the property information reflecting those used to create
     * loaders.
     */
    public Properties getPropertyInfo(Properties props) {
        // We don't handle this yet, because there isn't a good
        // mechanism for handling embedded objects defined in
        // properties for dynmaic property setting.
        return super.getPropertyInfo(props);
    }

}