TileServer.java

/*******************************************************************************
 * Copyright (c) 2008, 2012 Stepan Rutz.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *    Stepan Rutz - initial implementation
 *    Hallvard Trætteberg - further cleanup and development
 *******************************************************************************/

package org.eclipse.nebula.widgets.geomap;

import java.text.MessageFormat;
import java.util.HashMap;
import java.util.Map;

import org.eclipse.nebula.widgets.geomap.internal.TileRef;
import org.eclipse.nebula.widgets.geomap.internal.URLService;

/**
 * This class encapsulates a tileserver, which has the concept
 * of a baseurl and a maximum zoom level. 
 */
public class TileServer extends URLService {

    private String urlFormat = "{0}/{1}/{2}.png"; // slippy format z/x/y, must match getURLFormatArguments //$NON-NLS-1$
    private final int maxZoom;

    // See https://raw.github.com/follesoe/MapReplace/master/js/interceptors.js for a list of tile servers

    /**
     * Initializes a TileServer
     * @param url the base url of the TileServer
     * @param maxZoom the max zoom level supported by this TileServer
     * @param urlFormat the format of the url parameters that are appended to the base url
     */
    public TileServer(String url, int maxZoom, String urlFormat) {
    	super(url, urlFormat);
        this.maxZoom = maxZoom;
    }

    /**
     * Initializes a TileServer using the default slippy format
     * @param url the base url of the TileServer
     * @param maxZoom the max zoom level supported by this TileServer
     */
    public TileServer(String url, int maxZoom) {
    	parseUrl(url, "{0}/{1}/{2}.png"); //$NON-NLS-1$
    	this.maxZoom = maxZoom;
    }

    @Override
    protected Object[] getURLFormatArguments(Object ref) {
    	TileRef tile = (TileRef) ref;
    	return new Object[]{String.valueOf(tile.z), String.valueOf(tile.x), String.valueOf(tile.y)};
    }
    
    protected Map<String, String> createZXYMap(TileRef tile, String zKey, String xKey, String yKey) {
    	Map<String, String> formatMap = new HashMap<String, String>();
    	formatMap.put(zKey, String.valueOf(tile.z));
    	formatMap.put(xKey, String.valueOf(tile.x));
    	formatMap.put(yKey, String.valueOf(tile.y));
    	return formatMap;
    }
    
    protected Map<String, String> getURLFormatMap(TileRef tile) {
    	return createZXYMap(tile, "{0}", "{1}", "{2}");   //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
    }
    
    protected String getTileURL(TileRef tile, String urlFormat, Object[] formatArguments) {
    	return getURL() + MessageFormat.format(urlFormat, formatArguments);
    }

    protected String getTileURL(TileRef tile, String urlFormat, Map<String, String> formatMap) {
    	for (String key : formatMap.keySet()) {
			urlFormat = urlFormat.replace(key, formatMap.get(key));
		}
    	return getURL() + urlFormat;
    }

    public String getTileURL(TileRef tile) {
    	if (urlFormat != null) {
	    	Object[] urlFormatArguments = getURLFormatArguments(tile);
	    	if (urlFormatArguments != null) {
	    		return getTileURL(tile, urlFormat, urlFormatArguments);
	    	}
	    	Map<String, String> urlFormatMap = getURLFormatMap(tile);
	    	if (urlFormatMap != null) {
	    		return getTileURL(tile, urlFormat, urlFormatMap);
	    	}
    	}
    	return null;
    }
    
    public String toString() {
        return getURL();
    }

    /**
     * Gets the max zoom level supported by this TileServer
     * @return the max zoom level
     */
    public int getMaxZoom() {
        return maxZoom;
    }
}