GoogleAddon.java

/*
 * This is part of Geomajas, a GIS framework, http://www.geomajas.org/.
 *
 * Copyright 2008-2015 Geosparc nv, http://www.geosparc.com/, Belgium.
 *
 * The program is available in open source according to the GNU Affero
 * General Public License. All contributions in this program are covered
 * by the Geomajas Contributors License Agreement. For full licensing
 * details, see LICENSE.txt in the project root.
 */

package org.geomajas.gwt.client.gfx.paintable.mapaddon;

import org.geomajas.geometry.Coordinate;
import org.geomajas.gwt.client.gfx.PainterVisitor;
import org.geomajas.gwt.client.map.event.MapViewChangedEvent;
import org.geomajas.gwt.client.map.event.MapViewChangedHandler;
import org.geomajas.gwt.client.spatial.Bbox;
import org.geomajas.gwt.client.widget.MapWidget;

import com.google.gwt.core.client.JavaScriptObject;
import com.google.gwt.dom.client.Element;
import com.google.gwt.user.client.DOM;
import com.smartgwt.client.types.VerticalAlignment;

/**
 * <p>
 * Map add-on that displays the Google attribution (copyright + terms of use) on the map. It can also show the actual
 * Google map as opposed to the tiles that are calculated on the server. For normal Geomajas use this map should be
 * hidden as it does not automatically scale to continuous zoom levels. This add-on requires the Google maps library !
 * </p>
 * <p>
 * This MapAddon does not allow center positioning. Also it takes in the whole width of the map, so setting the
 * horizontal alignment is of little use. By default, this MapAddon will be placed 20 pixels from the bottom of the map.
 * </p>
 *
 * @author Jan De Moerloose
 * @deprecated use org.geomajas.layer.gwt.client.GoogleAddon from the geomajas-layer-google-gwt module instead
 */
@Deprecated
public class GoogleAddon extends MapAddon implements MapViewChangedHandler {

	private MapWidget map;

	private JavaScriptObject googleMap;

	private MapType type;

	private boolean showMap;

	private static final double MERCATOR_WIDTH = Math.PI * 6378137.0;

	/**
	 * Google map types as defined by the API.
	 */
	public enum MapType {
		NORMAL, SATELLITE, HYBRID, PHYSICAL
	}

	// Constructor:

	public GoogleAddon(String id, MapWidget map, MapType type, boolean showMap) {
		super(id, 0, 0);
		this.map = map;
		this.type = type;
		this.showMap = showMap;
		this.map.getMapModel().getMapView().addMapViewChangedHandler(this);

		// Default placement:
		setVerticalAlignment(VerticalAlignment.BOTTOM);
		setVerticalMargin(20);
	}

	// MapAddon implementation:

	public void accept(PainterVisitor visitor, Object group, Bbox bounds, boolean recursive) {
		if (googleMap == null) {
			// create as first child of raster group
			map.getRasterContext().drawGroup(null, this);
			String id = map.getRasterContext().getId(this);
			String graphicsId = map.getVectorContext().getId();

			googleMap = createGoogleMap(id, graphicsId, type.name(), showMap, getVerticalMargin(),
					getHorizontalMargin(), getVerticalAlignmentString());
		}
	}

	public void onDraw() {
	}

	public void onRemove() {
		String id = map.getRasterContext().getId(this);

		// Remove the terms of use:
		Element element = DOM.getElementById(id + "-googleAddon");
		if (element != null) {
			Element parent = element.getParentElement();
			parent.removeChild(element);
		}

		// Remove the Google map too:
		element = DOM.getElementById(id);
		if (element != null) {
			Element parent = element.getParentElement();
			parent.removeChild(element);
		}

		googleMap = null;
	}

	public void onMapViewChanged(MapViewChangedEvent event) {
		// assume google coordinates here
		if (googleMap != null) {
			Bbox latLon = convertToLatLon(event.getBounds());
			fitGoogleMapBounds(googleMap, latLon.getX(), latLon.getY(), latLon.getMaxX(), latLon.getMaxY());
		}
	}

	// ------------------------------------------------------------------------
	// Private methods:
	// ------------------------------------------------------------------------

	private native JavaScriptObject createGoogleMap(String mapId, String graphicsId, String mapType, boolean showMap,
			int verticalMargin, int horizontalMargin, String verticalAlignment)
	/*-{
	 	var mapDiv = $doc.getElementById(mapId);
		var map = new $wnd.GMap2(mapDiv);		
		if (mapType == "NORMAL") {
			map.setMapType($wnd.G_NORMAL_MAP);
		} else if (mapType == "SATELLITE") {
			map.setMapType($wnd.G_SATELLITE_MAP);
		} else if (mapType == "HYBRID") {
			map.setMapType($wnd.G_HYBRID_MAP);
		} else if (mapType == "PHYSICAL") {
			map.setMapType($wnd.G_PHYSICAL_MAP);
		}  
		if(!showMap) {
			mapDiv.style.visibility = "hidden";
		}
		var graphics = $doc.getElementById(graphicsId);
		var group = $doc.createElement("div");
		group.setAttribute("id", mapId + "-googleAddon");
		graphics.appendChild(group);

		var termsOfUse = mapDiv.lastChild;
		mapDiv.removeChild(termsOfUse);
		group.appendChild(termsOfUse);
		if ("top" == verticalAlignment) {
			termsOfUse.style.top = verticalMargin + "px";
		} else {
			termsOfUse.style.bottom = verticalMargin + "px";
		}
		termsOfUse.style.marginRight = horizontalMargin + "px";

		var poweredBy = mapDiv.lastChild;
		mapDiv.removeChild(poweredBy);
		group.appendChild(poweredBy);
		if ("top" == verticalAlignment) {
			poweredBy.style.top = verticalMargin + "px";
		} else {
			poweredBy.style.bottom = verticalMargin + "px";
		}
		poweredBy.style.marginLeft = horizontalMargin + "px";

		return map;
	}-*/;

	private native void fitGoogleMapBounds(JavaScriptObject map, double xmin, double ymin, double xmax, double ymax)
	/*-{
		var sw = new $wnd.GLatLng(xmin, ymin);
		var ne = new $wnd.GLatLng(xmax, ymax);
		var bounds = new $wnd.GLatLngBounds(sw,ne);
		map.setCenter(bounds.getCenter(), map.getBoundsZoomLevel(bounds)); 
	}-*/;

	private Bbox convertToLatLon(Bbox bounds) {
		// convert corners
		Coordinate orig = convertToLatLon(bounds.getOrigin());
		Coordinate end = convertToLatLon(bounds.getEndPoint());
		return new Bbox(orig.getX(), orig.getY(), end.getX() - orig.getX(), end.getY() - orig.getY());
	}

	private Coordinate convertToLatLon(Coordinate coordinate) {
		double lat = (coordinate.getY() / MERCATOR_WIDTH) * 180.0;
		double lon = (coordinate.getX() / MERCATOR_WIDTH) * 180.0;
		lat = 180 / Math.PI * (2 * Math.atan(Math.exp(lat * Math.PI / 180.0)) - Math.PI / 2.0);
		return new Coordinate(lat, lon);
	}

	private String getVerticalAlignmentString() {
		// No center position, just top and bottom:
		VerticalAlignment align = getVerticalAlignment();
		if (align != null && align.equals(VerticalAlignment.TOP)) {
			return "top";
		}
		return "bottom";
	}
}