geoportal-data-viewer-app/src/main/java/org/gcube/portlets/user/geoportaldataviewer/client/OLMapManager.java

package org.gcube.portlets.user.geoportaldataviewer.client;

import org.gcube.portlets.user.geoportaldataviewer.client.events.QueryDataEvent;
import org.gcube.portlets.user.geoportaldataviewer.client.events.ZoomOutOverMinimumEvent;
import org.gcube.portlets.user.geoportaldataviewer.client.gis.ExtentWrapped;
import org.gcube.portlets.user.geoportaldataviewer.client.gis.MapUtils;
import org.gcube.portlets.user.geoportaldataviewer.client.gis.OpenLayerOSM;
import org.gcube.portlets.user.geoportaldataviewer.shared.gis.GeoQuery;
import org.gcube.portlets.user.geoportaldataviewer.shared.gis.GeoQuery.TYPE;

import com.google.gwt.core.client.GWT;
import com.google.gwt.event.shared.HandlerManager;

import ol.Coordinate;
import ol.MapBrowserEvent;
import ol.MapEvent;
import ol.OLFactory;

/**
 * The Class OLMapManager.
 *
 * @author Francesco Mangiacrapa at ISTI-CNR (francesco.mangiacrapa@isti.cnr.it)
 * 
 * Nov 19, 2020
 */
public class OLMapManager {

	private String targetId;
	private HandlerManager layerManagerBus;
	private OpenLayerOSM olMap;
	private ol.Extent dragStartExtent = null;
	private Double zoomStart = null;
	private Double zoomEnd = null;
	private ol.Extent dragEndExtent = null;
	private static final int QUERY_MIN_ZOOM_LEVEL = 13;

	/**
	 * Instantiates a new OL map manager.
	 *
	 * @param targetId the target id
	 * @param layerManagerBus the layer manager bus
	 */
	public OLMapManager(String targetId, HandlerManager layerManagerBus) {
		this.targetId = targetId;
		this.layerManagerBus = layerManagerBus;
		instanceOLMap();
	}

	/**
	 * Instance OL map.
	 */
	public void instanceOLMap() {

		olMap = new OpenLayerOSM(targetId, layerManagerBus) {

			@Override
			public void clickListener(MapBrowserEvent event) {
				Coordinate coordinate = event.getCoordinate();
				if(!olMap.mapInstancied())
					return;
				
				if (olMap.isQueryPointActive()) {
					GeoQuery select = toDataPointQuery(coordinate);
					layerManagerBus.fireEvent(new QueryDataEvent(select, coordinate));

				}

			}

			@Override
			public void moveEndListener(MapEvent event) {
				//onInit
				if(!olMap.mapInstancied())
					return;
				
				checkSelectQuery();

			}

			@Override
			public void moveStartListener(MapEvent event) {
				
				//onInit
				if(!olMap.mapInstancied())
					return;

				setDragStart();
				
			}

			@Override
			public void mapZoomListener(MapEvent event) {
		
				//onInit
				if(!olMap.mapInstancied())
					return;
				
				setDragStart();
				zoomStart = olMap.getCurrentZoomLevel();
				GWT.log("zoomStart: "+zoomStart);

			}

			@Override
			public void mapZoomEndListener(MapEvent event) {
				//onInit
				//onInit
				if(!olMap.mapInstancied())
					return;
				
				setDragStart();
				zoomEnd = olMap.getCurrentZoomLevel();
				GWT.log("zoomEnd: "+zoomEnd);
				checkSelectQuery();

			}

		};

		// EPSG_4326_TO_ITALY
		Coordinate centerCoordinate = OLFactory.createCoordinate(GeoportalDataViewerConstants.ITALY_CENTER_LONG,
				GeoportalDataViewerConstants.ITALY_CENTER_LAT);
		Coordinate transformedCenterCoordinate = MapUtils.transformCoordiante(centerCoordinate,
				GeoportalDataViewerConstants.EPSG_4326, GeoportalDataViewerConstants.EPSG_3857);

		olMap.setCenter(transformedCenterCoordinate);
		olMap.setZoom(GeoportalDataViewerConstants.ITALY_FIT_ZOOM_ON);

	}

	/**
	 * To data point query.
	 *
	 * @param coordinate the coordinate
	 * @return the geo query
	 */
	public GeoQuery toDataPointQuery(Coordinate coordinate) {

		double lon = coordinate.getX();
		double lat = coordinate.getY();

		int w = (int) olMap.getSize().getWidth();
		int h = (int) olMap.getSize().getHeight();
		// handler.clickOnMap(x, y, w, h);

		// ratio - mapPixelWeight : bboxWeight = 20px : geoRectangleWidth
		// where 10px is the pixel diameter dimension of the clicked point
		double bboxWidth = Math.abs(olMap.getExtent().getLowerLeftX() - olMap.getExtent().getUpperRightX());
		double geoWidth = (bboxWidth / w) * (20 / 2);
		double x1 = Math.min(lon + geoWidth, lon - geoWidth);
		double x2 = Math.max(lon + geoWidth, lon - geoWidth);
		double y1 = Math.min(lat + geoWidth, lat - geoWidth);
		double y2 = Math.max(lat + geoWidth, lat - geoWidth);
		// GWT.log("("+x1+","+y1+")("+x2+","+y2+")");

//			Point pt = new Point(coordinate);
//			ol.Extent extent = pt.getExtent();
//			//new ClickDataInfo(x1, y1, x2, y2)
//			SelectDataInfo selectDataInfo
		// selectBox(new GeoQuery(x1, y1, x2, y2, GeoQuery.TYPE.POINT));
		GeoQuery select = new GeoQuery(x1, y1, x2, y2, TYPE.POINT);
		return select;
	}

	/**
	 * Gets the OLOSM map.
	 *
	 * @return the OLOSM map
	 */
	public OpenLayerOSM getOLOSMMap() {
		return olMap;
	}

	/**
	 * Check select query.
	 */
	private void checkSelectQuery() {
		
		GWT.log("Zoom is:" + olMap.getCurrentZoomLevel());

		if (dragStartExtent != null && olMap.getCurrentZoomLevel() > QUERY_MIN_ZOOM_LEVEL) {
			dragEndExtent = olMap.getExtent();
//			GWT.log("Drag end is: "+dragEndExtent);
			ExtentWrapped startExt = new ExtentWrapped(dragStartExtent.getLowerLeftX(), dragStartExtent.getLowerLeftY(),
					dragStartExtent.getUpperRightX(), dragStartExtent.getUpperRightY());
			ExtentWrapped endExt = new ExtentWrapped(dragEndExtent.getLowerLeftX(), dragEndExtent.getLowerLeftY(),
					dragEndExtent.getUpperRightX(), dragEndExtent.getUpperRightY());
//			GWT.log("start Ext: "+startExt);
//			GWT.log("endExt Ext: "+endExt);
			long dist = MapUtils.distanceBetweenCentroid(startExt, endExt);
			GWT.log("the distance is: " + dist);
			if (dist > 5000 || startExt.containsExtent(endExt)) {
				GeoQuery select = toDataBoxQuery(dragEndExtent);
				layerManagerBus.fireEvent(new QueryDataEvent(select, endExt.getCenter()));
			}
		}
		else if(zoomStart!=null && zoomEnd!=null) {
			
			if(zoomEnd<QUERY_MIN_ZOOM_LEVEL) {
				layerManagerBus.fireEvent(new ZoomOutOverMinimumEvent(zoomStart, zoomEnd, QUERY_MIN_ZOOM_LEVEL));
			}
		}

	}

	/**
	 * Sets the drag start.
	 */
	private void setDragStart() {
		if (olMap.getCurrentZoomLevel() > QUERY_MIN_ZOOM_LEVEL) {
			dragStartExtent = olMap.getExtent();
			GWT.log("Drag Start is: " + dragStartExtent);
		}
	}
	
	/**
	 * To data point query.
	 *
	 * @param extent the extent
	 * @return the geo query
	 */
	private GeoQuery toDataBoxQuery(ol.Extent extent) {
		
		return new GeoQuery(extent.getLowerLeftX(), extent.getLowerLeftY(), extent.getUpperRightX(), extent.getUpperRightY(), TYPE.BOX);
	}
	
	
	/**
	 * Checks if is query point active.
	 *
	 * @return true, if is query point active
	 */
	public boolean isQueryPointActive() {
		return olMap.isQueryPointActive();
	}

	/**
	 * Hide pop info.
	 */
	public void hidePopInfo() {
		olMap.hidePopup();
	}
	

}