PositionControl.java :  » GWT » ghetto-maps » com » moesol » gwt » maps » client » controls » Java Open Source

package com.moesol.gwt.maps.client.controls;

import mil.geotransj.GeoTransException;
import mil.geotransj.Geodetic;
import mil.geotransj.Mgrs;

import com.google.gwt.event.dom.client.MouseMoveEvent;
import com.google.gwt.event.dom.client.MouseMoveHandler;
import com.google.gwt.user.client.ui.Composite;
import com.moesol.gwt.maps.client.GeodeticCoords;
import com.moesol.gwt.maps.client.LatLonString;
import com.moesol.gwt.maps.client.MapView;
import com.moesol.gwt.maps.client.ViewCoords;
import com.moesol.gwt.maps.client.units.AngleUnit;

/**
 * Hook to MapView to display the Latitude, Longitude, and MGRS position of the
 * mouse over the map.
 */
public class PositionControl extends Composite {
  private final OutlinedLabel m_mousePosLabel = new OutlinedLabel();
  private final Mgrs m_mgrs = new Mgrs();
  private final Geodetic m_geo = new Geodetic();
  private final MapView m_mapView;
  private final ViewCoords m_vc = new ViewCoords();
  
  public PositionControl(MapView mapView) {
    m_mapView = mapView;
    initWidget(m_mousePosLabel);
    
    MouseMoveHandler handler = new MouseMoveHandler() {
      @Override
      public void onMouseMove(MouseMoveEvent event) {
        mouseMove(event.getX(), event.getY());
      }
    };
    addStyleName("map-PositionControl");
    m_mapView.addDomHandler(handler, MouseMoveEvent.getType());
  }
  
  public void mouseMove( int x, int y ) {
    m_vc.set(x,y);
    GeodeticCoords gc = m_mapView.getProjection().viewToGeodetic(m_vc);
    String pos = LatLonString.build(gc.getPhi(AngleUnit.DEGREES), 
                    gc.getLambda(AngleUnit.DEGREES));
    String mgrsPos = "";
    try {
      m_geo.setLatitude(gc.getPhi(AngleUnit.DEGREES));
      m_geo.setLongitude(gc.getLambda(AngleUnit.DEGREES));
      mgrsPos = m_mgrs.GeodeticToMgrs(m_geo, 5);
    } catch (GeoTransException e) {
      mgrsPos = "";
    }
    m_mousePosLabel.setText( pos + " " + mgrsPos );
  }
  
}