Android Open Source - android-open-street-map Osm Polygon Overlay

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License

The source code is released under:

Apache License

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Java Source Code

package com.android.lib.map.osm.overlay;
//w  ww. j a  v a2 s .c om
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import android.graphics.Canvas;
import android.graphics.Path;
import android.graphics.Point;
import android.view.View;

import com.android.lib.map.osm.GeoPoint;
import com.android.lib.map.osm.OsmMapView;

public class OsmPolygonOverlay extends OsmOverlay {

  private List<MapPolygon> mPolygons;
  private GeoPoint mStartLocation;
  private Map<MapPolygon, Point> mStartPoints;
  private OsmMapView mMapView;
  
  
  public OsmPolygonOverlay(OsmMapView mapView) {
    mMapView = mapView;
    mStartPoints = new HashMap<MapPolygon, Point>();
    mPolygons = new ArrayList<MapPolygon>();
  }
  
  public void addPolygon(MapPolygon polygon) {
    mPolygons.add(polygon);
  }
  
  public List<MapPolygon> getPolygons() {
    return mPolygons;
  }
  
  public void removePolygons() {
    for (MapPolygon mapPolygon : mPolygons)
      mapPolygon.getPath().reset();
    mPolygons.clear();
    mStartPoints.clear();
  }
  
  @Override
  public void draw(Canvas canvas, View view) {
    super.draw(canvas, view);
    
    for (MapPolygon mapPolygon : mPolygons) {
      Path path = mapPolygon.getPath();
      if (path.isEmpty())
        drawPathForMapPolygon(mapPolygon);
      offsetPath(path);
      canvas.drawPath(path, mapPolygon.getPaintStroke());
      canvas.drawPath(path, mapPolygon.getPaint());
    }
  }

  private void drawPathForMapPolygon(MapPolygon polygon) {

    Path path = polygon.getPath();
    
    if (!path.isEmpty())
      path.rewind();

    GeoPoint previousPoint = null;
    
    Point startPoint = new Point();
    startPoint.x = mMapView.getOffsetX();
    startPoint.y = mMapView.getOffsetY();
    mStartPoints.put(polygon, startPoint);
        
    for (GeoPoint g : polygon.getPolygon()) {

      if (previousPoint == null) {
        previousPoint = g;
        Point p = convertGeoPointToPixel(g);
        path.moveTo(p.x, p.y);
        
        if (mStartLocation == null)
          mStartLocation = g;

        continue;
      }

      drawLine(path, g);

      previousPoint = g;
    }

    path.close();
    
    previousPoint = null;
  }
  
  @Override
  public void onZoomLevelChanges(View view) {
    super.onZoomLevelChanges(view);

    for (MapPolygon polygon : mPolygons) {
      drawPathForMapPolygon(polygon);
    }
  }
  
  private void offsetPath(Path path) {
    Point startPoint = mStartPoints.get(path);

    if (startPoint == null && path != null && !path.isEmpty()) {
      for (MapPolygon polygon : mPolygons) {
        drawPathForMapPolygon(polygon);
      }
    }
    
    if (startPoint != null && !path.isEmpty()) {
      int x = mMapView.getOffsetX() - startPoint.x;
      int y = mMapView.getOffsetY() - startPoint.y;

      path.offset(x, y);
      startPoint.x = mMapView.getOffsetX();
      startPoint.y = mMapView.getOffsetY();
    }
  }

  private void drawLine(Path path, GeoPoint gp2) {
    Point p2 = convertGeoPointToPixel(gp2);
    path.lineTo(p2.x, p2.y);
  }

  private Point convertGeoPointToPixel(GeoPoint g) {
    return mMapView.geopointToPixelProjection(g);
  }
  
}

Java Source Code List