Android Open Source - SmartNavi Marker Clusterer

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License

The source code is released under:

Apache License

Java Source Code

package org.osmdroid.bonuspack.clustering;
/*from   www .  j a  va 2s.c  o m*/
import java.util.ArrayList;
import org.osmdroid.bonuspack.overlays.Marker;
import org.osmdroid.views.MapView;
import org.osmdroid.views.overlay.Overlay;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Point;
import android.view.MotionEvent;

/** 
 * An overlay allowing to perform markers clustering. 
 * Usage: put your markers inside with add(Marker), and add the MarkerClusterer to the map overlays. 
 * Depending on the zoom level, markers will be displayed separately, or grouped as a single Marker. <br/>
 * 
 * This abstract class provides the framework. Sub-classes have to implement the clustering algorithm, 
 * and the rendering of a cluster. 
 * 
 * @author M.Kergall
 *
 */
public abstract class MarkerClusterer extends Overlay {

  /** impossible value for zoom level, to force clustering */
  protected static final int FORCE_CLUSTERING = -1;
  
  protected ArrayList<Marker> mItems = new ArrayList<Marker>();
  protected Point mPoint = new Point();
  protected ArrayList<StaticCluster> mClusters = new ArrayList<StaticCluster>();;
  protected int mLastZoomLevel;
  protected Bitmap mClusterIcon;
  
  // abstract methods: 
  
  /** clustering algorithm */
  public abstract ArrayList<StaticCluster> clusterer(MapView mapView);
  /** Build the marker for a cluster. */
  public abstract Marker buildClusterMarker(StaticCluster cluster, MapView mapView);
  /** build clusters markers to be used at next draw */
  public abstract void renderer(ArrayList<StaticCluster> clusters, Canvas canvas, MapView mapView);
  
  public MarkerClusterer(Context ctx) {
    super(ctx);
    mLastZoomLevel = FORCE_CLUSTERING;
  }

  /** Set the cluster icon to be drawn when a cluster contains more than 1 marker. 
   * If not set, default will be the default osmdroid marker icon (which is really inappropriate as a cluster icon). */
  public void setIcon(Bitmap icon){
    mClusterIcon = icon;
  }
  
  /** Add the Marker. 
   * Important: Markers added in a MarkerClusterer should not be added in the map overlays. */
  public void add(Marker marker){
    mItems.add(marker);
  }
  
  /** Force a rebuild of clusters at next draw, even without a zooming action. 
   * Should be done when you changed the content of a MarkerClusterer. */
  public void invalidate(){
    mLastZoomLevel = FORCE_CLUSTERING; 
  }
  
  /** @return the Marker at id (starting at 0) */
  public Marker getItem(int id){
    return mItems.get(id);
  }
  
  /** @return the list of Markers. */
  public ArrayList<Marker> getItems(){
    return mItems;
  }
  
  @Override protected void draw(Canvas canvas, MapView mapView, boolean shadow) {
    //if zoom has changed and mapView is now stable, rebuild clusters:
    int zoomLevel = mapView.getZoomLevel();
    if (zoomLevel != mLastZoomLevel && !mapView.isAnimating()){
      mClusters = clusterer(mapView);
      renderer(mClusters, canvas, mapView);
      mLastZoomLevel = zoomLevel;
    }
    
    /*
    final Projection pj = mapView.getProjection();
    Drawable dd = new BitmapDrawable(mClusterIcon);
    dd.setBounds(-15, -15, 15, 15);
    */
    
    for (StaticCluster cluster:mClusters){
      cluster.getMarker().draw(canvas, mapView, shadow);
      
      /*
      if (cluster.getSize()>1){
        GeoPoint p1 = cluster.getPosition();
        GeoPoint p2 = new GeoPoint(p1.getLatitude()+gridSizeY, p1.getLongitude()-gridSizeX);
        Point p2Pixels= pj.toMapPixels(p2, null);
        drawAt(canvas, dd, p2Pixels.x, p2Pixels.y, false, 0.0f);
      }
      */
    }
  }

  @Override public boolean onSingleTapConfirmed(final MotionEvent event, final MapView mapView){
    for (StaticCluster cluster:mClusters){
      if (cluster.getMarker().onSingleTapConfirmed(event, mapView))
        return true;
    }
    return false;
  }
  
  @Override public boolean onLongPress(final MotionEvent event, final MapView mapView) {
    for (StaticCluster cluster:mClusters){
      if (cluster.getMarker().onLongPress(event, mapView))
        return true;
    }
    return false;
  }

  @Override public boolean onTouchEvent(final MotionEvent event, final MapView mapView) {
    for (StaticCluster cluster:mClusters){
      if (cluster.getMarker().onTouchEvent(event, mapView))
        return true;
    }
    return false;
  }
}

Java Source Code List

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