Android Maps Point Clustering
Is there any code for Point Clustering in android? How can i load thousand pinpoint without having performance issues?
Solution 1:
Last night i got into PointClustering on Android MapView. Saw that there was nothing out for the community so i would like to share.
Groups the geopoints if the projection of them in the mapView is too close. Also renders only the visible poins.
UPDATE
Code reworked from scrach.
Now available at GitHub
- Code Reworked from scratch
- Used GVM clustering algorithm (pretty fast but doesn't position clustered point as good as mine)
- Soon to add previous clustering algorithm too
Solution 2:
I have reworked in the above code and controlled the no of overlay icon in the map view and separated the group and single point.
My Code:
MMapView.java
import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.MapView;
import com.google.android.maps.Overlay;
import com.impiger.maphighlight.R;
//Reference - http://stackoverflow.com/questions/7447350/android-maps-point-clustering
public class MMapView extends MapView {
private static final String TAG = MMapView.class.getSimpleName();
private static final int MAX_VISIBLE_POINTS = 1;
private PMapViewOverlay itemizedOverlay;
private List<Overlay> mapOverlays;
private List<GeoPoint> geoPoints = new ArrayList<GeoPoint>();
private BitmapDrawable drawable;
private Context context;
private Drawable emptyDrawable;
private int count;
private int oldZoomLevel = -1;
ArrayList<OverlayItemExtended> mOverlays;
public MMapView(Context context, AttributeSet attrs) {
super(context, attrs);
this.context = context;
mapOverlays = getOverlays();
drawable = new BitmapDrawable(
BitmapFactory.decodeResource(getResources(),
R.drawable.blue_65));
itemizedOverlay = new PMapViewOverlay(drawable, context);
emptyDrawable = context.getResources().getDrawable(
R.drawable.marker);
mOverlays = new ArrayList<OverlayItemExtended>();
init();
}
private GeoPoint getPoint(double lat, double lon) {
return (new GeoPoint((int) (lat * 1000000.0), (int) (lon * 1000000.0)));
}
private void init(){
putPoint(11, 77, true);
putPoint(11.5, 76.6, false);
putPoint(10.98383, 77.32112, false);
putPoint(10, 77, false);
putPoint(11, 78, false);
putPoint(11, 77.5, false);
putPoint(10.5, 77, false);
putPoint(12, 77, false);
putPoint(11.77, 77.11, false);
putPoint(12.1, 78.33, false);
putPoint(11.83, 77.293, false);
putPoint(11.12, 77, false);
putPoint(11.13, 77, false);
putPoint(11.14, 77, false);
putPoint(11.15, 77, false);
putPoint(11.12, 77.2, false);
putPoint(11.13, 77.34, false);
putPoint(11.14, 77.4, false);
putPoint(11.15, 77.1977, false);
putPoint(11.347373, 77.5627783, true);
putPoint(11.53454, 76.696645, false);
putPoint(10.19282, 77.847373, false);
putPoint(10.4728, 76.39388, false);
putPoint(11.4563, 78, false);
putPoint(11.73663, 77.5927, false);
putPoint(10.5674, 77.6762, false);
putPoint(12.02882, 77.672782, false);
putPoint(11.7767876, 77.1123423, false);
putPoint(12.18332, 78.33, false);
putPoint(11.8393883, 77.293938783, false);
putPoint(11.388323, 77.9478723, false);
putPoint(11.1345645, 77.97723, false);
putPoint(11.1423423, 77.73774, false);
putPoint(11.1552, 77.793783, false);
putPoint(11.127895434, 77.2944554, false);
putPoint(11.13232345, 77.342234, false);
putPoint(11.14456573, 77.4, false);
putPoint(11.159765, 77.1977, false);
}
public void putPoint(double lat, double lon, boolean isMyPosition) {
int latitude = (int) (lat * 1E6);
int longitude = (int) (lon * 1E6);
GeoPoint geo = new GeoPoint(latitude, longitude);
geo = getPoint(lat, lon);
/*
* Remove doubles
*/
Boolean alreadyExists = false;
for (GeoPoint item : geoPoints) {
if (item.getLatitudeE6() == geo.getLatitudeE6()
&& item.getLongitudeE6() == geo.getLongitudeE6()) {
alreadyExists = true;
}
}
if (!alreadyExists) {
geoPoints.add(geo);
}
}
/*
* Place the overlays
*/
public void placeOverlays() {
itemizedOverlay.removeAllOverlays();
getOverlays().clear();
mapOverlays.clear();
mOverlays.clear();
int i = 1;
for (GeoPoint item : geoPoints) {
OverlayItemExtended overlayitem = new OverlayItemExtended(item,
"title "+i, "snippet");
// Here is where the magic happens
addOverlayItemClustered(overlayitem, this,
geoPoints.size());
i++;
}
for(int j=0;j<mOverlays.size();j++){
OverlayItemExtended overlayItem = mOverlays.get(j);
if(overlayItem.isMaster){
if(overlayItem.slaves.size() > 0){
itemizedOverlay = new PMapViewOverlay(drawable, context);
itemizedOverlay.addOverlayItem(overlayItem);
}else{
itemizedOverlay = new PMapViewOverlay(emptyDrawable, context);
itemizedOverlay.addOverlayItem(overlayItem);
}
mapOverlays.add(itemizedOverlay);
}
}
}
/*
* Update the points at panned / zoom etc
*/
public void dispatchDraw(Canvas canvas) {
super.dispatchDraw(canvas);
if (getZoomLevel() != oldZoomLevel) {
placeOverlays();
}
oldZoomLevel = getZoomLevel();
}
public void addOverlayItemClustered(OverlayItemExtended thisOverlay,
MapView mapView, int totalPoints) {
for (OverlayItemExtended otherOverlay : mOverlays) {
/*
* Thresshold for the clustering
*/
/*
* Zoom level >15 don't cluster If less than Max_Visible_points
* don't cluster
*/
if (mapView.getZoomLevel() >= 14
|| (MAX_VISIBLE_POINTS > totalPoints)
&& PointCluster.getOverLayItemDistance(thisOverlay,
otherOverlay, mapView) > 60) {
mOverlays.add(thisOverlay);
return;
}
if (PointCluster.getOverLayItemDistance(thisOverlay, otherOverlay,
mapView) < 90 && !thisOverlay.isClustered) {
// Here is where the clustering actually happens
if (otherOverlay.isMaster) {
thisOverlay.isMaster = false;
// otherOverlay.isMaster = false;
thisOverlay.isClustered = true;
otherOverlay.isClustered = true;
otherOverlay.slaves.push(thisOverlay);
thisOverlay.parent = otherOverlay;
} else if (PointCluster.getOverLayItemDistance(thisOverlay,
otherOverlay.parent, mapView) < 90
&& otherOverlay.isClustered) {
thisOverlay.isMaster = false;
thisOverlay.isClustered = true;
thisOverlay.parent = otherOverlay.parent;
otherOverlay.parent.slaves.push(thisOverlay);
}
}
}
mOverlays.add(thisOverlay);
}
}
OverlayItemExtended.java
import java.util.Stack;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.OverlayItem;
public class OverlayItemExtended extends OverlayItem {
public boolean isClustered = false;
public boolean isMaster = true;
public boolean isMe = false;
public OverlayItemExtended parent;
public Stack<OverlayItemExtended> slaves = new Stack<OverlayItemExtended>();
public OverlayItemExtended(GeoPoint point, String title, String snippet) {
super(point, title, snippet);
}
}
PMapViewOverlay.java
import java.util.ArrayList;
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Point;
import android.graphics.drawable.Drawable;
import android.widget.Toast;
import com.google.android.maps.GeoPoint;
import com.google.android.maps.ItemizedOverlay;
import com.google.android.maps.MapView;
@SuppressWarnings("rawtypes")
public class PMapViewOverlay extends ItemizedOverlay {
private static final String TAG = PMapViewOverlay.class.getSimpleName();
private Context context;
private ArrayList<OverlayItemExtended> mOverlays;
public PMapViewOverlay(Drawable defaultMarker, Context context) {
super(boundCenterBottom(defaultMarker));
this.context = context;
mOverlays = new ArrayList<OverlayItemExtended>();
paint.setTextAlign(Paint.Align.CENTER);
paint.setTextSize(25);
paint.setAntiAlias(true);
paint.setStrokeWidth(5);
paint.setColor(Color.WHITE);
}
@Override
protected OverlayItemExtended createItem(int i) {
return mOverlays.get(i);
}
@Override
public int size() {
return mOverlays.size();
}
public void addOverlayItem(OverlayItemExtended overlay) {
mOverlays.add(overlay);
populate();
}
public void removeAllOverlays() {
mOverlays.clear();
populate();
}
public void removePointsButMe() {
for (int i = 0; i < mOverlays.size(); i++) {
OverlayItemExtended overlay = mOverlays.get(i);
if (overlay.isMe) {
mOverlays.clear();
addOverlayItem(overlay);
break;
}
}
populate();
}
Paint paint = new Paint();
@Override
public void draw(Canvas canvas, MapView mapView, boolean shadow) {
super.draw(canvas, mapView, shadow);
// cycle through all overlays
for (int index = 0; index < mOverlays.size(); index++) {
OverlayItemExtended item = mOverlays.get(index);
// Converts lat/lng-Point to coordinates on the screen
GeoPoint point = item.getPoint();
Point ptScreenCoord = new Point();
mapView.getProjection().toPixels(point, ptScreenCoord);
if (item.isMaster) {
if (item.slaves.size() > 0) {
canvas.drawText(item.slaves.size() + 1 + "",
ptScreenCoord.x, ptScreenCoord.y - 13, paint);
}
}
}
}
@Override
protected boolean onTap(int index) {
OverlayItemExtended item = mOverlays.get(index);
if (item.isMaster) {
if (item.slaves.size() == 0) {
Toast.makeText(context, "You tapped item " + item.getTitle(),
Toast.LENGTH_LONG).show();
}
}
return super.onTap(index);
}
}
I didn't change any code in PointCluster.java.
I hope this will help somebody.
Solution 3:
Google's Android Map Utils has a solution for this: Google Maps Android Marker Clustering Utility.
Add dependency
implementation 'com.google.maps.android:android-maps-utils:0.5'
Make your own ClusterItem
class MyItem(
private val position: LatLng,
val title: String,
private val snippet: String
) : ClusterItem {
override fun getPosition() = position
override fun getTitle() = title
override fun getSnippet() = snippet
}
Setting up the cluster manager and adding items
override fun onMapReady(googleMap: GoogleMap) {
val clusterManager = ClusterManager<MyItem>(this, googleMap)
googleMap.setOnCameraIdleListener(clusterManager)
clusterManager.addItem(MyItem(LatLng(51.51, -0.12), "title", "snippet"))
}
That's it! Items are now shown as follows:
Customizing the icon
In order to customize the icon, add val icon: BitmapDescriptor to your ClusterItem and change the renderer of the cluster manager:
clusterManager.renderer = object : DefaultClusterRenderer<MyItem>(this, googleMap, clusterManager) {
override fun onBeforeClusterItemRendered(item: MyItem, markerOptions: MarkerOptions) {
markerOptions.icon(item.icon)
}
}
Making items clickable
As a rule of thumb, any interaction with markers should go through the cluster manager instead. The same applies to making items clickable.
googleMap.setOnMarkerClickListener(clusterManager)
clusterManager.setOnClusterItemClickListener {
Toast.makeText(this, "Clicked on item ${it.title}", Toast.LENGTH_SHORT).show()
true
}
Similarly, you can call googleMap.setOnInfoWindowClickListener(clusterManager) and clusterManager.setOnClusterItemInfoWindowClickListener to handle clicks on the info window.
Solution 4:
There is a nice sample for it. Check it here: http://code.google.com/p/android-playground-erdao/source/browse/trunk/SampleClusterMap/?r=226
Solution 5:
There is a pull request on github for the Polaris library (https://github.com/cyrilmottier/Polaris) which adds clustering:
https://github.com/cyrilmottier/Polaris/pull/20
https://github.com/damianflannery/Polaris/tree/clustering