Java tutorial
/* * Copyright (C) 2013 Maciej Grski * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package pl.mg6.newmaps.demo; import java.util.ArrayList; import java.util.List; import java.util.Random; import pl.mg6.newmaps.demo.util.GoogleMapHelper; import android.os.Bundle; import android.os.SystemClock; import android.support.v4.app.FragmentActivity; import android.util.Log; import com.google.android.gms.maps.GoogleMap; import com.google.android.gms.maps.GoogleMap.OnCameraChangeListener; import com.google.android.gms.maps.Projection; import com.google.android.gms.maps.model.CameraPosition; import com.google.android.gms.maps.model.LatLng; import com.google.android.gms.maps.model.LatLngBounds; import com.google.android.gms.maps.model.MarkerOptions; public class AddOnlyVisibleMarkersExampleActivity extends FragmentActivity { private static final String TAG = AddOnlyVisibleMarkersExampleActivity.class.getSimpleName(); @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.many_markers_example); final GoogleMap map = GoogleMapHelper.getMap(this, R.id.many_markers_map); final List<LatLng> positions = new ArrayList<LatLng>(); Random r = new Random(); long start = SystemClock.uptimeMillis(); for (int i = 0; i < ManyMarkersExampleActivity.MARKERS_COUNT; i++) { LatLng position = new LatLng((r.nextDouble() - 0.5) * 170.0, (r.nextDouble() - 0.5) * 360.0); positions.add(position); } long end = SystemClock.uptimeMillis(); Log.w(TAG, "generate time: " + (end - start)); map.setOnCameraChangeListener(new OnCameraChangeListener() { @Override public void onCameraChange(CameraPosition cameraPosition) { long start = SystemClock.uptimeMillis(); int count = 0; Projection projection = map.getProjection(); LatLngBounds bounds = projection.getVisibleRegion().latLngBounds; for (int i = positions.size() - 1; i >= 0; i--) { LatLng position = positions.get(i); if (bounds.contains(position)) { map.addMarker(new MarkerOptions().position(position)); positions.remove(i); count++; } } long end = SystemClock.uptimeMillis(); Log.w(TAG, "addMarkers time: " + (end - start) + ", added: " + count); } }); } }