Java tutorial
package com.laocuo.weather.presenter.impl; import android.Manifest; import android.app.Activity; import android.content.Context; import android.content.SharedPreferences; import android.content.pm.PackageManager; import android.location.Address; import android.location.Geocoder; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.preference.PreferenceManager; import android.support.v4.app.ActivityCompat; import android.text.TextUtils; import com.laocuo.weather.presenter.model.ILocationInterface; import com.laocuo.weather.utils.L; import java.io.IOException; import java.util.List; import java.util.Locale; /** Copyright (C) laocuo <laocuo@163.com> 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. */ public class LocationPresenter { private ILocationInterface mView; public void setView(ILocationInterface view) { mView = view; } private final String CITY_KEY = "pref_city"; private Context mContext; private LocationManager mLocationManager; private CityLocationListener mLocationListener; public LocationPresenter(Context context) { mContext = context; mLocationManager = (LocationManager) context.getSystemService(Context.LOCATION_SERVICE); mLocationListener = new CityLocationListener(); } public String getCityByLocation() { L.d("getCityBySharePreferences"); SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(mContext); String city = sp.getString(CITY_KEY, ""); if (TextUtils.isEmpty(city)) { L.d("getCityByLocation"); if (mLocationManager != null) { city = requestLocation(); } } return city; } public void updateCity(String city) { L.d("updateCity:" + city); SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(mContext); String prev_city = sp.getString(CITY_KEY, "nanjing"); if (!prev_city.equalsIgnoreCase(city)) { SharedPreferences.Editor editor = sp.edit(); editor.putString(CITY_KEY, city); editor.commit(); } } public String requestLocation() { String city = null; if (!checkLocationPermission(mContext)) { // TODO: Consider calling // ActivityCompat#requestPermissions // here to request the missing permissions, and then overriding // public void onRequestPermissionsResult(int requestCode, String[] permissions, // int[] grantResults) // to handle the case where the user grants the permission. See the documentation // for ActivityCompat#requestPermissions for more details. requestLocationPermission((Activity) mContext); return null; } Location l = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER); if (l != null) { L.d("getLastKnownLocation"); city = saveCityByLocation(l); } else { L.d("requestSingleUpdate"); if (!mLocationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)) { mView.openLocation(); mLocationManager.requestSingleUpdate(LocationManager.PASSIVE_PROVIDER, mLocationListener, null); } else { mLocationManager.requestSingleUpdate(LocationManager.NETWORK_PROVIDER, mLocationListener, null); } } return city; } private void removeLocationListener() { if (mLocationManager != null && mLocationListener != null) { if (!checkLocationPermission(mContext)) { return; } L.d("removeUpdates"); mLocationManager.removeUpdates(mLocationListener); } } private String saveCityByLocation(Location l) { String city = null; Double latitude = l.getLatitude(); Double longitude = l.getLongitude(); Geocoder gc = new Geocoder(mContext, Locale.getDefault()); List<Address> addressList = null; try { addressList = gc.getFromLocation(latitude, longitude, 10); Address address = addressList.get(0); L.d("Locality:" + address.getLocality()); city = address.getLocality(); if (TextUtils.isEmpty(city) == false) { SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(mContext).edit(); editor.putString(CITY_KEY, city); editor.commit(); } } catch (IOException e) { e.printStackTrace(); mView.getLocationFail(); } finally { return city; } } public void onExit() { removeLocationListener(); } public boolean handlePermissionsResult(int code, String[] permissions, int[] results) { if (code == REQUEST_LOCATION) { L.d("results[0]=" + results[0]); L.d("results[1]=" + results[1]); mView.requestLocationSuccess(); return true; } return false; } private class CityLocationListener implements LocationListener { @Override public void onLocationChanged(Location location) { L.d("onLocationChanged"); String city = saveCityByLocation(location); mView.getLoacationSuccess(city); } @Override public void onStatusChanged(String s, int i, Bundle bundle) { } @Override public void onProviderEnabled(String s) { L.d("onProviderEnabled"); } @Override public void onProviderDisabled(String s) { L.d("onProviderDisabled"); } } public static final int REQUEST_LOCATION = 1; private boolean checkLocationPermission(Context context) { return ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED; } private void requestLocationPermission(Activity activity) { ActivityCompat.requestPermissions(activity, new String[] { Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_COARSE_LOCATION }, REQUEST_LOCATION); } }