/**
* Copyright 2014 Google Inc. All Rights Reserved.
*
* 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 com.google.android.gms.location.sample.locationaddress;
import android.content.Intent;
import android.location.Geocoder;
import android.location.Location;
import android.os.Bundle;
import android.os.Handler;
import android.os.ResultReceiver;
import android.support.v7.app.ActionBarActivity;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.api.GoogleApiClient;
import com.google.android.gms.common.api.GoogleApiClient.ConnectionCallbacks;
import com.google.android.gms.common.api.GoogleApiClient.OnConnectionFailedListener;
import com.google.android.gms.location.LocationServices;
/**
* Getting the Location Address.
*
* Demonstrates how to use the {@link android.location.Geocoder} API and reverse geocoding to
* display a device's location as an address. Uses an IntentService to fetch the location address,
* and a ResultReceiver to process results sent by the IntentService.
*
* Android has two location request settings:
* {@code ACCESS_COARSE_LOCATION} and {@code ACCESS_FINE_LOCATION}. These settings control
* the accuracy of the current location. This sample uses ACCESS_FINE_LOCATION, as defined in
* the AndroidManifest.xml.
*
* For a starter example that displays the last known location of a device using a longitude and latitude,
* see https://github.com/googlesamples/android-play-location/tree/master/BasicLocation.
*
* For an example that shows location updates using the Fused Location Provider API, see
* https://github.com/googlesamples/android-play-location/tree/master/LocationUpdates.
*
* This sample uses Google Play services (GoogleApiClient) but does not need to authenticate a user.
* For an example that uses authentication, see
* https://github.com/googlesamples/android-google-accounts/tree/master/QuickStart.
*/
public class MainActivity extends ActionBarActivity implements
ConnectionCallbacks, OnConnectionFailedListener {
protected static final String TAG = "main-activity";
protected static final String ADDRESS_REQUESTED_KEY = "address-request-pending";
protected static final String LOCATION_ADDRESS_KEY = "location-address";
/**
* Provides the entry point to Google Play services.
*/
protected GoogleApiClient mGoogleApiClient;
/**
* Represents a geographical location.
*/
protected Location mLastLocation;
/**
* Tracks whether the user has requested an address. Becomes true when the user requests an
* address and false when the address (or an error message) is delivered.
* The user requests an address by pressing the Fetch Address button. This may happen
* before GoogleApiClient connects. This activity uses this boolean to keep track of the
* user's intent. If the value is true, the activity tries to fetch the address as soon as
* GoogleApiClient connects.
*/
protected boolean mAddressRequested;
/**
* The formatted location address.
*/
protected String mAddressOutput;
/**
* Receiver registered with this activity to get the response from FetchAddressIntentService.
*/
private AddressResultReceiver mResultReceiver;
/**
* Displays the location address.
*/
protected TextView mLocationAddressTextView;
/**
* Visible while the address is being fetched.
*/
ProgressBar mProgressBar;
/**
* Kicks off the request to fetch an address when pressed.
*/
Button mFetchAddressButton;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_activity);
mResultReceiver = new AddressResultReceiver(new Handler());
mLocationAddressTextView = (TextView) findViewById(R.id.location_address_view);
mProgressBar = (ProgressBar) findViewById(R.id.progress_bar);
mFetchAddressButton = (Button) findViewById(R.id.fetch_address_button);
// Set defaults, then update using values stored in the Bundle.
mAddressRequested = false;
mAddressOutput = "";
updateValuesFromBundle(savedInstanceState);
updateUIWidgets();
buildGoogleApiClient();
}
/**
* Updates fields based on data stored in the bundle.
*/
private void updateValuesFromBundle(Bundle savedInstanceState) {
if (savedInstanceState != null) {
// Check savedInstanceState to see if the address was previously requested.
if (savedInstanceState.keySet().contains(ADDRESS_REQUESTED_KEY)) {
mAddressRequested = savedInstanceState.getBoolean(ADDRESS_REQUESTED_KEY);
}
// Check savedInstanceState to see if the location address string was previously found
// and stored in the Bundle. If it was found, display the address string in the UI.
if (savedInstanceState.keySet().contains(LOCATION_ADDRESS_KEY)) {
mAddressOutput = savedInstanceState.getString(LOCATION_ADDRESS_KEY);
displayAddressOutput();
}
}
}
/**
* Builds a GoogleApiClient. Uses {@code #addApi} to request the LocationServices API.
*/
protected synchronized void buildGoogleApiClient() {
mGoogleApiClient = new GoogleApiClient.Builder(this)
.addConnectionCallbacks(this)
.addOnConnectionFailedListener(this)
.addApi(LocationServices.API)
.build();
}
/**
* Runs when user clicks the Fetch Address button. Starts the service to fetch the address if
* GoogleApiClient is connected.
*/
public void fetchAddressButtonHandler(View view) {
// We only start the service to fetch the address if GoogleApiClient is connected.
if (mGoogleApiClient.isConnected() && mLastLocation != null) {
startIntentService();
}
// If GoogleApiClient isn't connected, we process the user's request by setting
// mAddressRequested to true. Later, when GoogleApiClient connects, we launch the service to
// fetch the address. As far as the user is concerned, pressing the Fetch Address button
// immediately kicks off the process of getting the address.
mAddressRequested = true;
updateUIWidgets();
}
@Override
protected void onStart() {
super.onStart();
mGoogleApiClient.connect();
}
@Override
protected void onStop() {
super.onStop();
if (mGoogleApiClient.isConnected()) {
mGoogleApiClient.disconnect();
}
}
/**
* Runs when a GoogleApiClient object successfully connects.
*/
@Override
public void onConnected(Bundle connectionHint) {
// Gets the best and most recent location currently available, which may be null
// in rare cases when a location is not available.
mLastLocation = LocationServices.FusedLocationApi.getLastLocation(mGoogleApiClient);
if (mLastLocation != null) {
// Determine whether a Geocoder is available.
if (!Geocoder.isPresent()) {
Toast.makeText(this, R.string.no_geocoder_available, Toast.LENGTH_LONG).show();
return;
}
// It is possible that the user presses the button to get the address before the
// GoogleApiClient object successfully connects. In such a case, mAddressRequested
// is set to true, but no attempt is made to fetch the address (see
// fetchAddressButtonHandler()) . Instead, we start the intent service here if the
// user has requested an address, since we now have a connection to GoogleApiClient.
if (mAddressRequested) {
startIntentService();
}
}
}
/**
* Creates an intent, adds location data to it as an extra, and starts the intent service for
* fetching an address.
*/
protected void startIntentService() {
// Create an intent for passing to the intent service responsible for fetching the address.
Intent intent = new Intent(this, FetchAddressIntentService.class);
// Pass the result receiver as an extra to the service.
intent.putExtra(Constants.RECEIVER, mResultReceiver);
// Pass the location data as an extra to the service.
intent.putExtra(Constants.LOCATION_DATA_EXTRA, mLastLocation);
// Start the service. If the service isn't already running, it is instantiated and started
// (creating a process for it if needed); if it is running then it remains running. The
// service kills itself automatically once all intents are processed.
startService(intent);
}
@Override
public void onConnectionFailed(ConnectionResult result) {
// Refer to the javadoc for ConnectionResult to see what error codes might be returned in
// onConnectionFailed.
Log.i(TAG, "Connection failed: ConnectionResult.getErrorCode() = " + result.getErrorCode());
}
@Override
public void onConnectionSuspended(int cause) {
// The connection to Google Play services was lost for some reason. We call connect() to
// attempt to re-establish the connection.
Log.i(TAG, "Connection suspended");
mGoogleApiClient.connect();
}
/**
* Updates the address in the UI.
*/
protected void displayAddressOutput() {
mLocationAddressTextView.setText(mAddressOutput);
}
/**
* Toggles the visibility of the progress bar. Enables or disables the Fetch Address button.
*/
private void updateUIWidgets() {
if (mAddressRequested) {
mProgressBar.setVisibility(ProgressBar.VISIBLE);
mFetchAddressButton.setEnabled(false);
} else {
mProgressBar.setVisibility(ProgressBar.GONE);
mFetchAddressButton.setEnabled(true);
}
}
/**
* Shows a toast with the given text.
*/
protected void showToast(String text) {
Toast.makeText(this, text, Toast.LENGTH_SHORT).show();
}
@Override
public void onSaveInstanceState(Bundle savedInstanceState) {
// Save whether the address has been requested.
savedInstanceState.putBoolean(ADDRESS_REQUESTED_KEY, mAddressRequested);
// Save the address string.
savedInstanceState.putString(LOCATION_ADDRESS_KEY, mAddressOutput);
super.onSaveInstanceState(savedInstanceState);
}
/**
* Receiver for data sent from FetchAddressIntentService.
*/
class AddressResultReceiver extends ResultReceiver {
public AddressResultReceiver(Handler handler) {
super(handler);
}
/**
* Receives data sent from FetchAddressIntentService and updates the UI in MainActivity.
*/
@Override
protected void onReceiveResult(int resultCode, Bundle resultData) {
// Display the address string or an error message sent from the intent service.
mAddressOutput = resultData.getString(Constants.RESULT_DATA_KEY);
displayAddressOutput();
// Show a toast message if an address was found.
if (resultCode == Constants.SUCCESS_RESULT) {
showToast(getString(R.string.address_found));
}
// Reset. Enable the Fetch Address button and stop showing the progress bar.
mAddressRequested = false;
updateUIWidgets();
}
}
}