name.gumartinm.weather.information.fragment.map.MapProgressFragment.java Source code

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Here is the source code for name.gumartinm.weather.information.fragment.map.MapProgressFragment.java

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/**
 * Copyright 2014 Gustavo Martin Morcuende
 *
 * 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 name.gumartinm.weather.information.fragment.map;

import java.io.IOException;
import java.util.List;
import java.util.Locale;

import android.app.Activity;
import android.content.Context;
import android.location.Address;
import android.location.Geocoder;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import name.gumartinm.weather.information.R;
import name.gumartinm.weather.information.model.WeatherLocation;
import timber.log.Timber;

/**
 * {@link http://www.androiddesignpatterns.com/2013/04/retaining-objects-across-config-changes.html}
 *
 */
public class MapProgressFragment extends Fragment {

    /**
     * 
     * Callback interface through which the fragment will report the
     * task's progress and results back to the Activity.
     */
    public static interface TaskCallbacks {
        void onPostExecute(final WeatherLocation weatherLocation);
    }

    private TaskCallbacks mCallbacks;

    @Override
    public View onCreateView(final LayoutInflater inflater, final ViewGroup container,
            final Bundle savedInstanceState) {

        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.weather_map_progress, container, false);
    }

    /**
     * This method will only be called once when the retained
     * Fragment is first created.
     */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Retain this fragment across configuration changes.
        this.setRetainInstance(true);

        final Bundle bundle = this.getArguments();
        double latitude = bundle.getDouble("latitude");
        double longitude = bundle.getDouble("longitude");

        // Create and execute the background task.
        new GetAddressTask(this.getActivity().getApplicationContext()).execute(latitude, longitude);
    }

    /**
     * Hold a reference to the parent Activity so we can report the
     * task's current progress and results. The Android framework 
     * will pass us a reference to the newly created Activity after 
     * each configuration change.
     */
    @Override
    public void onAttach(final Activity activity) {
        super.onAttach(activity);
        mCallbacks = (TaskCallbacks) activity;
    }

    /**
     * Set the callback to null so we don't accidentally leak the 
     * Activity instance.
     */
    //   @Override
    //   public void onDetach() {
    //      super.onDetach();
    //      mCallbacks = null;
    //   }

    /**
     * I am not using onDetach because there are problems when my activity goes to background.
     * 
     * {@link http://www.androiddesignpatterns.com/2013/08/fragment-transaction-commit-state-loss.html}
     */
    @Override
    public void onPause() {
        super.onPause();
        mCallbacks = null;
    }

    private class GetAddressTask extends AsyncTask<Object, Void, WeatherLocation> {
        // Store the context passed to the AsyncTask when the system instantiates it.
        private final Context localContext;

        private GetAddressTask(final Context context) {
            this.localContext = context;
        }

        @Override
        protected WeatherLocation doInBackground(final Object... params) {
            final double latitude = (Double) params[0];
            final double longitude = (Double) params[1];

            WeatherLocation weatherLocation = this.doDefaultLocation(latitude, longitude);
            try {
                weatherLocation = this.getLocation(latitude, longitude);
            } catch (final Throwable e) { // Hopefully nothing goes wrong because of catching Throwable.
                Timber.e(e, "GetAddressTask doInBackground exception: ");
            }

            return weatherLocation;
        }

        @Override
        protected void onPostExecute(final WeatherLocation weatherLocation) {

            // Call updateUI on the UI thread.
            if (mCallbacks != null) {
                mCallbacks.onPostExecute(weatherLocation);
            }
        }

        private WeatherLocation getLocation(final double latitude, final double longitude) throws IOException {
            // TODO: i18n Locale.getDefault()
            final Geocoder geocoder = new Geocoder(this.localContext, Locale.US);
            final List<Address> addresses = geocoder.getFromLocation(latitude, longitude, 1);

            // Default values
            WeatherLocation weatherLocation = this.doDefaultLocation(latitude, longitude);

            if (addresses != null && addresses.size() > 0) {
                if (addresses.get(0).getLocality() != null) {
                    weatherLocation.setCity(addresses.get(0).getLocality());
                }
                if (addresses.get(0).getCountryName() != null) {
                    weatherLocation.setCountry(addresses.get(0).getCountryName());
                }
            }

            return weatherLocation;
        }

        private WeatherLocation doDefaultLocation(final double latitude, final double longitude) {
            // Default values
            String city = this.localContext.getString(R.string.city_not_found);
            String country = this.localContext.getString(R.string.country_not_found);

            return new WeatherLocation().setLatitude(latitude).setLongitude(longitude).setCity(city)
                    .setCountry(country);
        }
    }
}