Java tutorial
// * Copyright (C) 2014 The Android Open Source Project // * // * 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 tom.udacity.sample.sunrise; import android.content.Intent; import android.database.Cursor; import android.net.Uri; import android.os.Bundle; import android.support.annotation.Nullable; import android.support.v4.app.Fragment; import android.support.v4.app.LoaderManager; import android.support.v4.content.CursorLoader; import android.support.v4.content.Loader; import android.util.Log; import android.view.LayoutInflater; import android.view.Menu; import android.view.MenuInflater; import android.view.MenuItem; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.ListView; import java.util.Date; import tom.udacity.sample.sunrise.data.WeatherContract; import tom.udacity.sample.sunrise.sync.SunshineSyncAdapter; import tom.udacity.sample.sunrise.util.Utility; import static tom.udacity.sample.sunrise.data.WeatherContract.LocationEntry; import static tom.udacity.sample.sunrise.data.WeatherContract.WeatherEntry; public class ForecastFragment extends Fragment implements LoaderManager.LoaderCallbacks<Cursor> { private static final int FORECAST_LOADER = 0; public static final String LOG_TAG = ForecastFragment.class.getSimpleName(); // For the forecast view we're showing only a small subset of the stored data. // Specify the columns we need. private static final String[] FORECAST_COLUMNS = { // In this case the id needs to be fully qualified with a table name, since // the content provider joins the location & weather tables in the background // (both have an _id column) // On the one hand, that's annoying. On the other, you can search the weather table // using the location set by the user, which is only in the Location table. // So the convenience is worth it. WeatherEntry.TABLE_NAME + "." + WeatherEntry._ID, WeatherEntry.COLUMN_DATETEXT, WeatherEntry.COLUMN_SHORT_DESC, WeatherEntry.COLUMN_MAX_TEMP, WeatherEntry.COLUMN_MIN_TEMP, LocationEntry.COLUMN_LOCATION_SETTING, WeatherEntry.COLUMN_WEATHER_ID, LocationEntry.COLUMN_COORD_LAT, LocationEntry.COLUMN_COORD_LONG }; // These indices are tied to FORECAST_COLUMNS. If FORECAST_COLUMNS changes, these // must change. public static final int COL_WEATHER_ID = 0; public static final int COL_WEATHER_DATE = 1; public static final int COL_WEATHER_DESC = 2; public static final int COL_WEATHER_MAX_TEMP = 3; public static final int COL_WEATHER_MIN_TEMP = 4; public static final int COL_LOCATION_SETTING = 5; public static final int COL_WEATHER_CONDITION_ID = 6; public static final int COL_COORD_LAT = 7; public static final int COL_COORD_LONG = 8; private static final String POSITION_ARG = "POSITION"; private ForecastAdapter mForecastAdapter; private ListView mListView; private String mLocation; private int mPosition = ListView.INVALID_POSITION; private boolean mUseTodayLayout; /** * A callback interface that all activities containing this fragment must * implement. This mechanism allows activities to be notified of item * selections. */ public interface Callback { /** * DetailFragmentCallback for when an item has been selected. */ public void onItemSelected(String date); } public ForecastFragment() { setHasOptionsMenu(true); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View rootView = inflater.inflate(R.layout.fragment_main, container, false); // The SimpleCursorAdapter will take data from the database through the // Loader and use it to populate the ListView it's attached to. mForecastAdapter = new ForecastAdapter(getActivity(), null, 0); mListView = (ListView) rootView.findViewById(R.id.listview_forecast); mListView.setAdapter(mForecastAdapter); mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { mPosition = position; Cursor cursor = mForecastAdapter.getCursor(); if (cursor != null && cursor.moveToPosition(position)) { ((Callback) getActivity()).onItemSelected(cursor.getString(COL_WEATHER_DATE)); } } }); if (savedInstanceState != null && savedInstanceState.containsKey(POSITION_ARG)) { mPosition = savedInstanceState.getInt(POSITION_ARG); } mForecastAdapter.setUseTodayLayout(mUseTodayLayout); return rootView; } @Override public void onActivityCreated(@Nullable Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); getLoaderManager().initLoader(FORECAST_LOADER, null, this); } @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { super.onCreateOptionsMenu(menu, inflater); inflater.inflate(R.menu.forecastmenu, menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { boolean result = super.onOptionsItemSelected(item); int itemId = item.getItemId(); if (itemId == R.id.action_refresh) { updateWeather(); return true; } if (itemId == R.id.action_map) { openPreferredLocationInMap(); return true; } return result; } private void openPreferredLocationInMap() { // Using the URI scheme for showing a location found on a map. This super-handy // intent can is detailed in the "Common Intents" page of Android's developer site: // http://developer.android.com/guide/components/intents-common.html#Maps if (null != mForecastAdapter) { Cursor c = mForecastAdapter.getCursor(); if (null != c) { c.moveToPosition(0); String posLat = c.getString(COL_COORD_LAT); String posLong = c.getString(COL_COORD_LONG); Uri geoLocation = Uri.parse("geo:" + posLat + "," + posLong); Intent intent = new Intent(Intent.ACTION_VIEW); intent.setData(geoLocation); if (intent.resolveActivity(getActivity().getPackageManager()) != null) { startActivity(intent); } else { Log.d(LOG_TAG, "Couldn't call " + geoLocation.toString() + ", no receiving apps installed!"); } } } } private void updateWeather() { SunshineSyncAdapter.syncImmediately(getActivity()); } @Override public void onResume() { super.onResume(); if (mLocation != null && !mLocation.equals(Utility.getPreferredLocation(getActivity()))) { getLoaderManager().restartLoader(FORECAST_LOADER, null, this); } } @Override public Loader<Cursor> onCreateLoader(int id, Bundle args) { // This is called when a new Loader needs to be created. This // fragment only uses one loader, so we don't care about checking the id. // To only show current and future dates, get the String representation for today, // and filter the query to return weather only for dates after or including today. // Only return data after today. String startDate = WeatherContract.getDbDateString(new Date()); // Sort order: Ascending, by date. String sortOrder = WeatherEntry.COLUMN_DATETEXT + " ASC"; mLocation = Utility.getPreferredLocation(getActivity()); Uri weatherForLocationUri = WeatherEntry.buildWeatherLocationWithStartDate(mLocation, startDate); // Now create and return a CursorLoader that will take care of // creating a Cursor for the data being displayed. return new CursorLoader(getActivity(), weatherForLocationUri, FORECAST_COLUMNS, null, null, sortOrder); } @Override public void onLoadFinished(Loader<Cursor> loader, Cursor data) { mForecastAdapter.swapCursor(data); if (mPosition != ListView.INVALID_POSITION) { mListView.setSelection(mPosition); } } @Override public void onLoaderReset(Loader<Cursor> loader) { mForecastAdapter.swapCursor(null); } @Override public void onSaveInstanceState(Bundle outState) { outState.putInt(POSITION_ARG, mPosition); super.onSaveInstanceState(outState); } public void setUseTodayLayout(boolean useTodayLayout) { mUseTodayLayout = useTodayLayout; if (mForecastAdapter != null) { mForecastAdapter.setUseTodayLayout(mUseTodayLayout); } } }