Java tutorial
/* * Copyright 2014 WNCOutdoors.info * portions Copyright 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. * * InformationmapFragment.java * Fragment which controls the waterfall's map tab in the Information activity. * Allows offline maps to be displayed. */ package info.wncwaterfalls.app; import android.app.Activity; import android.database.Cursor; import android.os.AsyncTask; import android.os.Bundle; import android.support.v4.app.Fragment; import android.support.v4.app.LoaderManager; import android.support.v4.content.Loader; 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.Toast; import com.cocoahero.android.gmaps.addons.mapbox.MapBoxOfflineTileProvider; import com.commonsware.cwac.loaderex.acl.SQLiteCursorLoader; import com.google.android.gms.maps.CameraUpdateFactory; import com.google.android.gms.maps.GoogleMap; import com.google.android.gms.maps.MapView; import com.google.android.gms.maps.MapsInitializer; import com.google.android.gms.maps.model.BitmapDescriptorFactory; import com.google.android.gms.maps.model.CameraPosition; import com.google.android.gms.maps.model.LatLng; import com.google.android.gms.maps.model.Marker; import com.google.android.gms.maps.model.MarkerOptions; import com.google.android.gms.maps.model.TileOverlay; import com.google.android.gms.maps.model.TileOverlayOptions; import info.wncwaterfalls.app.R; import info.wncwaterfalls.app.InformationListFragment.OnWaterfallQueryListener; import java.io.File; public class InformationMapFragment extends Fragment implements LoaderManager.LoaderCallbacks<Cursor> { private static final String TAG = "InformationMapFragment"; private static final int WATERFALL_QUERY_LOADER = 0; private MapView mMapView; private static AttrDatabase mAttrDb = null; private MBTilesDatabase mTilesDB = null; private SQLiteCursorLoader cursorLoader = null; private MapBoxOfflineTileProvider mMapBoxTileProvider; private TileOverlay mMBTilesTileOverlay; private Menu mOptionsMenu; private boolean mOptionsMenuCreated; private boolean mOfflineMapCreated; private boolean mNotifiedTooFarIn = false; private boolean mNotifiedTooFarOut = false; private double mLat; private double mLon; private String mName; private String mMapName; private OnWaterfallQueryListener sQueryListener; // Listener for loader callbacks @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); setHasOptionsMenu(true); } @Override public void onAttach(Activity activity) { super.onAttach(activity); // Make sure the containing activity implements the search listener interface try { sQueryListener = (OnWaterfallQueryListener) activity; } catch (ClassCastException e) { throw new ClassCastException(activity.toString() + " must implement the correct query listeners."); } } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mAttrDb = new AttrDatabase(getActivity()); // TODO: Memory leak? use app context? // Get our loader manager, and initialize queries. getLoaderManager().initLoader(WATERFALL_QUERY_LOADER, null, this); // Waterfall } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.fragment_information_map, container, false); mMapView = (MapView) view.findViewById(R.id.information_map_view); mMapView.onCreate(savedInstanceState); MapsInitializer.initialize(getActivity()); // TODO: Check returned error code? return view; } @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { super.onCreateOptionsMenu(menu, inflater); inflater.inflate(R.menu.information_map_actions, menu); } @Override public void onPrepareOptionsMenu(Menu menu) { mOptionsMenuCreated = true; mOptionsMenu = menu; enableOfflineMapToggle(); } @Override public void onStart() { super.onStart(); if (mMapView == null) { mMapView = (MapView) getActivity().findViewById(R.id.information_map_view); setupMap(); } // MapView doesn't have onStart, so no need to route there. } @Override public void onResume() { super.onResume(); if (null != mMapView) { mMapView.onResume(); } } private boolean setMapTypeIfUnchecked(MenuItem item, int newType) { GoogleMap googleMap = mMapView.getMap(); if (!item.isChecked()) { googleMap.setMapType(newType); item.setChecked(true); } return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case R.id.menu_item_map_type_street: return setMapTypeIfUnchecked(item, GoogleMap.MAP_TYPE_NORMAL); case R.id.menu_item_map_type_terrain: return setMapTypeIfUnchecked(item, GoogleMap.MAP_TYPE_TERRAIN); case R.id.menu_item_map_type_none: return setMapTypeIfUnchecked(item, GoogleMap.MAP_TYPE_NONE); case R.id.menu_item_map_show_overlay: if (mMBTilesTileOverlay != null) { mMBTilesTileOverlay.setVisible(!mMBTilesTileOverlay.isVisible()); item.setChecked(!item.isChecked()); } return true; case R.id.menu_item_map_tracking: GoogleMap map = mMapView.getMap(); map.setMyLocationEnabled(!map.isMyLocationEnabled()); item.setChecked(!item.isChecked()); return true; default: return super.onOptionsItemSelected(item); } } // Route fragment lifecycle events to MapView @Override public void onPause() { super.onPause(); } @Override public void onStop() { mTilesDB = null; if (null != mMBTilesTileOverlay) { mMBTilesTileOverlay.clearTileCache(); mMBTilesTileOverlay = null; } if (null != mMapBoxTileProvider) { mMapBoxTileProvider.close(); mMapBoxTileProvider = null; } GoogleMap map = mMapView.getMap(); if (map != null) { map.clear(); } if (null != mMapView) { mMapView.onPause(); mMapView = null; } super.onStop(); } @Override public void onDestroy() { super.onDestroy(); if (null != mMapView) { mMapView.onDestroy(); } } @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); if (null != mMapView) { mMapView.onSaveInstanceState(outState); } } @Override public void onLowMemory() { super.onLowMemory(); if (null != mMapView) { mMapView.onLowMemory(); } } private void createOfflineTileProvider() { File tilesDBFile = mTilesDB.getDBFile(); MapBoxOfflineTileProvider mMapBoxTileProvider = new MapBoxOfflineTileProvider(tilesDBFile); // Create new TileOverlayOptions instance. TileOverlayOptions overlayOptions = new TileOverlayOptions(); // Set the tile provider on the TileOverlayOptions. overlayOptions.tileProvider(mMapBoxTileProvider); GoogleMap map = mMapView.getMap(); mMBTilesTileOverlay = map.addTileOverlay(overlayOptions); mOfflineMapCreated = true; enableOfflineMapToggle(); // Notify the user of zoom restrictions. Hard to actually enforce them, // however, since only both zoom controls can be disabled at once. map.setOnCameraChangeListener(new GoogleMap.OnCameraChangeListener() { @Override public void onCameraChange(CameraPosition position) { MenuItem item = mOptionsMenu.findItem(R.id.menu_item_map_show_overlay); if (item != null && item.isChecked()) { CharSequence whichWay = ""; if (position.zoom < 14.0 && !mNotifiedTooFarIn) { whichWay = "in"; mNotifiedTooFarIn = true; } else if (position.zoom > 16.0 && !mNotifiedTooFarOut) { whichWay = "out"; mNotifiedTooFarOut = true; } if (whichWay != "") { CharSequence error = "Zoom " + whichWay + " to see offline map."; int duration = Toast.LENGTH_SHORT; Toast toast = Toast.makeText(InformationMapFragment.this.getActivity(), error, duration); toast.show(); } } }; }); } private void enableOfflineMapToggle() { if (mOptionsMenuCreated && mOfflineMapCreated) { MenuItem item = mOptionsMenu.findItem(R.id.menu_item_map_show_overlay); if (item != null) { item.setEnabled(true); } } } private void setupMap() { // Update the Activity's title getActivity().setTitle(mName); // Get reference to the map GoogleMap map = mMapView.getMap(); map.getUiSettings().setMyLocationButtonEnabled(true); // Initialize to street map; user can switch. map.setMapType(GoogleMap.MAP_TYPE_NORMAL); if (null != mMapName && !mMapName.trim().isEmpty()) { // Initialize tiles mAttrDb and get file name // TODO: This may need to be off the main thread, or it may need to // be async within MBTilesDatabase mTilesDB = new MBTilesDatabase(getActivity(), mMapName); if (mTilesDB.dbFileExists()) { createOfflineTileProvider(); } else { // Unzip in async task new ExtractMBTilesTask().execute(mTilesDB); } } // Center and zoom the map. LatLng waterfallLocation = new LatLng(mLat, mLon); map.addMarker(new MarkerOptions().position(waterfallLocation) .icon(BitmapDescriptorFactory.defaultMarker(BitmapDescriptorFactory.HUE_AZURE)).title(mName)); map.moveCamera(CameraUpdateFactory.newLatLngZoom(waterfallLocation, 15)); } // LoaderManager.LoaderCallbacks<Cursor> methods @Override public Loader<Cursor> onCreateLoader(int loaderId, Bundle args) { // Get the query from our parent activity and pass it to the loader, which will execute it switch (loaderId) { case InformationMapFragment.WATERFALL_QUERY_LOADER: Bundle qBundle = sQueryListener.onWaterfallQuery(); cursorLoader = new SQLiteCursorLoader(getActivity(), mAttrDb, qBundle.getString("query"), qBundle.getStringArray("args")); break; } return cursorLoader; } @Override public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) { int loaderId = loader.getId(); if (cursor.moveToFirst()) { switch (loaderId) { case InformationMapFragment.WATERFALL_QUERY_LOADER: // Get some data from the db mLat = cursor.getDouble(AttrDatabase.COLUMNS.indexOf("geo_lat")); mLon = cursor.getDouble(AttrDatabase.COLUMNS.indexOf("geo_lon")); mName = cursor.getString(AttrDatabase.COLUMNS.indexOf("name")); mMapName = cursor.getString(AttrDatabase.COLUMNS.indexOf("map_name")); // Now that we have what we need... setupMap(); break; } } } @Override public void onLoaderReset(Loader<Cursor> loader) { //Log.d(TAG, "Inside InformationMapFragment onLoaderReset"); //TODO: Set to null to prevent memory leaks // mAdapter.changeCursor(cursor); } // AsyncTask used to unzip large MBTiles databases. private class ExtractMBTilesTask extends AsyncTask<MBTilesDatabase, Void, Boolean> { protected Boolean doInBackground(MBTilesDatabase... dbs) { MBTilesDatabase tilesDB = dbs[0]; boolean success = tilesDB.extractDBFile(); return success; } @Override protected void onPostExecute(Boolean result) { if (result) { createOfflineTileProvider(); } else { // Also notify - this impacts user experience. CharSequence error = "Offline map not available :("; int duration = Toast.LENGTH_SHORT; Toast toast = Toast.makeText(InformationMapFragment.this.getActivity(), error, duration); toast.show(); } } } }