Java tutorial
package com.guidewithme; import static com.guidewithme.util.Utils.hideIf; import static com.guidewithme.util.Utils.hideView; import static com.guidewithme.util.Utils.showView; import java.util.ArrayList; import android.app.Activity; import android.app.AlertDialog; import android.content.Context; import android.location.Location; import android.location.LocationListener; import android.location.LocationManager; import android.os.Bundle; import android.support.v4.app.ListFragment; import android.support.v4.app.LoaderManager.LoaderCallbacks; import android.support.v4.content.Loader; import android.text.Editable; import android.text.TextUtils; import android.text.TextWatcher; import android.view.LayoutInflater; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.webkit.WebView; import android.widget.ListView; import android.widget.TextView; import com.guidewithme.article.ArticleInfo; import com.guidewithme.async.QueryResultLoader; import com.guidewithme.cpp.Storage; import com.guidewithme.util.Utils; import com.guidewithme.widget.StorageArticleInfoAdapter; import com.mapswithme.maps.api.MWMPoint; import com.mapswithme.maps.api.MapsWithMeApi; /** * A list fragment representing a list of ArticleInfos. This fragment also * supports tablet devices by allowing list items to be given an 'activated' * state upon selection. This helps indicate which item is currently being * viewed in a {@link ArticleInfoDetailFragment}. * <p> * Activities containing this fragment MUST implement the {@link Callbacks} * interface. */ public class ArticleInfoListFragment extends ListFragment implements LoaderCallbacks<Storage>, TextWatcher, OnClickListener, LocationListener { public interface OnListIconClickedListener { public void onIconClicked(); } // First load public interface OnFirstLoadListener { void onLoad(ArticleInfo info); } private OnFirstLoadListener mOnFirstLoad; private static boolean mFirstLoad = true; public void setOnFirstLoadListener(OnFirstLoadListener listener) { mOnFirstLoad = listener; } // !First load private View mRootView; private TextView mSearchText; private View mCross; private View mListContainer; private View mProgressContainer; private View mHeader; private View mAbout; private View mShowMapForAll; // Location private LocationManager mLocationManager; private static long sLastLocationRequestTime = 0; private final static long LOCATION_UPDATE_INTERVAL = 30 * 60 * 1000; // !Location // private Storage mStorage; private static final String STATE_ACTIVATED_POSITION = "activated_position"; private Callbacks mCallbacks = sDummyCallbacks; private int mActivatedPosition = ListView.INVALID_POSITION; public interface Callbacks { public void onItemSelected(ArticleInfo info); } private static Callbacks sDummyCallbacks = new Callbacks() { @Override public void onItemSelected(ArticleInfo info) { } }; /** * Mandatory empty constructor for the fragment manager to instantiate the * fragment (e.g. upon screen orientation changes). */ public ArticleInfoListFragment() { } @Override public void onViewCreated(View view, Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); mLocationManager = (LocationManager) getActivity().getSystemService(Context.LOCATION_SERVICE); // Restore the previously serialized activated item position. if (savedInstanceState != null && savedInstanceState.containsKey(STATE_ACTIVATED_POSITION)) setActivatedPosition(savedInstanceState.getInt(STATE_ACTIVATED_POSITION)); } @Override public void onResume() { super.onResume(); Utils.hideKeyboard(getActivity()); checkLocation(); search(mSearchText.getText().toString()); } @Override public void onPause() { super.onPause(); mLocationManager.removeUpdates(this); } private void checkLocation() { if (System.currentTimeMillis() - sLastLocationRequestTime > LOCATION_UPDATE_INTERVAL) { // reqestSingleUpdate() listen for single update // and when get it will unsubscribe from LocationManager if (mLocationManager.isProviderEnabled(LocationManager.GPS_PROVIDER)) mLocationManager.requestSingleUpdate(LocationManager.GPS_PROVIDER, this, null); if (mLocationManager.isProviderEnabled(LocationManager.NETWORK_PROVIDER)) mLocationManager.requestSingleUpdate(LocationManager.NETWORK_PROVIDER, this, null); } } @Override public void onAttach(Activity activity) { super.onAttach(activity); // Activities containing this fragment must implement its callbacks. if (!(activity instanceof Callbacks)) throw new IllegalStateException("Activity must implement fragment's callbacks."); mCallbacks = (Callbacks) activity; } @Override public void onDetach() { super.onDetach(); // Reset the active callbacks interface to the dummy implementation. mCallbacks = sDummyCallbacks; if (getLoaderManager().hasRunningLoaders()) getLoaderManager().destroyLoader(SEARCH_LOADER); } @Override public void onListItemClick(ListView listView, View view, int position, long id) { super.onListItemClick(listView, view, position, id); mCallbacks.onItemSelected((ArticleInfo) getListAdapter().getItem(position)); } @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); if (mActivatedPosition != ListView.INVALID_POSITION) outState.putInt(STATE_ACTIVATED_POSITION, mActivatedPosition); } /** * Turns on activate-on-click mode. When this mode is on, list items will be * given the 'activated' state when touched. */ public void setActivateOnItemClick(boolean activateOnItemClick) { // When setting CHOICE_MODE_SINGLE, ListView will automatically // give items the 'activated' state when touched. getListView().setChoiceMode(activateOnItemClick ? ListView.CHOICE_MODE_SINGLE : ListView.CHOICE_MODE_NONE); } private void setActivatedPosition(int position) { if (position == ListView.INVALID_POSITION) { getListView().setItemChecked(mActivatedPosition, false); } else { getListView().setItemChecked(position, true); } mActivatedPosition = position; } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { mRootView = inflater.inflate(R.layout.fragment_articleinfo_list, null, false); mSearchText = (TextView) mRootView.findViewById(R.id.searchText); mCross = mRootView.findViewById(R.id.clearSearch); mListContainer = mRootView.findViewById(R.id.listContainer); mProgressContainer = mRootView.findViewById(R.id.progressContainer); mHeader = mRootView.findViewById(R.id.header); mAbout = mRootView.findViewById(R.id.about); mShowMapForAll = mRootView.findViewById(R.id.showMapForAll); // setup listeners mSearchText.addTextChangedListener(this); mCross.setOnClickListener(this); mAbout.setOnClickListener(this); mShowMapForAll.setOnClickListener(this); return mRootView; } public void setHeaderVisible(boolean visible) { hideIf(!visible, mHeader); } private static int SEARCH_LOADER = 0x1; private final String KEY_QUERY = "key_query"; @Override public Loader<Storage> onCreateLoader(int id, Bundle args) { if (id == SEARCH_LOADER) { final String query = args.getString(KEY_QUERY); showView(mProgressContainer); hideView(mListContainer); final Location loc = getLocation(); if (loc != null) return new QueryResultLoader(getActivity(), getStorage(), query, loc.getLatitude(), loc.getLongitude()); else return new QueryResultLoader(getActivity(), getStorage(), query); } return null; } @Override public void onLoadFinished(Loader<Storage> loader, Storage result) { setListAdapter(new StorageArticleInfoAdapter(result, getActivity())); showView(mListContainer); hideView(mProgressContainer); if (mFirstLoad && mOnFirstLoad != null && result.getResultSize() > 0) { mFirstLoad = false; mOnFirstLoad.onLoad(result.getArticleInfoByIndex(0)); } } @Override public void onLoaderReset(Loader<Storage> loader) { hideView(mProgressContainer); showView(mListContainer); } private void search(CharSequence s) { final Bundle args = new Bundle(1); args.putString(KEY_QUERY, s.toString()); getLoaderManager().restartLoader(SEARCH_LOADER, args, this); hideIf(TextUtils.isEmpty(s), mCross); } @Override public void onTextChanged(CharSequence s, int start, int before, int count) { } @Override public void afterTextChanged(Editable s) { search(s.toString()); } @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) { } @Override public void onClick(View v) { if (v.getId() == mCross.getId()) mSearchText.setText(""); // clean up text field else if (v.getId() == mAbout.getId()) showLicense(); else if (v.getId() == mShowMapForAll.getId()) openInMwm(); } private void showLicense() { final WebView wb = new WebView(getActivity()); wb.loadUrl("file:///android_asset/license.html"); final AlertDialog ad = new AlertDialog.Builder(getActivity()).setTitle(R.string.about).setCancelable(true) .create(); ad.setCanceledOnTouchOutside(true); ad.setView(wb); ad.show(); } private void openInMwm() { final int count = getStorage().getResultSize(); if (count < 1) return; final ArrayList<MWMPoint> points = new ArrayList<MWMPoint>(); for (int i = 0; i < count; ++i) { final ArticleInfo info = getStorage().getArticleInfoByIndex(i); if (info.isValidLatLon()) points.add(Utils.articleInfo2MwmPoint(info)); } if (points.size() < 1) return; MapsWithMeApi.showPointsOnMap(getActivity(), getString(R.string.app_name), ArticleInfoListActivity.createPendingIntent(getActivity()), points.toArray(new MWMPoint[points.size()])); } private Location getLocation() { Location loc = null; if ((loc = mLocationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER)) == null) loc = mLocationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER); return loc; } @Override public void onLocationChanged(Location location) { sLastLocationRequestTime = System.currentTimeMillis(); } @Override public void onProviderDisabled(String provider) { } @Override public void onProviderEnabled(String provider) { } @Override public void onStatusChanged(String provider, int status, Bundle extras) { } public Storage getStorage() { return Storage.get(getActivity()); } }