Java tutorial
/* * MIT License * * Copyright (c) 2016 Pablo L * * Permission is hereby granted, free of charge, to any person obtaining a copy * of this software and associated documentation files (the "Software"), to deal * in the Software without restriction, including without limitation the rights * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell * copies of the Software, and to permit persons to whom the Software is * furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included in all * copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE * SOFTWARE. */ package org.deafsapps.sordomartinezpabloluismarspics.fragments; import android.content.ContentValues; import android.content.Context; import android.database.Cursor; import android.os.Bundle; import android.support.annotation.Nullable; import android.support.v4.app.ListFragment; 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.View; import android.view.ViewGroup; import android.widget.ListView; import org.deafsapps.sordomartinezpabloluismarspics.BuildConfig; import org.deafsapps.sordomartinezpabloluismarspics.R; import org.deafsapps.sordomartinezpabloluismarspics.activities.MainActivity; import org.deafsapps.sordomartinezpabloluismarspics.data.MarsPicsContract; import org.deafsapps.sordomartinezpabloluismarspics.util.MarsPicsApiParser; import org.deafsapps.sordomartinezpabloluismarspics.util.MyListAdapter; import org.deafsapps.sordomartinezpabloluismarspics.util.Utility; /** * Created by ${USER} on ${DATE}. * * A simple {@link ListFragment} subclass. This object already includes some convenient * interfaces and inherits such as the overridden method * {@link ListFragment#onListItemClick(ListView, View, int, long)}. * Activities that contain this fragment must implement the {@link MainFragment.Callback} interface * to handle interaction events with the hosting Activity. */ public class MainFragment extends ListFragment implements LoaderManager.LoaderCallbacks<Cursor> { private static final String TAG_MAIN_FRAGMENT = MainFragment.class.getSimpleName(); private static final int CONTENT_PROVIDER_LOADER = 100; private static final int HTTP_API_LOADER = 200; private Callback mListener; private MyListAdapter mAdapter; private boolean isLandscape; private long mNumPage = 0; private final long mNumListItems = 20; public MainFragment() { } public static MainFragment newInstance(@Nullable Bundle bundle) { MainFragment mainFragment = new MainFragment(); if (bundle != null) { mainFragment.setArguments(bundle); } return mainFragment; } public void setLandscape(boolean landscape) { this.isLandscape = landscape; } @Override public void onCreate(@Nullable Bundle savedInstanceState) { Bundle args = getArguments(); setLandscape(args.getBoolean(MainActivity.KEY_LANDSCAPE_ORIENTATION)); super.onCreate(savedInstanceState); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // Inflate the layout for this fragment final View rootView = inflater.inflate(R.layout.fragment_main, container, false); mAdapter = new MyListAdapter(getActivity(), null); setListAdapter(mAdapter); return rootView; } @Override public void onActivityCreated(@Nullable Bundle savedInstanceState) { // Initializes the CursorLoader getLoaderManager().initLoader(CONTENT_PROVIDER_LOADER, null, this); getLoaderManager().initLoader(HTTP_API_LOADER, null, this); super.onActivityCreated(savedInstanceState); } @Override public void onAttach(Context context) { super.onAttach(context); if (context instanceof Callback) { mListener = (Callback) context; } else { throw new RuntimeException(context.toString() + " must implement OnFragmentInteractionListener"); } } @Override public void onDetach() { super.onDetach(); mListener = null; } @Override public void onListItemClick(ListView listView, View view, int position, long id) { super.onListItemClick(listView, view, position, id); listView.smoothScrollToPosition(position); view.setSelected(true); mListener.onMainFragmentInteraction(mNumPage * mNumListItems + position); } @Override public @Nullable Loader onCreateLoader(int loaderId, Bundle args) { switch (loaderId) { case CONTENT_PROVIDER_LOADER: return new CursorLoader(getContext(), MarsPicsContract.PicItemEntry.CONTENT_URI, null, MarsPicsContract.PicItemEntry._ID + ">=? AND " + MarsPicsContract.PicItemEntry._ID + "<?", new String[] { String.valueOf(mNumPage * mNumListItems), String.valueOf((1 + mNumPage) * mNumListItems) }, null); case HTTP_API_LOADER: return new MarsPicsApiParser(getContext()); default: // An invalid Id was passed in return null; } } @Override public void onLoadFinished(Loader loader, Cursor cursor) { // Moves the query results into the adapter, causing the ListView fronting this // adapter to re-display if (BuildConfig.DEBUG) { Log.d(TAG_MAIN_FRAGMENT, "Loader Id: " + loader.getId()); } switch (loader.getId()) { case CONTENT_PROVIDER_LOADER: if (BuildConfig.DEBUG) { Log.d(TAG_MAIN_FRAGMENT, "Provider loaded"); } mAdapter.swapCursor(cursor); break; case HTTP_API_LOADER: if (BuildConfig.DEBUG) { Log.d(TAG_MAIN_FRAGMENT, "HTTP query loaded"); } if (cursor != null) { ContentValues[] contentValues = Utility.buildContentValuesFromCursor(cursor); getContext().getContentResolver().bulkInsert(MarsPicsContract.PicItemEntry.CONTENT_URI, contentValues); mAdapter.notifyDataSetChanged(); } break; default: // An invalid Id was passed in } } @Override public void onLoaderReset(Loader loader) { /* * Clears out the adapter's reference to the Cursor to prevent memory leaks */ mAdapter.swapCursor(null); } /** * This interface must be implemented by activities that contain this * fragment to allow an interaction in this fragment to be communicated * to the activity and potentially other fragments contained in that * activity. */ public interface Callback { void onMainFragmentInteraction(long actualPosition); } }