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 in.dasilvacont.hearthstonecards.app; import android.content.Intent; import android.database.Cursor; import android.database.sqlite.SQLiteDatabase; import android.net.Uri; import android.os.Bundle; 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 in.dasilvacont.hearthstonecards.R; import in.dasilvacont.hearthstonecards.app.data.CardContract; import in.dasilvacont.hearthstonecards.app.data.CardDbHelper; /** * Encapsulates fetching the forecast and displaying it as a {@link ListView} layout. */ public class CardFragment extends Fragment implements LoaderManager.LoaderCallbacks<Cursor> { public static final String LOG_TAG = CardFragment.class.getSimpleName(); private static final int CARD_LOADER = 0; private CardAdapter mCardAdapter; private ListView mListView; private int mPosition = ListView.INVALID_POSITION; private static final String SELECTED_KEY = "selected_position"; private static final String[] CARD_COLUMNS = { CardContract.CardEntry._ID, CardContract.CardEntry.COLUMN_CARD_ID, CardContract.CardEntry.COLUMN_CARD_NAME, CardContract.CardEntry.COLUMN_TYPE, CardContract.CardEntry.COLUMN_RARITY, CardContract.CardEntry.COLUMN_COST, CardContract.CardEntry.COLUMN_ATTACK, CardContract.CardEntry.COLUMN_HEALTH, CardContract.CardEntry.COLUMN_TEXT, CardContract.CardEntry.COLUMN_PLAYER_CLASS }; // These indices are tied to CARD_COLUMNS. If CARD_COLUMNS changes, these // must change. static final int COL_ID = 0; static final int COL_CARD_ID = 1; static final int COL_CARD_NAME = 2; static final int COL_TYPE = 3; static final int COL_RARITY = 4; static final int COL_COST = 5; static final int COL_ATTACK = 6; static final int COL_HEALTH = 7; static final int COL_TEXT = 8; static final int COL_PLAYER_CLASS = 9; /** * 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(Uri cardUri); } public CardFragment() { } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Add this line in order for this fragment to handle menu events. setHasOptionsMenu(true); } @Override public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) { inflater.inflate(R.menu.cardfragment, menu); } @Override public boolean onOptionsItemSelected(MenuItem item) { int id = item.getItemId(); if (id == R.id.action_map) { // top kek return true; } return super.onOptionsItemSelected(item); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { // The CardAdapter will take data from a source and // use it to populate the ListView it's attached to. String sortOrder = CardContract.CardEntry.COLUMN_CARD_NAME + " ASC"; Cursor cur = getActivity().getContentResolver().query(CardContract.CardEntry.CONTENT_URI, null, null, null, sortOrder); if (cur.getCount() == 0) fetchCards(); mCardAdapter = new CardAdapter(getActivity(), cur, 0); Log.d(LOG_TAG, "Inflating CardFragment..."); View rootView = inflater.inflate(R.layout.fragment_main, container, false); // Get a reference to the ListView, and attach this adapter to it. mListView = (ListView) rootView.findViewById(R.id.listview_card); mListView.setAdapter(mCardAdapter); // We'll call our MainActivity mListView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> adapterView, View view, int position, long l) { // CursorAdapter returns a cursor at the correct position for getItem(), or null // if it cannot seek to that position. Cursor cursor = (Cursor) adapterView.getItemAtPosition(position); if (cursor != null) { /* ((Callback) getActivity()) .onItemSelected(CardContract.CardEntry.buildCardUri( cursor.getString(COL_CARD_ID) )); */ Intent intent = new Intent(getActivity(), DetailActivity.class).putExtra(Intent.EXTRA_TEXT, CardContract.CardEntry.buildCardUriNumerical(cursor.getLong(COL_ID))); startActivity(intent); } mPosition = position; } }); // If there's instance state, mine it for useful information. // The end-goal here is that the user never knows that turning their device sideways // does crazy lifecycle related things. It should feel like some stuff stretched out, // or magically appeared to take advantage of room, but data or place in the app was never // actually *lost*. if (savedInstanceState != null && savedInstanceState.containsKey(SELECTED_KEY)) { // The listview probably hasn't even been populated yet. Actually perform the // swapout in onLoadFinished. mPosition = savedInstanceState.getInt(SELECTED_KEY); mListView.smoothScrollToPosition(mPosition); mListView.setSelection(mPosition); } return rootView; } @Override public void onActivityCreated(Bundle savedInstanceState) { getLoaderManager().initLoader(CARD_LOADER, null, this); super.onActivityCreated(savedInstanceState); } private void fetchCards() { FetchCardTask weatherTask = new FetchCardTask(getActivity()); weatherTask.execute(); } @Override public void onStart() { super.onStart(); } @Override public Loader<Cursor> onCreateLoader(int i, Bundle bundle) { String sortOrder = CardContract.CardEntry.COLUMN_CARD_NAME + " ASC"; return new CursorLoader(getActivity(), CardContract.CardEntry.CONTENT_URI, null, null, null, sortOrder); } @Override public void onLoadFinished(Loader<Cursor> cursorLoader, Cursor cursor) { Log.d(LOG_TAG, "onLoadFinished"); mCardAdapter.swapCursor(cursor); } @Override public void onLoaderReset(Loader<Cursor> cursorLoader) { mCardAdapter.swapCursor(null); } @Override public void onSaveInstanceState(Bundle outState) { // When tablets rotate, the currently selected list item needs to be saved. // When no item is selected, mPosition will be set to Listview.INVALID_POSITION, // so check for that before storing. if (mPosition != ListView.INVALID_POSITION) { outState.putInt(SELECTED_KEY, mPosition); } super.onSaveInstanceState(outState); } }