Java tutorial
package edu.mit.mobile.android.livingpostcards; /* * Copyright (C) 2012-2013 MIT Mobile Experience Lab * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation version 2 * of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ import java.io.IOException; import android.content.ContentUris; import android.content.Context; import android.content.Intent; import android.database.Cursor; import android.graphics.drawable.Drawable; import android.graphics.drawable.InsetDrawable; import android.net.Uri; import android.os.Bundle; import android.support.v4.app.ListFragment; import android.support.v4.app.LoaderManager.LoaderCallbacks; import android.support.v4.content.CursorLoader; import android.support.v4.content.Loader; import android.util.Log; import android.view.ContextMenu; import android.view.ContextMenu.ContextMenuInfo; import android.view.LayoutInflater; import android.view.MenuItem; import android.view.View; import android.view.View.OnClickListener; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.AdapterView.OnItemClickListener; import android.widget.ListView; import android.widget.TextView; import android.widget.Toast; import com.stackoverflow.ArrayUtils; import edu.mit.mobile.android.flipr.R; import edu.mit.mobile.android.imagecache.ImageCache; import edu.mit.mobile.android.imagecache.ImageLoaderAdapter; import edu.mit.mobile.android.imagecache.SimpleThumbnailCursorAdapter; import edu.mit.mobile.android.livingpostcards.auth.Authenticator; import edu.mit.mobile.android.livingpostcards.data.Card; import edu.mit.mobile.android.locast.data.PrivatelyAuthorable; import edu.mit.mobile.android.locast.sync.LocastSyncService; public class CardListFragment extends ListFragment implements LoaderCallbacks<Cursor>, OnItemClickListener, OnClickListener { private static final String[] FROM = { Card.COL_TITLE, Card.COL_AUTHOR, Card.COL_COVER_PHOTO, Card.COL_THUMBNAIL, Card.COL_DRAFT }; private static final int[] TO = { R.id.title, R.id.author, R.id.card_media_thumbnail, R.id.card_media_thumbnail }; private static final String[] PROJECTION = ArrayUtils .concat(new String[] { Card._ID, Card.COL_PRIVACY, Card.COL_AUTHOR_URI, Card.COL_WEB_URL }, FROM); private SimpleThumbnailCursorAdapter mAdapter; ImageCache mImageCache; public static final String ARG_CARD_DIR_URI = "uri"; private Uri mCards = Card.CONTENT_URI; private float mDensity; private static final String TAG = CardListFragment.class.getSimpleName(); private static final int[] IMAGE_IDS = new int[] { R.id.card_media_thumbnail }; public CardListFragment() { super(); } public static CardListFragment instantiate(Uri cardDir) { final Bundle b = new Bundle(); b.putParcelable(ARG_CARD_DIR_URI, cardDir); final CardListFragment f = new CardListFragment(); f.setArguments(b); return f; } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); final Bundle args = getArguments(); if (args != null) { final Uri newUri = args.getParcelable(ARG_CARD_DIR_URI); mCards = newUri != null ? newUri : mCards; } } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { return inflater.inflate(R.layout.card_list_fragment, container, false); } @Override public void onViewCreated(View view, Bundle savedInstanceState) { view.findViewById(R.id.new_card).setOnClickListener(this); // add a footer so that there's enough room for the content even with the red button at the // bottom final ListView lv = getListView(); lv.addFooterView(getLayoutInflater(savedInstanceState).inflate(R.layout.scroll_footer, lv, false), null, false); super.onViewCreated(view, savedInstanceState); } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); mImageCache = ImageCache.getInstance(getActivity()); mAdapter = new SimpleThumbnailCursorAdapter(getActivity(), R.layout.card_list_item, null, FROM, TO, IMAGE_IDS, 0) { @Override public void bindView(View v, Context context, Cursor c) { super.bindView(v, context, c); ((TextView) v.findViewById(R.id.title)).setText(Card.getTitle(context, c)); } }; setListAdapter(new ImageLoaderAdapter(getActivity(), mAdapter, mImageCache, IMAGE_IDS, 133, 100, ImageLoaderAdapter.UNIT_DIP)); getListView().setOnItemClickListener(this); getLoaderManager().initLoader(0, null, this); LocastSyncService.startExpeditedAutomaticSync(getActivity(), mCards.buildUpon().query(null).build()); registerForContextMenu(getListView()); mDensity = getActivity().getResources().getDisplayMetrics().density; } @Override public Loader<Cursor> onCreateLoader(int arg0, Bundle arg1) { return new CursorLoader(getActivity(), mCards, PROJECTION, null, null, null); } @Override public void onLoadFinished(Loader<Cursor> arg0, Cursor c) { mAdapter.swapCursor(c); } @Override public void onLoaderReset(Loader<Cursor> arg0) { mAdapter.swapCursor(null); } @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { final Uri item = ContentUris.withAppendedId(mCards, id); final Cursor c = mAdapter.getCursor(); c.moveToPosition(position); if (Card.isDraft(c)) { startActivity(new Intent(Intent.ACTION_EDIT, item)); } else { startActivity(new Intent(Intent.ACTION_VIEW, item)); } } @Override public void onCreateContextMenu(ContextMenu menu, View v, ContextMenuInfo menuInfo) { getActivity().getMenuInflater().inflate(R.menu.activity_card_view, menu); final Cursor c = mAdapter.getCursor(); if (c == null) { return; } final String myUserUri = Authenticator.getUserUri(getActivity()); final boolean isEditable = PrivatelyAuthorable.canEdit(myUserUri, c); menu.findItem(R.id.delete).setVisible(isEditable); menu.findItem(R.id.edit).setVisible(isEditable); menu.setHeaderTitle(Card.getTitle(getActivity(), c)); Drawable icon; try { String iconUrl = c.getString(c.getColumnIndexOrThrow(Card.COL_COVER_PHOTO)); if (iconUrl == null || iconUrl.length() == 0) { iconUrl = c.getString(c.getColumnIndexOrThrow(Card.COL_THUMBNAIL)); } icon = mImageCache.loadImage(0, Uri.parse(iconUrl), (int) (133 * mDensity), (int) (100 * mDensity)); if (icon != null) { menu.setHeaderIcon(new InsetDrawable(icon, (int) (5 * mDensity))); } } catch (final IllegalArgumentException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (final IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } private void send(Cursor c) { final String mWebUrl = c.getString(c.getColumnIndexOrThrow(Card.COL_WEB_URL)); if (mWebUrl == null) { Toast.makeText(getActivity(), R.string.err_share_intent_no_web_url_editable, Toast.LENGTH_LONG).show(); return; } startActivity(Card.createShareIntent(getActivity(), mWebUrl, Card.getTitle(getActivity(), c))); } @Override public boolean onContextItemSelected(MenuItem item) { AdapterView.AdapterContextMenuInfo info; try { info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo(); } catch (final ClassCastException e) { Log.e(TAG, "bad menuInfo", e); return false; } final Uri card = ContentUris.withAppendedId(mCards, info.id); switch (item.getItemId()) { case R.id.share: send(mAdapter.getCursor()); return true; case R.id.edit: startActivity(new Intent(Intent.ACTION_EDIT, card)); return true; case R.id.delete: startActivity(new Intent(Intent.ACTION_DELETE, card)); return true; default: return super.onContextItemSelected(item); } } private void createNewCard() { final Intent intent = new Intent(Intent.ACTION_INSERT, Card.CONTENT_URI); startActivity(intent); } @Override public void onClick(View v) { switch (v.getId()) { case R.id.new_card: createNewCard(); break; default: break; } } }