Java tutorial
/* * Copyright 2011 Google Inc. * * 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 org.ietf.ietfsched.ui; import org.ietf.ietfsched.R; import org.ietf.ietfsched.provider.ScheduleContract; import org.ietf.ietfsched.util.NotifyingAsyncQueryHandler; import android.content.Intent; import android.database.Cursor; import android.net.Uri; import android.os.Bundle; import android.support.v4.app.ListFragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.ListView; /** * A simple {@link ListFragment} that renders a list of tracks with available sessions or vendors * (depending on {@link TracksFragment#EXTRA_NEXT_TYPE}) using a {@link TracksAdapter}. */ public class TracksFragment extends ListFragment implements NotifyingAsyncQueryHandler.AsyncQueryListener { public static final String EXTRA_NEXT_TYPE = "org.ietf.ietfsched.extra.NEXT_TYPE"; public static final String TAG = "TracksFragment"; public static final String NEXT_TYPE_SESSIONS = "sessions"; public static final String NEXT_TYPE_VENDORS = "vendors"; private TracksAdapter mAdapter; private NotifyingAsyncQueryHandler mHandler; private String mNextType; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); final Intent intent = BaseActivity.fragmentArgumentsToIntent(getArguments()); final Uri tracksUri = intent.getData(); mNextType = intent.getStringExtra(EXTRA_NEXT_TYPE); mAdapter = new TracksAdapter(getActivity()); setListAdapter(mAdapter); // Filter our tracks query to only include those with valid results String[] projection = TracksAdapter.TracksQuery.PROJECTION; String selection = null; if (NEXT_TYPE_SESSIONS.equals(mNextType)) { // Only show tracks with at least one session projection = TracksAdapter.TracksQuery.PROJECTION_WITH_SESSIONS_COUNT; selection = ScheduleContract.Tracks.SESSIONS_COUNT + ">0"; // AnalyticsUtils.getInstance(getActivity()).trackPageView("/Tracks"); } else if (NEXT_TYPE_VENDORS.equals(mNextType)) { // Only show tracks with at least one vendor // projection = TracksAdapter.TracksQuery.PROJECTION_WITH_VENDORS_COUNT; // selection = ScheduleContract.Tracks.VENDORS_COUNT + ">0"; // AnalyticsUtils.getInstance(getActivity()).trackPageView("/Sandbox"); } // Start background query to load tracks mHandler = new NotifyingAsyncQueryHandler(getActivity().getContentResolver(), this); mHandler.startQuery(tracksUri, projection, selection, null, ScheduleContract.Tracks.DEFAULT_SORT); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { ViewGroup root = (ViewGroup) inflater.inflate(R.layout.fragment_list_with_spinner, container, false); // For some reason, if we omit this, NoSaveStateFrameLayout thinks we are // FILL_PARENT / WRAP_CONTENT, making the progress bar stick to the top of the activity. root.setLayoutParams( new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT)); return root; } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); getListView().setChoiceMode(ListView.CHOICE_MODE_SINGLE); } /** {@inheritDoc} */ public void onQueryComplete(int token, Object cookie, Cursor cursor) { if (getActivity() == null) { return; } getActivity().startManagingCursor(cursor); mAdapter.setHasAllItem(true); mAdapter.setIsSessions(TracksFragment.NEXT_TYPE_SESSIONS.equals(mNextType)); mAdapter.changeCursor(cursor); } /** {@inheritDoc} */ @Override public void onListItemClick(ListView l, View v, int position, long id) { final Cursor cursor = (Cursor) mAdapter.getItem(position); final String trackId; int countSessions = -1; if (cursor != null) { trackId = cursor.getString(TracksAdapter.TracksQuery.TRACK_ID); countSessions = cursor.getInt(TracksAdapter.TracksQuery.SESSIONS_COUNT); // Log.d(TAG, "CountSessions" + countSessions); } else { trackId = ScheduleContract.Tracks.ALL_TRACK_ID; } final Intent intent = new Intent(Intent.ACTION_VIEW); final Uri trackUri = ScheduleContract.Tracks.buildTrackUri(trackId); intent.putExtra(SessionDetailFragment.EXTRA_TRACK, trackUri); if (NEXT_TYPE_SESSIONS.equals(mNextType)) { if (cursor == null) { intent.setData(ScheduleContract.Sessions.CONTENT_URI); } else { String sessionId = null; final Uri trackSessionsURI = ScheduleContract.Tracks.buildSessionsUri(trackId); if (countSessions == 1) { // Log.d(TAG, "Single Session / skip the sessions list, uri " + trackSessionsURI); Cursor c = null; try { c = getActivity().getContentResolver().query(trackSessionsURI, new String[] { ScheduleContract.Sessions.SESSION_ID }, null, null, null); sessionId = c != null && c.moveToFirst() ? c.getString(0) : null; } catch (Exception e) { } finally { if (c != null) c.close(); } } intent.setData(sessionId == null ? trackSessionsURI : ScheduleContract.Sessions.buildSessionUri(sessionId)); } } else if (NEXT_TYPE_VENDORS.equals(mNextType)) { /* if (cursor == null) { intent.setData(ScheduleContract.Vendors.CONTENT_URI); } else { intent.setData(ScheduleContract.Tracks.buildVendorsUri(trackId)); } */ } ((BaseActivity) getActivity()).openActivityOrFragment(intent); getListView().setItemChecked(position, true); } }