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 com.lullabot.android.apps.iosched.ui.tablet; import android.content.Intent; import android.content.res.Resources; import android.database.Cursor; import android.net.Uri; import android.os.Bundle; import android.support.v4.app.Fragment; import android.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.ListPopupWindow; import android.widget.PopupWindow; import android.widget.TextView; import com.lullabot.android.apps.iosched.R; import com.lullabot.android.apps.iosched.provider.ScheduleContract; import com.lullabot.android.apps.iosched.ui.BaseActivity; import com.lullabot.android.apps.iosched.ui.SessionDetailFragment; import com.lullabot.android.apps.iosched.ui.TracksAdapter; import com.lullabot.android.apps.iosched.ui.TracksFragment; import com.lullabot.android.apps.iosched.util.NotifyingAsyncQueryHandler; import com.lullabot.android.apps.iosched.util.UIUtils; /** * A tablet-specific fragment that is a giant {@link android.widget.Spinner}-like widget. It shows * a {@link ListPopupWindow} containing a list of tracks, using {@link TracksAdapter}. * * Requires API level 11 or later since {@link ListPopupWindow} is API level 11+. */ public class TracksDropdownFragment extends Fragment implements NotifyingAsyncQueryHandler.AsyncQueryListener, AdapterView.OnItemClickListener, PopupWindow.OnDismissListener { public static final String EXTRA_NEXT_TYPE = "com.google.android.iosched.extra.NEXT_TYPE"; public static final String NEXT_TYPE_SESSIONS = "sessions"; public static final String NEXT_TYPE_VENDORS = "vendors"; private boolean mAutoloadTarget = true; private Cursor mCursor; private TracksAdapter mAdapter; private String mNextType; private ListPopupWindow mListPopupWindow; private ViewGroup mRootView; private TextView mTitle; private TextView mAbstract; private NotifyingAsyncQueryHandler mHandler; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mHandler = new NotifyingAsyncQueryHandler(getActivity().getContentResolver(), this); mAdapter = new TracksAdapter(getActivity()); if (savedInstanceState != null) { // Prevent auto-load behavior on orientation change. mAutoloadTarget = false; } reloadFromArguments(getArguments()); } public void reloadFromArguments(Bundle arguments) { // Teardown from previous arguments if (mListPopupWindow != null) { mListPopupWindow.setAdapter(null); } if (mCursor != null) { getActivity().stopManagingCursor(mCursor); mCursor = null; } mHandler.cancelOperation(TracksAdapter.TracksQuery._TOKEN); // Load new arguments final Intent intent = BaseActivity.fragmentArgumentsToIntent(arguments); final Uri tracksUri = intent.getData(); if (tracksUri == null) { return; } mNextType = intent.getStringExtra(EXTRA_NEXT_TYPE); // Filter our tracks query to only include those with valid results String[] projection = TracksAdapter.TracksQuery.PROJECTION; String selection = null; if (TracksFragment.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"; } else if (TracksFragment.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"; } // Start background query to load tracks mHandler.startQuery(TracksAdapter.TracksQuery._TOKEN, null, tracksUri, projection, selection, null, ScheduleContract.Tracks.DEFAULT_SORT); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { mRootView = (ViewGroup) inflater.inflate(R.layout.fragment_tracks_dropdown, null); mTitle = (TextView) mRootView.findViewById(R.id.track_title); mAbstract = (TextView) mRootView.findViewById(R.id.track_abstract); mRootView.setOnClickListener(new View.OnClickListener() { public void onClick(View view) { mListPopupWindow = new ListPopupWindow(getActivity()); mListPopupWindow.setAdapter(mAdapter); mListPopupWindow.setModal(true); mListPopupWindow.setContentWidth(400); mListPopupWindow.setAnchorView(mRootView); mListPopupWindow.setOnItemClickListener(TracksDropdownFragment.this); mListPopupWindow.show(); mListPopupWindow.setOnDismissListener(TracksDropdownFragment.this); } }); return mRootView; } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); } /** {@inheritDoc} */ public void onQueryComplete(int token, Object cookie, Cursor cursor) { if (getActivity() == null || cursor == null) { return; } mCursor = cursor; getActivity().startManagingCursor(mCursor); // If there was a last-opened track, load it. Otherwise load the first track. cursor.moveToFirst(); String lastTrackID = UIUtils.getLastUsedTrackID(getActivity()); if (lastTrackID != null) { while (!cursor.isAfterLast()) { if (lastTrackID.equals(cursor.getString(TracksAdapter.TracksQuery.TRACK_ID))) { break; } cursor.moveToNext(); } if (cursor.isAfterLast()) { loadTrack(null, mAutoloadTarget); } else { loadTrack(cursor, mAutoloadTarget); } } else { loadTrack(null, mAutoloadTarget); } mAdapter.setHasAllItem(true); mAdapter.setIsSessions(TracksFragment.NEXT_TYPE_SESSIONS.equals(mNextType)); mAdapter.changeCursor(mCursor); } /** {@inheritDoc} */ public void onItemClick(AdapterView<?> parent, View view, int position, long id) { final Cursor cursor = (Cursor) mAdapter.getItem(position); loadTrack(cursor, true); if (cursor != null) { UIUtils.setLastUsedTrackID(getActivity(), cursor.getString(TracksAdapter.TracksQuery.TRACK_ID)); } else { UIUtils.setLastUsedTrackID(getActivity(), ScheduleContract.Tracks.ALL_TRACK_ID); } if (mListPopupWindow != null) { mListPopupWindow.dismiss(); } } public void loadTrack(Cursor cursor, boolean loadTargetFragment) { final String trackId; final int trackColor; final Resources res = getResources(); if (cursor != null) { trackColor = cursor.getInt(TracksAdapter.TracksQuery.TRACK_COLOR); trackId = cursor.getString(TracksAdapter.TracksQuery.TRACK_ID); mTitle.setText(cursor.getString(TracksAdapter.TracksQuery.TRACK_NAME)); mAbstract.setText(cursor.getString(TracksAdapter.TracksQuery.TRACK_ABSTRACT)); } else { trackColor = res.getColor(R.color.all_track_color); trackId = ScheduleContract.Tracks.ALL_TRACK_ID; mTitle.setText(TracksFragment.NEXT_TYPE_SESSIONS.equals(mNextType) ? R.string.all_sessions_title : R.string.all_sandbox_title); mAbstract.setText(TracksFragment.NEXT_TYPE_SESSIONS.equals(mNextType) ? R.string.all_sessions_subtitle : R.string.all_sandbox_subtitle); } boolean isDark = UIUtils.isColorDark(trackColor); mRootView.setBackgroundColor(trackColor); if (isDark) { mTitle.setTextColor(res.getColor(R.color.body_text_1_inverse)); mAbstract.setTextColor(res.getColor(R.color.body_text_2_inverse)); mRootView.findViewById(R.id.track_dropdown_arrow) .setBackgroundResource(R.drawable.track_dropdown_arrow_light); } else { mTitle.setTextColor(res.getColor(R.color.body_text_1)); mAbstract.setTextColor(res.getColor(R.color.body_text_2)); mRootView.findViewById(R.id.track_dropdown_arrow) .setBackgroundResource(R.drawable.track_dropdown_arrow_dark); } if (loadTargetFragment) { 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 { intent.setData(ScheduleContract.Tracks.buildSessionsUri(trackId)); } } 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); } } public void onDismiss() { mListPopupWindow = null; } }