Java tutorial
/* * Copyright 2012 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 ua.org.gdg.devfest.iosched.ui.tablet; import ua.org.gdg.devfest.iosched.R; import ua.org.gdg.devfest.iosched.provider.ScheduleContract; import ua.org.gdg.devfest.iosched.ui.TracksAdapter; import ua.org.gdg.devfest.iosched.util.ParserUtils; import android.annotation.TargetApi; import android.app.Activity; import android.content.res.Resources; import android.database.Cursor; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.drawable.BitmapDrawable; import android.os.Build; import android.os.Bundle; import android.os.Handler; 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.view.LayoutInflater; import android.view.View; import android.view.ViewGroup; import android.widget.AdapterView; import android.widget.ImageView; import android.widget.ListPopupWindow; import android.widget.PopupWindow; import android.widget.TextView; /** * 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+. */ @TargetApi(Build.VERSION_CODES.HONEYCOMB) public class TracksDropdownFragment extends Fragment implements LoaderManager.LoaderCallbacks<Cursor>, AdapterView.OnItemClickListener, PopupWindow.OnDismissListener { public static final int VIEW_TYPE_SESSIONS = 0; public static final int VIEW_TYPE_OFFICE_HOURS = 1; public static final int VIEW_TYPE_SANDBOX = 2; private static final String STATE_VIEW_TYPE = "viewType"; private static final String STATE_SELECTED_TRACK_ID = "selectedTrackId"; private TracksAdapter mAdapter; private int mViewType; private Handler mHandler = new Handler(); private ListPopupWindow mListPopupWindow; private ViewGroup mRootView; private ImageView mIcon; private TextView mTitle; private TextView mAbstract; private String mTrackId; public interface Callbacks { public void onTrackSelected(String trackId); public void onTrackNameAvailable(String trackId, String trackName); } private static Callbacks sDummyCallbacks = new Callbacks() { @Override public void onTrackSelected(String trackId) { } @Override public void onTrackNameAvailable(String trackId, String trackName) { } }; private Callbacks mCallbacks = sDummyCallbacks; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); mAdapter = new TracksAdapter(getActivity(), true); if (savedInstanceState != null) { // Since this fragment doesn't rely on fragment arguments, we must // handle state restores and saves ourselves. mViewType = savedInstanceState.getInt(STATE_VIEW_TYPE); mTrackId = savedInstanceState.getString(STATE_SELECTED_TRACK_ID); } } @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); outState.putInt(STATE_VIEW_TYPE, mViewType); outState.putString(STATE_SELECTED_TRACK_ID, mTrackId); } public String getSelectedTrackId() { return mTrackId; } public void selectTrack(String trackId) { loadTrackList(mViewType, trackId); } public void loadTrackList(int viewType) { loadTrackList(viewType, mTrackId); } public void loadTrackList(int viewType, String selectTrackId) { // Teardown from previous arguments if (mListPopupWindow != null) { mListPopupWindow.setAdapter(null); } mViewType = viewType; mTrackId = selectTrackId; // Start background query to load tracks getLoaderManager().restartLoader(TracksAdapter.TracksQuery._TOKEN, null, this); } @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { mRootView = (ViewGroup) inflater.inflate(R.layout.fragment_tracks_dropdown, null); mIcon = (ImageView) mRootView.findViewById(R.id.track_icon); 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(getResources().getDimensionPixelSize(R.dimen.track_dropdown_width)); mListPopupWindow.setAnchorView(mRootView); mListPopupWindow.setOnItemClickListener(TracksDropdownFragment.this); mListPopupWindow.show(); mListPopupWindow.setOnDismissListener(TracksDropdownFragment.this); } }); return mRootView; } @Override public void onAttach(Activity activity) { super.onAttach(activity); if (!(activity instanceof Callbacks)) { throw new ClassCastException("Activity must implement fragment's callbacks."); } mCallbacks = (Callbacks) activity; } @Override public void onDetach() { super.onDetach(); mCallbacks = sDummyCallbacks; if (mListPopupWindow != null) { mListPopupWindow.dismiss(); } } /** {@inheritDoc} */ public void onItemClick(AdapterView<?> parent, View view, int position, long id) { final Cursor cursor = (Cursor) mAdapter.getItem(position); loadTrack(cursor, true); if (mListPopupWindow != null) { mListPopupWindow.dismiss(); } } public String getTrackName() { return (String) mTitle.getText(); } private void loadTrack(Cursor cursor, boolean triggerCallback) { final int trackColor; final Resources res = getResources(); if (cursor != null) { trackColor = cursor.getInt(TracksAdapter.TracksQuery.TRACK_COLOR); mTrackId = cursor.getString(TracksAdapter.TracksQuery.TRACK_ID); String trackName = cursor.getString(TracksAdapter.TracksQuery.TRACK_NAME); mTitle.setText(trackName); mAbstract.setText(cursor.getString(TracksAdapter.TracksQuery.TRACK_ABSTRACT)); int iconResId = res.getIdentifier("track_" + ParserUtils.sanitizeId(trackName), "drawable", getActivity().getPackageName()); if (iconResId != 0) { BitmapDrawable sourceIconDrawable = (BitmapDrawable) res.getDrawable(iconResId); Bitmap icon = Bitmap.createBitmap(sourceIconDrawable.getIntrinsicWidth(), sourceIconDrawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(icon); sourceIconDrawable.setBounds(0, 0, icon.getWidth(), icon.getHeight()); sourceIconDrawable.draw(canvas); BitmapDrawable iconDrawable = new BitmapDrawable(res, icon); mIcon.setImageDrawable(iconDrawable); } else { mIcon.setImageDrawable(null); } } else { trackColor = res.getColor(R.color.all_track_color); mTrackId = ScheduleContract.Tracks.ALL_TRACK_ID; mIcon.setImageDrawable(null); switch (mViewType) { case VIEW_TYPE_SESSIONS: mTitle.setText(R.string.all_tracks_sessions); mAbstract.setText(R.string.all_tracks_subtitle_sessions); break; case VIEW_TYPE_OFFICE_HOURS: mTitle.setText(R.string.all_tracks_office_hours); mAbstract.setText(R.string.all_tracks_subtitle_office_hours); break; case VIEW_TYPE_SANDBOX: mTitle.setText(R.string.all_tracks_sandbox); mAbstract.setText(R.string.all_tracks_subtitle_sandbox); break; } } mRootView.setBackgroundColor(trackColor); mCallbacks.onTrackNameAvailable(mTrackId, mTitle.getText().toString()); if (triggerCallback) { mHandler.post(new Runnable() { @Override public void run() { mCallbacks.onTrackSelected(mTrackId); } }); } } public void onDismiss() { mListPopupWindow = null; } @Override public Loader<Cursor> onCreateLoader(int id, Bundle data) { // Filter our tracks query to only include those with valid results String[] projection = TracksAdapter.TracksQuery.PROJECTION; String selection = null; switch (mViewType) { case VIEW_TYPE_SESSIONS: // Only show tracks with at least one session projection = TracksAdapter.TracksQuery.PROJECTION_WITH_SESSIONS_COUNT; selection = ScheduleContract.Tracks.SESSIONS_COUNT + ">0"; break; case VIEW_TYPE_OFFICE_HOURS: // Only show tracks with at least one office hours projection = TracksAdapter.TracksQuery.PROJECTION_WITH_OFFICE_HOURS_COUNT; selection = ScheduleContract.Tracks.OFFICE_HOURS_COUNT + ">0"; break; case VIEW_TYPE_SANDBOX: // Only show tracks with at least one company projection = TracksAdapter.TracksQuery.PROJECTION_WITH_SANDBOX_COUNT; selection = ScheduleContract.Tracks.SANDBOX_COUNT + ">0"; break; } return new CursorLoader(getActivity(), ScheduleContract.Tracks.CONTENT_URI, projection, selection, null, ScheduleContract.Tracks.DEFAULT_SORT); } @Override public void onLoadFinished(Loader<Cursor> loader, Cursor cursor) { if (getActivity() == null || cursor == null) { return; } boolean trackLoaded = false; if (mTrackId != null) { cursor.moveToFirst(); while (!cursor.isAfterLast()) { if (mTrackId.equals(cursor.getString(TracksAdapter.TracksQuery.TRACK_ID))) { loadTrack(cursor, false); trackLoaded = true; break; } cursor.moveToNext(); } } if (!trackLoaded) { loadTrack(null, false); } mAdapter.setHasAllItem(true); mAdapter.changeCursor(cursor); } @Override public void onLoaderReset(Loader<Cursor> cusor) { } }