Java tutorial
/* * Copyright 2011 Peter Kuterna * * 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 net.peterkuterna.android.apps.devoxxfrsched.ui; import net.peterkuterna.android.apps.devoxxfrsched.R; import net.peterkuterna.android.apps.devoxxfrsched.provider.CfpContract; import net.peterkuterna.android.apps.devoxxfrsched.provider.CfpContract.Speakers; import net.peterkuterna.android.apps.devoxxfrsched.util.ActivityHelper; import net.peterkuterna.android.apps.devoxxfrsched.util.AnalyticsUtils; import net.peterkuterna.android.apps.devoxxfrsched.util.UIUtils; import android.annotation.SuppressLint; import android.content.Intent; import android.database.ContentObserver; import android.database.Cursor; import android.net.Uri; import android.os.Bundle; import android.os.Handler; import android.provider.BaseColumns; import android.support.v4.app.LoaderManager; import android.support.v4.app.LoaderManager.LoaderCallbacks; import android.support.v4.content.CursorLoader; import android.support.v4.content.Loader; import android.support.v4.widget.CursorAdapter; import android.view.View; import android.widget.GridView; public class SpeakersGridFragment extends GridFragment { private static final String STATE_CHECKED_POSITION = "checkedPosition"; private CursorAdapter mAdapter; private int mCheckedPosition = -1; private Uri mSpeakersUri; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); AnalyticsUtils.getInstance(getActivity()).trackPageView("/Speakers"); } @Override public void onViewCreated(View view, Bundle savedInstanceState) { super.onViewCreated(view, savedInstanceState); final GridView gridView = getGridView(); float sf = getResources().getDisplayMetrics().density; final int padding = (int) (5.0 * sf); final int spacing = (int) (20.0 * sf); gridView.setNumColumns(GridView.AUTO_FIT); gridView.setColumnWidth((int) (120 * sf)); gridView.setStretchMode(GridView.STRETCH_SPACING); gridView.setVerticalFadingEdgeEnabled(true); gridView.setPadding(padding, padding, padding, padding); gridView.setHorizontalSpacing(spacing); gridView.setVerticalSpacing(spacing); } @SuppressLint("NewApi") @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); setEmptyText(getString(R.string.empty_speakers)); if (UIUtils.isHoneycombTablet(getActivity())) { getGridView().setChoiceMode(GridView.CHOICE_MODE_SINGLE); } reloadFromArguments(getArguments()); setGridShown(false); if (savedInstanceState != null) { mCheckedPosition = savedInstanceState.getInt(STATE_CHECKED_POSITION, -1); } } public void reloadFromArguments(Bundle arguments) { mCheckedPosition = -1; // Load new arguments final Intent intent = ActivityHelper.fragmentArgumentsToIntent(arguments); mSpeakersUri = intent.getData(); if (mSpeakersUri == null) { return; } mAdapter = new SpeakersAdapter(getActivity(), null, R.layout.grid_item_speaker); getGridView().setAdapter(mAdapter); getLoaderManager().initLoader(SpeakersAdapter.SpeakersQuery._TOKEN, null, mSpeakersLoaderCallback); } @Override public void onResume() { super.onResume(); getActivity().getContentResolver().registerContentObserver(CfpContract.Speakers.CONTENT_URI, true, mSpeakerChangesObserver); if (mSpeakersUri != null) { getLoaderManager().restartLoader(SpeakersAdapter.SpeakersQuery._TOKEN, null, mSpeakersLoaderCallback); } } @Override public void onPause() { super.onPause(); getActivity().getContentResolver().unregisterContentObserver(mSpeakerChangesObserver); } @Override public void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); outState.putInt(STATE_CHECKED_POSITION, mCheckedPosition); } @SuppressLint("NewApi") @Override public void onGridItemClick(GridView gv, View v, int position, long id) { final Cursor cursor = (Cursor) mAdapter.getItem(position); final String speakerId = cursor.getString(SpeakersAdapter.SpeakersQuery.SPEAKER_ID); final String firstName = cursor.getString(SpeakersAdapter.SpeakersQuery.SPEAKER_FIRSTNAME); final String lastName = cursor.getString(SpeakersAdapter.SpeakersQuery.SPEAKER_LASTNAME); final String speakerName = UIUtils.formatSpeakerName(firstName, lastName); final String title = getResources().getString(R.string.title_sessions_of, speakerName); AnalyticsUtils.getInstance(getActivity()).trackEvent("Speakers Grid", "Click", speakerName, 0); final Uri sessionsUri = CfpContract.Speakers.buildSessionsDirUri(speakerId); final Intent intent = new Intent(Intent.ACTION_VIEW, sessionsUri); intent.putExtra(Intent.EXTRA_TITLE, title); ((AbstractActivity) getActivity()).openActivityOrFragment(intent); if (UIUtils.isHoneycombTablet(getActivity())) { getGridView().setItemChecked(position, true); mCheckedPosition = position; } } @SuppressLint("NewApi") public void clearCheckedPosition() { if (mCheckedPosition >= 0 && UIUtils.isHoneycomb()) { getGridView().setItemChecked(mCheckedPosition, false); mCheckedPosition = -1; } } private LoaderManager.LoaderCallbacks<Cursor> mSpeakersLoaderCallback = new LoaderCallbacks<Cursor>() { @Override public Loader<Cursor> onCreateLoader(int id, Bundle args) { return new CursorLoader(getActivity(), mSpeakersUri, SpeakersAdapter.SpeakersQuery.PROJECTION, null, null, CfpContract.Speakers.DEFAULT_SORT); } @SuppressLint("NewApi") @Override public void onLoadFinished(Loader<Cursor> loader, Cursor data) { mAdapter.swapCursor(data); if (isResumed()) { setGridShown(true); } else { setGridShownNoAnimation(true); } if (mCheckedPosition >= 0 && getView() != null && UIUtils.isHoneycomb()) { getGridView().setItemChecked(mCheckedPosition, true); } } @Override public void onLoaderReset(Loader<Cursor> loader) { mAdapter.swapCursor(null); } }; private ContentObserver mSpeakerChangesObserver = new ContentObserver(new Handler()) { @Override public void onChange(boolean selfChange) { if (getActivity() != null) { if (mSpeakersUri != null) { getLoaderManager().restartLoader(SpeakersAdapter.SpeakersQuery._TOKEN, null, mSpeakersLoaderCallback); } } } }; /** * {@link Speakers} query parameters. */ private interface SpeakersQuery { int _TOKEN = 0x1; String[] PROJECTION = { BaseColumns._ID, CfpContract.Speakers.SPEAKER_ID, CfpContract.Speakers.SPEAKER_FIRSTNAME, CfpContract.Speakers.SPEAKER_LASTNAME, CfpContract.Speakers.SPEAKER_COMPANY, CfpContract.Speakers.SPEAKER_BIO, CfpContract.Speakers.SPEAKER_IMAGE_URL, }; int _ID = 0; int SPEAKER_ID = 1; int SPEAKER_FIRSTNAME = 2; int SPEAKER_LASTNAME = 3; int SPEAKER_COMPANY = 4; int SPEAKER_BIO = 5; int SPEAKER_IMAGE_URL = 6; } }