Java tutorial
/* * SettingsActivity.java * * Copyright (C) 2014 Jakob Wenzel * * Authors: * Jakob Wenzel <jakobwenzel92@gmail.com> * * 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, either version 3 of the License, or * (at your option) any later version. * * 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/>. */ package de.yazo_games.mensaguthaben; import android.annotation.TargetApi; import android.content.Context; import android.content.SharedPreferences; import android.content.res.Configuration; import android.net.Uri; import android.os.Build; import android.os.Bundle; import android.preference.CheckBoxPreference; import android.preference.ListPreference; import android.preference.Preference; import android.preference.PreferenceActivity; import android.preference.PreferenceCategory; import android.preference.PreferenceFragment; import android.preference.PreferenceManager; import android.text.TextUtils; import android.view.MenuItem; import android.support.v4.app.NavUtils; import java.util.List; /** * A {@link PreferenceActivity} that presents a set of application settings. On * handset devices, settings are presented as a single list. On tablets, * settings are split by category, with category headers shown to the left of * the list of settings. * <p> * See <a href="http://developer.android.com/design/patterns/settings.html"> * Android Design: Settings</a> for design guidelines and the <a * href="http://developer.android.com/guide/topics/ui/settings.html">Settings * API Guide</a> for more information on developing a Settings UI. */ public class SettingsActivity extends PreferenceActivity implements SharedPreferences.OnSharedPreferenceChangeListener { /** * Determines whether to always show the simplified settings UI, where * settings are presented in a single list. When false, settings are shown * as a master/detail two-pane view on tablets. When true, a single pane is * shown on tablets. */ private static final boolean ALWAYS_SIMPLE_PREFS = false; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setupActionBar(); } /** * Set up the {@link android.app.ActionBar}, if the API is available. */ @TargetApi(Build.VERSION_CODES.HONEYCOMB) private void setupActionBar() { if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) { // Show the Up button in the action bar. getActionBar().setDisplayHomeAsUpEnabled(true); } } @Override public boolean onOptionsItemSelected(MenuItem item) { switch (item.getItemId()) { case android.R.id.home: // This ID represents the Home or Up button. In the case of this // activity, the Up button is shown. Use NavUtils to allow users // to navigate up one level in the application structure. For // more details, see the Navigation pattern on Android Design: // // http://developer.android.com/design/patterns/navigation.html#up-vs-back // // TODO: If Settings has multiple levels, Up should navigate up // that hierarchy. NavUtils.navigateUpFromSameTask(this); return true; } return super.onOptionsItemSelected(item); } @Override protected void onPostCreate(Bundle savedInstanceState) { super.onPostCreate(savedInstanceState); setupSimplePreferencesScreen(); } /** * Shows the simplified settings UI if the device configuration if the * device configuration dictates that a simplified, single-pane UI should be * shown. */ private void setupSimplePreferencesScreen() { if (!isSimplePreferences(this)) { return; } // In the simplified UI, fragments are not used at all and we instead // use the older PreferenceActivity APIs. // Add 'general' preferences. addPreferencesFromResource(R.xml.pref_general); } /** {@inheritDoc} */ @Override public boolean onIsMultiPane() { return isXLargeTablet(this) && !isSimplePreferences(this); } /** * Helper method to determine if the device has an extra-large screen. For * example, 10" tablets are extra-large. */ private static boolean isXLargeTablet(Context context) { return (context.getResources().getConfiguration().screenLayout & Configuration.SCREENLAYOUT_SIZE_MASK) >= Configuration.SCREENLAYOUT_SIZE_XLARGE; } /** * Determines whether the simplified settings UI should be shown. This is * true if this is forced via {@link #ALWAYS_SIMPLE_PREFS}, or the device * doesn't have newer APIs like {@link PreferenceFragment}, or the device * doesn't have an extra-large screen. In these cases, a single-pane * "simplified" settings UI should be shown. */ private static boolean isSimplePreferences(Context context) { return ALWAYS_SIMPLE_PREFS || Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB || !isXLargeTablet(context); } /** {@inheritDoc} */ @Override @TargetApi(Build.VERSION_CODES.HONEYCOMB) public void onBuildHeaders(List<Header> target) { if (!isSimplePreferences(this)) { loadHeadersFromResource(R.xml.pref_headers, target); } } /** * Settings changed, so register or unregister nfc listener */ public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) { if (key.equals("autostart")) { Boolean value = sharedPreferences.getBoolean(key, true); AutostartRegister.register(getPackageManager(), value); } } @Override protected void onResume() { super.onResume(); getPreferenceScreen().getSharedPreferences().registerOnSharedPreferenceChangeListener(this); } @Override protected void onPause() { super.onPause(); getPreferenceScreen().getSharedPreferences().unregisterOnSharedPreferenceChangeListener(this); } /** * This fragment shows general preferences only. It is used when the * activity is showing a two-pane settings UI. */ @TargetApi(Build.VERSION_CODES.HONEYCOMB) public static class GeneralPreferenceFragment extends PreferenceFragment { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.pref_general); } } }