Java tutorial
/* * Copyright (c) 2016 Martin Norbert * 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.site_monitor.activity; import android.app.ActionBar; import android.content.Context; import android.content.Intent; import android.content.res.Configuration; import android.media.Ringtone; import android.media.RingtoneManager; import android.net.Uri; import android.os.Bundle; import android.preference.ListPreference; import android.preference.Preference; import android.preference.PreferenceActivity; import android.preference.PreferenceFragment; import android.preference.PreferenceManager; import android.preference.RingtonePreference; import android.support.v4.app.NavUtils; import android.text.TextUtils; import android.view.MenuItem; import org.site_monitor.R; import org.site_monitor.receiver.StartupBootReceiver; import org.site_monitor.util.AlarmUtil; import org.site_monitor.util.TimeUtil; 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 PrefSettingsActivity extends AppCompatPreferenceActivity { public static final String NOTIFICATIONS_VIBRATE = "notifications_vibrate"; public static final String NOTIFICATIONS_RINGTONE = "notifications_ringtone"; public static final String NOTIFICATION_ENABLE = "notifications_enable"; public static final String NOTIFICATION_LIMIT_TO_NEW_FAIL = "notifications_limit_to_new_fail"; public static final String NOTIFICATION_LIGHT_COLOR = "notification_light_color"; public static final String BOOT_START = "boot_start"; public static final String FREQUENCY = "frequency"; /** * 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; private static AlarmUtil alarmUtil = AlarmUtil.instance(); /** * A preference value change listener that updates the preference's summary to reflect its new value. */ private static Preference.OnPreferenceChangeListener sBindPreferenceSummaryToValueListener = new Preference.OnPreferenceChangeListener() { @Override public boolean onPreferenceChange(Preference preference, Object value) { String stringValue = value.toString(); if (preference instanceof ListPreference) { // For list preferences, look up the correct display value in the preference's 'entries' list. ListPreference listPreference = (ListPreference) preference; int index = listPreference.findIndexOfValue(stringValue); preference.setSummary(index >= 0 ? listPreference.getEntries()[index] : null); if (preference.getKey().equals(FREQUENCY)) { String currentValue = preference.getSharedPreferences().getString(FREQUENCY, ""); if (!currentValue.equals(stringValue)) { alarmUtil.rescheduleAlarm(preference.getContext(), Long.parseLong(stringValue) * TimeUtil.MINUTE_2_MILLISEC); } } } else if (preference instanceof RingtonePreference) { // For ringtone preferences, look up the correct display value using RingtoneManager. if (TextUtils.isEmpty(stringValue)) { preference.setSummary(R.string.pref_ringtone_silent); } else { Ringtone ringtone = RingtoneManager.getRingtone(preference.getContext(), Uri.parse(stringValue)); if (ringtone == null) { // Clear the summary if there was a lookup error. preference.setSummary(null); } else { String name = ringtone.getTitle(preference.getContext()); preference.setSummary(name); } } } else { // For all other preferences, set the summary to the value's simple string representation. preference.setSummary(stringValue); } return true; } }; private static Preference.OnPreferenceChangeListener sPreferenceListener = new Preference.OnPreferenceChangeListener() { @Override public boolean onPreferenceChange(Preference preference, Object value) { boolean state = (Boolean) value; if (preference.getKey().equals(BOOT_START)) { StartupBootReceiver.setCanBeInitiatedBySystem(preference.getContext(), state); } return true; } }; /** * 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 !isXLargeTablet(context) || ALWAYS_SIMPLE_PREFS; } /** * Binds a preference's summary to its value. More specifically, when the preference's value is changed, its summary (line of text below the * preference title) is dataChanged to reflect the value. The summary is also immediately dataChanged upon calling this method. The exact display format is * dependent on the type of preference. * * @see #sBindPreferenceSummaryToValueListener */ private static void bindPreferenceSummaryToValue(Preference preference) { // Set the listener to watch for value changes. preference.setOnPreferenceChangeListener(sBindPreferenceSummaryToValueListener); // Trigger the listener immediately with the preference's current value. sBindPreferenceSummaryToValueListener.onPreferenceChange(preference, PreferenceManager .getDefaultSharedPreferences(preference.getContext()).getString(preference.getKey(), "")); } public static void start(Context context) { context.startActivity(new Intent(context, PrefSettingsActivity.class)); } @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setupActionBar(); } @Override protected void onPostCreate(Bundle savedInstanceState) { super.onPostCreate(savedInstanceState); setupSimplePreferencesScreen(); } /** * {@inheritDoc} */ @Override public boolean onIsMultiPane() { return isXLargeTablet(this) && !isSimplePreferences(this); } /** * {@inheritDoc} */ @Override public void onBuildHeaders(List<Header> target) { if (!isSimplePreferences(this)) { loadHeadersFromResource(R.xml.pref_headers, target); } } /** * Set up the {@link android.app.ActionBar} */ private void setupActionBar() { // Show the Up button in the action bar. ActionBar actionBar = getActionBar(); if (actionBar != null) { actionBar.setDisplayHomeAsUpEnabled(true); } } @Override protected void onResume() { super.onResume(); } @Override public boolean onOptionsItemSelected(MenuItem item) { int id = item.getItemId(); if (id == 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 // NavUtils.navigateUpFromSameTask(this); return true; } return super.onOptionsItemSelected(item); } @Override protected boolean isValidFragment(String fragmentName) { return true; } /** * 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. addPreferencesFromResource(R.xml.pref_monitoring); addPreferencesFromResource(R.xml.pref_notification); addPreferencesFromResource(R.xml.pref_history); // Bind the summaries of EditText/List/Dialog/Ringtone preferences to their values. When their values change, // their summaries are dataChanged to reflect the new value, per the Android Design guidelines. bindPreferenceSummaryToValue(findPreference(NOTIFICATIONS_RINGTONE)); bindPreferenceSummaryToValue(findPreference(FREQUENCY)); bindPreferenceSummaryToValue(findPreference(NOTIFICATION_LIGHT_COLOR)); findPreference(BOOT_START).setOnPreferenceChangeListener(sPreferenceListener); findPreference(NOTIFICATION_LIMIT_TO_NEW_FAIL).setOnPreferenceChangeListener(sPreferenceListener); findPreference(NOTIFICATION_ENABLE).setOnPreferenceChangeListener(sPreferenceListener); } /** * This fragment shows notification preferences only. It is used when the activity is showing a two-pane settings UI. */ public static class NotificationPreferenceFragment extends PreferenceFragment { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.pref_notification); // Bind the summaries of EditText/List/Dialog/Ringtone preferences to their values. When their values change, their summaries are // dataChanged to reflect the new value, per the Android Design guidelines. bindPreferenceSummaryToValue(findPreference(NOTIFICATIONS_RINGTONE)); bindPreferenceSummaryToValue(findPreference(NOTIFICATION_LIGHT_COLOR)); findPreference(NOTIFICATION_ENABLE).setOnPreferenceChangeListener(sPreferenceListener); findPreference(NOTIFICATION_LIMIT_TO_NEW_FAIL).setOnPreferenceChangeListener(sPreferenceListener); } } /** * This fragment shows monitoring preferences only. */ public static class MonitoringPreferenceFragment extends PreferenceFragment { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.pref_monitoring); // Bind the summaries of EditText/List/Dialog/Ringtone preferences to their values. When their values change, their summaries are // dataChanged to reflect the new value, per the Android Design guidelines. bindPreferenceSummaryToValue(findPreference(FREQUENCY)); findPreference(BOOT_START).setOnPreferenceChangeListener(sPreferenceListener); } } /** * This fragment shows history preferences only. */ public static class HistoryPreferenceFragment extends PreferenceFragment { @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.pref_history); } } }