Java tutorial
/* * Copyright 2013 Ian Kavanagh * * 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 ie.clashoftheash.timetabler.ui; import ie.clashoftheash.timetabler.R; import ie.clashoftheash.timetabler.authenticator.AccountUtils; import ie.clashoftheash.timetabler.provider.Timetable; import ie.clashoftheash.timetabler.ui.dialogs.RemoveAccountFragment; import java.util.List; import android.accounts.Account; import android.annotation.TargetApi; import android.content.ContentResolver; import android.content.Context; import android.content.Intent; import android.content.SharedPreferences; import android.content.SharedPreferences.OnSharedPreferenceChangeListener; import android.content.res.Configuration; import android.media.Ringtone; import android.media.RingtoneManager; import android.net.Uri; import android.os.AsyncTask; import android.os.Build; import android.os.Bundle; 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.preference.RingtonePreference; import android.support.v4.app.NavUtils; import android.text.TextUtils; import android.view.Menu; import android.view.MenuItem; /** * 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 OnSharedPreferenceChangeListener, RemoveAccountFragment.OnAccountRemovalListener { private SharedPreferences prefs; private static ListPreference syncFreqPreference; private static String prefKeyProgrammeCode, prefKeyYear, prefKeyFreq; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setupActionBar(); prefs = PreferenceManager.getDefaultSharedPreferences(this); prefKeyProgrammeCode = getString(R.string.pref_key_programme_code); prefKeyYear = getString(R.string.pref_key_year); prefKeyFreq = getString(R.string.pref_key_sync_frequency); } @Override protected void onPostCreate(Bundle savedInstanceState) { super.onPostCreate(savedInstanceState); setupSimplePreferencesScreen(); } @Override protected void onResume() { super.onResume(); AccountUtils.checkAccountExists(this); prefs.registerOnSharedPreferenceChangeListener(this); // Check if sync setting was changed outside of app new VerifySyncPreference().execute(getSyncFreqPref()); } @Override protected void onPause() { super.onPause(); prefs.unregisterOnSharedPreferenceChangeListener(this); } @Override public boolean onCreateOptionsMenu(Menu menu) { getMenuInflater().inflate(R.menu.activity_settings, menu); return 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 NavUtils.navigateUpTo(this, new Intent(this, EventListActivity.class)); return true; case R.id.menu_remove_account: new RemoveAccountFragment().show(getFragmentManager(), "RemoveAccountFragment"); return true; } return super.onOptionsItemSelected(item); } @Override public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) { if (key.equals(prefKeyProgrammeCode) || key.equals(prefKeyYear)) { // Update account String programme = sharedPreferences.getString(prefKeyProgrammeCode, AccountUtils.getProgrammeCode(this)); String year = sharedPreferences.getString(prefKeyYear, AccountUtils.getYear(this)); new AccountUtils(this).updateAccount(programme, year); } else if (key.equals(prefKeyFreq)) { long pollFrequency = getSyncFreqPref(); Account acc = AccountUtils.getAccount(this); String authority = Timetable.AUTHORITY; if (pollFrequency > 0) { ContentResolver.setSyncAutomatically(acc, authority, true); ContentResolver.addPeriodicSync(acc, authority, new Bundle(), pollFrequency); } else { ContentResolver.setSyncAutomatically(acc, authority, false); ContentResolver.removePeriodicSync(acc, authority, new Bundle()); } } } @Override public void onAccountRemoval(boolean result) { if (result) { // Call cleanup task to remove database and preferences new RemoveAccountFragment.CleanupAccountTask().execute(this); RemoveAccountFragment.accountRemoved(this); } else RemoveAccountFragment.accountNotRemoved(this); } /** * 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); } } /** * Helper method to return the users sync frequency preference * * @return how frequently the sync should be performed, in seconds */ private long getSyncFreqPref() { return Long.parseLong(prefs.getString(getString(R.string.pref_key_sync_frequency), getString(R.string.pref_default_sync_frequency))); } /** * 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 (isXLargeTablet(this)) return; getFragmentManager().beginTransaction().replace(android.R.id.content, new GeneralPreferenceFragment()) .commit(); } @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 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 Build.VERSION.SDK_INT < Build.VERSION_CODES.HONEYCOMB || !isXLargeTablet(context); } @Override @TargetApi(Build.VERSION_CODES.HONEYCOMB) public void onBuildHeaders(List<Header> target) { if (!isSimplePreferences(this)) { loadHeadersFromResource(R.xml.pref_headers, target); } } /** * A preference value change listener that updates the preference's summary * to reflect its new value. */ private static final 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); // Set the summary to reflect the new value. preference.setSummary(index >= 0 ? listPreference.getEntries()[index] : null); } else if (preference instanceof RingtonePreference) { // For ringtone preferences, look up the correct display value // using RingtoneManager. if (TextUtils.isEmpty(stringValue)) { // Empty values correspond to 'silent' (no ringtone). 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 { // Set the summary to reflect the new ringtone display // name. 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; } }; /** * 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 updated to reflect the value. The summary is also * immediately updated 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(), "")); } /** * This fragment shows all preferences. It is used when the activity is show * a single-pane settings UI. */ @TargetApi(Build.VERSION_CODES.HONEYCOMB) public static class GeneralPreferenceFragment extends PreferenceFragment { /** * Mandatory empty constructor for the fragment manager to instantiate * the fragment (e.g. upon screen orientation changes). */ public GeneralPreferenceFragment() { } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); // Add 'account' preferences, and a corresponding header addPreferencesFromResource(R.xml.pref_account); // Add 'data and sync' preferences, and a corresponding header. PreferenceCategory fakeHeader = new PreferenceCategory(getActivity()); fakeHeader.setTitle(R.string.pref_header_data_sync); getPreferenceScreen().addPreference(fakeHeader); addPreferencesFromResource(R.xml.pref_data_sync); // Bind the summaries of EditText/List/Dialog/Ringtone preferences // to their values. When their values change, their summaries are // updated to reflect the new value, per the Android Design // guidelines. syncFreqPreference = (ListPreference) findPreference(prefKeyFreq); bindPreferenceSummaryToValue(findPreference(prefKeyProgrammeCode)); bindPreferenceSummaryToValue(findPreference(prefKeyYear)); bindPreferenceSummaryToValue(syncFreqPreference); } } /** * 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 AccountPreferenceFragment extends PreferenceFragment { /** * Mandatory empty constructor for the fragment manager to instantiate * the fragment (e.g. upon screen orientation changes). */ public AccountPreferenceFragment() { } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.pref_account); // Bind the summaries of EditText/List/Dialog/Ringtone preferences // to their values. When their values change, their summaries are // updated to reflect the new value, per the Android Design // guidelines. bindPreferenceSummaryToValue(findPreference(prefKeyProgrammeCode)); bindPreferenceSummaryToValue(findPreference(prefKeyYear)); } } /** * This fragment shows data and sync preferences only. It is used when the * activity is showing a two-pane settings UI. */ @TargetApi(Build.VERSION_CODES.HONEYCOMB) public static class DataSyncPreferenceFragment extends PreferenceFragment { /** * Mandatory empty constructor for the fragment manager to instantiate * the fragment (e.g. upon screen orientation changes). */ public DataSyncPreferenceFragment() { } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.pref_data_sync); // Bind the summaries of EditText/List/Dialog/Ringtone preferences // to their values. When their values change, their summaries are // updated to reflect the new value, per the Android Design // guidelines. syncFreqPreference = (ListPreference) findPreference(prefKeyFreq); bindPreferenceSummaryToValue(syncFreqPreference); } } /** * This fragment shows about and support preferences only. It is used when * the activity is showing a two-pane settings UI. */ @TargetApi(Build.VERSION_CODES.HONEYCOMB) public static class AboutSupportPreferenceFragment extends PreferenceFragment { /** * Mandatory empty constructor for the fragment manager to instantiate * the fragment (e.g. upon screen orientation changes). */ public AboutSupportPreferenceFragment() { } @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); addPreferencesFromResource(R.xml.pref_about_support); } } /** * Verifies if the current sync preference stored in the * {@link android.content.SharedPreferences} is the same as that set in the * systems global settings and configures the settings to be valid and match * the systems settings * * Takes as a parameter the current sync frequency preference * * @author Ian Kavanagh */ private class VerifySyncPreference extends AsyncTask<Long, Void, String> { @Override protected String doInBackground(Long... params) { long pollFrequency = params[0]; Context context = getApplicationContext(); Account acc = AccountUtils.getAccount(context); String authority = Timetable.AUTHORITY; boolean setToSync = ContentResolver.getSyncAutomatically(acc, authority); String value = null; if (setToSync != (pollFrequency > 0)) { SharedPreferences.Editor editor = PreferenceManager.getDefaultSharedPreferences(context).edit(); if (setToSync) { value = getString(R.string.pref_default_sync_frequency); if (acc != null) ContentResolver.addPeriodicSync(acc, authority, new Bundle(), Long.parseLong(value)); editor.putString(prefKeyFreq, value); } else { value = "-1"; // Don't sync if (acc != null) ContentResolver.removePeriodicSync(acc, authority, new Bundle()); editor.putString(prefKeyFreq, value); } editor.apply(); } return value; } @Override protected void onPostExecute(String result) { // Null occurs if UI has not been created yet // TODO: check on tablet if correct setting is still displayed // even though update here does not occur if (syncFreqPreference != null && result != null) { syncFreqPreference.setValue(result); bindPreferenceSummaryToValue(syncFreqPreference); } } } }