Java tutorial
/* * Copyright (C) 2010 The Android Open Source Project * * 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 com.android.email; import android.app.Notification; import android.app.Notification.Builder; import android.app.NotificationManager; import android.app.PendingIntent; import android.content.ContentResolver; import android.content.ContentUris; import android.content.Context; import android.content.Intent; import android.database.ContentObserver; import android.database.Cursor; import android.graphics.Bitmap; import android.net.Uri; import android.os.Handler; import android.os.Looper; import android.os.Process; import android.provider.Settings; import android.support.v4.app.NotificationCompat; import android.text.TextUtils; import android.text.format.DateUtils; import com.android.email.activity.setup.AccountSecurity; import com.android.email.activity.setup.AccountSettings; import com.android.email.provider.EmailProvider; import com.android.email.service.EmailServiceUtils; import com.android.emailcommon.provider.Account; import com.android.emailcommon.provider.EmailContent; import com.android.emailcommon.provider.EmailContent.Attachment; import com.android.emailcommon.provider.EmailContent.Message; import com.android.emailcommon.provider.Mailbox; import com.android.emailcommon.utility.EmailAsyncTask; import com.android.emailcommon.utility.NotifyIconUtilities; import com.android.mail.preferences.FolderPreferences; import com.android.mail.providers.Folder; import com.android.mail.providers.UIProvider; import com.android.mail.utils.Clock; import com.android.mail.utils.LogTag; import com.android.mail.utils.LogUtils; import com.android.mail.utils.NotificationUtils; import java.util.HashMap; import java.util.HashSet; import java.util.Map; import java.util.Set; /** * Class that manages notifications. */ public class NotificationController { private static final String LOG_TAG = LogTag.getLogTag(); /** Reserved for {@link com.android.exchange.CalendarSyncEnabler} */ @SuppressWarnings("unused") private static final int NOTIFICATION_ID_EXCHANGE_CALENDAR_ADDED = 2; private static final int NOTIFICATION_ID_ATTACHMENT_WARNING = 3; private static final int NOTIFICATION_ID_PASSWORD_EXPIRING = 4; private static final int NOTIFICATION_ID_PASSWORD_EXPIRED = 5; private static final int NOTIFICATION_ID_BASE_MASK = 0xF0000000; private static final int NOTIFICATION_ID_BASE_LOGIN_WARNING = 0x20000000; private static final int NOTIFICATION_ID_BASE_SECURITY_NEEDED = 0x30000000; private static final int NOTIFICATION_ID_BASE_SECURITY_CHANGED = 0x40000000; private static NotificationThread sNotificationThread; private static Handler sNotificationHandler; private static NotificationController sInstance; private final Context mContext; private final NotificationManager mNotificationManager; private final Clock mClock; /** Maps account id to its observer */ private final Map<Long, ContentObserver> mNotificationMap = new HashMap<Long, ContentObserver>(); private ContentObserver mAccountObserver; /** Constructor */ protected NotificationController(Context context, Clock clock) { mContext = context.getApplicationContext(); EmailContent.init(context); mNotificationManager = (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE); mClock = clock; } /** Singleton access */ public static synchronized NotificationController getInstance(Context context) { if (sInstance == null) { sInstance = new NotificationController(context, Clock.INSTANCE); } return sInstance; } /** * Return whether or not a notification, based on the passed-in id, needs to be "ongoing" * @param notificationId the notification id to check * @return whether or not the notification must be "ongoing" */ private static boolean needsOngoingNotification(int notificationId) { // "Security needed" must be ongoing so that the user doesn't close it; otherwise, sync will // be prevented until a reboot. Consider also doing this for password expired. return (notificationId & NOTIFICATION_ID_BASE_MASK) == NOTIFICATION_ID_BASE_SECURITY_NEEDED; } /** * Returns a {@link android.support.v4.app.NotificationCompat.Builder} for an event with the * given account. The account contains specific rules on ring tone usage and these will be used * to modify the notification behaviour. * * @param accountId The id of the account this notification is being built for. * @param ticker Text displayed when the notification is first shown. May be {@code null}. * @param title The first line of text. May NOT be {@code null}. * @param contentText The second line of text. May NOT be {@code null}. * @param intent The intent to start if the user clicks on the notification. * @param largeIcon A large icon. May be {@code null} * @param number A number to display using {@link Builder#setNumber(int)}. May be {@code null}. * @param enableAudio If {@code false}, do not play any sound. Otherwise, play sound according * to the settings for the given account. * @return A {@link Notification} that can be sent to the notification service. */ private NotificationCompat.Builder createBaseAccountNotificationBuilder(long accountId, String ticker, CharSequence title, String contentText, Intent intent, Bitmap largeIcon, Integer number, boolean enableAudio, boolean ongoing) { // Pending Intent PendingIntent pending = null; if (intent != null) { pending = PendingIntent.getActivity(mContext, 0, intent, PendingIntent.FLAG_UPDATE_CURRENT); } Account account = Account.restoreAccountWithId(mContext, accountId); int iconResId = NotifyIconUtilities.findNotifyIconForAccountDomain(mContext, R.drawable.stat_notify_email, account.mEmailAddress, R.drawable.stat_notify_email); // NOTE: the ticker is not shown for notifications in the Holo UX final NotificationCompat.Builder builder = new NotificationCompat.Builder(mContext).setContentTitle(title) .setContentText(contentText).setContentIntent(pending).setLargeIcon(largeIcon) .setNumber(number == null ? 0 : number).setSmallIcon(iconResId).setWhen(mClock.getTime()) .setTicker(ticker).setOngoing(ongoing); if (enableAudio) { setupSoundAndVibration(builder, account); } return builder; } /** * Generic notifier for any account. Uses notification rules from account. * * @param accountId The account id this notification is being built for. * @param ticker Text displayed when the notification is first shown. May be {@code null}. * @param title The first line of text. May NOT be {@code null}. * @param contentText The second line of text. May NOT be {@code null}. * @param intent The intent to start if the user clicks on the notification. * @param notificationId The ID of the notification to register with the service. */ private void showNotification(long accountId, String ticker, String title, String contentText, Intent intent, int notificationId) { final NotificationCompat.Builder builder = createBaseAccountNotificationBuilder(accountId, ticker, title, contentText, intent, null, null, true, needsOngoingNotification(notificationId)); mNotificationManager.notify(notificationId, builder.build()); } /** * Tells the notification controller if it should be watching for changes to the message table. * This is the main life cycle method for message notifications. When we stop observing * database changes, we save the state [e.g. message ID and count] of the most recent * notification shown to the user. And, when we start observing database changes, we restore * the saved state. */ public void watchForMessages() { ensureHandlerExists(); // Run this on the message notification handler sNotificationHandler.post(new Runnable() { @Override public void run() { ContentResolver resolver = mContext.getContentResolver(); // otherwise, start new observers for all notified accounts registerMessageNotification(Account.ACCOUNT_ID_COMBINED_VIEW); // If we're already observing account changes, don't do anything else if (mAccountObserver == null) { LogUtils.i(LOG_TAG, "Observing account changes for notifications"); mAccountObserver = new AccountContentObserver(sNotificationHandler, mContext); resolver.registerContentObserver(Account.NOTIFIER_URI, true, mAccountObserver); } } }); } /** * Ensures the notification handler exists and is ready to handle requests. */ /** * TODO: Notifications jump around too much because we get too many content updates. * We should try to make the provider generate fewer updates instead. */ private static final int NOTIFICATION_DELAYED_MESSAGE = 0; private static final long NOTIFICATION_DELAY = 15 * DateUtils.SECOND_IN_MILLIS; // True if we're coalescing notification updates private static boolean sNotificationDelayedMessagePending; // True if accounts have changed and we need to refresh everything private static boolean sRefreshAllNeeded; // Set of accounts we need to regenerate notifications for private static final HashSet<Long> sRefreshAccountSet = new HashSet<Long>(); // These should all be accessed on-thread, but just in case... private static final Object sNotificationDelayedMessageLock = new Object(); private static synchronized void ensureHandlerExists() { if (sNotificationThread == null) { sNotificationThread = new NotificationThread(); sNotificationHandler = new Handler(sNotificationThread.getLooper(), new Handler.Callback() { @Override public boolean handleMessage(final android.os.Message message) { /** * To reduce spamming the notifications, we quiesce updates for a few * seconds to batch them up, then handle them here. */ LogUtils.d(LOG_TAG, "Delayed notification processing"); synchronized (sNotificationDelayedMessageLock) { sNotificationDelayedMessagePending = false; final Context context = (Context) message.obj; if (sRefreshAllNeeded) { sRefreshAllNeeded = false; refreshAllNotificationsInternal(context); } for (final Long accountId : sRefreshAccountSet) { refreshNotificationsForAccountInternal(context, accountId); } sRefreshAccountSet.clear(); } return true; } }); } } /** * Registers an observer for changes to mailboxes in the given account. * NOTE: This must be called on the notification handler thread. * @param accountId The ID of the account to register the observer for. May be * {@link Account#ACCOUNT_ID_COMBINED_VIEW} to register observers for all * accounts that allow for user notification. */ private void registerMessageNotification(final long accountId) { ContentResolver resolver = mContext.getContentResolver(); if (accountId == Account.ACCOUNT_ID_COMBINED_VIEW) { Cursor c = resolver.query(Account.CONTENT_URI, EmailContent.ID_PROJECTION, null, null, null); try { while (c.moveToNext()) { long id = c.getLong(EmailContent.ID_PROJECTION_COLUMN); registerMessageNotification(id); } } finally { c.close(); } } else { ContentObserver obs = mNotificationMap.get(accountId); if (obs != null) return; // we're already observing; nothing to do LogUtils.i(LOG_TAG, "Registering for notifications for account " + accountId); ContentObserver observer = new MessageContentObserver(sNotificationHandler, mContext, accountId); resolver.registerContentObserver(Message.NOTIFIER_URI, true, observer); mNotificationMap.put(accountId, observer); // Now, ping the observer for any initial notifications observer.onChange(true); } } /** * Unregisters the observer for the given account. If the specified account does not have * a registered observer, no action is performed. This will not clear any existing notification * for the specified account. Use {@link NotificationManager#cancel(int)}. * NOTE: This must be called on the notification handler thread. * @param accountId The ID of the account to unregister from. To unregister all accounts that * have observers, specify an ID of {@link Account#ACCOUNT_ID_COMBINED_VIEW}. */ private void unregisterMessageNotification(final long accountId) { ContentResolver resolver = mContext.getContentResolver(); if (accountId == Account.ACCOUNT_ID_COMBINED_VIEW) { LogUtils.i(LOG_TAG, "Unregistering notifications for all accounts"); // cancel all existing message observers for (ContentObserver observer : mNotificationMap.values()) { resolver.unregisterContentObserver(observer); } mNotificationMap.clear(); } else { LogUtils.i(LOG_TAG, "Unregistering notifications for account " + accountId); ContentObserver observer = mNotificationMap.remove(accountId); if (observer != null) { resolver.unregisterContentObserver(observer); } } } public static final String EXTRA_ACCOUNT = "account"; public static final String EXTRA_CONVERSATION = "conversationUri"; public static final String EXTRA_FOLDER = "folder"; /** Sets up the notification's sound and vibration based upon account details. */ private void setupSoundAndVibration(NotificationCompat.Builder builder, Account account) { String ringtoneUri = Settings.System.DEFAULT_NOTIFICATION_URI.toString(); boolean vibrate = false; // Use the Inbox notification preferences final Cursor accountCursor = mContext.getContentResolver().query( EmailProvider.uiUri("uiaccount", account.mId), UIProvider.ACCOUNTS_PROJECTION, null, null, null); com.android.mail.providers.Account uiAccount = null; try { if (accountCursor.moveToFirst()) { uiAccount = new com.android.mail.providers.Account(accountCursor); } } finally { accountCursor.close(); } if (uiAccount != null) { final Cursor folderCursor = mContext.getContentResolver().query(uiAccount.settings.defaultInbox, UIProvider.FOLDERS_PROJECTION, null, null, null); if (folderCursor == null) { // This can happen when the notification is for the security policy notification // that happens before the account is setup LogUtils.w(LOG_TAG, "Null folder cursor for mailbox %s", uiAccount.settings.defaultInbox); } else { Folder folder = null; try { if (folderCursor.moveToFirst()) { folder = new Folder(folderCursor); } } finally { folderCursor.close(); } if (folder != null) { final FolderPreferences folderPreferences = new FolderPreferences(mContext, uiAccount.getEmailAddress(), folder, true /* inbox */); ringtoneUri = folderPreferences.getNotificationRingtoneUri(); vibrate = folderPreferences.isNotificationVibrateEnabled(); } else { LogUtils.e(LOG_TAG, "Null folder for mailbox %s", uiAccount.settings.defaultInbox); } } } else { LogUtils.e(LOG_TAG, "Null uiAccount for account id %d", account.mId); } int defaults = Notification.DEFAULT_LIGHTS; if (vibrate) { defaults |= Notification.DEFAULT_VIBRATE; } builder.setSound(TextUtils.isEmpty(ringtoneUri) ? null : Uri.parse(ringtoneUri)).setDefaults(defaults); } /** * Show (or update) a notification that the given attachment could not be forwarded. This * is a very unusual case, and perhaps we shouldn't even send a notification. For now, * it's helpful for debugging. * * NOTE: DO NOT CALL THIS METHOD FROM THE UI THREAD (DATABASE ACCESS) */ public void showDownloadForwardFailedNotification(Attachment attachment) { Message message = Message.restoreMessageWithId(mContext, attachment.mMessageKey); if (message == null) return; Mailbox mailbox = Mailbox.restoreMailboxWithId(mContext, message.mMailboxKey); showNotification(mailbox.mAccountKey, mContext.getString(R.string.forward_download_failed_ticker), mContext.getString(R.string.forward_download_failed_title), attachment.mFileName, null, NOTIFICATION_ID_ATTACHMENT_WARNING); } /** * Returns a notification ID for login failed notifications for the given account account. */ private static int getLoginFailedNotificationId(long accountId) { return NOTIFICATION_ID_BASE_LOGIN_WARNING + (int) accountId; } /** * Show (or update) a notification that there was a login failure for the given account. * * NOTE: DO NOT CALL THIS METHOD FROM THE UI THREAD (DATABASE ACCESS) */ public void showLoginFailedNotification(long accountId) { showLoginFailedNotification(accountId, null); } public void showLoginFailedNotification(long accountId, String reason) { final Account account = Account.restoreAccountWithId(mContext, accountId); if (account == null) return; final Mailbox mailbox = Mailbox.restoreMailboxOfType(mContext, account.mId, Mailbox.TYPE_INBOX); if (mailbox == null) return; showNotification(mailbox.mAccountKey, mContext.getString(R.string.login_failed_ticker, account.mDisplayName), mContext.getString(R.string.login_failed_title), account.getDisplayName(), AccountSettings.createAccountSettingsIntent(accountId, account.mDisplayName, reason), getLoginFailedNotificationId(accountId)); } /** * Cancels the login failed notification for the given account. */ public void cancelLoginFailedNotification(long accountId) { mNotificationManager.cancel(getLoginFailedNotificationId(accountId)); } /** * Show (or update) a notification that the user's password is expiring. The given account * is used to update the display text, but, all accounts share the same notification ID. * * NOTE: DO NOT CALL THIS METHOD FROM THE UI THREAD (DATABASE ACCESS) */ public void showPasswordExpiringNotification(long accountId) { Account account = Account.restoreAccountWithId(mContext, accountId); if (account == null) return; Intent intent = AccountSecurity.actionDevicePasswordExpirationIntent(mContext, accountId, false); String accountName = account.getDisplayName(); String ticker = mContext.getString(R.string.password_expire_warning_ticker_fmt, accountName); String title = mContext.getString(R.string.password_expire_warning_content_title); showNotification(accountId, ticker, title, accountName, intent, NOTIFICATION_ID_PASSWORD_EXPIRING); } /** * Show (or update) a notification that the user's password has expired. The given account * is used to update the display text, but, all accounts share the same notification ID. * * NOTE: DO NOT CALL THIS METHOD FROM THE UI THREAD (DATABASE ACCESS) */ public void showPasswordExpiredNotification(long accountId) { Account account = Account.restoreAccountWithId(mContext, accountId); if (account == null) return; Intent intent = AccountSecurity.actionDevicePasswordExpirationIntent(mContext, accountId, true); String accountName = account.getDisplayName(); String ticker = mContext.getString(R.string.password_expired_ticker); String title = mContext.getString(R.string.password_expired_content_title); showNotification(accountId, ticker, title, accountName, intent, NOTIFICATION_ID_PASSWORD_EXPIRED); } /** * Cancels any password expire notifications [both expired & expiring]. */ public void cancelPasswordExpirationNotifications() { mNotificationManager.cancel(NOTIFICATION_ID_PASSWORD_EXPIRING); mNotificationManager.cancel(NOTIFICATION_ID_PASSWORD_EXPIRED); } /** * Show (or update) a security needed notification. If tapped, the user is taken to a * dialog asking whether he wants to update his settings. */ public void showSecurityNeededNotification(Account account) { Intent intent = AccountSecurity.actionUpdateSecurityIntent(mContext, account.mId, true); String accountName = account.getDisplayName(); String ticker = mContext.getString(R.string.security_needed_ticker_fmt, accountName); String title = mContext.getString(R.string.security_notification_content_update_title); showNotification(account.mId, ticker, title, accountName, intent, (int) (NOTIFICATION_ID_BASE_SECURITY_NEEDED + account.mId)); } /** * Show (or update) a security changed notification. If tapped, the user is taken to the * account settings screen where he can view the list of enforced policies */ public void showSecurityChangedNotification(Account account) { Intent intent = AccountSettings.createAccountSettingsIntent(account.mId, null, null); String accountName = account.getDisplayName(); String ticker = mContext.getString(R.string.security_changed_ticker_fmt, accountName); String title = mContext.getString(R.string.security_notification_content_change_title); showNotification(account.mId, ticker, title, accountName, intent, (int) (NOTIFICATION_ID_BASE_SECURITY_CHANGED + account.mId)); } /** * Show (or update) a security unsupported notification. If tapped, the user is taken to the * account settings screen where he can view the list of unsupported policies */ public void showSecurityUnsupportedNotification(Account account) { Intent intent = AccountSettings.createAccountSettingsIntent(account.mId, null, null); String accountName = account.getDisplayName(); String ticker = mContext.getString(R.string.security_unsupported_ticker_fmt, accountName); String title = mContext.getString(R.string.security_notification_content_unsupported_title); showNotification(account.mId, ticker, title, accountName, intent, (int) (NOTIFICATION_ID_BASE_SECURITY_NEEDED + account.mId)); } /** * Cancels all security needed notifications. */ public void cancelSecurityNeededNotification() { EmailAsyncTask.runAsyncParallel(new Runnable() { @Override public void run() { Cursor c = mContext.getContentResolver().query(Account.CONTENT_URI, Account.ID_PROJECTION, null, null, null); try { while (c.moveToNext()) { long id = c.getLong(Account.ID_PROJECTION_COLUMN); mNotificationManager.cancel((int) (NOTIFICATION_ID_BASE_SECURITY_NEEDED + id)); } } finally { c.close(); } } }); } /** * Cancels all notifications for the specified account id. This includes new mail notifications, * as well as special login/security notifications. */ public static void cancelNotifications(final Context context, final Account account) { final EmailServiceUtils.EmailServiceInfo serviceInfo = EmailServiceUtils.getServiceInfoForAccount(context, account.mId); if (serviceInfo == null) { LogUtils.d(LOG_TAG, "Can't cancel notification for missing account %d", account.mId); return; } final android.accounts.Account notifAccount = account.getAccountManagerAccount(serviceInfo.accountType); NotificationUtils.clearAccountNotifications(context, notifAccount); final NotificationManager notificationManager = getInstance(context).mNotificationManager; notificationManager.cancel((int) (NOTIFICATION_ID_BASE_LOGIN_WARNING + account.mId)); notificationManager.cancel((int) (NOTIFICATION_ID_BASE_SECURITY_NEEDED + account.mId)); notificationManager.cancel((int) (NOTIFICATION_ID_BASE_SECURITY_CHANGED + account.mId)); } private static void refreshNotificationsForAccount(final Context context, final long accountId) { synchronized (sNotificationDelayedMessageLock) { if (sNotificationDelayedMessagePending) { sRefreshAccountSet.add(accountId); } else { ensureHandlerExists(); sNotificationHandler.sendMessageDelayed( android.os.Message.obtain(sNotificationHandler, NOTIFICATION_DELAYED_MESSAGE, context), NOTIFICATION_DELAY); sNotificationDelayedMessagePending = true; refreshNotificationsForAccountInternal(context, accountId); } } } private static void refreshNotificationsForAccountInternal(final Context context, final long accountId) { final ContentResolver contentResolver = context.getContentResolver(); final Cursor accountCursor = contentResolver.query(EmailProvider.uiUri("uiaccount", accountId), UIProvider.ACCOUNTS_PROJECTION, null, null, null); if (accountCursor == null) { LogUtils.e(LOG_TAG, "Null account cursor for account id %d", accountId); return; } com.android.mail.providers.Account account = null; try { if (accountCursor.moveToFirst()) { account = new com.android.mail.providers.Account(accountCursor); } } finally { accountCursor.close(); } if (account == null) { LogUtils.d(LOG_TAG, "Tried to create a notification for a missing account %d", accountId); return; } final Cursor mailboxCursor = contentResolver.query( ContentUris.withAppendedId(EmailContent.MAILBOX_NOTIFICATION_URI, accountId), null, null, null, null); try { while (mailboxCursor.moveToNext()) { final long mailboxId = mailboxCursor.getLong(EmailContent.NOTIFICATION_MAILBOX_ID_COLUMN); if (mailboxId == 0) continue; final int unreadCount = mailboxCursor.getInt(EmailContent.NOTIFICATION_MAILBOX_UNREAD_COUNT_COLUMN); final int unseenCount = mailboxCursor.getInt(EmailContent.NOTIFICATION_MAILBOX_UNSEEN_COUNT_COLUMN); final Cursor folderCursor = contentResolver.query(EmailProvider.uiUri("uifolder", mailboxId), UIProvider.FOLDERS_PROJECTION, null, null, null); if (folderCursor == null) { LogUtils.e(LOG_TAG, "Null folder cursor for account %d, mailbox %d", accountId, mailboxId); continue; } Folder folder = null; try { if (folderCursor.moveToFirst()) { folder = new Folder(folderCursor); } else { LogUtils.e(LOG_TAG, "Empty folder cursor for account %d, mailbox %d", accountId, mailboxId); continue; } } finally { folderCursor.close(); } LogUtils.d(LOG_TAG, "Changes to account " + account.name + ", folder: " + folder.name + ", unreadCount: " + unreadCount + ", unseenCount: " + unseenCount); NotificationUtils.setNewEmailIndicator(context, unreadCount, unseenCount, account, folder, true); } } finally { mailboxCursor.close(); } } private static void refreshAllNotifications(final Context context) { synchronized (sNotificationDelayedMessageLock) { if (sNotificationDelayedMessagePending) { sRefreshAllNeeded = true; } else { ensureHandlerExists(); sNotificationHandler.sendMessageDelayed( android.os.Message.obtain(sNotificationHandler, NOTIFICATION_DELAYED_MESSAGE, context), NOTIFICATION_DELAY); sNotificationDelayedMessagePending = true; refreshAllNotificationsInternal(context); } } } private static void refreshAllNotificationsInternal(final Context context) { NotificationUtils.resendNotifications(context, false, null, null); } /** * Observer invoked whenever a message we're notifying the user about changes. */ private static class MessageContentObserver extends ContentObserver { private final Context mContext; private final long mAccountId; public MessageContentObserver(final Handler handler, final Context context, final long accountId) { super(handler); mContext = context; mAccountId = accountId; } @Override public void onChange(final boolean selfChange) { refreshNotificationsForAccount(mContext, mAccountId); } } /** * Observer invoked whenever an account is modified. This could mean the user changed the * notification settings. */ private static class AccountContentObserver extends ContentObserver { private final Context mContext; public AccountContentObserver(final Handler handler, final Context context) { super(handler); mContext = context; } @Override public void onChange(final boolean selfChange) { final ContentResolver resolver = mContext.getContentResolver(); final Cursor c = resolver.query(Account.CONTENT_URI, EmailContent.ID_PROJECTION, null, null, null); final Set<Long> newAccountList = new HashSet<Long>(); final Set<Long> removedAccountList = new HashSet<Long>(); if (c == null) { // Suspender time ... theoretically, this will never happen LogUtils.wtf(LOG_TAG, "#onChange(); NULL response for account id query"); return; } try { while (c.moveToNext()) { long accountId = c.getLong(EmailContent.ID_PROJECTION_COLUMN); newAccountList.add(accountId); } } finally { c.close(); } // NOTE: Looping over three lists is not necessarily the most efficient. However, the // account lists are going to be very small, so, this will not be necessarily bad. // Cycle through existing notification list and adjust as necessary for (final long accountId : sInstance.mNotificationMap.keySet()) { if (!newAccountList.remove(accountId)) { // account id not in the current set of notifiable accounts removedAccountList.add(accountId); } } // A new account was added to the notification list for (final long accountId : newAccountList) { sInstance.registerMessageNotification(accountId); } // An account was removed from the notification list for (final long accountId : removedAccountList) { sInstance.unregisterMessageNotification(accountId); } refreshAllNotifications(mContext); } } /** * Thread to handle all notification actions through its own {@link Looper}. */ private static class NotificationThread implements Runnable { /** Lock to ensure proper initialization */ private final Object mLock = new Object(); /** The {@link Looper} that handles messages for this thread */ private Looper mLooper; public NotificationThread() { new Thread(null, this, "EmailNotification").start(); synchronized (mLock) { while (mLooper == null) { try { mLock.wait(); } catch (InterruptedException ex) { // Loop around and wait again } } } } @Override public void run() { synchronized (mLock) { Looper.prepare(); mLooper = Looper.myLooper(); mLock.notifyAll(); } Process.setThreadPriority(Process.THREAD_PRIORITY_BACKGROUND); Looper.loop(); } public Looper getLooper() { return mLooper; } } }