xref: /packages/apps/Calendar/src/com/android/calendar/alerts/AlertService.java

/*
 * Copyright (C) 2008 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.calendar.alerts;

import com.android.calendar.GeneralPreferences;
import com.android.calendar.R;

import android.app.AlarmManager;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.Service;
import android.content.ContentResolver;
import android.content.ContentUris;
import android.content.ContentValues;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.media.AudioManager;
import android.net.Uri;
import android.os.Bundle;
import android.os.Handler;
import android.os.HandlerThread;
import android.os.IBinder;
import android.os.Looper;
import android.os.Message;
import android.os.Process;
import android.provider.CalendarContract;
import android.provider.CalendarContract.Attendees;
import android.provider.CalendarContract.CalendarAlerts;
import android.text.TextUtils;
import android.text.format.DateUtils;
import android.util.Log;

import java.util.ArrayList;
import java.util.HashMap;

/**
 * This service is used to handle calendar event reminders.
 */
public class AlertService extends Service {
    static final boolean DEBUG = true;
    private static final String TAG = "AlertService";

    private volatile Looper mServiceLooper;
    private volatile ServiceHandler mServiceHandler;

    private static final String[] ALERT_PROJECTION = new String[] {
        CalendarAlerts._ID,                     // 0
        CalendarAlerts.EVENT_ID,                // 1
        CalendarAlerts.STATE,                   // 2
        CalendarAlerts.TITLE,                   // 3
        CalendarAlerts.EVENT_LOCATION,          // 4
        CalendarAlerts.SELF_ATTENDEE_STATUS,    // 5
        CalendarAlerts.ALL_DAY,                 // 6
        CalendarAlerts.ALARM_TIME,              // 7
        CalendarAlerts.MINUTES,                 // 8
        CalendarAlerts.BEGIN,                   // 9
        CalendarAlerts.END,                     // 10
        CalendarAlerts.DESCRIPTION,             // 11
    };

    private static final int ALERT_INDEX_ID = 0;
    private static final int ALERT_INDEX_EVENT_ID = 1;
    private static final int ALERT_INDEX_STATE = 2;
    private static final int ALERT_INDEX_TITLE = 3;
    private static final int ALERT_INDEX_EVENT_LOCATION = 4;
    private static final int ALERT_INDEX_SELF_ATTENDEE_STATUS = 5;
    private static final int ALERT_INDEX_ALL_DAY = 6;
    private static final int ALERT_INDEX_ALARM_TIME = 7;
    private static final int ALERT_INDEX_MINUTES = 8;
    private static final int ALERT_INDEX_BEGIN = 9;
    private static final int ALERT_INDEX_END = 10;
    private static final int ALERT_INDEX_DESCRIPTION = 11;

    private static final String ACTIVE_ALERTS_SELECTION = "(" + CalendarAlerts.STATE + "=? OR "
            + CalendarAlerts.STATE + "=?) AND " + CalendarAlerts.ALARM_TIME + "<=";

    private static final String[] ACTIVE_ALERTS_SELECTION_ARGS = new String[] {
            Integer.toString(CalendarAlerts.STATE_FIRED),
            Integer.toString(CalendarAlerts.STATE_SCHEDULED)
    };

    private static final String ACTIVE_ALERTS_SORT = "begin DESC, end DESC";

    private static final String DISMISS_OLD_SELECTION = CalendarAlerts.END + "<? AND "
            + CalendarAlerts.STATE + "=?";

    // The grace period before changing a notification's priority bucket.
    private static final int DEPRIORITIZE_GRACE_PERIOD_MS = 15 * 60 * 1000;

    void processMessage(Message msg) {
        Bundle bundle = (Bundle) msg.obj;

        // On reboot, update the notification bar with the contents of the
        // CalendarAlerts table.
        String action = bundle.getString("action");
        if (DEBUG) {
            Log.d(TAG, bundle.getLong(android.provider.CalendarContract.CalendarAlerts.ALARM_TIME)
                    + " Action = " + action);
        }

        if (action.equals(Intent.ACTION_BOOT_COMPLETED)
                || action.equals(Intent.ACTION_TIME_CHANGED)) {
            doTimeChanged();
            return;
        }

        if (!action.equals(android.provider.CalendarContract.ACTION_EVENT_REMINDER)
                && !action.equals(Intent.ACTION_LOCALE_CHANGED)
                && !action.equals(AlertReceiver.ACTION_DISMISS_OLD_REMINDERS)) {
            Log.w(TAG, "Invalid action: " + action);
            return;
        }
        if (action.equals(AlertReceiver.ACTION_DISMISS_OLD_REMINDERS)) {
            dismissOldAlerts(this);
        }

        if (action.equals(android.provider.CalendarContract.ACTION_EVENT_REMINDER) &&
                bundle.getBoolean(AlertUtils.QUIET_UPDATE_KEY)) {
            updateAlertNotification(this, true);
        } else {
            updateAlertNotification(this, false);
        }
    }

    static void dismissOldAlerts(Context context) {
        ContentResolver cr = context.getContentResolver();
        final long currentTime = System.currentTimeMillis();
        ContentValues vals = new ContentValues();
        vals.put(CalendarAlerts.STATE, CalendarAlerts.STATE_DISMISSED);
        cr.update(CalendarAlerts.CONTENT_URI, vals, DISMISS_OLD_SELECTION, new String[] {
                Long.toString(currentTime), Integer.toString(CalendarAlerts.STATE_SCHEDULED)
        });
    }

    static boolean updateAlertNotification(Context context, boolean quietUpdate) {
        ContentResolver cr = context.getContentResolver();
        NotificationManager nm =
                (NotificationManager) context.getSystemService(Context.NOTIFICATION_SERVICE);
        final long currentTime = System.currentTimeMillis();
        SharedPreferences prefs = GeneralPreferences.getSharedPreferences(context);

        boolean doAlert = prefs.getBoolean(GeneralPreferences.KEY_ALERTS, true);
        if (!doAlert) {
            if (DEBUG) {
                Log.d(TAG, "alert preference is OFF");
            }

            // If we shouldn't be showing notifications cancel any existing ones
            // and return.
            nm.cancelAll();
            return true;
        }

        Cursor alertCursor = cr.query(CalendarAlerts.CONTENT_URI, ALERT_PROJECTION,
                (ACTIVE_ALERTS_SELECTION + currentTime), ACTIVE_ALERTS_SELECTION_ARGS,
                ACTIVE_ALERTS_SORT);

        if (alertCursor == null || alertCursor.getCount() == 0) {
            if (alertCursor != null) {
                alertCursor.close();
            }

            if (DEBUG) Log.d(TAG, "No fired or scheduled alerts");
            nm.cancelAll();
            return false;
        }

        if (DEBUG) {
            Log.d(TAG, "alert count:" + alertCursor.getCount());
        }

        // Process the query results and bucketize events.
        ArrayList<NotificationInfo> highPriorityEvents = new ArrayList<NotificationInfo>();
        ArrayList<NotificationInfo> mediumPriorityEvents = new ArrayList<NotificationInfo>();
        ArrayList<NotificationInfo> expiredEvents = new ArrayList<NotificationInfo>();
        StringBuilder expiredDigestTitleBuilder = new StringBuilder();
        int numFired = processQuery(alertCursor, cr, currentTime, highPriorityEvents,
                mediumPriorityEvents, expiredEvents, expiredDigestTitleBuilder);
        String expiredDigestTitle = expiredDigestTitleBuilder.toString();

        if (highPriorityEvents.size() + mediumPriorityEvents.size() + expiredEvents.size() == 0) {
            nm.cancelAll();
            return true;
        }

        quietUpdate = quietUpdate || (numFired == 0);
        boolean doPopup = numFired > 0 &&
                prefs.getBoolean(GeneralPreferences.KEY_ALERTS_POPUP, false);
        boolean defaultVibrate = shouldUseDefaultVibrate(context, prefs);
        String ringtone = quietUpdate ? null : prefs.getString(
                GeneralPreferences.KEY_ALERTS_RINGTONE, null);
        boolean notificationPosted = false;
        long nextRefreshTime = Long.MAX_VALUE;

        // Post the individual higher priority events (future and recently started
        // concurrent events).  Order these so that earlier start times appear higher in
        // the notification list.
        for (NotificationInfo info : highPriorityEvents) {
            String summaryText = AlertUtils.formatTimeLocation(context, info.startMillis,
                    info.allDay, info.location);
            postNotification(info, summaryText, context, quietUpdate, doPopup, defaultVibrate,
                    ringtone, true, notificationPosted, nm);
            notificationPosted = true;
        }

        // Post the medium priority events (concurrent events that started a while ago).
        // Order these so more recent start times appear higher in the notification list.
        for (int i = mediumPriorityEvents.size() - 1; i >= 0; i--) {
            NotificationInfo info = mediumPriorityEvents.get(i);
            // TODO: Change to a relative time description like: "Started 40 minutes ago".
            // This requires constant refreshing to the message as time goes.
            String summaryText = AlertUtils.formatTimeLocation(context, info.startMillis,
                    info.allDay, info.location);

            // Refresh when concurrent event ends so it will drop into the expired digest.
            nextRefreshTime = Math.min(nextRefreshTime, info.endMillis);

            postNotification(info, summaryText, context, quietUpdate, false, defaultVibrate,
                    ringtone, false, notificationPosted, nm);
            notificationPosted = true;
        }

        // Post the expired events as 1 combined notification.
        int numExpired = expiredEvents.size();
        if (numExpired > 0) {
            Notification notification;
            if (numExpired == 1) {
                // If only 1 expired event, display an "old-style" basic alert.
                NotificationInfo info = expiredEvents.get(0);
                String summaryText = AlertUtils.formatTimeLocation(context, info.startMillis,
                        info.allDay, info.location);
                notification = AlertReceiver.makeBasicNotification(context, info.eventName,
                        summaryText, info.startMillis, info.endMillis, info.eventId,
                        info.notificationId, false);
            } else {
                // Multiple expired events are listed in a digest.
                notification = AlertReceiver.makeDigestNotification(context,
                    expiredEvents, expiredDigestTitle, false);
            }

            // Add options for a quiet update.
            addNotificationOptions(notification, true, expiredDigestTitle, defaultVibrate,
                    ringtone, notificationPosted);

            // Remove any individual expired notifications before posting.
            for (NotificationInfo expiredInfo : expiredEvents) {
                nm.cancel(expiredInfo.notificationId);
            }

            // Post the new notification for the group.
            nm.notify(AlertUtils.EXPIRED_GROUP_NOTIFICATION_ID, notification);
            notificationPosted = true;

            if (DEBUG) {
                Log.d(TAG, "Posting digest alarm notification, numEvents:" + expiredEvents.size()
                        + ", notificationId:" + AlertUtils.EXPIRED_GROUP_NOTIFICATION_ID
                        + (quietUpdate ? ", quiet" : ", loud"));
            }
        } else {
            nm.cancel(AlertUtils.EXPIRED_GROUP_NOTIFICATION_ID);
        }

        // Schedule the next silent refresh time so notifications will change
        // buckets (eg. drop into expired digest, etc).
        if (nextRefreshTime > currentTime) {
            AlertUtils.scheduleNextNotificationRefresh(context, null, nextRefreshTime);
        } else if (nextRefreshTime < currentTime) {
            Log.e(TAG, "Illegal state: next notification refresh time found to be in the past.");
        }

        return true;
    }

    /**
     * Processes the query results and bucketizes the alerts.
     *
     * @param highPriorityEvents This will contain future events, and concurrent events
     *     that started recently (less than the interval DEPRIORITIZE_GRACE_PERIOD_MS).
     * @param mediumPriorityEvents This will contain concurrent events that started
     *     more than DEPRIORITIZE_GRACE_PERIOD_MS ago.
     * @param expiredEvents Will contain events that have ended.
     * @param expiredDigestTitle Should pass in an empty StringBuilder; this will be
     *     modified to contain a title consolidating all expired event titles.
     * @return Returns the number of new alerts to fire.  If this is 0, it implies
     *     a quiet update.
     */
    private static int processQuery(final Cursor alertCursor, final ContentResolver cr,
            final long currentTime, ArrayList<NotificationInfo> highPriorityEvents,
            ArrayList<NotificationInfo> mediumPriorityEvents,
            ArrayList<NotificationInfo> expiredEvents, StringBuilder expiredDigestTitle) {
        HashMap<Long, Long> eventIds = new HashMap<Long, Long>();
        int numFired = 0;
        try {
            while (alertCursor.moveToNext()) {
                final long alertId = alertCursor.getLong(ALERT_INDEX_ID);
                final long eventId = alertCursor.getLong(ALERT_INDEX_EVENT_ID);
                final int minutes = alertCursor.getInt(ALERT_INDEX_MINUTES);
                final String eventName = alertCursor.getString(ALERT_INDEX_TITLE);
                final String description = alertCursor.getString(ALERT_INDEX_DESCRIPTION);
                final String location = alertCursor.getString(ALERT_INDEX_EVENT_LOCATION);
                final int status = alertCursor.getInt(ALERT_INDEX_SELF_ATTENDEE_STATUS);
                final boolean declined = status == Attendees.ATTENDEE_STATUS_DECLINED;
                final long beginTime = alertCursor.getLong(ALERT_INDEX_BEGIN);
                final long endTime = alertCursor.getLong(ALERT_INDEX_END);
                final Uri alertUri = ContentUris
                        .withAppendedId(CalendarAlerts.CONTENT_URI, alertId);
                final long alarmTime = alertCursor.getLong(ALERT_INDEX_ALARM_TIME);
                int state = alertCursor.getInt(ALERT_INDEX_STATE);
                final boolean allDay = alertCursor.getInt(ALERT_INDEX_ALL_DAY) != 0;

                if (DEBUG) {
                    Log.d(TAG, "alarmTime:" + alarmTime + " alertId:" + alertId
                            + " eventId:" + eventId + " state: " + state + " minutes:" + minutes
                            + " declined:" + declined + " beginTime:" + beginTime
                            + " endTime:" + endTime);
                }

                ContentValues values = new ContentValues();
                int newState = -1;

                // Uncomment for the behavior of clearing out alerts after the
                // events ended. b/1880369
                //
                // if (endTime < currentTime) {
                //     newState = CalendarAlerts.DISMISSED;
                // } else

                // Remove declined events
                if (!declined) {
                    if (state == CalendarAlerts.STATE_SCHEDULED) {
                        newState = CalendarAlerts.STATE_FIRED;
                        numFired++;

                        // Record the received time in the CalendarAlerts table.
                        // This is useful for finding bugs that cause alarms to be
                        // missed or delayed.
                        values.put(CalendarAlerts.RECEIVED_TIME, currentTime);
                    }
                } else {
                    newState = CalendarAlerts.STATE_DISMISSED;
                }

                // Update row if state changed
                if (newState != -1) {
                    values.put(CalendarAlerts.STATE, newState);
                    state = newState;
                }

                if (state == CalendarAlerts.STATE_FIRED) {
                    // Record the time posting to notification manager.
                    // This is used for debugging missed alarms.
                    values.put(CalendarAlerts.NOTIFY_TIME, currentTime);
                }

                // Write row to if anything changed
                if (values.size() > 0) cr.update(alertUri, values, null, null);

                if (state != CalendarAlerts.STATE_FIRED) {
                    continue;
                }

                // Pick an Event title for the notification panel by the latest
                // alertTime and give prefer accepted events in case of ties.
                int newStatus;
                switch (status) {
                    case Attendees.ATTENDEE_STATUS_ACCEPTED:
                        newStatus = 2;
                        break;
                    case Attendees.ATTENDEE_STATUS_TENTATIVE:
                        newStatus = 1;
                        break;
                    default:
                        newStatus = 0;
                }

                // Don't count duplicate alerts for the same event
                if (eventIds.put(eventId, beginTime) == null) {
                    NotificationInfo notificationInfo = new NotificationInfo(eventName, location,
                            description, beginTime, endTime, eventId, allDay);

                    // TODO: Prioritize by "primary" calendar
                    long highPriorityCutoff = currentTime - DEPRIORITIZE_GRACE_PERIOD_MS;
                    if (beginTime > highPriorityCutoff) {
                        highPriorityEvents.add(notificationInfo);
                    } else if (endTime >= currentTime) {
                        mediumPriorityEvents.add(notificationInfo);
                    } else {
                        expiredEvents.add(notificationInfo);
                        if (!TextUtils.isEmpty(eventName)) {
                            if (expiredDigestTitle.length() > 0) {
                                expiredDigestTitle.append(", ");
                            }
                            expiredDigestTitle.append(eventName);
                        }
                    }
                }
            }
        } finally {
            if (alertCursor != null) {
                alertCursor.close();
            }
        }
        return numFired;
    }

    private static void postNotification(NotificationInfo info, String summaryText,
            Context context, boolean quietUpdate, boolean doPopup, boolean defaultVibrate,
            String ringtone, boolean highPriority, boolean invokedNotify,
            NotificationManager notificationMgr) {
        String tickerText = getTickerText(info.eventName, info.location);
        Notification notification = AlertReceiver.makeExpandingNotification(context,
                info.eventName, summaryText, info.description, info.startMillis,
                info.endMillis, info.eventId, info.notificationId, doPopup, highPriority);
        addNotificationOptions(notification, quietUpdate, tickerText, defaultVibrate,
                ringtone, invokedNotify);
        notificationMgr.notify(info.notificationId, notification);

        if (DEBUG) {
            Log.d(TAG, "Posting individual alarm notification, eventId:" + info.eventId
                    + ", notificationId:" + info.notificationId
                    + (quietUpdate ? ", quiet" : ", loud")
                    + (highPriority ? ", high-priority" : ""));
        }
    }

    private static String getTickerText(String eventName, String location) {
        String tickerText = eventName;
        if (!TextUtils.isEmpty(location)) {
            tickerText = eventName + " - " + location;
        }
        return tickerText;
    }

    static class NotificationInfo {
        String eventName;
        String location;
        String description;
        long startMillis;
        long endMillis;
        long eventId;
        int notificationId;
        boolean allDay;

        NotificationInfo(String eventName, String location, String description, long startMillis,
                long endMillis, long eventId, boolean allDay) {
            this.eventName = eventName;
            this.location = location;
            this.description = description;
            this.startMillis = startMillis;
            this.endMillis = endMillis;
            this.eventId = eventId;
            this.allDay = allDay;
            this.notificationId = getNotificationId(eventId, startMillis);
        }

        /*
         * Convert reminder into the ID for posting notifications.  Use hash so we don't
         * have to worry about any limits (but handle the case of a collision with the ID
         * reserved for representing the expired notification digest).
         */
        private static int getNotificationId(long eventId, long startMillis) {
            long result = 17;
            result = 37 * result + eventId;
            result = 37 * result + startMillis;
            int notificationId = Long.valueOf(result).hashCode();
            if (notificationId == AlertUtils.EXPIRED_GROUP_NOTIFICATION_ID) {
                notificationId = Integer.MAX_VALUE;
            }
            return notificationId;
        }
    }

    private static boolean shouldUseDefaultVibrate(Context context, SharedPreferences prefs) {
        // Find out the circumstances under which to vibrate.
        // Migrate from pre-Froyo boolean setting if necessary.
        String vibrateWhen; // "always" or "silent" or "never"
        if(prefs.contains(GeneralPreferences.KEY_ALERTS_VIBRATE_WHEN))
        {
            // Look up Froyo setting
            vibrateWhen =
                prefs.getString(GeneralPreferences.KEY_ALERTS_VIBRATE_WHEN, null);
        } else if(prefs.contains(GeneralPreferences.KEY_ALERTS_VIBRATE)) {
            // No Froyo setting. Migrate pre-Froyo setting to new Froyo-defined value.
            boolean vibrate =
                prefs.getBoolean(GeneralPreferences.KEY_ALERTS_VIBRATE, false);
            vibrateWhen = vibrate ?
                context.getString(R.string.prefDefault_alerts_vibrate_true) :
                context.getString(R.string.prefDefault_alerts_vibrate_false);
        } else {
            // No setting. Use Froyo-defined default.
            vibrateWhen = context.getString(R.string.prefDefault_alerts_vibrateWhen);
        }

        if (vibrateWhen.equals("always")) {
            return true;
        }
        if (!vibrateWhen.equals("silent")) {
            return false;
        }

        // Settings are to vibrate when silent.  Return true if it is now silent.
        AudioManager audioManager =
            (AudioManager)context.getSystemService(Context.AUDIO_SERVICE);
        return audioManager.getRingerMode() == AudioManager.RINGER_MODE_VIBRATE;
    }

    private static void addNotificationOptions(Notification notification, boolean quietUpdate,
            String tickerText, boolean defaultVibrate, String reminderRingtone,
            boolean invokedNotify) {
        notification.defaults |= Notification.DEFAULT_LIGHTS;

        // Quietly update notification bar. Nothing new. Maybe something just got deleted.
        if (!quietUpdate) {
            // Flash ticker in status bar
            if (!TextUtils.isEmpty(tickerText)) {
                notification.tickerText = tickerText;
            }

            // If we've already posted a notification, don't play any more sounds so only
            // 1 sound per group of notifications.
            if (!invokedNotify) {

                // Generate either a pop-up dialog, status bar notification, or
                // neither. Pop-up dialog and status bar notification may include a
                // sound, an alert, or both. A status bar notification also includes
                // a toast.
                if (defaultVibrate) {
                    notification.defaults |= Notification.DEFAULT_VIBRATE;
                }

                // Possibly generate a sound. If 'Silent' is chosen, the ringtone
                // string will be empty.
                notification.sound = TextUtils.isEmpty(reminderRingtone) ? null : Uri
                        .parse(reminderRingtone);
            }
        }
    }

    private void doTimeChanged() {
        ContentResolver cr = getContentResolver();
        Object service = getSystemService(Context.ALARM_SERVICE);
        AlarmManager manager = (AlarmManager) service;
        // TODO Move this into Provider
        rescheduleMissedAlarms(cr, this, manager);
        updateAlertNotification(this, false);
    }

    private static final String SORT_ORDER_ALARMTIME_ASC =
            CalendarContract.CalendarAlerts.ALARM_TIME + " ASC";

    private static final String WHERE_RESCHEDULE_MISSED_ALARMS =
            CalendarContract.CalendarAlerts.STATE
            + "="
            + CalendarContract.CalendarAlerts.STATE_SCHEDULED
            + " AND "
            + CalendarContract.CalendarAlerts.ALARM_TIME
            + "<?"
            + " AND "
            + CalendarContract.CalendarAlerts.ALARM_TIME
            + ">?"
            + " AND "
            + CalendarContract.CalendarAlerts.END + ">=?";

    /**
     * Searches the CalendarAlerts table for alarms that should have fired but
     * have not and then reschedules them. This method can be called at boot
     * time to restore alarms that may have been lost due to a phone reboot.
     *
     * @param cr the ContentResolver
     * @param context the Context
     * @param manager the AlarmManager
     */
    public static final void rescheduleMissedAlarms(ContentResolver cr, Context context,
            AlarmManager manager) {
        // Get all the alerts that have been scheduled but have not fired
        // and should have fired by now and are not too old.
        long now = System.currentTimeMillis();
        long ancient = now - DateUtils.DAY_IN_MILLIS;
        String[] projection = new String[] {
            CalendarContract.CalendarAlerts.ALARM_TIME,
        };

        // TODO: construct an explicit SQL query so that we can add
        // "GROUPBY" instead of doing a sort and de-dup
        Cursor cursor = cr.query(CalendarAlerts.CONTENT_URI, projection,
                WHERE_RESCHEDULE_MISSED_ALARMS, (new String[] {
                        Long.toString(now), Long.toString(ancient), Long.toString(now)
                }), SORT_ORDER_ALARMTIME_ASC);
        if (cursor == null) {
            return;
        }

        if (DEBUG) {
            Log.d(TAG, "missed alarms found: " + cursor.getCount());
        }

        try {
            long alarmTime = -1;

            while (cursor.moveToNext()) {
                long newAlarmTime = cursor.getLong(0);
                if (alarmTime != newAlarmTime) {
                    if (DEBUG) {
                        Log.w(TAG, "rescheduling missed alarm. alarmTime: " + newAlarmTime);
                    }
                    AlertUtils.scheduleAlarm(context, manager, newAlarmTime);
                    alarmTime = newAlarmTime;
                }
            }
        } finally {
            cursor.close();
        }
    }

    private final class ServiceHandler extends Handler {
        public ServiceHandler(Looper looper) {
            super(looper);
        }

        @Override
        public void handleMessage(Message msg) {
            processMessage(msg);
            // NOTE: We MUST not call stopSelf() directly, since we need to
            // make sure the wake lock acquired by AlertReceiver is released.
            AlertReceiver.finishStartingService(AlertService.this, msg.arg1);
        }
    }

    @Override
    public void onCreate() {
        HandlerThread thread = new HandlerThread("AlertService",
                Process.THREAD_PRIORITY_BACKGROUND);
        thread.start();

        mServiceLooper = thread.getLooper();
        mServiceHandler = new ServiceHandler(mServiceLooper);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        if (intent != null) {
            Message msg = mServiceHandler.obtainMessage();
            msg.arg1 = startId;
            msg.obj = intent.getExtras();
            mServiceHandler.sendMessage(msg);
        }
        return START_REDELIVER_INTENT;
    }

    @Override
    public void onDestroy() {
        mServiceLooper.quit();
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }
}