com.google.android.apps.paco.AlarmCreator2.java Source code

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Here is the source code for com.google.android.apps.paco.AlarmCreator2.java

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/*
* Copyright 2011 Google Inc. All Rights Reserved.
* 
* 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.google.android.apps.paco;

import java.util.List;

import org.joda.time.DateTime;

import android.app.AlarmManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.util.Log;

import com.google.android.apps.paco.ExperimentAlarms.TimeExperiment;

/**
 * Class that is responsible for keeping the alarm schedule.
 * 
 * Android drops alarms. This class retrieves them from an AlarmStore, and also 
 * uses a generator to generate alarms for a survey according to user preferences.
 * 
 * It's a bit overly decoupled at the moment, that will change as the surveys become 
 * first class objects with different scheduling frequencies.
 * 
 * 
 *
 */
public class AlarmCreator2 {

    private static final int ALARM_RECEIVER_INTENT_REQUEST_CODE = 1;

    /**
     * Produce an AlarmCreator with a context.
     * 
     * @param context Android context from caller.
     * @return AlarmCreator 
     */
    public static AlarmCreator2 createAlarmCreator(Context context) {
        AlarmManager alarmManager = (AlarmManager) context.getSystemService(Service.ALARM_SERVICE);
        Context contextForPendingIntent = context.getApplicationContext();
        return new AlarmCreator2(alarmManager, contextForPendingIntent);
    }

    private AlarmManager alarmManager;
    private Context pendingIntentContext;

    /**
     * An Alarm creator will generate alarms to a given schedule for a 
     * given Experiment.
     * 
     * @param alarmManager
     * @param contextForPendingIntent An Android Context that provides access to system services.
     */
    AlarmCreator2(AlarmManager alarmManager, Context contextForPendingIntent) {
        this.alarmManager = alarmManager;
        this.pendingIntentContext = contextForPendingIntent;
    }

    /**
     * Generate an Android alarm for the next due experiment. 
     * 
     * @param regenerateAlarms
     */
    public void updateAlarm() {
        ExperimentProviderUtil experimentProviderUtil = new ExperimentProviderUtil(pendingIntentContext);
        List<Experiment> experiments = experimentProviderUtil.getJoinedExperiments();
        if (experiments.isEmpty()) {
            Log.i(PacoConstants.TAG, "No joined experiments. Not creating alarms.");
            return;
        }

        List<TimeExperiment> experimentTimes = ExperimentAlarms.arrangeExperimentsByNextTime(experiments,
                pendingIntentContext);
        if (experimentTimes.isEmpty()) {
            Log.i(PacoConstants.TAG, "No experiments with a next time to signal.");
            return;
        }
        TimeExperiment nextNearestAlarmTime = experimentTimes.get(0);
        createAlarm(nextNearestAlarmTime.time, nextNearestAlarmTime.experiment);
    }

    void createAlarm(DateTime alarmTime, Experiment experiment) {
        Log.i(PacoConstants.TAG,
                "Creating alarm: " + alarmTime.toString() + " for experiment: " + experiment.getTitle());
        PendingIntent intent = createAlarmReceiverIntentForExperiment(alarmTime);
        alarmManager.cancel(intent);
        alarmManager.set(AlarmManager.RTC_WAKEUP, alarmTime.getMillis(), intent);
    }

    /**
     * Create an AlarmReceiver PendingIntent for the next experiment.
     *  
     * @param alarmTime Time to trigger notification
     * @return
     */
    private PendingIntent createAlarmReceiverIntentForExperiment(DateTime alarmTime) {
        Intent ultimateIntent = new Intent(pendingIntentContext, AlarmReceiver.class);
        ultimateIntent.putExtra(Experiment.SCHEDULED_TIME, alarmTime.getMillis());
        return PendingIntent.getBroadcast(pendingIntentContext, ALARM_RECEIVER_INTENT_REQUEST_CODE, ultimateIntent,
                PendingIntent.FLAG_UPDATE_CURRENT);
    }

}