Wake the device up when app prompts user

Question

I\'m using handler to repeatedly prompt user for an input every e.g. 5 minutes. When the device goes into sleeping mode and screen is locked, how can I wake the device up wh

Answer 1

Take a look for AlarmManager class http://developer.android.com/reference/android/app/AlarmManager.html It's something like "cron"

Ok, here is a piece of working code - first comes the activity class:

import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Intent;
import android.os.Bundle;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;

public class MainActivity extends Activity {
    private WakeLock wl;

    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        //acquire wake lock
        PowerManager pm = (PowerManager) getSystemService(POWER_SERVICE);
        wl = pm.newWakeLock(PowerManager.ACQUIRE_CAUSES_WAKEUP|PowerManager.SCREEN_BRIGHT_WAKE_LOCK, "TAG");
        wl.acquire();

        // schedule alarm
        Intent i = new Intent();
        i.setAction(WakeReciever.WAKE_INTENT);
        PendingIntent pIntent = PendingIntent.getBroadcast(this, 0, i, 0);

        AlarmManager am = (AlarmManager) getSystemService(ALARM_SERVICE);
        am.set(AlarmManager.RTC_WAKEUP, System.currentTimeMillis() + 120000,
                pIntent);
    }

    @Override
    protected void onPause() {
        wl.release();
        super.onPause();
    }

}

Next comes BroadcastReceiver:

package com.test;

import android.content.BroadcastReceiver;
import android.content.Intent;
import android.content.Context;
import android.os.PowerManager;
import android.os.PowerManager.WakeLock;

public class WakeReciever extends BroadcastReceiver {
    public static final String WAKE_INTENT = "com.test.WAKE"; 


    /**
     * @see android.content.BroadcastReceiver#onReceive(Context,Intent)
     */
    @Override
    public void onReceive(Context context, Intent intent) {
        //acquire wake lock

        PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
        WakeLock wl = pm.newWakeLock(PowerManager.FULL_WAKE_LOCK | PowerManager.ACQUIRE_CAUSES_WAKEUP, "TAG");
        wl.acquire();


        //start activity
        Intent i = new Intent();
        i.setClassName("com.test", "com.test.MainActivity");
        i.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);

        context.startActivity(i);

        wl.release();
    }
}

And finally don't forget about the manifest file: