Program description:
This program will demo how to create alarms which will repeat at irregular intervals.
This program has one activity with one button, and a broadcast receiver.
On clicking the button, we will set an alarm for next 1 second, which triggers broadcast receiver.
Our program aim is to repeat next alarm at 2 seconds, next at 4 seconds, next at 8 seconds and so on.. For this requirement we can't use setRepeating() function of alarm manager.
We have to set the alarm manually in the receiver.
Once the first alarm (which was set for 1 second) is triggered, it will call broadcast receiver. In the receiver set alarm for next 2 seconds from that time. Which will again call same broadcast receiver after 2 seconds. Again set one more alarm for next 4 seconds in that receiver. For this we have to write a generic logic, because alarm has to repeat for n number of times.
First Activity:
This program will demo how to create alarms which will repeat at irregular intervals.
This program has one activity with one button, and a broadcast receiver.
On clicking the button, we will set an alarm for next 1 second, which triggers broadcast receiver.
Our program aim is to repeat next alarm at 2 seconds, next at 4 seconds, next at 8 seconds and so on.. For this requirement we can't use setRepeating() function of alarm manager.
We have to set the alarm manually in the receiver.
Once the first alarm (which was set for 1 second) is triggered, it will call broadcast receiver. In the receiver set alarm for next 2 seconds from that time. Which will again call same broadcast receiver after 2 seconds. Again set one more alarm for next 4 seconds in that receiver. For this we have to write a generic logic, because alarm has to repeat for n number of times.
First Activity:
package com.techpalle.b15_alarm_asg2;
import android.os.Bundle;
import android.app.Activity;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MainActivity extends Activity {
AlarmManager am;
Button b;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
am = (AlarmManager) getSystemService(Context.ALARM_SERVICE);
b = (Button) findViewById(R.id.button1);
b.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Intent in = new Intent();
in.setAction("com.techpalle.action.ALARM_INDEF");
int i=1;
in.putExtra("val", i);
PendingIntent pi = PendingIntent.getBroadcast(
getApplicationContext(),
0,
in,
0);
am.set(AlarmManager.RTC_WAKEUP,
System.currentTimeMillis()+1000,
pi);
}
});
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// TODO Auto-generated method stub
return super.onOptionsItemSelected(item);
}
}
Broadcast receiver
File name : AlarmRecvr.java
package com.techpalle.b15_alarm_asg2;
import android.app.AlarmManager;
import android.app.PendingIntent;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.view.ViewDebug.FlagToString;
import android.widget.Toast;
public class AlarmRecvr extends BroadcastReceiver {
//public static int i = 1;
@Override
public void onReceive(Context context, Intent intent) {
int i = intent.getExtras().getInt("val");
i = i*2;
Toast.makeText(context, "Got", 0).show();
Intent in = new Intent();
in.setAction("com.techpalle.action.ALARM_INDEF");
in.putExtra("val", i);
PendingIntent pi = PendingIntent.getBroadcast(
context, 0, in, PendingIntent.FLAG_UPDATE_CURRENT);
AlarmManager am = (AlarmManager) context.getSystemService(context.ALARM_SERVICE);
am.set(AlarmManager.RTC_WAKEUP,
System.currentTimeMillis()+(i*1000),
pi);
}
}
xml file for first activity
File name : activity_main.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context=".MainActivity" >
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/hello_world" />
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignLeft="@+id/textView1"
android:layout_below="@+id/textView1"
android:layout_marginLeft="41dp"
android:layout_marginTop="70dp"
android:text="Start alarms.." />
</RelativeLayout>
Manifest file
File name : AndroidManifest.xml
<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.techpalle.b15_alarm_asg2"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="17" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name="com.techpalle.b15_alarm_asg2.MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<receiver android:name="AlarmRecvr">
<intent-filter >
<action android:name="com.techpalle.action.ALARM_INDEF"/>
</intent-filter>
</receiver>
</application>
</manifest>
Download complete code : Click to download
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