<RelativeLayout xmlns:androclass="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:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" />

</RelativeLayout>

package com.example.callstatebroadcastreceiver;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class MainActivity extends Activity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
    }


    @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;
    }
    
}

package com.example.callstatebroadcastreceiver;

import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.telephony.TelephonyManager;
import android.widget.Toast;


 public class IncommingCallReceiver extends BroadcastReceiver{
      Context context;
       
      @Override
      public void onReceive(Context context, Intent intent){
          try{
           String state = intent.getStringExtra(TelephonyManager.EXTRA_STATE);

              if(state.equals(TelephonyManager.EXTRA_STATE_RINGING)){
                   Toast.makeText(context, "Phone Is Ringing", Toast.LENGTH_LONG).show();
              }
              
              if(state.equals(TelephonyManager.EXTRA_STATE_OFFHOOK)){
                   Toast.makeText(context, "Call Recieved", Toast.LENGTH_LONG).show();
              }
              
              if (state.equals(TelephonyManager.EXTRA_STATE_IDLE)){
                   Toast.makeText(context, "Phone Is Idle", Toast.LENGTH_LONG).show();
              }
          }
          catch(Exception e){e.printStackTrace();}
      }
      
}