Q.

Write a program to demonstrate all the private TextView broadcastTextView;

system broadcast messages.
@Override
activity_main.java
protected void onCreate(Bundle
<?xml version="1.0" encoding="utf-8"?> savedInstanceState) {
<LinearLayout super.onCreate(savedInstanceState);
xmlns:android="http://schemas.android.com/apk/r setContentView(R.layout.activity_main);
es/android"
android:layout_width="match_parent" // Initialize TextView to display broadcast
android:layout_height="match_parent" messages
android:orientation="vertical" broadcastTextView =
android:background="@color/white" findViewById(R.id.broadcastTextView);
android:gravity="center"
android:padding="16dp"> // Register a dynamic BroadcastReceiver for
<TextView system events
android:id="@+id/broadcastTextView" IntentFilter filter = new IntentFilter();
android:layout_width="match_parent"
android:layout_height="wrap_content" filter.addAction(Intent.ACTION_AIRPLANE_MO
android:text="Waiting for System DE_CHANGED);
Broadcasts..."
android:gravity="center" filter.addAction(Intent.ACTION_BATTERY_CHA
android:textColor="@color/black" NGED);
android:textSize="25sp" />
</LinearLayout> filter.addAction(Intent.ACTION_POWER_CONN
ECTED);
MainActivity.java
filter.addAction(Intent.ACTION_POWER_DISC
package com.example.practicalno21; ONNECTED);

import android.content.BroadcastReceiver; filter.addAction(Intent.ACTION_SCREEN_ON);

import android.content.Context;
import android.content.Intent; filter.addAction(Intent.ACTION_SCREEN_OFF);
import android.content.IntentFilter;
import android.os.BatteryManager; filter.addAction(Intent.ACTION_USER_PRESEN
import android.os.Bundle; T);
import android.widget.TextView;
import registerReceiver(new
androidx.appcompat.app.AppCompatActivity; SystemBroadcastReceiver(), filter);
}
public class MainActivity extends
AppCompatActivity { // Inner class to handle system-wide broadcasts
dynamically
 private class SystemBroadcastReceiver extends break;
BroadcastReceiver {
@Override case Intent.ACTION_USER_PRESENT:
public void onReceive(Context context, message = "User Present";
Intent intent) { break;
String action = intent.getAction();
String message = ""; default:
message = "Unknown Action
switch (action) { Received";
case }
Intent.ACTION_AIRPLANE_MODE_CHANGED:
boolean isAirplaneModeOn = // Update the TextView with the broadcast
intent.getBooleanExtra("state", false); message
message = "Airplane Mode Changed: broadcastTextView.setText(message);
" + (isAirplaneModeOn ? "ON" : "OFF"); }
break; }

case // Static inner class to handle

Intent.ACTION_BATTERY_CHANGED: BOOT_COMPLETED broadcast
int level = public static class BootCompletedReceiver
intent.getIntExtra(BatteryManager.EXTRA_LEVE extends BroadcastReceiver {
L, -1); @Override
message = "Battery Level: " + level + public void onReceive(Context context,
"%"; Intent intent) {
break; if
(Intent.ACTION_BOOT_COMPLETED.equals(int
case ent.getAction())) {
Intent.ACTION_POWER_CONNECTED: // Start MainActivity after boot
message = "Power Connected"; completed
break; Intent startIntent = new Intent(context,
MainActivity.class);
case
Intent.ACTION_POWER_DISCONNECTED: startIntent.addFlags(Intent.FLAG_ACTIVITY_NE
message = "Power Disconnected"; W_TASK);
break; context.startActivity(startIntent);
}
case Intent.ACTION_SCREEN_ON: }
message = "Screen Turned ON"; }
break; }

case Intent.ACTION_SCREEN_OFF: AndroidManifest.xml

message = "Screen Turned OFF";
<?xml version="1.0" encoding="utf-8"?> </activity>
<manifest
xmlns:android="http://schemas.android.com/apk/r <!-- Receiver for BOOT_COMPLETED -->
es/android" <receiver

xmlns:tools="http://schemas.android.com/tools"> android:name=".MainActivity$BootCompletedRe
ceiver"
<!-- Permission to receive android:enabled="true"
BOOT_COMPLETED broadcast --> android:exported="true">
<uses-permission <intent-filter>
android:name="android.permission.RECEIVE_B <action
OOT_COMPLETED" /> android:name="android.intent.action.BOOT_CO
MPLETED" />
<application <category
android:allowBackup="true" android:name="android.intent.category.DEFAUL
T" />
android:dataExtractionRules="@xml/data_extract </intent-filter>
ion_rules" </receiver>
</application>
android:fullBackupContent="@xml/backup_rules
" </manifest>
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"

android:roundIcon="@mipmap/ic_launcher_roun
d"
android:supportsRtl="true"

android:theme="@style/Theme.PracticalNo21"
tools:targetApi="31">

<!-- Main Activity -->

<activity
android:name=".MainActivity"
android:exported="true">
<intent-filter>
<action
android:name="android.intent.action.MAIN" />
<category
android:name="android.intent.category.LAUNCH
ER" />
</intent-filter>