Using Notifications and Taking Action

1. International Islamic University H-10, Islamabad, Pakistan
Mobile Applications Development
Week 08
Using Notifications
in Android
Engr. Rashid Farid Chishti
http://youtube.com/rfchishti
http://sites.google.com/site/chisht
i

2.  In Android, Notifications are messages that your app shows outside its UI,
usually in the device’s status bar and notification drawer, to inform the user
about something important.
 A Notification is a way for an app to alert the user about events, updates, or
actions that need attention, even when the app is not running in the
foreground.
 Examples of Notifications
 A new WhatsApp message
 A missed call alert
 A calendar reminder
 A download completed message
What are Notifications?

3.  Key Features
 Appears as an icon in the status bar.
 Can expand in the notification drawer with more details.
 Can have actions (e.g., Reply, Mark as Read, Snooze).
 Can make sounds, vibrations, or lights depending on importance.
 Basic Steps to Create a Notification
 Create a Notification Channel (Android 8.0+).
 Use NotificationCompat.Builder to define content.
 Use NotificationManager to issue the notification.
What are Notifications?

4.  Components:
 NotificationManager → Manages notifications.
 NotificationChannel (Android 8.0+) → Categorizes notifications.
 NotificationCompat.Builder → Builds notification content.
 Types of Notifications:
 Simple Text Notification → Title + Text
 Notifications with Actions → Reply, Dismiss, Open App
 Expandable Notification → With big text or Big Picture
 Foreground Service Notification → For ongoing tasks like music players or
downloads
Overview of Android Notification System

5. 1. Notification: Add an Icon

6. <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android">
<uses-permission android:name="android.permission.POST_NOTIFICATIONS"/>
<application
android:allowBackup="true"
android:dataExtractionRules="@xml/data_extraction_rules"
android:fullBackupContent="@xml/backup_rules"
android:icon="@mipmap/ic_launcher"
android:label="@string/app_name"
android:roundIcon="@mipmap/ic_launcher_round"
android:supportsRtl="true"
android:theme="@style/Theme.MyFirstApp">
<activity android:name=".Activity_Second" android:exported="false" />
<activity android:name=".MainActivity" android:exported="true">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter> </activity> </application> </manifest>
1. Notification: Add Permission (AndroidManifest.xml)

7. <?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:gravity="bottom"
tools:context=".MainActivity">
<Button
android:id="@+id/btn_show_notification"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:textSize="32dp"
android:layout_margin="20dp"
android:text="Show Notification" />
</LinearLayout>
1. Notification (activity_main.xml)

8. package com.example.myfirstapp
import android.app.NotificationChannel
import android.app.NotificationManager
import android.widget.Button
import android.content.Context
import android.content.pm.PackageManager
import android.os.Build
import android.os.Bundle
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.app.NotificationCompat
import androidx.core.app.NotificationManagerCompat
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
class MainActivity : AppCompatActivity() {
val CHANNEL_ID = "my_channel_id"
var NOTIFICATION_ID = 1
1. Notification (MainActivity.kt) (1/5)

9. override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState); enableEdgeToEdge()
setContentView(R.layout.activity_main)
ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets -
>
val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
v.setPadding(systemBars.left, systemBars.top, systemBars.right,
systemBars.bottom)
insets
}
// Calls a helper function to create a notification channel (for Android
8+).
createNotificationChannel() // Step 1: Create channel once
// Step 2: Find button and set listener
val button = findViewById<Button>(R.id.btn_show_notification)
button.setOnClickListener {
showNotification()
1. Notification (MainActivity.kt) (2/5)

10. private fun createNotificationChannel() {
// From Android 8.0 (API 26), notifications must belong to a channel.
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
val name = "MyChannel"
val descriptionText = "Channel for app notifications"
val importance = NotificationManager.IMPORTANCE_HIGH
val channel = NotificationChannel(CHANNEL_ID, name, importance).apply
{
description = descriptionText
}
// Register channel with the system’s NotificationManager
val notificationManager =
getSystemService(Context.NOTIFICATION_SERVICE) as
NotificationManager
notificationManager.createNotificationChannel(channel)
1. Notification (MainActivity.kt) (3/5)

11. private fun showNotification() {
val builder = NotificationCompat.Builder(this, CHANNEL_ID)
.setSmallIcon(R.drawable.ic_alert)
.setContentTitle("Hello Android")
.setContentText("This is your first notification 🚀")
.setPriority(NotificationCompat.PRIORITY_HIGH)
// Check notification permission (Android 13+)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
if
(checkSelfPermission(android.Manifest.permission.POST_NOTIFICATIONS)
!= PackageManager.PERMISSION_GRANTED
) {
// Ask for permission
requestPermissions(arrayOf(android.Manifest.permission.POST_NOTIFICATIONS),
100)
1. Notification (MainActivity.kt) (4/5)

12. // NotificationManagerCompat is a helper class to send notifications.
with(NotificationManagerCompat.from(this)) {
// notify(id, notification) actually displays it.
notify(NOTIFICATION_ID++, builder.build())
}
}
}
// CHANNEL_ID: Unique ID for the notification channel
// (required on Android 8+).
// NOTIFICATION_ID: Integer counter to distinguish multiple
// notifications. Each time you call notify(), it increments
// so new notifications don’t overwrite the old ones.
1. Notification (MainActivity.kt) (5/5)

13.  Let’s extend the example so that when the user taps the notification, it will
open your app (or a different activity inside your app).
2. Adding Actions to Notifications

14. private fun showNotification() {
// Intent to open SecondActivity
val intent = Intent(this, Activity_Second::class.java).apply {
// Clear the current task’s back stack.
// Start Activity_Second as the root activity.
// If the user presses Back, the app will exit instead of going back to
the
// previous activity.
flags = Intent.FLAG_ACTIVITY_NEW_TASK or
Intent.FLAG_ACTIVITY_CLEAR_TASK
}
val pendingIntent: PendingIntent = PendingIntent.getActivity(
this, 0, intent,
PendingIntent.FLAG_IMMUTABLE )
val builder = NotificationCompat.Builder(this, "my_channel_id")
.setSmallIcon(android.R.drawable.ic_dialog_info)
.setContentTitle("Hello from MyApp")
.setContentText("Tap to open SecondActivity")
.setPriority(NotificationCompat.PRIORITY_DEFAULT)
2. Notification (MainActivity.kt) (1/2)

15. // Check notification permission (Android 13+)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
if
(checkSelfPermission(android.Manifest.permission.POST_NOTIFICATIONS)
!=
PackageManager.PERMISSION_GRANTED) {
// Ask for permission
requestPermissions(
arrayOf(android.Manifest.permission.POST_NOTIFICATIONS),100 )
return
}
}
with(NotificationManagerCompat.from(this)) {
notify(NOTIFICATION_ID, builder.build())
}
}
2. Notification (MainActivity.kt) (2/2)

16. <?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".Activity_Second">
<TextView
android:id="@+id/tv_message"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Opened from Notification!"
android:layout_margin="20dp" />
</LinearLayout>
2. Notification (activity_second.xml)

17. package com.example.myfirstapp
import android.os.Bundle
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
class Activity_Second : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState); enableEdgeToEdge()
setContentView(R.layout.activity_second)
ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets -
>
val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
v.setPadding(systemBars.left, systemBars.top, systemBars.right,
systemBars.bottom)
insets
}
}
2. Notification (Activity_Second.kt)

18.  Always create channels for better user control.
 Use priority levels appropriately.
 Avoid spamming users.
 Use expandable notifications for more details.
 Support notification actions for quick tasks.
Best Practices

19.  User receives a new message.
 Notification shows sender name + preview text.
 Action buttons: Reply and Mark as Read.
 On tap → opens chat screen.
Practical Example – Chat App Notification