Lecture 5 – Intents and Navigation

Android Intents and Navigation with easy examples. Understand explicit vs implicit intents, passing data between activities, splash screens, and navigation drawer setup.

What Are Intents in Android?

An Intent is a message object that allows different components of an Android app (like Activities, Services, and Broadcast Receivers) to communicate with each other.
It tells the system what action to perform and which component should handle it.

Example:

• Move from Login screen → Home screen
• Open camera, share content, or make a call

Explicit vs Implicit Intents

Explicit Intent

Used when you want to open a specific Activity inside your own app.

Example (Kotlin):

val intent = Intent(this, ProfileActivity::class.java)
startActivity(intent)

Example (Java):

Intent intent = new Intent(this, ProfileActivity.class);
startActivity(intent);

Use Case: Login → Dashboard, List → Detail screen

Implicit Intent

Used when you want the system to perform an action using another app that can handle it.

Example (Dial a Number):

val intent = Intent(Intent.ACTION_DIAL)
intent.data = Uri.parse("tel:03001234567")
startActivity(intent)

Example (Open a Web Page):

Intent i = new Intent(Intent.ACTION_VIEW, Uri.parse("https://electuresai.com"));
startActivity(i);

Passing Data Between Activities

You can send information from one Activity to another using Intent Extras.

Using Extras

Sender Activity:

val i = Intent(this, DetailActivity::class.java)
i.putExtra("USER_NAME", "Ali")
i.putExtra("AGE", 22)
startActivity(i)

Receiver Activity:

val name = intent.getStringExtra("USER_NAME")
val age = intent.getIntExtra("AGE", 0)

Sending Complex Objects with Parcelable

Parcelable makes it easy to send full objects between Activities.

Example:

@Parcelize
data class User(val id: Int, val name: String): Parcelable

Send:

val intent = Intent(this, DetailActivity::class.java)
intent.putExtra("USER", user)
startActivity(intent)

Receive:

val user = intent.getParcelableExtra<User>("USER")

Getting Result Back (Activity Result API)

Newer, modern method (replaces startActivityForResult).

Example:

private val imagePicker = registerForActivityResult(ActivityResultContracts.GetContent()) { uri ->
    imageView.setImageURI(uri)
}
buttonPick.setOnClickListener { imagePicker.launch("image/*") }

Splash Screen Basics

A Splash Screen is shown briefly when your app launches — used for branding or loading setup.

Steps:

Add dependency:

implementation "androidx.core:core-splashscreen:1.0.1"

Add theme in styles.xml:

<style name="Theme.MyApp.Splash" parent="Theme.SplashScreen">
    <item name="windowSplashScreenAnimatedIcon">@drawable/ic_logo</item>
    <item name="windowSplashScreenBackground">@color/black</item>
</style>

Apply it in AndroidManifest.xml:

<activity
    android:name=".MainActivity"
    android:theme="@style/Theme.MyApp.Splash" />

Use in code:

installSplashScreen()

Navigation Drawer Basics

A Navigation Drawer slides in from the left edge and allows users to navigate through different sections of your app.

Layout Example:

<androidx.drawerlayout.widget.DrawerLayout
    android:id="@+id/drawerLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <!-- Main Content -->
    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        
        <androidx.appcompat.widget.Toolbar
            android:id="@+id/toolbar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content" />
    </LinearLayout>

    <!-- Drawer Menu -->
    <com.google.android.material.navigation.NavigationView
        android:id="@+id/navView"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        app:menu="@menu/menu_drawer" />
</androidx.drawerlayout.widget.DrawerLayout>

Code Example (Kotlin):

val toggle = ActionBarDrawerToggle(this, drawerLayout, toolbar, R.string.open, R.string.close)
drawerLayout.addDrawerListener(toggle)
toggle.syncState()

The approach followed at E Lectures reflects both academic depth and easy-to-understand explanations.

Summary

After completing this lecture, students will:

• Understand explicit vs. implicit intents
• Know how to pass data between activities
• Implement splash screens
• Create a navigation drawer for app navigation

People also ask:

val intent = Intent(this, DetailActivity::class.java)
intent.putExtra("USERNAME", "Ali")
startActivity(intent)

val name = intent.getStringExtra("USERNAME")

<activity
    android:name=".MainActivity"
    android:theme="@style/Theme.MyApp.Splash" />