Photo by TechieTech Tech on Unsplash

Developing for Foldable and Multi-Screen Devices with Jetpack Compose

With the rise of foldable and multi-screen devices, Android developers have new opportunities and challenges in creating responsive and adaptive user interfaces. These devices offer unique form factors that can enhance user experiences but require careful consideration and design.

Jetpack Compose, Android’s modern toolkit for building native UIs, simplifies creating flexible and dynamic layouts that adapt to various screen sizes and configurations. In this blog, we’ll explore best practices and strategies for developing Android applications that leverage the capabilities of foldable and multi-screen devices using Jetpack Compose.

Let’s get the Basics first…

Foldable Devices: These devices feature a flexible display that can be folded. They typically have two states: folded and unfolded. The unfolded state provides a larger screen area, while the folded state offers a more compact form factor.

Multi-Screen Devices: These devices have two or more separate screens. They can be used in various configurations, such as dual-screen laptops or tablets, where each screen can function independently or in tandem.

Some Concepts and Terminology…

1. Screen Continuity: Ensuring a seamless transition when a device is folded or unfolded. Your app should adapt to the new screen size and aspect ratio without disrupting the user experience.
2. Multi-Window Mode: Supporting multiple app windows on the same screen. This is crucial for multitasking and improving productivity on larger displays.
3. Hinge Angle Sensor: Detecting the angle of the fold to adjust the UI accordingly. This sensor helps create adaptive layouts that respond to the device’s physical state.

Let’s explore different approaches…

Using Responsive Layouts: Jetpack Compose simplifies the creation of responsive layouts with its declarative approach. Use the Modifier.fillMaxSize() and Compose's layout components to build flexible UIs that adapt to different screen sizes and orientations.

@Composable
fun ResponsiveLayout() {
    Column(
        modifier = Modifier
            .fillMaxSize()
            .padding(16.dp)
    ) {
        Text(text = "Welcome to the Foldable World", style = MaterialTheme.typography.h4)
        Spacer(modifier = Modifier.height(8.dp))
        Text(text = "This is an example of a responsive layout using Jetpack Compose.")
    }
}

Handling Configuration Changes: Compose handles configuration changes more gracefully than traditional Views, but you still need to ensure your UI adapts correctly. Use LocalConfiguration to react to changes in screen size or orientation.

@Composable
fun AdaptiveLayout() {
    val configuration = LocalConfiguration.current
    val screenWidth = configuration.screenWidthDp.dp

    if (screenWidth > 600.dp) {
        // Layout for larger screens
        LargeScreenLayout()
    } else {
        // Layout for smaller screens
        SmallScreenLayout()
    }
}

@Composable
fun LargeScreenLayout() {
    // Implementation for larger screens
}

@Composable
fun SmallScreenLayout() {
    // Implementation for smaller screens
}

Leveraging Multi-Window Support: Ensure your Compose app supports multi-window mode by designing your UI to handle multiple instances and different configurations. Compose’s state management and navigation components make it easier to manage multiple windows.

@Composable
fun MultiWindowSupport() {
    val navController = rememberNavController()
    NavHost(navController, startDestination = "main") {
        composable("main") { MainScreen(navController) }
        composable("details") { DetailsScreen(navController) }
    }
}

@Composable
fun MainScreen(navController: NavController) {
    Column {
        Button(onClick = { navController.navigate("details") }) {
            Text(text = "Go to Details")
        }
    }
}

@Composable
fun DetailsScreen(navController: NavController) {
    Text(text = "Details Screen")
}

Using Hinge Angle Sensor: Utilize the hinge angle sensor to create adaptive layouts that respond to the device’s physical state. Compose allows you to handle sensor input and adjust the UI dynamically.

@Composable
fun HingeAwareLayout() {
    val sensorManager = LocalContext.current.getSystemService(Context.SENSOR_SERVICE) as SensorManager
    val hingeSensor = sensorManager.getDefaultSensor(Sensor.TYPE_HINGE_ANGLE)

    var hingeAngle by remember { mutableStateOf(0f) }

    DisposableEffect(Unit) {
        val listener = object : SensorEventListener {
            override fun onSensorChanged(event: SensorEvent) {
                hingeAngle = event.values[0]
            }

            override fun onAccuracyChanged(sensor: Sensor, accuracy: Int) {}
        }
        sensorManager.registerListener(listener, hingeSensor, SensorManager.SENSOR_DELAY_NORMAL)
        onDispose { sensorManager.unregisterListener(listener) }
    }

    Text(text = "Hinge Angle: $hingeAngle")
}

Testing on Real Devices and Emulators: Test your Compose app on real foldable and multi-screen devices to ensure it behaves as expected. Use Android Studio’s built-in emulators to simulate different foldable and multi-screen scenarios.

$ emulator -avd Pixel_4_XL_API_30 -prop hw.foldable=yes

Use Cases and Examples

• Dual-Screen Notes App: A note-taking app that uses one screen for the note list and the other for the note content, allowing users to easily browse and edit notes simultaneously.
• Foldable Gaming Experience: A game that adapts to both folded and unfolded states, providing a compact UI for casual play and a larger, immersive experience when fully opened.
• Enhanced Multi-Tasking: Productivity apps that take advantage of multi-window mode to display multiple documents or tools side by side, improving user efficiency.

Conclusion

Developing foldable and multi-screen devices opens up new possibilities for creating innovative and engaging user experiences. Jetpack Compose, with its modern declarative approach, simplifies building flexible and dynamic UIs that can adapt to various screen sizes and configurations.

By understanding the unique characteristics of these devices and following best practices for responsive layouts, configuration handling, and multi-window support, you can create applications that not only look great but also enhance usability and productivity.

As the market for these devices grows, staying ahead with these development techniques will position you well in the evolving landscape of Android development.

Cheers 🥂, till the next one.