Queueing Multiple Snackbars in Jetpack Compose: Best Practices

Snackbars are an essential component of modern Android design, providing users with brief, unobtrusive feedback about operations. However, managing multiple snackbars in Jetpack Compose can be a challenge. This blog post explores advanced techniques and best practices for queueing multiple snackbars in Jetpack Compose, ensuring a smooth and intuitive user experience.

Understanding Snackbar Behavior in Jetpack Compose

Snackbars in Jetpack Compose are part of the Scaffold layout, which provides a structured way to design app layouts. The SnackbarHost is responsible for displaying snackbars, but unlike traditional Toast messages, snackbars are transient UI components tied to the lifecycle of their host.

The Challenge with Multiple Snackbars

Jetpack Compose doesn’t natively support queueing multiple snackbars out of the box. Without a proper queueing mechanism, triggering multiple snackbars simultaneously can lead to UI glitches or overwrite messages, resulting in a poor user experience.

To address this, we’ll build a robust system for managing and displaying multiple snackbars sequentially.

Implementing a Snackbar Queue

Step 1: Create a Snackbar Data Model

Define a data class to encapsulate the details of a snackbar, such as the message, action label, and duration:

data class SnackbarData(
    val message: String,
    val actionLabel: String? = null,
    val duration: SnackbarDuration = SnackbarDuration.Short
)

This data class will serve as the blueprint for all snackbar messages.

Step 2: Manage the Queue with a ViewModel

Using a ViewModel ensures that the snackbar queue survives configuration changes. Here’s how you can set up a SnackbarQueueViewModel:

class SnackbarQueueViewModel : ViewModel() {
    private val _snackbarQueue = mutableStateListOf<SnackbarData>()
    private val _currentSnackbar = mutableStateOf<SnackbarData?>(null)

    val currentSnackbar: State<SnackbarData?> = _currentSnackbar

    fun enqueueSnackbar(data: SnackbarData) {
        _snackbarQueue.add(data)
        if (_currentSnackbar.value == null) {
            showNextSnackbar()
        }
    }

    private fun showNextSnackbar() {
        if (_snackbarQueue.isNotEmpty()) {
            _currentSnackbar.value = _snackbarQueue.removeFirst()
        }
    }

    fun onSnackbarDismissed() {
        _currentSnackbar.value = null
        showNextSnackbar()
    }
}

This implementation ensures that only one snackbar is displayed at a time, and subsequent snackbars appear sequentially.

Step 3: Integrate with the UI

In your Scaffold, observe the current snackbar and display it using a SnackbarHost:

@Composable
fun SnackbarQueueScreen(viewModel: SnackbarQueueViewModel) {
    val currentSnackbar by viewModel.currentSnackbar

    Scaffold(
        snackbarHost = {
            SnackbarHost(hostState = SnackbarHostState()) { snackbarData ->
                currentSnackbar?.let {
                    Snackbar(
                        action = {
                            it.actionLabel?.let { label ->
                                Button(onClick = { /* Handle action */ }) {
                                    Text(label)
                                }
                            }
                        }
                    ) {
                        Text(it.message)
                    }
                }
            }
        }
    ) {
        // Your screen content
    }

    if (currentSnackbar != null) {
        LaunchedEffect(currentSnackbar) {
            delay(currentSnackbar!!.duration.toMillis())
            viewModel.onSnackbarDismissed()
        }
    }
}

The SnackbarQueueScreen observes the ViewModel and displays snackbars sequentially based on the queue.

Best Practices for Managing Snackbars

1. Avoid Overloading Users

Only queue snackbars that are necessary. Avoid overwhelming users with excessive feedback, as it can reduce the impact of critical messages.

2. Use Priority Levels

Enhance the SnackbarData class to include a priority field, allowing important messages to take precedence:

data class SnackbarData(
    val message: String,
    val actionLabel: String? = null,
    val duration: SnackbarDuration = SnackbarDuration.Short,
    val priority: Int = 0
)

Sort the queue by priority when adding new snackbars:

_snackbarQueue.sortByDescending { it.priority }

3. Handle Configuration Changes Gracefully

Leverage ViewModel and rememberSaveable to preserve the snackbar queue and current state during configuration changes, ensuring a seamless user experience.

4. Test for Edge Cases

Ensure your implementation handles edge cases, such as:

• Rapidly enqueuing multiple snackbars

• Displaying snackbars during heavy UI transitions

• Handling null or invalid data gracefully

Advanced Use Case: Snackbar with Custom Composables

Jetpack Compose allows for highly customizable snackbars. Instead of plain text, you can design rich content within snackbars:

@Composable
fun CustomSnackbar(data: SnackbarData) {
    Snackbar(
        backgroundColor = MaterialTheme.colorScheme.primary,
        contentColor = MaterialTheme.colorScheme.onPrimary
    ) {
        Row(verticalAlignment = Alignment.CenterVertically) {
            Icon(imageVector = Icons.Default.Info, contentDescription = null)
            Spacer(modifier = Modifier.width(8.dp))
            Text(text = data.message)
        }
    }
}

Integrate this custom snackbar into your SnackbarHost for a polished design.

Conclusion

Queueing multiple snackbars in Jetpack Compose is not only achievable but also opens the door to a more intuitive and user-friendly app experience. By following the strategies outlined in this post, you can implement a reliable, flexible system that handles sequential snackbars gracefully.

Whether you’re designing a simple feedback system or a sophisticated, priority-based notification framework, Jetpack Compose’s declarative paradigm and Kotlin’s power make the process efficient and elegant.

Feel free to share your experiences or ask questions in the comments below. Happy coding!