'Jetpack Compose collapsing toolbar

I can't find any doc on the matter, is there something similar to a CollapsingToolbar in Compose?

All I found was a mention of it here, but nothing on how to set it up

Solution 1:^[1]

I found this in Android docs, I think the documentation you linked in the question is talking about doing it like this with nested scrolling.

val toolbarHeight = 48.dp
    val toolbarHeightPx = with(LocalDensity.current) { toolbarHeight.roundToPx().toFloat() }
    val toolbarOffsetHeightPx = remember { mutableStateOf(0f) }

    val nestedScrollConnection = remember {
        object : NestedScrollConnection {
            override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {

                val delta = available.y
                val newOffset = toolbarOffsetHeightPx.value + delta
                toolbarOffsetHeightPx.value = newOffset.coerceIn(-toolbarHeightPx, 0f)
                return Offset.Zero
            }
        }
    }
    Box(
        Modifier
            .fillMaxSize()

            .nestedScroll(nestedScrollConnection)
    ) {

        LazyColumn(contentPadding = PaddingValues(top = toolbarHeight)) {
            items(100) { index ->
                Text("I'm item $index", modifier = Modifier
                    .fillMaxWidth()
                    .padding(16.dp))
            }
        }
        TopAppBar(
            modifier = Modifier
                .height(toolbarHeight)
                .offset { IntOffset(x = 0, y = toolbarOffsetHeightPx.value.roundToInt()) },
            title = { Text("toolbar offset is ${toolbarOffsetHeightPx.value}") }
        )
    }

Solution 2:^[2]

Jetpack Compose implementation of Material Design 3 includes 4 types of Top App Bars (https://m3.material.io/components/top-app-bar/implementation):

CenterAlignedTopAppBar
SmallTopAppBar
MediumTopAppBar
LargeTopAppBar

https://developer.android.com/reference/kotlin/androidx/compose/material3/package-summary

They all have a scrollBehavior parameter, which can be used for collapsing the toolbar. There are 3 basic types of scroll behavior in the library:

TopAppBarDefaults.pinnedScrollBehavior
TopAppBarDefaults.enterAlwaysScrollBehavior
TopAppBarDefaults.exitUntilCollapsedScrollBehavior

https://developer.android.com/reference/kotlin/androidx/compose/material3/TopAppBarDefaults

Note: This API is annotated as experimental at the moment.

Sample usage:

@OptIn(ExperimentalMaterial3Api::class)
@Composable
fun Test() {
    val scrollBehavior = remember { TopAppBarDefaults.enterAlwaysScrollBehavior() }
    Scaffold(
        modifier = Modifier.nestedScroll(scrollBehavior.nestedScrollConnection),
        topBar = {
            MediumTopAppBar(
                title = { Text(text = "Scroll Behavior Test") },
                navigationIcon = {
                    IconButton(onClick = { /*TODO*/ }) {
                        Icon(imageVector = Icons.Default.Menu, contentDescription = "")
                    }
                },
                scrollBehavior = scrollBehavior
            )
        }
    ) {
        LazyColumn(modifier = Modifier.fillMaxWidth()) {
            items((1..50).toList()) { item ->
                Text(modifier = Modifier.padding(8.dp), text = "Item $item")
            }
        }
    }
}

Solution 3:^[3]

You can use the compose-collapsing-toolbar library.

Instalation : implementation "me.onebone:toolbar-compose:2.1.0"

Usage - Exemple

Preview

Here are some gif images from the Readme.md of the library:

jetpack compose collapsing toolbar

Solution 4:^[4]

You can follow the example in the docs to create a toolbar which expands/collapses on every scroll up/down.

To create a toolbar which expands only when the list is scrolled to the top, you can make a slight adaptation to the original example:

val toolbarHeight = 48.dp
val toolbarHeightPx = with(LocalDensity.current) { toolbarHeight.roundToPx().toFloat() }
var toolbarOffsetHeightPx by remember { mutableStateOf(0f) }
var totalScrollOffsetPx = remember { 0f }

val nestedScrollConnection = remember {
    object : NestedScrollConnection {
        override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {

            val delta = available.y
            totalScrollOffsetPx += delta
            
            if (totalScrollOffsetPx in -toolbarHeightPx..0f) {
                toolbarOffsetHeightPx = totalScrollOffsetPx
            }

            return Offset.Zero
        }
    }
}

By doing so, you have a flexibility which would enable you to create your own CollapsibleScaffold which could accept params like scrollBehaviour, appBarLayout and list composables etc.

That way, for instance, you could also programmatically calculate the height of the app bar and get rid of the high amount of boilerplate, making the code used in your screens neat and clean.

Solution 5:^[5]

Compose-collapsing-toolbar A simple implementation of CollapsingToolbarLayout for Jetpack Compose

https://github.com/onebone/compose-collapsing-toolbar

Sources

This article follows the attribution requirements of Stack Overflow and is licensed under CC BY-SA 3.0.

Source: Stack Overflow

Solution	Source
Solution 1
Solution 2	Manveru
Solution 3	sitatech
Solution 4	Luja93
Solution 5	essid

'Jetpack Compose collapsing toolbar

Solution 1:[1]

Solution 2:[2]

Sample usage:

Solution 3:[3]