Develop Reference

Jetpack compose - Heterogenous list does not recompose on item click

I am creating Heterogenous list using jetpack compose. I have an issue with recomposition when one of the item is clicked.
My Idea is to update the list with new item when an item clicked, I am receiving update list but list is not recomposed.
Please find below code:
//Initial function that prepared screen where content of list is wrapped in Scafold
#Composable fun PrepareOverViewScreen(overViewList: List<OverViewListItem>) {
val infoList = remember {mutableStateOf(overViewList) }
Scaffold(topBar = { TopBar("OverView") },
content = { DisplayOverViewScreen(overViewList = overViewList) },
backgroundColor = Color(0xFFf2f2f2)
)
}
//Displays list using LazyColumn when in itemType OverViewHeaderItem I am trying to recompose list with latest data , but not succesful.
#Composable fun DisplayOverViewScreen(
modifier: Modifier = Modifier, overViewList: List<OverViewListItem>
) {
val infoList = remember {mutableStateOf(overViewList) }
LazyColumn(modifier = modifier) {
items(infoList.value) { data ->
when (data) {
is OverViewHeaderItem -> {
HeaderItem(data,infoList.value,onClick = { newValue ->
println("New Value is $newValue")
infoList.value = newValue.toMutableList()
})
}
is OverViewChildItem -> {
ChildListBasedOnListType(data)
}
}
}
}
}
//In this function the onClick is executed when clicked on Image()
#Composable fun HeaderItem(overViewHeaderItem: OverViewHeaderItem,overViewList: List<OverViewListItem>,onClick: (List<OverViewListItem>) -> Unit) {
var angle by remember {
mutableStateOf(0f)
}
Row(modifier = Modifier
.fillMaxWidth()
.height(50.dp)
.background(color = Color(0xffd7d7d7)),
horizontalArrangement = Arrangement.Start, verticalAlignment = Alignment.CenterVertically) {
Text(
text = stringResource(R.string.history_yesterday), color = Color.Black,
modifier = Modifier.padding(start = 16.dp)
)
// Spacer(Modifier.weight(1f))
Image(
painter = painterResource(id = R.drawable.ic_expand_more),
modifier = Modifier
.padding(end = 5.dp)
.rotate(angle)
.clickable {
angle = (angle + 180) % 360f
// canDisplayChild = ! canDisplayChild
overViewList.map {
when (it) {
is OverViewChildItem -> {
if (it.listType == ItemType.HISTORY_YESTERDAY_CHILD) {
it.canShowHistoryChild = true
}
}
else -> {}
}
}
onClick(overViewList)
},
contentDescription = "Expandable Image"
)
}
}
Please help me resolve this issue.
#Composable fun ChildListBasedOnListType(overViewChildItem: OverViewChildItem){
when(overViewChildItem.listType){
ItemType.HISTORY_YESTERDAY_CHILD -> {
if(overViewChildItem.canShowHistoryChild){
ChildListItem(overViewChildItem)
Divider(color = Color(0xffd7d7d7), thickness = 1.dp)
}
}
else -> {
ChildListItem(overViewChildItem)
Divider(color = Color(0xffd7d7d7), thickness = 1.dp)
}
}
}
#Composable fun ChildListItem(overViewChildItem: OverViewChildItem) {
ConstraintLayout(
constraintSet = getConstraints(),
modifier = Modifier
.fillMaxSize()
.height(60.dp)
.background(color = Color(0xffffffff))
) {
Text(
text = overViewChildItem.article.articleName, Modifier
.layoutId("articleLabel")
.padding(start = 16.dp)
.fillMaxWidth()
.wrapContentHeight()
)
Text(
text = overViewChildItem.article.description, Modifier
.layoutId("desc")
.padding(start = 16.dp)
.fillMaxWidth()
.wrapContentHeight()
)
Image(
painter = painterResource(id = R.drawable.ic_baseline_chevron_right_24),
modifier = Modifier.layoutId("detail"), contentDescription = "Detail Image"
)
}
}
#Composable fun getConstraints(): ConstraintSet {
return ConstraintSet {
val articleLabel = createRefFor("articleLabel")
val articleDesc = createRefFor("desc")
val detailImage = createRefFor("detail")
createVerticalChain(articleLabel, articleDesc, chainStyle = ChainStyle.Packed)
constrain(articleLabel) {
top.linkTo(parent.top)
start.linkTo(parent.start)
end.linkTo(parent.end)
}
constrain(articleDesc) {
top.linkTo(articleLabel.bottom)
start.linkTo(parent.start)
end.linkTo(parent.end)
}
constrain(detailImage){
top.linkTo(parent.top)
end.linkTo(parent.end,5.dp)
bottom.linkTo(parent.bottom)
}
}
}

animation o a lazycolumn android

I have a list with 10 items one of them have this elements "rankingCurrentPlace", "rankingPastPlace" and "isUser:true".
What i need to do its an animation on the lazycolumn if the api esponse is like this
"isUser:true", "rankingPastPlace:3" , "rankingCurrentPlace:7"
i need to show an animation in the list where the row starts in the third place and descend to the seventh place
is there a way to do this?
this is what I actually have
LazyColumn(
contentPadding = PaddingValues(horizontal = 10.dp, vertical = 0.dp),
) {
items(
items = leaderboard,
key = { leaderBoard ->
leaderBoard.rankingPlace
}
) { leaderBoard ->
RowComposable( modifier = Modifier
.fillMaxWidth(),
topicsItem = leaderBoard,)
}

This answer works except when swapping first item with any item even with basic swap function without animation. I think it would be better to ask a new question about why swapping first item doesn't work or if it is bug. Other than that works as expected. If you need to move to items that are not in screen you can lazyListState.layoutInfo.visibleItemsInfo and compare with initial item and scroll to it before animation
1.Have a SnapshotStateList of data to trigger recomposition when we swap 2 items
class MyData(val uuid: String, val value: String)
val items: SnapshotStateList<MyData> = remember {
mutableStateListOf<MyData>().apply {
repeat(20) {
add(MyData( uuid = UUID.randomUUID().toString(), "Row $it"))
}
}
}
2.Function to swap items
private fun swap(list: SnapshotStateList<MyData>, from: Int, to: Int) {
val size = list.size
if (from in 0 until size && to in 0 until size) {
val temp = list[from]
list[from] = list[to]
list[to] = temp
}
}
3.Function to swap items one by one. There is a bug with swapping first item. Even if it's with function above when swapping first item other one moves up without showing animation via Modififer.animateItemPlacement().
#Composable
private fun animatedSwap(
lazyListState: LazyListState,
items: SnapshotStateList<MyData>,
from: Int,
to: Int,
onFinish: () -> Unit
) {
LaunchedEffect(key1 = Unit) {
val difference = from - to
val increasing = difference < 0
var currentValue: Int = from
repeat(abs(difference)) {
val temp = currentValue
if (increasing) {
currentValue++
} else {
currentValue--
}
swap(items, temp, currentValue)
if (!increasing && currentValue == 0) {
delay(300)
lazyListState.scrollToItem(0)
}
delay(350)
}
onFinish()
}
}
4.List with items that have Modifier.animateItemPlacement()
val lazyListState = rememberLazyListState()
LazyColumn(
modifier = Modifier
.fillMaxWidth()
.weight(1f),
state = lazyListState,
contentPadding = PaddingValues(horizontal = 10.dp, vertical = 0.dp),
verticalArrangement = Arrangement.spacedBy(4.dp)
) {
items(
items = items,
key = {
it.uuid
}
) {
Row(
modifier = Modifier
.animateItemPlacement(
tween(durationMillis = 200)
)
.shadow(1.dp, RoundedCornerShape(8.dp))
.background(Color.White)
.fillMaxWidth()
.padding(8.dp),
verticalAlignment = Alignment.CenterVertically
) {
Image(
modifier = Modifier
.clip(RoundedCornerShape(10.dp))
.size(50.dp),
painter = painterResource(id = R.drawable.landscape1),
contentScale = ContentScale.FillBounds,
contentDescription = null
)
Spacer(modifier = Modifier.width(10.dp))
Text(it.value, fontSize = 18.sp)
}
}
}
Demo
#OptIn(ExperimentalFoundationApi::class)
#Composable
private fun AnimatedList() {
Column(modifier = Modifier.fillMaxSize()) {
val items: SnapshotStateList<MyData> = remember {
mutableStateListOf<MyData>().apply {
repeat(20) {
add(MyData(uuid = UUID.randomUUID().toString(), "Row $it"))
}
}
}
val lazyListState = rememberLazyListState()
LazyColumn(
modifier = Modifier
.fillMaxWidth()
.weight(1f),
state = lazyListState,
contentPadding = PaddingValues(horizontal = 10.dp, vertical = 0.dp),
verticalArrangement = Arrangement.spacedBy(4.dp)
) {
items(
items = items,
key = {
it.uuid
}
) {
Row(
modifier = Modifier
.animateItemPlacement(
tween(durationMillis = 200)
)
.shadow(1.dp, RoundedCornerShape(8.dp))
.background(Color.White)
.fillMaxWidth()
.padding(8.dp),
verticalAlignment = Alignment.CenterVertically
) {
Image(
modifier = Modifier
.clip(RoundedCornerShape(10.dp))
.size(50.dp),
painter = painterResource(id = R.drawable.landscape1),
contentScale = ContentScale.FillBounds,
contentDescription = null
)
Spacer(modifier = Modifier.width(10.dp))
Text(it.value, fontSize = 18.sp)
}
}
}
var fromString by remember {
mutableStateOf("7")
}
var toString by remember {
mutableStateOf("3")
}
var animate by remember { mutableStateOf(false) }
if (animate) {
val from = try {
Integer.parseInt(fromString)
} catch (e: Exception) {
0
}
val to = try {
Integer.parseInt(toString)
} catch (e: Exception) {
0
}
animatedSwap(
lazyListState = lazyListState,
items = items,
from = from,
to = to
) {
animate = false
}
}
Row(modifier = Modifier.fillMaxWidth()) {
TextField(
value = fromString,
onValueChange = {
fromString = it
},
keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number)
)
TextField(
value = toString,
onValueChange = {
toString = it
},
keyboardOptions = KeyboardOptions(keyboardType = KeyboardType.Number)
)
}
Button(
modifier = Modifier
.padding(8.dp)
.fillMaxWidth(),
onClick = {
animate = true
}
) {
Text("Swap")
}
}
}
Edit: Animating with Animatable
Another method for animating is using Animatable with Integer vector.
val IntToVector: TwoWayConverter<Int, AnimationVector1D> =
TwoWayConverter({ AnimationVector1D(it.toFloat()) }, { it.value.toInt() })
val coroutineScope = rememberCoroutineScope()
val animatable = remember { Animatable(0, IntToVector) }
And can be used as
private fun alternativeAnimate(
from: Int,
to: Int,
coroutineScope: CoroutineScope,
animatable: Animatable<Int, AnimationVector1D>,
items: SnapshotStateList<MyData>
) {
val difference = from - to
var currentValue: Int = from
coroutineScope.launch {
animatable.snapTo(from)
animatable.animateTo(to,
tween(350 * abs(difference), easing = LinearEasing),
block = {
val nextValue = this.value
if (abs(currentValue -nextValue) ==1) {
swap(items, currentValue, nextValue)
currentValue = nextValue
}
}
)
}
}
on button click, i'm getting values from TextField fo i convert from String
Button(
modifier = Modifier
.padding(8.dp)
.fillMaxWidth(),
onClick = {
val from = try {
Integer.parseInt(fromString)
} catch (e: Exception) {
0
}
val to = try {
Integer.parseInt(toString)
} catch (e: Exception) {
0
}
alternativeAnimate(from, to, coroutineScope, animatable, items)
}
) {
Text("Swap")
}
Result

I suggest you to get your items from a data class. If your other items does not contain the variables you mentioned you can make them nullable in data class and put a condition checker in your lazycolumn
Like this
data class Items(
val otherItems: Other,
val rankingCurrentPlace: Int?,
val rankingLastPlace: Int?,
val isUser: Boolean?
)
Then you can make a list from this data class and pass it to lazycolumn
LazyColumn{
items(list){
(elements with condition)
}
}

Jetpack Compose - Search bar won't allow me to search and the cursor will not show up

I have a custom search bar will not allow me to place a cursor and type text into it. Before adding the viewmodel and state, I was able to have the TextField work and allow typing text into it.
I've tried using state variables within the composable instead of separating the logic into the view model and unfortunatly recieved the same result. I have a feeling it's something simple that I'm missing but can't quite find it.
Custom Search Bar:
#Composable
fun SearchBar(
modifier: Modifier,
viewModel: ToolSetListViewModel = hiltViewModel()
){
Surface (
modifier = modifier
.fillMaxWidth()
.height(74.dp)
.padding(20.dp, 15.dp, 20.dp, 0.dp),
elevation = 10.dp,
color = MaterialTheme.colors.primary,
shape = RoundedCornerShape(25)
){
TextField(
modifier = modifier
.fillMaxWidth(),
value = viewModel.searchText,
onValueChange = {
viewModel.onEvent(ToolSetListEvent.OnSearchToolSet(it))
},
placeholder = {
Text(
modifier = modifier
.alpha(ContentAlpha.medium),
text = "Search...",
color = White
)
},
textStyle = TextStyle(
fontSize = MaterialTheme.typography.subtitle1.fontSize,
),
singleLine = true,
colors = TextFieldDefaults.textFieldColors(
backgroundColor = Color.Transparent,
cursorColor = White
)
)
}
Screen:
#Composable
fun ToolSetListScreen(
onNavigate: (UiEvent.Navigate) -> Unit,
viewModel: ToolSetListViewModel = hiltViewModel()
) {
val toolSets = viewModel.toolSets.collectAsState(initial = emptyList())
LaunchedEffect(key1 = true) {
viewModel.uiEvent.collect { event ->
when(event) {
is UiEvent.Navigate -> onNavigate(event)
}
}
}
Scaffold (
floatingActionButton = {
FloatingActionButton(onClick = {
viewModel.onEvent(ToolSetListEvent.OnAddToolSetClick)
}) {
Icon(
imageVector = Icons.Default.Add,
contentDescription = "Add")
}
}
) {
SearchBar(
modifier = Modifier,
)
LazyColumn(
modifier = Modifier.fillMaxSize()
.padding(0.dp, 20.dp)
) {
items(toolSets.value) { toolset ->
ToolSetItem(
toolSet = toolset,
onEvent = viewModel::onEvent,
modifier = Modifier
.fillMaxWidth()
.padding(16.dp)
.clickable {
viewModel.onEvent(ToolSetListEvent.OnToolSetClick(toolset))
}
)
}
}
}
}
ViewModel:
#HiltViewModel
class ToolSetListViewModel #Inject constructor(
private val repository: ToolSetRepository
): ViewModel() {
val toolSets = repository.getAllToolSets()
private val _uiEvent = Channel<UiEvent>()
val uiEvent = _uiEvent.receiveAsFlow()
var searchText by mutableStateOf("")
private set
fun onEvent(event: ToolSetListEvent) {
when(event) {
is ToolSetListEvent.OnToolSetClick -> {
sendUiEvent(UiEvent.Navigate(Routes.ADD_EDIT_TOOL_SET + "?PONumber=${event.toolSet.PONumber}"))
}
is ToolSetListEvent.OnDeleteToolSetClick -> {
viewModelScope.launch {
repository.deleteToolSet(event.toolset)
}
}
is ToolSetListEvent.OnAddToolSetClick -> {
sendUiEvent(UiEvent.Navigate(Routes.ADD_EDIT_TOOL_SET))
}
is ToolSetListEvent.OnSearchToolSet -> {
viewModelScope.launch {
if (event.searchText.isNotBlank()) {
searchText = event.searchText
repository.getToolSetByPO(event.searchText)
}
}
}
}
}
private fun sendUiEvent(event: UiEvent) {
viewModelScope.launch {
_uiEvent.send(event)
}
}
MainActivity:
#AndroidEntryPoint
class MainActivity : ComponentActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContent {
PunchesManagerTheme {
val navController = rememberNavController()
Scaffold (
content = {
Navigation(navController)
},
bottomBar = { BottomNavigationBar(navController = navController) },
)
}
}
}
}
#Composable
fun BottomNavigationBar(navController: NavHostController) {
BottomNavigation {
val backStackEntry by navController.currentBackStackEntryAsState()
val currentRoute = backStackEntry?.destination?.route
NavBarItems.bottomNavItem.forEach { navItem ->
BottomNavigationItem(selected = currentRoute == navItem.route, onClick = {
navController.navigate(navItem.route) {
popUpTo(navController.graph.findStartDestination().id) {
saveState = false
}
launchSingleTop = true
restoreState = true
}
},
icon = {
Icon(imageVector = navItem.icon,
contentDescription = navItem.name)
},
label = {
Text(text = navItem.name)
},
)
}
}
}
Any suggestions on what the issue may be?

I think I found the fix!
I adjusted the layout of my scaffoled in my ToolSetListScreen:
Scaffold (
content = {
SearchBar(
modifier = Modifier,
)
LazyColumn(
modifier = Modifier.fillMaxSize()
.padding(0.dp, 75.dp)
) {
items(toolSets.value) { toolset ->
ToolSetItem(
toolSet = toolset,
onEvent = viewModel::onEvent,
modifier = Modifier
.fillMaxWidth()
.padding(16.dp)
.clickable {
viewModel.onEvent(ToolSetListEvent.OnToolSetClick(toolset))
}
)
}
}
},
floatingActionButton = {
FloatingActionButton(onClick = {
viewModel.onEvent(ToolSetListEvent.OnAddToolSetClick)
}) {
Icon(
imageVector = Icons.Default.Add,
contentDescription = "Add")
}
}
)
}
and this seemed to work.

How to apply bottom sheet for multiple text in jetpack compose?

I am try to learning jetpack compose those days, so I want to learning bottom sheet in jetpack compose, I do it just for one text, but I want to use it for multiple text, I have one example here, but I am not sure how to implement to my project, is there any solution for more than two text button to apply bottom sheet?
#Composable
fun BottomSheetMyScreen() {
val modalBottomSheetState = rememberModalBottomSheetState(initialValue =
ModalBottomSheetValue.Hidden)
val scope = rememberCoroutineScope()
ModalBottomSheetLayout(
sheetContent = {
BottomSheetFirstScreen()
},
sheetState = modalBottomSheetState,
sheetShape = RoundedCornerShape(topStart = 5.dp, topEnd = 5.dp),
sheetBackgroundColor = Color.Red,
) {
Scaffold(
backgroundColor = Color.Red
) {
MyScreen(
scope = scope, state = modalBottomSheetState
)}}}
#Composable
fun MyScreen(
scope: CoroutineScope, state: ModalBottomSheetState,
) {
MainRow(
name = "name1",
onClick = { scope.launch {
state.show()
}}
)
MainRow(
name = "name2",
onClick = { scope.launch {
state.show()
} }
)}}
#Composable
fun MainRow(
name: String,
onClick: () -> Unit
) {
Row(
modifier = Modifier
.fillMaxWidth()
.padding(10.dp)
.clickable(onClick = onClick),
verticalAlignment = Alignment.CenterVertically
) {
Column(
modifier = Modifier
.width(150.dp)
) {
Text(
text = name,
)}}}

I edit Your Code, you can use this code:
#OptIn(ExperimentalMaterialApi::class)
#Composable
fun BottomSheetMyScreen() {
val modalBottomSheetState = rememberModalBottomSheetState(
initialValue =
ModalBottomSheetValue.Hidden
)
val scope = rememberCoroutineScope()
val sheetContentState = remember {
mutableStateOf(0)
}
ModalBottomSheetLayout(
sheetContent = {
when (sheetContentState.value) {
0 -> {
BottomSheetFirstScreen()
}
1 -> {
BottomSheetSecondScreen()
}
}
},
sheetState = modalBottomSheetState,
sheetShape = RoundedCornerShape(topStart = 5.dp, topEnd = 5.dp),
sheetBackgroundColor = Color.Red,
) {
Scaffold(
backgroundColor = Color.Red
) {
MyScreen(
scope = scope, state = modalBottomSheetState, sheetContentState = sheetContentState
)
}
}
}
Main Row
#Composable
fun MainRow(
name: String,
onClick: () -> Unit
) {
Row(
modifier = Modifier
.fillMaxWidth()
.padding(10.dp),
verticalAlignment = Alignment.CenterVertically
) {
Text(
text = name,
modifier = Modifier.clickable { onClick.invoke() }
)
}
}
And MyScreen
#OptIn(ExperimentalMaterialApi::class)
#Composable
fun MyScreen(
scope: CoroutineScope,
state: ModalBottomSheetState,
sheetContentState: MutableState<Int>
) {
Column(modifier = Modifier.fillMaxWidth()) {
MainRow(
name = "name 1",
onClick = {
scope.launch {
sheetContentState.value = 0
state.show()
}
}
)
MainRow(
name = "name 2",
onClick = {
scope.launch {
sheetContentState.value = 1
state.show()
}
}
)
}
}

ConstraintLayout inside ConstraintLayout not working in Jetpack Compose

I've two components Brand and SignInCreateAccount. Each component created by ConstraintLayout. Now, I create WelcomeScreen from above components.
Usecase 1: WelcomeScreen using still ConstraintLayout (ConstraintLayout inside ConstraintLayout)
#Composable
fun WelcomeScreen(modifier: Modifier = Modifier) {
ConstraintLayout {
val (brand, formSignIn) = createRefs()
Brand(modifier = modifier.constrainAs(brand) {
start.linkTo(parent.start)
end.linkTo(parent.end)
top.linkTo(parent.top)
})
SignInCreateAccount(modifier = modifier.constrainAs(formSignIn) {
start.linkTo(brand.start)
end.linkTo(brand.end)
top.linkTo(brand.bottom)
})
}
}
Result: Layout preview not show anything
Usecase 2: WelcomeScreen using Column(ConstrantLayout inside Column)
#Composable
fun WelcomeScreen(modifier: Modifier = Modifier) {
Column {
Brand()
SignInCreateAccount()
}
}
Result: Layout preview show expected result
Brand and SignInCreateAccount components
#Composable
fun SignInCreateAccount(modifier: Modifier = Modifier) {
ConstraintLayout {
val (titleSignIn, email, buttonContinue, titleOr, buttonSignGuest) = createRefs()
Text(
text = stringResource(id = R.string.sign_in_create_account),
modifier = modifier.constrainAs(titleSignIn) {
start.linkTo(parent.start)
end.linkTo(parent.end)
top.linkTo(parent.top)
})
Text(text = "... Enter your mail", modifier = modifier.constrainAs(email) {
start.linkTo(titleSignIn.start)
end.linkTo(titleSignIn.end)
top.linkTo(titleSignIn.bottom)
})
}
}
#Composable
fun Brand(modifier: Modifier = Modifier) {
ConstraintLayout {
val (logo, slogan) = createRefs()
Logo(modifier = modifier.constrainAs(logo) {
start.linkTo(parent.start)
end.linkTo(parent.end)
top.linkTo(parent.top)
})
Text(text = stringResource(id = R.string.app_tagline),
modifier = modifier.constrainAs(slogan) {
start.linkTo(logo.start)
end.linkTo(logo.end)
top.linkTo(logo.bottom)
})
}
}
#Composable
fun Logo(
modifier: Modifier = Modifier,
lightTheme: Boolean = MaterialTheme.colors.isLight
) {
val assetId = if (lightTheme) {
R.drawable.ic_logo_light
} else {
R.drawable.ic_logo_dark
}
Image(
painter = painterResource(id = assetId),
modifier = modifier,
contentDescription = null
)
}
I want to using ConstraintLayout(as hobby) as use case 1. But I don't know what I did wrong or is there something wrong with ConstraintLayout.
Update: I missed a modifier parameter to the inner constraint layouts. However, another problem arose. That layout rearanged correct, but it not show anything: text, image.
WelcomeScreen.kt
#Composable
fun WelcomeScreen(modifier: Modifier = Modifier) {
ConstraintLayout(modifier = modifier) {
val (brand, formSignIn) = createRefs()
Brand(modifier = modifier.constrainAs(brand) {
start.linkTo(parent.start)
end.linkTo(parent.end)
top.linkTo(parent.top)
})
SignInCreateAccount(modifier = modifier.constrainAs(formSignIn) {
start.linkTo(brand.start)
end.linkTo(brand.end)
top.linkTo(brand.bottom)
})
}
}
#Composable
fun SignInCreateAccount(modifier: Modifier = Modifier) {
ConstraintLayout(modifier = modifier) {
val (titleSignIn, email, buttonContinue, titleOr, buttonSignGuest) = createRefs()
Text(
text = stringResource(id = R.string.sign_in_create_account),
modifier = modifier.constrainAs(titleSignIn) {
start.linkTo(parent.start)
end.linkTo(parent.end)
top.linkTo(parent.top)
})
Text(text = "... Enter your mail", modifier = modifier.constrainAs(email) {
start.linkTo(titleSignIn.start)
end.linkTo(titleSignIn.end)
top.linkTo(titleSignIn.bottom)
})
}
}
#Composable
fun Brand(modifier: Modifier = Modifier) {
ConstraintLayout(modifier = modifier) {
val (logo, slogan) = createRefs()
Logo(modifier = modifier.constrainAs(logo) {
start.linkTo(parent.start)
end.linkTo(parent.end)
top.linkTo(parent.top)
})
Text(text = stringResource(id = R.string.app_tagline),
modifier = modifier.constrainAs(slogan) {
start.linkTo(logo.start)
end.linkTo(logo.end)
top.linkTo(logo.bottom)
})
}
}
#Composable
fun Logo(
modifier: Modifier = Modifier,
lightTheme: Boolean = MaterialTheme.colors.isLight
) {
val assetId = if (lightTheme) {
R.drawable.ic_logo_light
} else {
R.drawable.ic_logo_dark
}
Image(
painter = painterResource(id = assetId),
modifier = modifier,
contentDescription = null
)
}
#Preview
#Composable
fun DevPreview() {
JetsurveyTheme(darkTheme = false) {
WelcomeScreen()
}
}

You are not passing the modifier parameter to the inner constraint layouts (ones in Brand and SignInCreateAccount), so all the constraints you set on them from the WelcomeScreen don't get passed along, and therefore not appearing on the screen.
For example your Brand composable should like something like this:
#Composable
fun Brand(modifier: Modifier = Modifier) {
ConstraintLayout(modifier = modifier) {
val (logo, slogan) = createRefs()
Logo(modifier = modifier.constrainAs(logo) {
start.linkTo(parent.start)
end.linkTo(parent.end)
top.linkTo(parent.top)
})
Text(text = stringResource(id = R.string.app_tagline),
modifier = modifier.constrainAs(slogan) {
start.linkTo(logo.start)
end.linkTo(logo.end)
top.linkTo(logo.bottom)
})
}
}
And the SignInCreateAccount would look like this
#Composable
fun SignInCreateAccount(modifier: Modifier = Modifier) {
ConstraintLayout(modifier = modifier) {
val (titleSignIn, email, buttonContinue, titleOr, buttonSignGuest) = createRefs()
Text(
text = stringResource(id = R.string.sign_in_create_account),
modifier = modifier.constrainAs(titleSignIn) {
start.linkTo(parent.start)
end.linkTo(parent.end)
top.linkTo(parent.top)
})
Text(text = "... Enter your mail", modifier = modifier.constrainAs(email) {
start.linkTo(titleSignIn.start)
end.linkTo(titleSignIn.end)
top.linkTo(titleSignIn.bottom)
})
}
}