I am trying to solve this problem. Basically I'm creating a function in which I will put a webview.
Both above this function and below this function there will be other UI components.
when I scroll up the part of the UI above the webview shrinks to half of its height.
What I do is to record the page scroll events to make this animation.
Unfortunately, however, it happens that the webview does not ONLY occupy the space available on the screen but in height it is as high as all the contents of the WebView. Below you can see what I would like to achieve in the first image:
And here instead what I actually get:
This is a problem because when a page asks to accept cookies and the relevant popup appears, being the page so high I get an overlay that looks like an error but is simply given by the popup that asks you to accept cookies and which however is below, and on some devices it is not even visible
What I am trying to achieve, unsuccessfully, would be the XML equivalent of 0dp, in height.
To do this I thought I could use ConstraintLayouts for compose (implementation ("androidx.constraintlayout:constraintlayout-compose:1.0.0")) but they are not working. In fact, the result I get is as if I had "wrap content" and not 0dp and in fact a small page shrinks the box, a large page expands beyond the size of the screen.
Below is the code I am using. I started with the new compose feature whose example is well explained in this link
private val ToolbarHeight = 300.dp
#Composable
fun CollapsingToolbarComposeViewComposeNestedScrollInteropSample(content: #Composable () -> Unit) {
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)
logger.debug("Offset.Zero : ${Offset.Zero} .... $newOffset, $delta")
return Offset.Zero
}
}
}
// Compose Scrollable
Box(
Modifier
.fillMaxSize()
.nestedScroll(nestedScrollConnection)
) {
// Android View
AndroidView(
factory = { context -> AndroidViewWithCompose(context, content) },
modifier = Modifier.fillMaxWidth()
)
TopAppBar(
modifier = Modifier
.height(ToolbarHeight)
.offset {
IntOffset(
x = 0,
y = toolbarOffsetHeightPx.value
.coerceAtLeast(-200f)
.coerceAtMost(0f)
.roundToInt()
)
},
title = { Text("toolbar offset is ${toolbarOffsetHeightPx.value}") }
)
}
}
private fun AndroidViewWithCompose(context: Context, content: #Composable () -> Unit): View {
return LayoutInflater.from(context)
.inflate(R.layout.three_fold_nested_scroll_interop, null).apply {
with(findViewById<ComposeView>(R.id.compose_view)) {
// Compose
setContent { LazyColumnWithNestedScrollInteropEnabled(content) }
}
}.also {
ViewCompat.setNestedScrollingEnabled(it, true)
}
}
#OptIn(ExperimentalComposeUiApi::class)
#Composable
private fun LazyColumnWithNestedScrollInteropEnabled(content: #Composable () -> Unit) {
ConstraintLayout() {
val (wv) = createRefs()
LazyColumn(
modifier = Modifier
.constrainAs(wv) {
top.linkTo(parent.top)
bottom.linkTo(parent.top)
}
.nestedScroll(
rememberNestedScrollInteropConnection()
),
contentPadding = PaddingValues(top = ToolbarHeight)
) {
item {
Text("This is a Lazy Column")
}
items(1) { _ ->
Box(modifier = Modifier.fillMaxSize()
) {
content()
}
}
}
}
}
the content() is just my webView:
AndroidView(
factory = {
WebView(it).apply {
webViewClient = WebViewClient()
settings.javaScriptEnabled = true
loadUrl("https://stackoverflow.com/posts/72259954/edit")
}
}
)
Related
I'm new to Jetpack Compose and I'm not quite sure how to do what I need. In the screen below, I want to scroll the whole screen and not just the list at the bottom and when the scroll reaches the end of the list below, it still applies the paging library and goes to get more elements. I managed to get the Paging Library to work and the scroll in the list below too, but I can't make the rest of the page elements scroll as well - this is because only the list has scroll and not the rest of the page. Whenever I'm trying to do that, I get the following crash:
Vertically scrollable component was measured with an infinity maximum height constraints, which is disallowed. One of the common reasons is nesting layouts like LazyColumn and Column(Modifier.verticalScroll()). If you want to add a header before the list of items please add a header as a separate item() before the main items() inside the LazyColumn scope. There are could be other reasons for this to happen: your ComposeView was added into a LinearLayout with some weight, you applied Modifier.wrapContentSize(unbounded = true) or wrote a custom layout. Please try to remove the source of infinite constraints in the hierarchy above the scrolling container.
and I don't really know why.
I leave you the code below and two screenshots: the first is the current state, where I can only scroll through the list. The second is what I intend, which is to scroll the entire page.
#Edit: I was able to implement all screen scroll with fixed height on the children lazy column, but that is not what I want.
#Composable
#ExperimentalFoundationApi
private fun MainActivityLayout(navController: NavHostController) {
LazyColumn(
modifier = Modifier
.paint(
painter = painterResource(id = R.drawable.main_background),
contentScale = ContentScale.FillBounds
)
.fillMaxSize(),
horizontalAlignment = Alignment.CenterHorizontally
) {
item {
HeightSpacer(Dimen40)
Image(
painter = painterResource(id = R.drawable.ic_clearjobs_logo_2x),
contentDescription = null
)
HeightSpacer(Dimen47)
Navigation(navController = navController)
}
}
}
#Composable
#ExperimentalFoundationApi
fun JobOpeningsScreen(viewModel: JobOpeningsViewModel = hiltViewModel()) {
val uiState by viewModel.uiState.collectAsState()
Column {
ClearJobsScreenTitle(
lightTitle = stringResource(id = R.string.job_openings_light_title),
boldTitle = stringResource(id = R.string.job_openings_bold_title)
)
HeightSpacer(Dimen60)
Row {
CategoryButton()
WidthSpacer(Dimen2)
OrderByButton()
}
HeightSpacer(Dimen30)
SearchTextField()
HeightSpacer(Dimen60)
when (uiState) {
is BaseViewState.Data -> JobOpeningsContent(
viewState = uiState.cast<BaseViewState.Data<JobOpeningsViewState>>().value
)
is BaseViewState.Loading -> {
LoadingView()
}
else -> {}
}
LaunchedEffect(key1 = viewModel, block = {
viewModel.onTriggerEvent(JobOpeningsEvent.LoadJobOffers)
})
}
}
#Composable
fun JobOpeningsContent(viewState: JobOpeningsViewState) {
val pagingItems = rememberFlowWithLifecycle(viewState.pagedData).collectAsLazyPagingItems()
SwipeRefresh(
state = rememberSwipeRefreshState(
isRefreshing = pagingItems.loadState.refresh == LoadState.Loading
),
onRefresh = { pagingItems.refresh() },
indicator = { state, trigger ->
SwipeRefreshIndicator(
state = state,
refreshTriggerDistance = trigger,
scale = true
)
},
content = {
LazyColumn(
modifier = Modifier.width(Dimen320),
verticalArrangement = Arrangement.spacedBy(Dimen30)
) {
items(pagingItems.itemCount) { index ->
pagingItems[index]?.let {
JobOpeningsRow(dto = it)
}
}
if (pagingItems.loadState.append == LoadState.Loading) {
item {
Box(
Modifier
.padding(24.dp)
) {
CircularProgressIndicator(Modifier.align(Alignment.Center))
}
}
}
}
}
)
}
I found the solution to this problem, although it is not 100% and in terms of code it is not as good as I would like.
The error speaks for itself, we can't have infinite vertical scroll, Jetpack Compose doesn't allow it. I had the option of putting a fixed height on the Lazy Column of my list, but it wasn't what I wanted and it didn't work properly. The solution was to put everything inside a single LazyColumn and remove the Column from MainActivity, using a Box element and contentAlignment. I leave you below the final code that I used to solve the problem.
MainScreen function that before was MainActivityLayout function:
#Preview
#Composable
#ExperimentalFoundationApi
fun MainScreen() {
val navController = rememberNavController()
val topLevelDestinations = listOf(
NavigationItem.JobOpenings,
NavigationItem.Profile,
NavigationItem.About
)
val isTopLevelDestination =
navController
.currentBackStackEntryAsState()
.value
?.destination
?.route in topLevelDestinations.map { it.route }
val backStackEntryState = navController.currentBackStackEntryAsState()
Scaffold(
bottomBar = {
if (isTopLevelDestination) {
BottomNavBar(
navController = navController,
backStackEntryState = backStackEntryState,
bottomNavItems = topLevelDestinations
)
}
}
) {
Box(
modifier = Modifier
.paint(
painter = painterResource(id = R.drawable.main_background),
contentScale = ContentScale.FillBounds
)
.fillMaxSize(),
contentAlignment = Alignment.Center
) {
Navigation(navController = navController)
}
}
}
New JobOpenings fun that is mixed with old JobOpeningsContent function:
#Composable
#ExperimentalFoundationApi
fun JobOpeningsScreen(viewModel: JobOpeningsViewModel = hiltViewModel()) {
val uiState by viewModel.uiState.collectAsState()
when (uiState) {
is BaseViewState.Data -> {
val pagedData = uiState.cast<BaseViewState.Data<JobOpeningsViewState>>().value.pagedData
val pagingItems = rememberFlowWithLifecycle(pagedData).collectAsLazyPagingItems()
SwipeRefresh(
state = rememberSwipeRefreshState(
isRefreshing = pagingItems.loadState.refresh == LoadState.Loading
),
onRefresh = { pagingItems.refresh() },
indicator = { state, trigger ->
SwipeRefreshIndicator(
state = state,
refreshTriggerDistance = trigger,
scale = true
)
},
content = {
LazyColumn(
modifier = Modifier
.width(Dimen320),
verticalArrangement = Arrangement.spacedBy(Dimen30)
) {
item {
ScreenHeader(
lightTitle = stringResource(id = R.string.job_openings_light_title),
boldTitle = stringResource(id = R.string.job_openings_bold_title)
)
HeightSpacer(Dimen60)
Row {
CategoryButton()
WidthSpacer(Dimen2)
OrderByButton()
}
HeightSpacer(Dimen30)
SearchTextField()
HeightSpacer(Dimen60)
}
items(pagingItems.itemCount) { index ->
pagingItems[index]?.let {
JobOpeningsRow(dto = it)
}
}
if (pagingItems.loadState.append == LoadState.Loading) {
item {
Box(Modifier.padding(Dimen24)) {
CircularProgressIndicator(Modifier.align(Alignment.Center))
}
}
}
}
}
)
}
is BaseViewState.Loading -> LoadingView()
else -> {}
}
LaunchedEffect(key1 = viewModel, block = {
viewModel.onTriggerEvent(JobOpeningsEvent.LoadJobOffers)
})
}
#ExperimentalFoundationApi
#Preview
#Composable
fun JobOpenings() {
JobOpeningsScreen()
}
Problems that I found with this solution:
LoadingView appears at the top of the screen instead at the top of the list.
If anyone has any suggestion to improve this, I am open to it. This works perfectly with Paging Library + Swipe Refresh (Accompanist) and full page scroll.
I use the SwipeRefresh composable from the accompanist library, I checked the examples, but I could not find sample that matches my needs. I want to implement element that is hidden above the main UI, so when the user starts swiping the box is slowly shown up. I implemented this logic by setting the padding of the box that is below the hidden box. The obvious reason is that by changing the padding, all the composables are recreated and that leads to lags as seen from this report. Is there a way to fix it?
#Composable
fun HomeScreen(viewModel: CityWeatherViewModel) {
val scrollState = rememberScrollState()
val maxTopOffset = 200f
SwipeRefresh(
state = rememberSwipeRefreshState(isRefreshing = isRefreshing),
onRefresh = {
},
indicator = { state, triggerDp ->
if (state.isRefreshing) {
} else {
val triggerPx = with(LocalDensity.current) { triggerDp.toPx() }
val progress = (state.indicatorOffset / triggerPx).coerceIn(0f, 1f)
viewModel.apply {
rotateSwipeRefreshArrow(progress >= 0.9)
setSwipeRefreshTopPadding(progress * maxTopOffset)
}
}
}
) {
Column(
modifier = Modifier
.fillMaxSize()
.verticalScroll(state = scrollState, enabled = true)
.padding(top = viewModel.swipeRefreshPaddingTop.value.dp)
) {
HiddenSwipeRefreshBox(viewModel)
MainBox(viewModel)
}
}
}
#Composable
fun HiddenSwipeRefreshBox(viewModel: CityWeatherViewModel) {
}
#Composable
fun MainBox(viewModel: CityWeatherViewModel) {
}
#HiltViewModel
class CityWeatherViewModel #Inject constructor(
private val getCityWeather: GetCityWeather
) : ViewModel() {
private val _swipeRefreshPaddingTop = mutableStateOf(0f)
val swipeRefreshPaddingTop: State<Float> = _swipeRefreshPaddingTop
fun setSwipeRefreshTopPadding(padding: Float) {
_swipeRefreshPaddingTop.value = padding
}
}
I managed to fix it, by replacing the padding with offset, so the code for the Column is changed to:
Column(
modifier = Modifier
.fillMaxSize()
.verticalScroll(state = scrollState, enabled = true)
.offset { IntOffset(0, viewModel.swipeRefreshPaddingTop.value.roundToInt()) }
) {
}
And now there is no more lagging, even on older devices with 2GB RAM! I have no idea how this is related to the padding lagging, but it works. I found the code from HERE
I have VideoListScreen with LazyColumn and as my item I use VideoItem. This LazyColumn it's created with grid items to have lazy grid view with Category header. Tag is tag of category. Category details is information about category colors, title etc.:
#Composable
fun VideoItem(
videoPath: String,
brush: Brush,
modifier: Modifier = Modifier,
onClick: () -> Unit
) {
val assetFileDescriptor = LocalContext.current.assets.open(videoPath)
Surface(
modifier = modifier
.padding(5.dp)
.aspectRatio(1f)
.clickable { onClick() },
shape = Shapes.small,
elevation = 1.dp
) {
GlideImage(
imageModel = assetFileDescriptor.readBytes(),
contentScale = ContentScale.Crop,
requestOptions = RequestOptions.diskCacheStrategyOf(DiskCacheStrategy.NONE),
shimmerParams = ShimmerParams(
baseColor = MaterialTheme.colors.background,
highlightColor = Blue200,
durationMillis = 650,
dropOff = 0.65f,
tilt = 20f
)
)
Box(modifier = Modifier
.background(brush)
.fillMaxSize() )
}
}
VideoListScreen:
#Composable
fun VideoListScreen(
navController: NavHostController,
tag: String
) {
val cells = 2
val context = LocalContext.current
val categoryDetails = getCategoryDetailsBy(tag)
val videos = fetchVideos(context, tag)
LazyColumn(contentPadding = PaddingValues(5.dp)) {
item {
CategoryElement(
categoryDetails = categoryDetails,
modifier = Modifier
.fillMaxWidth()
.height(130.dp)
.padding(5.dp),
customTitle = "O kategorii"
)
}
gridItems(videos, cells) { assetFileName ->
val videoPath = "$tag/$assetFileName"
VideoItem(
videoPath = videoPath,
brush = categoryDetails.transparentBrush
) { navController.navigateToPlayer(videoPath) } //onClick function
}
}
}
private fun fetchVideos(context: Context, tag: String): List<String> {
return context.resources.assets.list("$tag/")?.toList() ?: listOf()
}
gridItems extension function:
fun <T> LazyListScope.gridItems(
data: List<T>,
cells: Int,
itemContent: #Composable BoxScope.(T) -> Unit,
) {
items(data.chunked(cells)) { row ->
Row(Modifier.fillMaxWidth()) {
for ((index, item) in row.withIndex()) {
Box(Modifier.fillMaxWidth(1f / (cells - index))) {
itemContent.invoke(this, item)
}
}
}
}
}
The problem is that when I try to apply clickability on this item (no matter where) the thumbnail loading (from the assets) becomes almost twice as slow. What's interesting when onClick function is empty, performance issue disappearing. In function called "navigateToPlayer(videoPath)" I navigate to another screen and send "videoPath" with navController.
If you have any questions, feel free to ask!
In compose you're creating UI with view builders. This function can be called many times, when you start using animations it even can be recomposed on each frame.
That's why you shouldn't perform any heavy work directly in composable function. And if you do, you need to store the result so you don't need recalculation on the next recomposition.
Both fetchVideos and assets.open are quite heavy operations, and even result of getCategoryDetailsBy(not sure what's that) should be cached. To do that you need to use remember or rememberSaveable. Check out how are these different and more about state in composables.
So update your declarations like this:
val categoryDetails = remember { getCategoryDetailsBy(tag) }
val videos = remember { fetchVideos(context, tag) }
val context = LocalContext.current
val assetFileDescriptor = remember { context.assets.open(videoPath) }
I'm looking forward to a way to implement a Collapsing effect while scrolling on LazyColumn list. I have been checking the docs but I didn't found nothing related. How can I implement it?
At the moment I'm using a BottomNavigation setted inside my Scaffold and I can add the inner paddings to the screen coming from the scaffold content lambda. But I didn't find any kind of scrollable state or something close to it.
You can use the nestedScroll modifier.
Something like:
val bottomBarHeight = 48.dp
val bottomBarHeightPx = with(LocalDensity.current) { bottomBarHeight.roundToPx().toFloat() }
val bottomBarOffsetHeightPx = remember { mutableStateOf(0f) }
// connection to the nested scroll system and listen to the scroll
// happening inside child LazyColumn
val nestedScrollConnection = remember {
object : NestedScrollConnection {
override fun onPreScroll(available: Offset, source: NestedScrollSource): Offset {
val delta = available.y
val newOffset = bottomBarOffsetHeightPx.value + delta
bottomBarOffsetHeightPx.value = newOffset.coerceIn(-bottomBarHeightPx, 0f)
return Offset.Zero
}
}
}
and then apply the nestedScroll to the Scaffold:
Scaffold(
Modifier.nestedScroll(nestedScrollConnection),
scaffoldState = scaffoldState,
//..
bottomBar = {
BottomAppBar(modifier = Modifier
.height(bottomBarHeight)
.offset { IntOffset(x = 0, y = -bottomBarOffsetHeightPx.value.roundToInt()) }) {
IconButton(
onClick = {
coroutineScope.launch { scaffoldState.drawerState.open() }
}
) {
Icon(Icons.Filled.Menu, contentDescription = "Localized description")
}
}
},
content = { innerPadding ->
LazyColumn(contentPadding = innerPadding) {
items(count = 100) {
Box(
Modifier
.fillMaxWidth()
.height(50.dp)
.background(colors[it % colors.size])
)
}
}
}
)
I want to implement a screen which can show two different bottom sheets.
Since ModalBottomSheetLayout only has a slot for one sheet I decided to change the sheetContent of the ModalBottomSheetLayout dynamically using a selected state when I want to show either of the two sheets (full code).
val sheetState = rememberModalBottomSheetState(initialValue = ModalBottomSheetValue.Hidden)
val (selected, setSelected) = remember(calculation = { mutableStateOf(0) })
ModalBottomSheetLayout(sheetState = sheetState, sheetContent = {
when (selected) {
0 -> Layout1()
1 -> Layout2()
}
}) {
Content(sheetState = sheetState, setSelected = setSelected)
}
This works fine for very similar sheets, but as soon as you add more complexity to either of the two sheet layouts the sheet will not show when the button is pressed for the first time, it will only show after the button is pressed twice as you can see here:
Here you can find a reproducible example
I had a similar usecase, where I needed to show 2-3 stacked bottomsheets.
I ended up copying large part of Compose BottomSheet and added the desired behavior:
enum class BottomSheetValue { SHOWING, HIDDEN }
#Composable
fun BottomSheet(
parentHeight: Int,
topOffset: Dp = 0.dp,
fillMaxHeight: Boolean = false,
sheetState: SwipeableState<BottomSheetValue>,
shape: Shape = bottomSheetShape,
backgroundColor: Color = MaterialTheme.colors.background,
contentColor: Color = contentColorFor(backgroundColor),
elevation: Dp = 0.dp,
content: #Composable () -> Unit
) {
val topOffsetPx = with(LocalDensity.current) { topOffset.roundToPx() }
var bottomSheetHeight by remember { mutableStateOf(parentHeight.toFloat())}
val scrollConnection = sheetState.PreUpPostDownNestedScrollConnection
BottomSheetLayout(
maxHeight = parentHeight - topOffsetPx,
fillMaxHeight = fillMaxHeight
) {
val swipeable = Modifier.swipeable(
state = sheetState,
anchors = mapOf(
parentHeight.toFloat() to BottomSheetValue.HIDDEN,
parentHeight - bottomSheetHeight to BottomSheetValue.SHOWING
),
orientation = Orientation.Vertical,
resistance = null
)
Surface(
shape = shape,
color = backgroundColor,
contentColor = contentColor,
elevation = elevation,
modifier = Modifier
.nestedScroll(scrollConnection)
.offset { IntOffset(0, sheetState.offset.value.roundToInt()) }
.then(swipeable)
.onGloballyPositioned {
bottomSheetHeight = it.size.height.toFloat()
},
) {
content()
}
}
}
#Composable
private fun BottomSheetLayout(
maxHeight: Int,
fillMaxHeight: Boolean,
content: #Composable () -> Unit
) {
Layout(content = content) { measurables, constraints ->
val sheetConstraints =
if (fillMaxHeight) {
constraints.copy(minHeight = maxHeight, maxHeight = maxHeight)
} else {
constraints.copy(maxHeight = maxHeight)
}
val placeable = measurables.first().measure(sheetConstraints)
layout(placeable.width, placeable.height) {
placeable.placeRelative(0, 0)
}
}
}
TopOffset e.g. allows to place the bottomSheet below the AppBar:
BoxWithConstraints {
BottomSheet(
parentHeight = constraints.maxHeight,
topOffset = with(LocalDensity.current) {56.toDp()}
fillMaxHeight = true,
sheetState = yourSheetState,
) {
content()
}
}
I wanted to implement the same thing and because of the big soln, I wrote a post on dev.to that solves this problem, Here is the link
I implemented it like this. It looks pretty simple, but I still could not figure out how to pass the argument to "mutableStateOf ()" directly, I had to create a variable "content"
fun Screen() {
val bottomSheetState = rememberModalBottomSheetState(ModalBottomSheetValue.Hidden)
val scope = rememberCoroutineScope()
val content: #Composable (() -> Unit) = { Text("NULL") }
var customSheetContent by remember { mutableStateOf(content) }
ModalBottomSheetLayout(
sheetState = bottomSheetState,
sheetContent = {
customSheetContent()
}
) {
Column {
Button(
onClick = {
customSheetContent = { SomeComposable1() }
scope.launch { bottomSheetState.show() }
}) {
Text("First Button")
}
Button(
onClick = {
customSheetContent = { SomeComposable2() }
scope.launch { bottomSheetState.show() }
}) {
Text("Second Button")
}
}
}
I just tried your code. I am not sure but looks like when you click first time, since selected state changes, Content function tries to recompose itself and it somehow blocks sheetState. Because i can see that when i click first time, bottom sheet shows up a little and disappears immediately. But second time i click same button, since selected state doesnt change, sheetState works properly.