Arrange a single item inside a LazyColumn by using weight modifier - android

I am looking to have a result like this. Two block with 2/3 size and 1/3 size respectively.
I am getting the expected result with this code.
#Preview(showBackground = true)
#Composable
fun LayoutCheck() {
Column(
modifier = Modifier.fillMaxSize(),
horizontalAlignment = Alignment.CenterHorizontally
) {
Surface(
modifier = Modifier
.width(200.dp)
.weight(3f),
color = MaterialTheme.colors.primary
) {}
Surface(
modifier = Modifier
.width(200.dp)
.weight(1f),
color = MaterialTheme.colors.secondary
) {}
}
}
But when i put that inside a lazycolumn, nothing seems working. Not even getting a display.
#Preview(showBackground = true)
#Composable
fun LayoutCheck() {
Box(
modifier = Modifier.fillMaxSize(),
contentAlignment = Alignment.Center
) {
LazyColumn(
modifier = Modifier.fillMaxSize(),
contentPadding = PaddingValues(20.dp)
) {
item {
Column(
modifier = Modifier.fillMaxSize(),
horizontalAlignment = Alignment.CenterHorizontally
) {
Surface(
modifier = Modifier
.width(200.dp)
.weight(3f),
color = MaterialTheme.colors.primary
) {}
Surface(
modifier = Modifier
.width(200.dp)
.weight(1f),
color = MaterialTheme.colors.secondary
) {}
}
}
}
}
}
If i remove t he weight and put some height,it works. But i don't want to hardcode there. So how to make it work with weight. Expecting some help..
Thanks
NB: I want scroll functionality, that's why going with LazyColumn
Real World scenario :
A Login Screen, with Logo at the first 2/3 portion and a Text and Button at the bottom 1/3 portion
Scenario 1 : Working Perfectly:
Scenario 2: If users font is bigger or screen is rotated, they wont be able to see the button

Since you have only one item just use a Column with a verticalScroll:
val scrollState = rememberScrollState()
Column(
modifier = Modifier
.verticalScroll(scrollState),
horizontalAlignment = Alignment.CenterHorizontally,
) {
//...
}
Also if you want 2/3 and 1/3, use in the 1st Surface the weight(2f) modififer.

You prevent the text from being resized by applying the weight modifier. Instead, I suggest that you make the element spacing flexible, like this:
Column(
modifier = Modifier.fillMaxSize(),
horizontalAlignment = Alignment.CenterHorizontally
) {
Spacer(Modifier.weight(1f))
Image(
painter = painterResource(id = R.drawable.my_image),
contentDescription = "",
)
Spacer(Modifier.weight(1.35f))
Text(
"Your app is being reviewed",
)
Spacer(Modifier.weight(0.2f))
Button(onClick = { /*TODO*/ }) {
Text("Log out")
}
Spacer(Modifier.weight(0.2f))
}
Spacers explanation:

Related

Change alignment of child in column in jetpack compose

I want to change the horizontalAlignment of particular child and remaining will use the same horizontalAlignment. Is this possible in Column?
For example, Column parent modifier use horizontalAlignment = Alignment.CenterHorizontally, and I want particular child modifier will be different horizontalAlignment.
Column(
modifier = Modifier
.padding(16.dp)
.fillMaxSize()
.verticalScroll(rememberScrollState()),
horizontalAlignment = Alignment.CenterHorizontally,
) {
ScreenImage()
Description()
if (viewModel.isBluetoothEnabled) {
ScanDeviceList(scanDeviceList)
} else {
Warning()
Spacer(modifier = Modifier.weight(1f))
TryAgainButtonView { tryAgainAction() }
ButtonView { openSettingAction() }
}
}
I want to change ScanDeviceList() to be different horizontalAlignment
#Composable
fun ColumnScope.ScanDeviceList(scanDeviceList: List<ScanResult>) {
Spacer(modifier = Modifier.height(20.dp))
AnimatedVisibility(scanDeviceList.isNotEmpty()) {
Text(
text = stringResource(R.string.vailable_device),
)
}
}
Many Thanks
You can use Modifier.align(Alignment.Start) to align a particular child.
So for example to make your ScanDeviceList() at the Start of the column the code will be like this:
#Composable
fun ColumnScope.ScanDeviceList(scanDeviceList: List<ScanResult>) {
Spacer(modifier = Modifier.height(20.dp))
AnimatedVisibility(
scanDeviceList.isNotEmpty(),
modifier = Modifier.align(Alignment.Start)
) {
Text(
text = stringResource(R.string.vailable_device),
)
}
}
You can also pass the modifier as an argument to ScanDeviceList composable function to make it more generic to the code will be like this:
#Composable
fun ColumnScope.ScanDeviceList(
scanDeviceList: List<ScanResult>,
modifier: Modifier = Modifier
) {
Spacer(modifier = Modifier.height(20.dp))
AnimatedVisibility(
scanDeviceList.isNotEmpty(),
modifier = modifier
) {
Text(
text = stringResource(R.string.vailable_device),
)
}
}
And when you call it you can specify the alignment that you want:
ScanDeviceList(scanDeviceList, modifier = Modifier.align(Alignment.Start))
Note: adding the modifier an argument to your composable functions is considered as a best practice because it will make the function reusable like the example above you can call ScanDeviceList with Alignment.Start or Alignment.End without changing the function itself, just by passing a different modifier as a parameter.

Compose elements not overlapping

I am trying to overlap two different compose elements. I want to show a toast kind of message at the top whenever there is an error message. I don't want to use a third party lib for such an easy use case. I plan to use the toast in every other composable screen for displaying error message. Below is the layout which i want to achieve
So I want to achieve the toast message saying "Invalid PIN, please try again".
#Composable
fun MyToast(title: String) {
Card(
modifier = Modifier
.absoluteOffset(x = 0.dp, y = 40.dp)
.background(
color = MaterialTheme.colors.primaryVariant,
shape = RoundedCornerShape(10.dp)
), elevation = 20.dp
) {
Row(
modifier = Modifier
.background(color = MaterialTheme.colors.primaryVariant)
.padding(12.dp),
horizontalArrangement = Arrangement.Start,
verticalAlignment = Alignment.CenterVertically
) {
Image(
painter = painterResource(id = R.drawable.error_circle),
contentDescription = title
)
Text(
text = title,
fontFamily = FontFamily(Font(R.font.inter_medium)),
fontSize = 12.sp,
color = MaterialTheme.colors.primary,
modifier = Modifier.padding(horizontal = 10.dp)
)
}
}
}
and my screen composable is as follows
#Composable
fun Registration(navController: NavController, registrationViewModel: RegistrationViewModel) {
Scaffold() {
Box(){
MyToast(
title = "Invalid pin, please try again"
)
Column() {
//my other screen components
}
}
}
I will add the AnimatedVisibility modifier later to MyToast composable. First I need to overlap MyToast over all the other elements and somehow MyToast is just not visible
If you want the child of a Box to overlay/overlap its siblings behind, you should put it at the last part in the code
Box(
modifier = Modifier.fillMaxSize(),
contentAlignment = Alignment.Center
) {
Box(
modifier = Modifier.background(Color.Red).size(150.dp)
)
// your Toast
Box(
modifier = Modifier.background(Color.Green).size(80.dp)
)
}
So if I put the green box before the bigger red box like this
Box(
modifier = Modifier.fillMaxSize(),
contentAlignment = Alignment.Center
) {
// your Toast
Box(
modifier = Modifier.background(Color.Green).size(80.dp)
)
Box(
modifier = Modifier.background(Color.Red).size(150.dp)
)
}
the green box will hide behind the red one
You have to solutions, you can either put the Toast in the bottom of your code because order matters in compose:
#Composable
fun Registration(navController: NavController, registrationViewModel: RegistrationViewModel) {
Scaffold() {
Box() {
Column() {
//my other screen components
}
MyToast(
title = "Invalid pin, please try again"
)
}
}
}
Or you can keep it as it is, but add zIndex to the Toast:
#Composable
fun MyToast(title: String) {
Card(
modifier = Modifier
.absoluteOffset(x = 0.dp, y = 40.dp)
.zIndex(10f) // add z index here
.background(
color = MaterialTheme.colors.primaryVariant,
shape = RoundedCornerShape(10.dp)
), elevation = 20.dp
) {
Row(
modifier = Modifier
.background(color = MaterialTheme.colors.primaryVariant)
.padding(12.dp),
horizontalArrangement = Arrangement.Start,
verticalAlignment = Alignment.CenterVertically
) {
Image(
painter = painterResource(id = R.drawable.error_circle),
contentDescription = title
)
Text(
text = title,
fontFamily = FontFamily(Font(R.font.inter_medium)),
fontSize = 12.sp,
color = MaterialTheme.colors.primary,
modifier = Modifier.padding(horizontal = 10.dp)
)
}
}
}
Note: elevation in Card composable is not the same as elevation in XML so it's not going to make the composable in the top, it will just add a shadow but if you want to give the composable a higher z order use Modifier.zIndex(10f)

Android compose, Indicator size problem with coil

Recently, I try to migrate to Jetpack compose.
So, I want to show 'card' where has 'indicator' while loading
but I can't change 'indicator' size in 'SubcomposeAsyncImage'
#Composable
private fun SponsorDialogContent(
imgUrl: String,
) {
Card(
modifier = Modifier
.width(300.dp)
.wrapContentHeight(),
elevation = CardDefaults.cardElevation(0.dp),
shape = RoundedCornerShape(10.dp)
) {
Box() {
SubcomposeAsyncImage(
modifier = Modifier
.fillMaxWidth()
.wrapContentHeight()
.heightIn(min = 200.dp),
model = imgUrl,
contentDescription = null,
loading = {
CircularProgressIndicator(modifier = Modifier.size(30.dp).align(Alignment.Center), progress = 1f)
},
alignment = Alignment.Center,
contentScale = ContentScale.FillWidth
)
CircularProgressIndicator(1f, Modifier.width(30.dp).align(Alignment.Center))
}
}
}
So. I have try the code below
#Composable
private fun SponsorDialogContent(
imgUrl: String,
) {
Card(
modifier = Modifier
.width(300.dp)
.wrapContentHeight(),
elevation = CardDefaults.cardElevation(0.dp),
shape = RoundedCornerShape(10.dp)
) {
Box() {
SubcomposeAsyncImage(
modifier = Modifier
.fillMaxWidth()
.wrapContentHeight()
.heightIn(min = 200.dp),
model = imgUrl,
contentDescription = null,
loading = {
Box(contentAlignment = Alignment.Center) {
CircularProgressIndicator()
}
},
alignment = Alignment.Center,
contentScale = ContentScale.FillWidth
)
}
}
}
Then, works well, but I don't know why
Does anyone know why?
I tried to find how to work this code but failed
As #Jan Bina mentioned it has propagateMinConstraints = true which means it forces minimum constraints to its direct child only. I explained in this answer how it effects with Surface because Surface is a Box with propagateMinConstraints = true. You can try out these with Box and you will see the same outcomes
Surface(
modifier = Modifier.size(200.dp),
onClick = {}) {
Column(
modifier = Modifier
.size(50.dp)
.background(Color.Red, RoundedCornerShape(6.dp))
) {}
}
Spacer(modifier = Modifier.height(20.dp))
Surface(
modifier = Modifier.size(200.dp),
onClick = {}) {
Column(
modifier = Modifier
.size(50.dp)
.background(Color.Red, RoundedCornerShape(6.dp))
) {
Column(
modifier = Modifier
.size(50.dp)
.background(Color.Green, RoundedCornerShape(6.dp))
) {}
}
}
Spacer(modifier = Modifier.height(20.dp))
Box(
modifier = Modifier.size(200.dp)
) {
Column(
modifier = Modifier
.size(50.dp)
.background(Color.Red, RoundedCornerShape(6.dp))
) {
Column(
modifier = Modifier
.size(50.dp)
.background(Color.Green, RoundedCornerShape(6.dp))
) {}
}
}
In first example on Surface forces Column to have 200.dp size even though it has Modifier.size(50.dp).
In second example Box inside Column has 50.dp size because it's not a direct descendant of Surface.
In third example if we replace Surface(Box with propagateMinConstraints true) with Box it allows direct descendant to use its own constraints or dimensions.
And when you set Modifier.fillMaxWidth you set Constraints as minWidth = parent width, maxWidth = parentWidth
I answered about Constraint types here
If you browse the source code of SubcomposeAsyncImage, you will get to the point where you can see this:
BoxWithConstraints(
modifier = modifier, // this is the modifier you passed to SubcomposeAsyncImage
contentAlignment = alignment,
propagateMinConstraints = true,
) {
// image or your loading content based on state
}
So the behavior you describe is because of your modifier that has heightIn(min = 200.dp) and your progress indicator that ends up being direct child of this Box which has propagateMinConstraints = true.

How to fillMaxSize() the Box() inside row - Compose

I want to align the button in the BottomEnd of the Box in Row (In the BottonEnd of the bellow Card). I have Card with Row who is devided in two parts - Card and Box, and I want the Box to fill max of the rest of the row. I cannot implement it how I would wanted. Bellow I attached the visualization of the current code.
.
#Composable
fun ProductItem(product: ProductModel, onItemClick: () -> Unit, onAddToCardButton: () -> Unit) {
Card(
modifier = Modifier
.fillMaxSize()
.padding(7.dp)
.clickable { onItemClick() },
shape = MaterialTheme.shapes.large,
elevation = 4.dp
) {
Row(
modifier = Modifier.fillMaxSize()
) {
Card(
modifier = Modifier
.weight(1f),
shape = MaterialTheme.shapes.small,
elevation = 2.dp
) {
Image(
painter = painterResource(id = R.drawable.ic_splash_screen),
contentDescription = "Image of ${product.name}",
)
}
Box(
modifier = Modifier
.weight(2f)
.fillMaxHeight()
.padding(6.dp)
.background(Color.Green)
) {
Column(modifier = Modifier.align(Alignment.TopStart)) {
Text(
text = "${product.number}. ${product.name}",
fontWeight = FontWeight.Bold,
style = MaterialTheme.typography.h4,
)
Text(
text = product.ingredients, fontStyle = FontStyle.Italic
)
}
Button(
modifier = Modifier.align(Alignment.BottomEnd),
onClick = {
onAddToCardButton()
},
shape = RoundedCornerShape(8.dp),
) {
if (product.type == "pizza") {
Text(text = "od ${String.format("%.2f", product.price[0])} zł")
} else {
Text(text = "${String.format("%.2f", product.price[0])} zł")
}
}
}
}
}
}
I expect you display this item in LazyColumn or inside a vertical scrollable.
Modifier.fillMaxHeight doesn't work in this case, because parent height constraint is equal to infinity.
To solve this you ofc can use a static value, but in this case intrinsic measurements can be used to wrap content size.
Add Modifier.height(IntrinsicSize.Max) to your Row.
The code looks good to me at first sight, even tried it and the button is on the bottom right corner. Where do you define the height of your ProductItem card?
Maybe you can try to define it in the code you provided by changing the
.fillMaxSize()
modifier to
.fillMaxWidth()
.requiredHeight(**.dp)
at your first Card composable.
So it would look something like this:
#Composable
fun ProductItem(product: ProductModel, onItemClick: () -> Unit, onAddToCardButton: () -> Unit) {
Card(
modifier = Modifier
.fillMaxWidth()
.requiredHeight(**.dp)
.padding(7.dp)
.clickable { onItemClick() },
shape = MaterialTheme.shapes.large,
elevation = 4.dp
) {
...
}
As Phil Dukhov answered Modifier.height(IntrinsicSize.Max) works for me.
Just set the modifier to the Root element in your Row. In your case it's Card (change .fillMaxWidth() to .height(IntrinsicSize.Max)):
Card(
modifier = Modifier
.height(IntrinsicSize.Max)
.padding(7.dp)
.clickable { onItemClick() },
shape = MaterialTheme.shapes.large,
elevation = 4.dp
)

How to optimise laggy JetPack Compose layout

I'm using a HorizontalPager from accompanist package. The pager will have 1 page for each exercise stored by the user.
Each page in the pager has a LazyColumn which contain multiple cards with controls such as IconButtons and BasicTextField. The number of cards depends on number of sets configured by the user. I expect the typical number to be between 1 to 8 but only 3 to 5 would be visible on the screen at any given time (depending on the screen size and resolution).
The issue is that when this layout produces noticeable lag (animations skip frames) every time the HorizontalPager needs to build a new page that has more than 3 cards. This happens when swapping between pages. The same happens in debug and release versions running on a real device (Galaxy S10e) and emulator.
I'm trying to optimise this layout, so each frame renders in no more than 16ms regardless of the number of cards shown on the screen.
I've previously tried to solve this issue by setting fixed heights to some composables but that didn't help much. I've also tried using Text instead of BasicTextField, which would be then replaced with BasicTextField when users taps on the text but this hasn't helped much, therefore I removed this implementation.
Do you have some suggestions how performance of this layout could be improved to eliminate the lag?
Below is my code, screen shoot of the app screen and profiler:
#ExperimentalPagerApi
#Composable
fun WorkoutSessionScreen(
navHostController: NavHostController,
) {
val pagerState = rememberPagerState()
Scaffold(
topBar = { MyTopAppBar(navHostController = navHostController) }
) {
Box(
modifier = Modifier
.fillMaxHeight()
.fillMaxWidth()
.background(MaterialTheme.colors.background)
.imePadding()
) {
HorizontalPager(
count = 10, state =
pagerState,
itemSpacing = 16.dp
) {
Log.e("==>", "Building horizontal pager")
TrackingControls()
}
Box(
modifier = Modifier
.height(70.dp)
.fillMaxWidth()
.background(Color(0xFAF7F7FF))
.align(Alignment.BottomCenter)
) {
Column(
Modifier.fillMaxWidth()
) {
Divider(color = Color(0x2A5C5C5C))
BottomControls()
}
}
}
}
}
#Composable
private fun TrackingControls() {
LazyColumn(
Modifier
.fillMaxHeight()
.fillMaxWidth(),
contentPadding = PaddingValues(vertical = 8.dp)
) {
items(6) { item ->
SetsAndRepsTrackingControls(
modifier = Modifier
)
}
}
}
#Composable
private fun BottomControls() {
Text(text = "Bottom Controlls")
}
#Composable
fun SetsAndRepsTrackingControls(modifier: Modifier = Modifier) {
val add = painterResource(id = R.drawable.ic_round_add_24)
val remove = painterResource(id = R.drawable.ic_round_remove_24)
Card(
modifier
.fillMaxWidth()
.height(200.dp)
.padding(vertical = 16.dp, horizontal = 8.dp),
backgroundColor = MaterialTheme.colors.surface,
shape = RoundedCornerShape(12.dp),
) {
Column() {
ControlsHeader()
TrackingInput(label = "REPS", add, remove)
Divider(color = Color.LightGray)
TrackingInput(label = "WEIGHT (KG)", add, remove)
}
}
}
#Composable
private fun ControlsHeader() {
Row(
modifier = Modifier
.height(56.dp)
.fillMaxWidth()
.background(MaterialTheme.colors.primary, RoundedCornerShape(12.dp))
.padding(horizontal = 16.dp),
verticalAlignment = Alignment.CenterVertically,
horizontalArrangement = Arrangement.SpaceBetween
) {
Text(text = "Set 1")
Text(text = "CheckBox")
}
}
#Composable
private fun TrackingInput(label: String = "Preview", add: Painter, remove: Painter) {
Row(
modifier = Modifier
.fillMaxWidth()
.height(60.dp),
horizontalArrangement = Arrangement.SpaceBetween,
verticalAlignment = Alignment.CenterVertically
) {
IconButton(onClick = {}) {
Icon(
painter = painterResource(id = R.drawable.ic_round_remove_24),
contentDescription = "Minus",
tint = MaterialTheme.colors.onSurface
)
}
Column(
horizontalAlignment = Alignment.CenterHorizontally
) {
BasicTextField(
singleLine = true,
value = "8",
onValueChange = {},
textStyle = TextStyle(
textAlign = TextAlign.Center,
color = MaterialTheme.colors.onSurface
),
)
Spacer(modifier = Modifier.height(4.dp))
Text(
text = label,
style = MaterialTheme.typography.overline.copy(color = MaterialTheme.colors.onSurface)
)
}
IconButton(onClick = { Log.d("==>", "tada") }) {
Icon(
painter = painterResource(id = R.drawable.ic_round_add_24),
contentDescription = "Minus",
tint = MaterialTheme.colors.onSurface
)
}
}
}
This profiler print screen shows rendering of a single card called SetsAndRepsTrackingControls

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