Develop Reference

Compose - `fillMaxSize` not working after using `Modifier.verticalScroll`

I am creating a simple app in Compose with the following layout:
val viewModel: HomeScreenViewModel = viewModel()
val scrollState = rememberScrollState()
Column(
modifier = Modifier.verticalScroll(scrollState).fillMaxSize()
) {
Text(
"Editor picks".uppercase(),
style = MaterialTheme.typography.labelMedium,
modifier = Modifier.padding(8.dp),
)
ElevatedCard(
modifier = Modifier.clickable {
}.fillMaxSize()
) {
Column {
AsyncImage(
viewModel.topVideo?.thumbnailSrc,
contentDescription = null,
modifier = Modifier.fillMaxWidth()
)
}
}
}
The output looks like so:
The image is not taking up all of the space which I need, it only works if I remove the Modifier.verticalScroll, so that the topmost element is just a simple column. When I do that, the output is what I expected:
I am extremely confused as to why this is happening, as I did not believe that making the root element scrollable would have any effect on the output.
I tried to look for a couple of hours online for solutions and I didn't find anything or any info as to why applying this modifier is ruining the layout.
This other person asked a similar question but the answer didn't work.

If you want your image to fill the entire screen width maintaining the correct aspect ratio, you can set contentScale to ContentScale.FillWidth for the Image composable.
Column(
modifier = Modifier.verticalScroll(scrollState)
) {
Text(
"Editor picks".uppercase(),
modifier = Modifier.padding(8.dp),
)
Card(
modifier = Modifier.clickable {}
) {
Column {
AsyncImage(
model = viewModel.topVideo?.thumbnailSrc,
contentDescription = null,
contentScale = ContentScale.FillWidth,
modifier = Modifier.fillMaxWidth()
)
}
}
}

Kotlin Jetpack compose Center text in Column inside a LazyColum

I'am new to jetpack compose and i really liked it. But ran into a problem : I want to create a card and inside of it, i would like to display a list of item with divider between them. I was almost able to achieved it here is my code :
Box(modifier = Modifier.background(Color(0xFFf4f4f4))
.fillMaxSize()
.padding(top = 20.dp)) {
Card(
modifier = Modifier
.fillMaxWidth(),
shape = RoundedCornerShape(20.dp),
elevation = 5.dp
) {
val colorNamesList = listOf("Red", "Green", "Blue", "Indigo")
LazyColumn() {
itemsIndexed(
colorNamesList,
) { index, item ->
Column(
modifier = Modifier
.background(
color = Color(0xFFf2f2f2),
)
.clickable {
println(item)
},
horizontalAlignment = Alignment.CenterHorizontally,//those 2 does nothing
verticalArrangement = Arrangement.Center //when i change it nothing change
) {
println(item + index)
Text(
text = "Item at $item",
modifier = Modifier
.fillMaxWidth()
.height(50.dp),
//textAlign = TextAlign.Center, without it image 1, with it image 2
color = Color.Black,
)
if (index < colorNamesList.lastIndex) {
Divider(
color = Color.Black.copy(alpha = 0.2f),
modifier = Modifier
.padding(horizontal = 80.dp),
)
}
}
}
}
}
}
It's almost good but i didn't managed to align the text inside it, i searched some answer but Alignment and Arrangement doesn't change anything in my situation.
I was able to align horizontally by adding textAlign = TextAlign.Center as i commented in my code but, i couldn't align vertically, the text stay on the top of his cell :
What i want to do is text center in every cell of the column. Thanks for the help.

You can achieve this by adding similar xml attribute like "wrap_content" as height in compose too.
Add "wrapContentHeight()" to modifier and you will get it to align to centre of the page.
Text(
text = "Item at $item",
modifier = Modifier
.fillMaxWidth()
.height(50.dp)
.wrapContentHeight(),
textAlign = TextAlign.Center
color = Color.Black,
)

How to remove RadioButton's padding in Jetpack Compose?

I have a problem with RadioButton component in my Jetpack Compose application. I have some RadioButtons with text and this have a lot of padding by default. Can I remove this padding or to set a custom padding to avoid a lot of space between each?
Currently I have this:
My code is:
Column {
MyEnum.values().filter { rb -> rb.visible }.forEach { rb ->
Row(
Modifier
.fillMaxWidth()
.padding(horizontal = 0.dp, vertical = 0.dp)
.clickable(
interactionSource = interactionSource,
indication = null
) {
TODO()
},
verticalAlignment = Alignment.CenterVertically
) {
RadioButton(
selected = (rb.position == selectedOption),
onClick = {
TODO()
},
colors = RadioButtonDefaults.colors(
selectedColor = DialogOutlinedTextFocus,
unselectedColor = DialogOutlinedTextUnfocus
)
)
Text(
text = stringResource(id = rb.idText),
color = Color.Black,
fontSize = 14.sp,
modifier = Modifier
.padding(horizontal = 3.dp, vertical = 2.dp)
)
}
}
}
I tried with contentPadding, but this property does not exist in RadioButton component.

The source code for RadioButton.kt sets the padding modifier at line 108. With modifiers, order matters. Even if you provide your own padding modifier it will be overridden by line 108.
The sizing values are hardcoded at the bottom of the file.
If you really want to "reduce the padding", apply a size modifier. I use 20.dp because it's equal to radioButtonSize in RadioButton.kt so the button doesn't get clipped. This should work for your purposes since the entire row is clickable.
RadioButton(
modifier = Modifier.size(20.dp),
selected = selected,
onClick = { TODO() },
)
Although, you're probably better off in the long term making custom components you can control. Luckily, the source code is ready available. Just copy, paste and adjust to your needs.

You could specify the Row height in the Row.Modifier
like this:
Row(
Modifier
.fillMaxWidth()
//HERE YOU GO
.height(30.dp)
.padding(horizontal = 0.dp, vertical = 0.dp)

How to align Text to Top, Bottom and Center Vertically in Jetpack Compose?

How can I align the text using Text composable function vertically. Is there a way to do it without having to add another extra view to contain the Text.
The textAlign parameter of Text only has the following options:
TextAlign.
Left
Right
Center
Justify
Start
End
I have tried using textAlign = TextAlign.Center but it only centers it horizontally. How can I center it vertically without wrapping it in another view?
Text(
text = "Text",
modifier = Modifier.size(100.dp),
textAlign = TextAlign.Center
)
Result:
What I am trying to achieve:

You have to use a parent container and align the composable inside it.
For example a Box:
Box(
modifier = Modifier.fillMaxSize(),
contentAlignment = Center
) {
Text(
text = "Text",
)
}
or a Column:
Column(
modifier = Modifier.fillMaxSize(),
verticalArrangement = Arrangement.Center,
horizontalAlignment = Alignment.CenterHorizontally
) {
Text(
text = "Text",
)
}

first use .wrapContentHeight() in modifier, then you can use align(CenterVertically) param to center the text.

It is difficult to give an exact answer without seeing your code, but I would say you need to use container's Alignment.CenterVertically instead of TextAlign
Something like:
Row {
Text(
text = "Text",
modifier = Modifier.align(alignment = Alignment.CenterVertically)
)
Image(
...
)
}
or:
Column(
modifier = Modifier
.align(Alignment.CenterVertically)
) {
Text(text = "Text")
Text(text = "Text 2")
}

I asked the same question here which is done with android:gravity param using views, as answered by PhilipDukhov it's not possible only with Text, you need to have another container, preferably Box to align Text component inside.

Create a simple composable function to show anything in center:
#Composable
fun Center(
modifier: Modifier = Modifier,
content: #Composable () -> Unit,
) {
Box(
modifier = modifier,
contentAlignment = Alignment.Center
) {
content()
}
}
Call it from any other function:
#Composable
fun CenterAlignedText() {
Center(Modifier.fillMaxSize()) {
Text("Hello World!")
}
}

Modifier .weight() not setted automatically in column and can't add

i am new to jetpack compose and also have some experience with flutter so when move to compose its a little bit similar to flutter declarative UI style but i don't quite understand
like in flutter when i want some widget to expanded and want it to take full available space we can use Exapanded widget and if i use this in Column its automatically add flex of 1 or weight in terms of jetpack compose so i want to do same thing in jetpack compose but its seems like jetpack column not automatically and weight to its children and also i cant add
Modifier.weight(1f) in Card of NetworkCardComposable so i have to pass Modifier from as Parameter and in when using this Compoasable in columns this Modifier.weight(1f) have to set through parameter which is odd i think.
#Preview(showBackground = true, widthDp = 500, heightDp = 200)
#Composable
fun NetworkCardComposable(modifier: Modifier = Modifier) {
Card(
modifier = modifier
.fillMaxSize(1f)
.padding(16.dp),
shape = RoundedCornerShape(16.dp),
backgroundColor = colorResource(id = R.color.jazz_color_primary)
) {
Row {
Card(
modifier = Modifier
.weight(2f)
.fillMaxSize()
.padding(8.dp),
shape = RoundedCornerShape(16.dp),
) {
Image(
modifier = Modifier
.padding(8.dp),
painter = painterResource(R.drawable.jazz_logo),
contentDescription = null,
)
}
Row(
modifier = Modifier
.weight(2f)
.fillMaxSize(),
verticalAlignment = Alignment.CenterVertically,
) {
Text(
modifier = Modifier
.weight(1f)
.fillMaxWidth(),
text = "Bundles & Offers",
color = Color.White,
textAlign = TextAlign.Center,
fontSize = MaterialTheme.typography.h5.fontSize,
)
Icon(
modifier = Modifier.size(56.dp),
imageVector = Icons.Default.ChevronRight,
tint = Color.White,
contentDescription = null,
)
}
}
}
}
#Preview(showBackground = true, showSystemUi = true)
#Composable
fun networkCard() {
Column(Modifier.fillMaxSize()) {
NetworkCardComposable(Modifier.weight(1f))
NetworkCardComposable(Modifier.weight(1f))
NetworkCardComposable(Modifier.weight(1f))
NetworkCardComposable(Modifier.weight(1f))
}
}
all thought i have acheive my desired layout but if there is any better approach to this please answer

Jetpack Compose aims at providing the maximum control over the UI. Hence, by default, the elements of a container like column default to wrap content. If you want them to occupy Max available space of the container, the proper way to do it is using Modifier.fillMaxSize()
As far as weights are concerned, if you do not specify then explicitly while adding more than one elements inside a container, the weights are calculated accordingly, based on the minimum required dimensions, (i.e., again, wrapContentSize ())