Jetpack Compose - Show trailingIcon in BasicTextField? - android-jetpack-compose

TextField has way too much padding by default for the screen I'm building, so I'm forced to use BasicTextField (see: this post on default TextField padding)
The problem is, BasicTextField doesn't take in a trailingIcon parameter. Is there a way to get around this?

Starting with 1.2.0 you can use the TextFieldDecorationBox with the BasicTextField. Here you can use the trailingIcon and contentPadding attributes:
BasicTextField(
value = value,
onValueChange = onValueChange,
interactionSource = interactionSource,
enabled = enabled,
singleLine = singleLine
) {
TextFieldDefaults.TextFieldDecorationBox(
value = value,
innerTextField = it,
singleLine = singleLine,
enabled = enabled,
visualTransformation = VisualTransformation.None,
trailingIcon = { /* ... */ },
interactionSource = interactionSource,
contentPadding = TextFieldDefaults.textFieldWithoutLabelPadding(
//...top = 0.dp, bottom = 0.dp
)
)
}

Related

Bug in default behavior of ScalingLazyColumn (Jetpack Compose Wear OS)

I'm using ScalingLazyColumn with a very long Text inside as follows:
#Preview(device = Devices.WEAR_OS_SMALL_ROUND, showSystemUi = true)
#Composable
fun Test(modifier: Modifier = Modifier) {
val scalingLazyState = remember { ScalingLazyListState() }
val focusRequester = remember { FocusRequester() }
Scaffold(
modifier = modifier,
positionIndicator = { PositionIndicator(scalingLazyListState = scalingLazyState) }
) {
ScalingLazyColumn(
modifier = Modifier.scrollableColumn(focusRequester, scalingLazyState),
state = scalingLazyState,
) {
item {
Text(
longText,
Modifier
.padding(top = 20.dp, start = 16.dp, end = 16.dp, bottom = 48.dp),
textAlign = TextAlign.Center,
)
}
}
}
}
val longText =
"Take the plunge\n" +
"\n" +
"commit oneself to a course of action about which one is nervous.\n" +
"\n" +
"\"she wondered whether to enter for the race, but decided to take the plunge\"\n" +
"\"They're finally taking the plunge and getting married.\"\n" +
"\n" +
"\n" +
"plunge:\n" +
"jump or dive quickly and energetically.\n" +
"\"our daughters whooped as they plunged into the sea\"\n"
But for some reason when I launch the app the focus goes to the bottom of the text, instead of the beginning, which looks like a bug. I've tried playing with different parameters of ScalingLazyColumn (anchorType, autoCentering, scalingParams) to no avail.
Any idea how to fix it and make the ScalingLazyColumn focus on the beginning of the first element when I launch the app?
Switching off autoCentering is an option, but I would try and avoid it in most cases as it will will make handling getting the padding right on different devices sizes more difficult and often results in being able to over scroll the list items either at the beginning or the end.
I am not sure exactly what you want to achieve when you say that you want the focus to be on the start of the first item but the following should give you what you need.
Set the state initial item to 0
Set the anchor type to ScalingLazyListAnchorType.ItemStart
Remove top padding from your item
Apply an offset to the state initialItem initialCenterItemScrollOffset to shift the start of you item up a little.
Optionally adjust the autoCentering to make sure that the limit of the scrolling matches the initial position selected in the state
#Preview(device = Devices.WEAR_OS_SMALL_ROUND, showSystemUi = true)
#Composable
fun SingleItemSLCWithLongText(modifier: Modifier = Modifier) {
val scalingLazyState = remember { ScalingLazyListState(initialCenterItemIndex = 0, initialCenterItemScrollOffset = 80) }
val focusRequester = remember { FocusRequester() }
Scaffold(
modifier = modifier.background(Color.Black),
positionIndicator = { PositionIndicator(scalingLazyListState = scalingLazyState) }
) {
ScalingLazyColumn(
modifier = Modifier.scrollableColumn(focusRequester, scalingLazyState),
autoCentering = AutoCenteringParams(itemIndex = 0, itemOffset = 80),
state = scalingLazyState,
anchorType = ScalingLazyListAnchorType.ItemStart
) {
item {
Text(
longText,
Modifier
.padding(start = 16.dp, end = 16.dp, bottom = 48.dp),
textAlign = TextAlign.Center,
)
}
}
}
}
Here is a screenshot of how the screen initially looks
Initial screen
This test activity let's you play with all the params to see starting position
https://github.com/google/horologist/blob/a1241ff25b7008f7c1337f4425b98d14ce30d96d/sample/src/main/java/com/google/android/horologist/scratch/ScratchActivity.kt
After a few hours of frustration I finally found a solution.
If you read the documentation for ScalingLazyColumn it says:
"If the developer wants custom control over position and spacing they
can switch off autoCentering and provide contentPadding."
So all you need to do is to just add autoCentering = null in ScalingLazyColumn.
This is a working code where the focus will be in the beginning of the Text:
val scalingLazyState = remember { ScalingLazyListState() }
val focusRequester = remember { FocusRequester() }
Scaffold(
modifier = modifier,
positionIndicator = { PositionIndicator(scalingLazyListState = scalingLazyState) }
) {
ScalingLazyColumn(
modifier = Modifier.scrollableColumn(focusRequester, scalingLazyState),
state = scalingLazyState,
autoCentering = null,
) {
item {
Text(
longText,
Modifier
.padding(top = 20.dp, start = 16.dp, end = 16.dp, bottom = 48.dp),
textAlign = TextAlign.Center,
)
}
}
}
ScalingLazyListState defaults to the center of the second item (index 1). You can tell it to instead start in the first item and even jn the ScalingLazyColumn parameters use the start of items.
val scalingLazyState = remember { ScalingLazyListState(initialCenterItemIndex = 0) }
val focusRequester = remember { FocusRequester() }
Scaffold(
modifier = Modifier,
positionIndicator = { PositionIndicator(scalingLazyListState = scalingLazyState) }
) {
ScalingLazyColumn(
modifier = Modifier.scrollableColumn(focusRequester, scalingLazyState),
state = scalingLazyState,
anchorType = ScalingLazyListAnchorType.ItemStart
) {
item {
Text(
longText,
Modifier
.padding(top = 20.dp, start = 16.dp, end = 16.dp, bottom = 48.dp),
textAlign = TextAlign.Center,
)
}
}
}

Why is MediumTopAppBar (and Large) showing two TextField in compose?

I am trying to make the title of a screen editable.
MediumTopAppBar(
title = {
val name: String? = "Some Title"
var input by remember { mutableStateOf(name ?: "") }
when (state.isEditingTitle) {
true ->
TextField(
value = input,
onValueChange = { input = it },
keyboardOptions = KeyboardOptions.Default.copy(imeAction = ImeAction.Done),
keyboardActions = KeyboardActions(onDone = {
callbacks.onEditTitleChange(editTitle = false, updatedTitle = input)
})
)
false -> {
Text(
modifier = Modifier.clickable { callbacks.onEditTitleChange(true, null) },
text = name ?: "(No Title)"
)
}
}
},
... more app bar parameters
}
When I click on the title Text(...) and the view gets recomposed the AppBar shows two TextFields
How do I ignore the top one and only show the one in the bottom, like the Text() is only shown in the bottom?
(Fyi: the two TextInputs have their own remembered state and calls the callback with their own respective value)
Bonus question: How do I handle the remembered state "input" so that it resets every time the onDone keyboard action is triggered? Instead of val name: String? = "Some Title" it would of course be something in the line of val name: String? = state.stateModel.title
I found out why it does this, but I have no idea how to solve it (except for just making my own views and placing it close by)
It's easy to see when looking at the function for the MediumTopBar
// androidx.compose.material3.AppBar.kt
#ExperimentalMaterial3Api
#Composable
fun MediumTopAppBar(
title: #Composable () -> Unit,
modifier: Modifier = Modifier,
navigationIcon: #Composable () -> Unit = {},
actions: #Composable RowScope.() -> Unit = {},
windowInsets: WindowInsets = TopAppBarDefaults.windowInsets,
colors: TopAppBarColors = TopAppBarDefaults.mediumTopAppBarColors(),
scrollBehavior: TopAppBarScrollBehavior? = null
) {
TwoRowsTopAppBar(
modifier = modifier,
title = title,
titleTextStyle = MaterialTheme.typography.fromToken(TopAppBarMediumTokens.HeadlineFont),
smallTitleTextStyle = MaterialTheme.typography.fromToken(TopAppBarSmallTokens.HeadlineFont),
titleBottomPadding = MediumTitleBottomPadding,
smallTitle = title, // <- this thing, right here
navigationIcon = navigationIcon,
actions = actions,
colors = colors,
windowInsets = windowInsets,
maxHeight = TopAppBarMediumTokens.ContainerHeight,
pinnedHeight = TopAppBarSmallTokens.ContainerHeight,
scrollBehavior = scrollBehavior
)
}
There's some internal state shenanigans going on, probably checking for a Text being shown in the 2nd TopAppBarLayout (more digging required to find that), but not for any other view.
TwoRowsTopAppBar and TopAppBarLayout are not public, and can't be used directly.
This is explains why, but it would be interesting to see how to solve it (still using Medium or Large -TopAppBar)
it is stupid thing devs overlooked and should be warned against, at least. The answer is do not give default colors to your Typography TextStyles.
private val BodySmall = TextStyle(
fontSize = 10.sp,
lineHeight = 12.sp,
fontWeight = FontWeight.SemiBold,
fontFamily = Manrope,
color = Color.Black // REMOVE THIS
)
val OurTypography = Typography(
...
bodySmall = BodySmall
)

BottomNavigationItems padding

Is there any way to remove this padding from the BottomNavigationItem?
Image
If I have very large text, I have to use ResponsiveText to manage this, but that's not what I intended. What I need is that it doesn't have that side padding/margin, both on the left and on the right, in order to occupy as much space as possible.
My code:
#Composable
fun BottomNavBar(
backStackEntryState: State<NavBackStackEntry?>,
navController: NavController,
bottomNavItems: List<NavigationItem>
) {
BottomNavigation(
backgroundColor = DarkGray.copy(alpha = 0.6f),
elevation = Dimen0,
modifier = Modifier
.padding(Dimen10, Dimen20, Dimen10, Dimen20)
.clip(RoundedCornerShape(Dimen13, Dimen13, Dimen13, Dimen13))
) {
bottomNavItems.forEach { item ->
val isSelected = item.route == backStackEntryState.value?.destination?.route
BottomNavigationItem(
icon = {
Icon(
painter = painterResource(id = item.icon.orZero()),
contentDescription = stringResource(id = item.title)
)
},
label = {
ResponsiveText(
text = stringResource(id = item.title),
textStyle = TextStyle14,
maxLines = 1
)
},
selectedContentColor = Color.White,
unselectedContentColor = Color.White,
alwaysShowLabel = true,
selected = isSelected,
onClick = {
navController.navigate(item.route) {
navController.graph.startDestinationRoute?.let { route ->
popUpTo(route = route) {
saveState = true
}
}
launchSingleTop = true
restoreState = true
}
},
modifier = if (isSelected) {
Modifier
.clip(RoundedCornerShape(Dimen13, Dimen13, Dimen13, Dimen13))
.background(color = DarkGray)
} else {
Modifier.background(color = Color.Unspecified)
}
)
}
}
}
Apparently this is currently (I am using compose version '1.2.0-rc03') not possible when using BottomNavigation, as there is padding set for each element in these lines:
.padding(horizontal = BottomNavigationItemHorizontalPadding)
Here is what is said about this value:
/**
* Padding at the start and end of a [BottomNavigationItem]
*/
private val BottomNavigationItemHorizontalPadding = 12.dp
[Solution]
Just copy BottomNavigation from androidx and remov this line:
.padding(horizontal = BottomNavigationItemHorizontalPadding)
However, it is necessary that the first and last elements still have padding, so add the innerHorizontalPaddings parameter to the your CustomBottomNavigation constructor
There are a few more changes, you can see the full code of my CustomBottomNavigation here
Example of usage:
CustomBottomNavigation(
...,
innerHorizontalPaddings = 12.dp
) {
items.forEach { item ->
BottomNavigationItem(
icon = {
Icon(...)
},
label = {
Text(
...
softWrap = false,
overflow = TextOverflow.Ellipsis,
modifier = Modifier.padding(horizontal = 2.dp)
)
},
...
)
}
}
Another solution is to wrap the label in a BoxWithConstraints and draw outside of it:
BottomNavigationItem(
label = {
/**
* Because of [BottomNavigationItemHorizontalPadding] (12.dp), we need to
* think (and draw) outside the box.
*/
BoxWithConstraints {
Text(
modifier = Modifier
.wrapContentWidth(unbounded = true)
.requiredWidth(maxWidth + 24.dp), // 24.dp = the padding * 2
text = "Centered text and clipped at the end if too long",
softWrap = false,
textAlign = TextAlign.Center
)
}
},
...
)
To get a little bit of padding, you can set requiredWidth(maxWidth + 18.dp).
With this solution, you don't need to copy the enire BottomNavigation :)

goneMargin in ConstraintLayout with Compose

I'm trying to use ConstraintLayout in Compose. I want the second Composable to be constrained at the end of the first Composable. The first composable can exist or not. In each case, I would like to have different margins. Thus, I use goneMargin but this seems to not be respected. Do I need to do something else?
ConstraintLayout {
val (firstItemRef, secondItemRef) = createRefs()
if (isFirstItemVisible) {
Text(
text = "First",
modifier = Modifier.constrainAs(firstItemRef) {
top.linkTo(anchor = parent.top)
start.linkTo(anchor = parent.start)
}
)
}
Text(
text = "Second",
modifier = Modifier.constrainAs(secondItemRef) {
top.linkTo(anchor = parent.top)
start.linkTo(anchor = firstItemRef.end, margin = 8.dp, goneMargin = 16.dp)
}
)
}
As a workaround, we could do something like that, but this seems to counterfeit the purpose of goneMargin
Text(
text = "Second",
modifier = Modifier.constrainAs(secondItemRef) {
val margin = if (isFirstItemVisible) 8.dp else 16.dp
val end = if (isFirstItemVisible) firstItemRef.end else parent.end
top.linkTo(anchor = parent.top)
start.linkTo(anchor = end, margin = margin)
}
)
You have to use the visibility property in ConstrainScope like this:
ConstraintLayout(Modifier.fillMaxSize()) {
val (firstItemRef, secondItemRef) = createRefs()
Text(
text = "First",
modifier = Modifier.constrainAs(firstItemRef) {
top.linkTo(anchor = parent.top)
start.linkTo(anchor = parent.start)
// >> This is what you want <<<
visibility = if (isFirstItemVisible) Visibility.Visible else Visibility.Gone
}
)
Text(
text = "Second",
modifier = Modifier.constrainAs(secondItemRef) {
top.linkTo(anchor = parent.top)
start.linkTo(anchor = firstItemRef.end, margin = 8.dp, goneMargin = 16.dp)
}
)
}

how can we create a circular checkbox in jetpack compose?

It is usually possible to assign different shapes to a composable using a modifier, but this is not done in this composable.
I want the part marked in the image to be a circle
You can see the code I wrote below
#Composable
fun StandardCheckbox(
text: String = "",
checked: Boolean,
onCheckedChange: ((Boolean) -> Unit)?,
) {
Row(
Modifier.padding(horizontal = SpaceMedium)
) {
Checkbox(
modifier = Modifier
.clip(CircleShape),
checked = checked,
onCheckedChange = onCheckedChange,
enabled = true,
colors = CheckboxDefaults.colors(
checkedColor = MaterialTheme.colors.primary,
checkmarkColor = MaterialTheme.colors.onPrimary,
uncheckedColor = MaterialTheme.colors.onBackground.copy(alpha = 0.3f)
)
)
Spacer(modifier = Modifier.width(SpaceSmall))
Text(
text = text,
color = MaterialTheme.colors.primary,
modifier = Modifier.clickable {
if (onCheckedChange != null) {
onCheckedChange(!checked)
}
}
)
}
}
In order to achieve a circular checkbox with a native experience, and retain the body color and click ripple effect, and keep it simple, IconButton is the best choice.
#Composable
fun CircleCheckbox(selected: Boolean, enabled: Boolean = true, onChecked: () -> Unit) {
val color = MaterialTheme.colorScheme
val imageVector = if (selected) Icons.Filled.CheckCircle else Icons.Outlined.Circle
val tint = if (selected) color.primary.copy(alpha = 0.8f) else color.white.copy(alpha = 0.8f)
val background = if (selected) color.white else Color.Transparent
IconButton(onClick = { onChecked() },
modifier = Modifier.offset(x = 4.dp, y = 4.dp),
enabled = enabled) {
Icon(imageVector = imageVector, tint = tint,
modifier = Modifier.background(background, shape = CircleShape),
contentDescription = "checkbox")
}
}
The code below is from CheckboxImpl composable
Canvas(modifier.wrapContentSize(Alignment.Center).requiredSize(CheckboxSize)) {
val strokeWidthPx = floor(StrokeWidth.toPx())
drawBox(
boxColor = boxColor,
borderColor = borderColor,
radius = RadiusSize.toPx(),
strokeWidth = strokeWidthPx
)
drawCheck(
checkColor = checkColor,
checkFraction = checkDrawFraction,
crossCenterGravitation = checkCenterGravitationShiftFraction,
strokeWidthPx = strokeWidthPx,
drawingCache = checkCache
)
}
drawBox will always draw a rounded rectangle. It can't be be customised.
To implement the circular checkbox you need to write a custom Composable and draw Circle instead of Rectangle. You can use RadioButton and CheckboxImpl composable as reference.

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