kotlinlang #compose

I noticed a strange issue on textField with KeyboardType.Number. when i click to enter text, the keyboard shows right. But when i request focus manually, the keyboard shows an extra bar with undesirable inputs. Like this:

julioromano

01/24/2022, 3:01 PM

Does

derivedStateOf

track reads of

State

objects at run time or compile time (or perhaps I should say dynamically or statically)? 🧵

marios proto

01/24/2022, 3:32 PM

Hi 👋 , I have an accessibility issue with Compose, if anyone could help please. Let’s say I have a

Row { 
Text()
Button()
}

and on using the largest font in the device I want to have them both visible, text and button, and if needed to break the content in two lines, is it even possible? So far, I only managed to have them both visible with ellipse of their text

myanmarking

01/24/2022, 4:04 PM

Is it possible to align text inside Row, vertically and by baseline ?

➕ 1

Filip Stanis

01/24/2022, 6:37 PM

Hey all! Is there an advantage to passing a lambda vs wrapping it? E.g.

@Composable
fun MyButton(onClick: () -> Unit) {
    Button(onClick = onClick) { ... }
}
// vs
@Composable
fun MyButton(onClick: () -> Unit) {
    Button(onClick = { onClick() } { ... }
}

(this is probably a more general kotlin question, but I see both patterns in compose code and it's unclear if one is better / worse than the other)

Billy Newman

01/24/2022, 6:44 PM

Hello all. I have a question about button text color in regards to the primary color. Should the text color automatically change from black to white based on the buttons primary color? Example in reply.

myanmarking

01/24/2022, 6:49 PM

what would be the correct KeyboardType for number only (not decimal). NumberPassword or Phone ?

Arun Joseph

01/24/2022, 7:39 PM

Can we somehow simplify this?

if (enabled) {
                    Icon(
                        painter = painterResource(id = iconId),
                        contentDescription = null,
                        modifier = Modifier.size(32.dp),
                        tint = iconColor
                    )
                } else {
                    Icon(
                        painter = painterResource(id = iconId),
                        contentDescription = null,
                        modifier = Modifier.size(32.dp),
                    )
                }

I am trying something along these lines

Icon(
                        painter = painterResource(id = iconId),
                        contentDescription = null,
                        modifier = Modifier.size(32.dp),
                        tint = if (enabled) iconColor else ...
                    )

henrikhorbovyi

01/25/2022, 12:48 AM

Hello, everyone 🙂 What's the best way to implement a nested scroll screen on Compose? My hierarchy is:

MyScreen:
    Column():
        Text("Nice Title")
        LazyVerticalGrid:
            items(n) { MyItem() }

➕ 2

iona bartishvili

01/25/2022, 7:35 AM

Hey, everyone. i have a question regarding the Snackbar in androidx.compose.material. i have an action text which shows up at the start of the snackbar view. Instead, i want this text to show up at the end of the snackbar view. can enyone tell me what i am missing ?

Marcin Środa

01/25/2022, 9:00 AM

Hey, does anyone implemented custom emoji picker in Compose?

Matthew Laser

01/25/2022, 3:22 PM

hey all - is the best practice when using compose to still use fragments, or are the composable functions intended to just live in an activity without that layer

Jan

01/25/2022, 5:35 PM

I have a question for ViewModel. I know that I can just use something like that for getting the newest entries:

class AbsenceViewModel : ViewModel() {

    val absencesFlow = MutableStateFlow<List<DBItem>>(emptyList())

    init {
        viewModelScope.launch {
            kotlin.runCatching {
                AbsenceRepository.getAll()
            }.onSuccess {
                absencesFlow.value = it.toList()
            }.onFailure {
                absencesFlow.value = emptyList()
            }
        }
    }

}

but whats when I modify the entries on the rest api? Or if I want to modify them locally?

Filip Stanis

01/25/2022, 6:32 PM

I'm wrapping a multiline

TextField

in a scrollable column and I realized that by default the column won't scroll to the bottom if it goes off screen. Attached gif of what I mean - the

TextField

grows until it reached the height of the

Column

, then it goes off-screen - but I can still scroll to it. Can I make the scroll position follow focus? I'd expected that to happen by default, maybe I'm doing something wrong?

val scrollState by remember { mutableStateOf(ScrollState(0)) }
var value by remember { mutableStateOf("") }
Column(
    Modifier
        .padding(8.dp)
        .height(60.dp)
        .verticalScroll(scrollState)
) {
    BasicTextField(
        modifier = Modifier
            .fillMaxWidth()
            .background(Color.White)
            .padding(8.dp),
        value = value,
        onValueChange = { value = it }
    )
}

Lucien Guimaraes

01/25/2022, 7:34 PM

Is possible to have a navigation between Standard sheets? ModalBottomSheetLayout from Accompanist only works for Modal sheets. And even by setting the

scrimColor

parameter to

Color.Unspecified

, to make sheets looks like standard sheets, we don't have control over the peekHeight.

vgonda

01/25/2022, 8:29 PM

Can you use

AndroidComposeTestRule

for end-to-end tests that work through multiple activities?

👀 1

myanmarking

01/25/2022, 8:58 PM

What is the different between this two. And what purpose each ones serves:

LazyColumn{

item(item, {item.key}){

MyItem()

LazyColumn{

item(item){

key(item.key){

MyItem()

Marko Novakovic

01/25/2022, 9:49 PM

am a bit confused. when using

AnimatedNavHost

from

Accompanist

composable(...) {...}

is recomposed multiple times due to animation. so every value inside the

composable

lambda should be `remember`ed right? for extracting arguments it doesn't really matter because they are static but with

remember

we avoid constant extraction of arguments? what about

hiltViewModel

inside

composable

lambda? is it ok to do something like this:

composable(
    route = Screen.Checkout.route,
    arguments = ...,
    enterTransition = { forwardTransitionSharedAxisXIn() },
    exitTransition = { backwardsTransitionSharedAxisXOut() },
) { backStackEntry ->
    val someArg = remember { backStackEntry.arguments!!.getFloat("arg") }
    val viewModel = hiltViewModel<CheckoutViewModel>(backStackEntry)
    CheckoutScreen(
        ...
        navigateUp = navController::popBackStack,
    )
}

Aditya Murthy

01/25/2022, 11:22 PM

I have container that houses a few composable buttons in it. Is there a way to make the contents of the container visible, without making them clickable? I know I can individually add logic to the buttons and make them un-clickable, but I wanted to check if I can control this at a higher level (Similar to a glass panel - you can still see everything behind the panel, but can't interact with it)

marios proto

01/26/2022, 12:02 AM

👋 Is there any way to have a

Lazycolumn

inside an

AbstractComposeView

, contained in a ScrollView(in an xml layout)? it seems there is no way around the exception of

Nesting scrollable in the same direction layouts like LazyColumn and Column(Modifier.verticalScroll()) is not allowed.

👀 1

jannis

01/26/2022, 9:56 AM

Is there a good way to detect that the user pasted something via the context menu instead of writing in a

TextField

Jan Skrasek

01/26/2022, 10:31 AM

I have some Composable accepting an icon and I wanna be more strict about the accepted type. What is the proper way? •

Painter

- seems to have mutability issues and I didn't found any copy/clone method. •

@Composable () -> Unit

- for custom rendering icon is too benevolent for me •

@Composable () -> Painter

- is what I'm ended up. Is it the correct solution?

Ashu

01/26/2022, 2:13 PM

How can I intercept click events on child composables? I have a form where I am trying to show a toast to the user if the form is not editable. So clicking on form elements which normally would trigger some form action needs to be intercepted and instead I want to show a toast to the user.

Teck Wei Chan

01/26/2022, 2:25 PM

Okay, I'm not really sure what's going on... But

var show by rememberSaveable { mutableStateOf(false) }

causes

ClassCastException: Boolean can't be cast to String

on configuration change.

remember { ... }

works fine, of course. afaik,

rememberSaveable

uses bundle to save values so it should be fine, no?

Guilherme Delgado

01/26/2022, 3:01 PM

Is there any

animateItemPlacement

implementation (or alternative) for

LazyGridScope

? 🤔

Colton Idle

01/26/2022, 4:18 PM

I have this in my composable screen, but ideally I'd like to control this state from my vm. Is that frowned upon or is it normal to move these

remember*State

calls to my VM? Example:

val bottomSheetScaffoldState = rememberBottomSheetScaffoldState(bottomSheetState = BottomSheetState(BottomSheetValue.Collapsed))

myanmarking

01/26/2022, 7:28 PM

I don’t understand why the image is not loading with coil. Can some1 spot the mistake? It’s a valid url

Simon Stahl

01/26/2022, 7:48 PM

Anyone knows if there is something in the works to support previews with viewmodels?

Filip Wiesner

01/26/2022, 7:50 PM

Another snapshot question: When I have snapshot inside snapshot (nested snapshot) and I change some state twice inside the inner snapshot and apply, shouldn't the outer snapshot see only one write? I am seeing the write observer being triggered twice 🤔 Code in a thread :thread-please:

Title

Filip Wiesner

01/26/2022, 7:50 PM

val writeObserver: (Any) -> Unit = { writtenState ->
    val s = writtenState as MutableState<String>
    println("State was changed to ${s.value}")
}


var state by mutableStateOf("")

val snap = Snapshot.takeMutableSnapshot(writeObserver = writeObserver)
snap.enter {
    state = "A"
    Snapshot.withMutableSnapshot {
        state = "B"
        state = "C"
    }
}

snap.apply()
snap.dispose()

//The Result is:
//  State was changed to A
//  State was changed to B
//  State was changed to C

The documentation (of

takeNestedMutableSnapshot

which is called by

takeMutableSnapshot

) clearly states that this shouldn't be the case:

Take a mutable snapshot of the state values in this snapshot. Entering this snapshot by calling enter allows state objects to be modified that are not visible to the this, the parent snapshot, until the apply is called.

What am I missing?

Ok, this works:

val snap = Snapshot.takeMutableSnapshot()
snap.enter {
    Snapshot.observe(writeObserver = writeObserver) {
        state = "A"

        val nestedSnap = snap.takeNestedMutableSnapshot()
        nestedSnap.enter {
            state = "B"
            state = "C"
        }
        nestedSnap.apply()
        nestedSnap.dispose()
    }
}
snap.apply()
snap.dispose()

//The Result is:
//  State was changed to A

But frankly I have no idea why. And it also doesn't work like I thought it will. It observes only the "A" change but not the "C" change which kinda makes sense.

Maybe the

currentSnapshot()

function returns the global snapshot and not the

snap

like I thought it will. So when I create snapshot inside another, they are both in GlobalSnapshot. But even then it doesn't make sense to me 😞

@Adam Powell I am really sorry for the ping but I am out of ideas. What am I getting wrong?

Adam Powell

02/02/2022, 4:49 PM

I would need to sit down and read this more closely than I can at the moment, @Chuck Jazdzewski [G] might get to it before I do

Chuck Jazdzewski [G]

02/02/2022, 5:11 PM

The write observer is not an apply observer. The read and write observers observe all reads and writes, respectively, at the time they are performed and parent snapshots observe all reads and writes of the child snapshots at the time they are performed. The intent of write observers is to notify the observe when a change might be arriving, such as the

GlobalSnapshotManager

does, so it can schedule some action. It is not intended to be used as apply observer which will only send a notification at most once for each change.

objects to be modified that are not visible to the this, the parent snapshot, until the apply is called.

This is referring to the values of the objects not the notification sent to the read and write observers. Changing the value of

state

nestedSnap

is not visible in

snap

until

nestedSnap

is applied.

View count: 3