Are Ambients a Service Locator / Dependency Injection API? I haven’t seen official documentation describing them as such, and I think that’s pretty much what it is. I could achieve the same thing with Dagger/Hilt, though the dependencies are scoped within the Composable Hierarchy, instead of Activities/Fragments/Application/ViewModel

Results in NPE:

is this exception known

Layer is redrawn for LayoutNode in state NeedsRelayout

?

Hi, All. Jetpack Compose uses function. but, I think there were some discussion on

function

vs `class`(as swiftUI also based on function but also able to use struct) So, I just tried to use

class

for Composable if it’s meaningful. Kindly review if it’s reasonable or not. the below is the sample code with

class

Screen(Composable class)

class ApiSingleScreen(private val model: ApiSingleViewModel = ApiSingleViewModel()) : Screen(model) {
    override val title: String = R.string.single_call.resourceToString()

    //for Composer to recognize the class
    @Composable
    override fun compose() {
        super.compose()
    }

    @Composable
    override fun view() {
        Column {
            Text("current value : ${+model.result}")
            SampleTextField("Input value", model.input)
            Button("update") {
                model.onClick()
            }
        }
    }
}

ViewModel

class ApiSingleViewModel(private val api: PreferenceApi = serviceLocator.preferenceApi) : BaseViewModel() {

	//DataFlow will be migrated to MutableSharedFlow. as coroutine-native-mt 1.4.0 is not yet released. I customized Flow.
    val result by lazy { DataFlow<String>() }

    //if result is changed, input also changed.
    val input by add { DataFlow<String>().withSource(result) }


    override fun onInit() {
    	//initStatus is connected with loading, error ui. so, when call api, loading, error ui is shown by the state
        result.load(initStatus) {
            api.getString(KEY) ?: ""
        }
    }

    fun onClick() {
        result.load(status) {
            val text = input.value?: error("please input")
            api.setString(KEY, text)
            text//set changed text after api call is success
        }
    }
}

If There is something wrong on my opinion. kindly advise me to learn.🙏

Hey, since we won't need multiple fragments anymore with compose navigation and can go single activity, what would be the best practice for injecting viewmodels with hilt? Injecting them all in the activity and then pass them down?

Hi, i try to integrate compose in production project to test it. When i try to build project i got :

Execution failed for task ':app:prepareDevDebugKotlinCompileTask'.
> org/jetbrains/kotlin/gradle/tasks/KotlinCompile

Exception says:

Caused by: java.lang.NoClassDefFoundError: org/jetbrains/kotlin/gradle/tasks/KotlinCompile
	at com.android.build.gradle.tasks.PrepareKotlinCompileTask.doTaskAction(PrepareKotlinCompileTask.kt:71)

Maybe someone got similar issue or knows how to fix it?

Why NavControllerAmbient removed, why it is need to pass to composable functions explicitly

Hi, not sure why, but

createBottomBarrier

started to crash since

1.0.0-alpha05

with this:

java.lang.NullPointerException: Attempt to invoke interface method 'androidx.constraintlayout.core.widgets.ConstraintWidget androidx.constraintlayout.core.state.Reference.getConstraintWidget()' on a null object reference

. I assume something changed?

Any ideas on how to pause and resume a transition? I have the following transition:

transitionDefinition<StoryState>{
    state(StoryState.START) {
        this[progress] = 0f
    }

    state(StoryState.END) {
        this[progress] = 1f
    }

    transition(StoryState.START to StoryState.END) {
        progress using tween(5000, delayMillis = 500, easing = LinearEasing)
    }
}

I'd like to pause and resume the transition on a certain event. I guess we can't do that so what can I do?

How stupid is it to use

androidx.navigation:navigation-compose:1.0.0-SNAPSHOT

I do want to avoid Fragments, but I do not want to rewrite it every day because its a snapshot

Looks like the thing that everyone who’s tried to write a navigation library in Compose has been waiting for is in review: https://android-review.googlesource.com/c/platform/frameworks/support/+/1425674 This looks great, it’s gonna be super handy!

New experimental api RestorableStateHolder. It allows to save the state defined with [savedInstanceState] and [rememberSavedInstanceState] for the subtree before disposing it to make it possible to compose it back next time with the restored state.

Also, Compose sources seem to be browseable again in Android Studio 4.2 canary 14! 🎉

https://developer.android.com/jetpack/compose/state 👀

Is anyone else using androidx.compose.navigation:navigation snapshot? Or do we have a normal alpha of it yet?

Hello everyone I've encountered some weird behaviour with

.clickable()

modifier when i scale up a

@composable

using

.drawLayer()

the hit box not only it does not scale up but it actually scales down and moves down and to the right proportionate to where the the

@composable

is placed inside of the available space. Should i just change the size instead or is this just a bug and scaling a

@composable

should also scale the hit box?

Hello guys, I’m new to Android and Jetpack Compose and I was wondering if there is any way of having a global state of the application? Just like React-Native has Redux? I know there’s a library called ReduxKotlin, I was wondering if anybody else used it or have any suggestions about how this can be achieved. (not necessarily through the ReduxKotlin library)

Has anyone looked into crafting shared element transitions between composables? I know Android's Transition API wasn't much loved, but I'm really missing something like it in Compose 😅

Here you go https://github.com/yashovardhan99/ComposeNotes/ @Spikey Sanju

Is anyone working with multiple sets of compose components & planning to launch it as a library? How was your experience? Any tips?

HI! A question for compose: Is this the best way to create custom colors and shapes values?

@Composable
val Colors.success: Color
    get() = if (isSystemInDarkTheme()) {
        green200
    } else {
        green800
    }

@Composable
val Shapes.fab: Shape
    get() = RoundedCornerShape(percent = 50)

MaterialThemes.Colors.success
MaterialThemes.Shapes.fab

How can I change the background of Radio Button ?

when we should use key() is there like some guide to that?

What is the best way to get a composable to recalculate its own height, when a sibling forces a parent to grow? I have an issue where an image of unknown height causes a Row to grow. This in turn messes with a sibling, which has

fillMaxHeight

set. The sibling does not grow to fill the new height of its parent. I have made a gif to illustrate what I mean, the sibling is highlighted blue. If I set the Row to a fixed height, the issue does not happen.

I have my own typography system (i.e. not

MaterialTheme.Typography

), but I’d like to lean on Material for a number of components such as

Button

. Specifically looking at

Button

, I’d like to use my own

FancyTheme.typography.button

instead of

MaterialTheme.typography.button

. My first thought was to do something like

@Composable
fun FancyButton(content: @Composable RowScope.() -> Unit) {
  Button {
    ProvideTextStyle(
      value = FancyTheme.typography.button,
      children = content
    )
  }
}

But that doesn’t quite work since

ProvideTextStyle

’s content doesn’t accept a

RowScope

receiver. Is there a better way to do this?

Hey everyone, just wanted to say that I have learned a lot just by reading the questions / answers in this channel. People ask me questions about Compose every now and then and I usually say “I think someone mentioned it somewhere in the slack channel…” So I compiled a list of those remarks that I find insightful: https://collectednotes.com/brunoaybar/compose-insights I’m just referencing existing answers (not posting personal opinions), but please feel free reach out if you think any of those may be inaccurate / misleading / outdated / not helpful 😅

Hey. Does anyone know where to do a feature request for

navigation-compose

? Specifically, adding a

NavOptions?

parameter to the

NavController.navigate

extension function.

hey, what would be the best approach to guarantee that any children that I define are always expanded to match the full width? I wanted to achieve something like this:

VerticalButtonContainer(
    top = {
         TertiaryButton(
            text = "Tertiary",
            onClick = { },
          )
     },
     bottom = {
          PrimaryButton(
              text = "Primary",
              onClick = {},
          )
     }
)

@Composable
fun VerticalButtonContainer(
    top: @Composable () -> Unit,
    bottom: @Composable () -> Unit
) {
    Column(
        Modifier
            .fillMaxWidth()
            .padding(16.dp)
    ) {

        top()
        Spacer(Modifier.height(16.dp))
        bottom()
    }
}

In this case both

top

and

bottom

would ideally expand to the max width of the container. However (naturally) the buttons are still wrapping the content. Any way I can tweak the internals of this

VerticalButtonContainer

to force the children to expand the width?

Has anyone had this compilation error happen when they were trying to add compose to an existing project?

Unable to load class 'org.jetbrains.kotlin.gradle.tasks.KotlinCompile'.

For reference it’s on kotlin

1.14.10

,

1.0.0-alpha05

for the compose version, android gradle

4.1.0

, and on android studio 4.2 canary 14,

So if we initialize a map partially with mutableStateMapOf and partially by adding items directly, are the added items also mutableState? What is the correct way of doing this?