kotlinlang #compose

Minor help request: I am not being able to scroll the contents. Am I doing something wrong here?@Composable
fun ArtistsList(artistsLiveData: LiveData<List<Artist>>) {
    val artists = +state { artistsLiveData.value }
    val artistObserver = Observer<List<Artist>> {
        artists.value = it
    }
    +onActive {
        artistsLiveData.observeForever(artistObserver)
    }
    +onDispose {
        artistsLiveData.removeObserver(artistObserver)
    }
    VerticalScroller {
        Column(modifier = Expanded) {
            artists.value?.forEach {
                Row(modifier = ExpandedWidth wraps Spacing(all = 8.dp)) {
                    Container(Spacing(4.dp), width = 40.dp, height = 40.dp) {
                        val image = +state<Image?> { null }
                        prepareImage(url = it.picture_small, state = image)
                        image.value?.let {
                            DrawImage(image = it)
                        }
                    }
                    Text(
                        text = it.name,
                        modifier = ExpandedWidth,
                        style = (+ambient(Typography)).body1
                    )
                }
            }
        }
    }
}

Ian Warwick

01/29/2020, 7:33 PM

did we just get a new release? 😄 🎆

👀 4

Ian Warwick

01/29/2020, 7:33 PM

e: /Users/ian.warwick/Documents/sdev/memset/router/src/main/java/com/citizenwarwick/memset/router/Router.kt: (94, 32): Using 'unaryPlus(): T' is an error. The unary plus for effects is no longer needed. Remove it.

tcracknell

01/29/2020, 8:23 PM

Hello! I'm happy to announce that the Jetpack Compose dev04 drop has just been released! You can get it on Google’s Maven Repository or by upgrading your version in the latest Android Studio canary. Compose is developed in the open, so the latest changes were always available, but we are moving to a continuous release model for binaries to make it easier to dogfood the latest API changes. Release notes are linked at https://developer.android.com/jetpack/compose. Thank you for your continued feedback, and please continue logging issues at https://issuetracker.google.com/issues/new?component=612128!

🎉 10

🚀 21

Egor Trutenko

01/29/2020, 9:20 PM

Hi! Probably was already asked, but I'll try and duplicate: why do we need constraint layout in Compose? Isn't Compose layout system able to flatten complex nested hierarchies?

Zach Klippenstein (he/him) [MOD]

01/29/2020, 9:29 PM

As of dev04, I’m getting a compilation error any time any of my composables tries accessing an ambient. Is there any new gradle/compiler configuration we need? Error + stacktrace in thread.

Zach Klippenstein (he/him) [MOD]

01/29/2020, 10:38 PM

It looks like it’s still not possible to host an Android

View

nested inside a compose container, is that true?

dimsuz

01/29/2020, 11:09 PM

From changelog:

Added DrawModifier, a modifier type that is allowed to draw on the surface of the modified layout.

I have a fear that this modifier-stuff has a potential to make API quite messy where you can do everything in modifier and they'll be misused. Like some widget will decide that it wants to draw its content with DrawModifier and I can't theme it. Or it will decide to size itself through modifier constraints in some clever way and won't let me size it in the usual way. etc etc Tell me I'm wrong! :)

➕ 2

codeslubber

01/30/2020, 12:05 AM

Looks like

HeightSpacer

and

WidthSpacer

are gone in 04? cannot find info on their replacements..

codeslubber

01/30/2020, 3:04 AM

We have to put

@Composable

on onClick lambdas now?? ugh…

codeslubber

01/30/2020, 3:59 AM

So I did a stepper in Compose and followed an example where I had the state in the Composable method, then called a stepper function and passed it the state. Worked in 03, does not compile in 04, tells me I cannot mutate a val.

@Composable
fun MeasureQuestionView() {
    val typography = (MaterialTheme.typography())

    val rangeOfValues = 115..125
    val currentValue = state {rangeOfValues.first}

    Card(shape = RoundedCornerShape(8.dp)) {
        Column(modifier = Spacing(16.dp)) {
            Text("What was your blood sugar reading?", style = typography.h6)
            numberStepper(currentValue, rangeOfValues, "mg/dL")
        }
    }

}

@Composable
fun numberStepper(currentValue: State<Int>, range: IntRange, units: String) {
    val typography = (MaterialTheme.typography())

    Container(height = 75.dp) {
        Row(Spacing(20.dp)) {
            Button(text = "-", onClick = {
                if (currentValue.value > range.first) {
                    currentValue.value -= 1
                }
            })
            Spacer(LayoutWidth(10.dp))
            Text(currentValue.value.toString(), style = typography.h5)
            Spacer(LayoutWidth(10.dp))
            Button(text = "+", onClick = {
                if (currentValue.value < range.last) currentValue.value += 1
            })
            Spacer(LayoutWidth(10.dp))
            Align(Alignment.CenterLeft){
                Text(units)
            }
        }
    }

}

zhuinden

01/30/2020, 4:27 AM

e: java.lang.IllegalStateException: Backend Internal error: Exception during code generation
Element is unknownThe root cause java.util.NoSuchElementException was thrown at: androidx.compose.plugins.kotlin.compiler.lower.ComposableCallTransformer.irComposableExpr(ComposableCallTransformer.kt:1362)
	at org.jetbrains.kotlin.codegen.CompilationErrorHandler.lambda$static$0(CompilationErrorHandler.java:35)
	at org.jetbrains.kotlin.backend.jvm.JvmBackendFacade.doGenerateFilesInternal$backend_jvm(JvmBackendFacade.kt:93)
	at org.jetbrains.kotlin.backend.jvm.JvmBackendFacade.doGenerateFilesInternal$backend_jvm$default(JvmBackendFacade.kt:64)
	at org.jetbrains.kotlin.backend.jvm.JvmBackendFacade.doGenerateFilesInternal$backend_jvm(JvmBackendFacade.kt:52)
	at org.jetbrains.kotlin.backend.jvm.JvmIrCodegenFactory.generateModule(JvmIrCodegenFactory.kt:36)
	at org.jetbrains.kotlin.codegen.KotlinCodegenFacade.doGenerateFiles(KotlinCodegenFacade.java:47)
	at org.jetbrains.kotlin.codegen.KotlinCodegenFacade.compileCorrectFiles(KotlinCodegenFacade.java:39)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.generate(KotlinToJVMBytecodeCompiler.kt:638)
	at org.jetbrains.kotlin.cli.jvm.compiler.KotlinToJVMBytecodeCompiler.compileModules$cli(KotlinToJVMBytecodeCompiler.kt:198)
	at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:172)
	at org.jetbrains.kotlin.cli.jvm.K2JVMCompiler.doExecute(K2JVMCompiler.kt:56)
	at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:85)
	at org.jetbrains.kotlin.cli.common.CLICompiler.execImpl(CLICompiler.kt:43)
	at org.jetbrains.kotlin.cli.common.CLITool.exec(CLITool.kt:104)
Caused by: java.util.NoSuchElementException: Collection contains no element matching the predicate.
	at androidx.compose.plugins.kotlin.compiler.lower.ComposableCallTransformer.irComposableExpr(ComposableCallTransformer.kt:1362)
	at androidx.compose.plugins.kotlin.compiler.lower.ComposableCallTransformer.visitBlock(ComposableCallTransformer.kt:252)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitBlock(IrElementTransformerVoid.kt:128)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitBlock(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.expressions.impl.IrBlockImpl.accept(IrBlockImpl.kt:52)
	at org.jetbrains.kotlin.ir.expressions.IrExpression$DefaultImpls.transform(IrExpression.kt:28)
	at org.jetbrains.kotlin.ir.expressions.impl.IrExpressionBase.transform(IrExpressionBase.kt:24)
	at org.jetbrains.kotlin.ir.expressions.impl.IrTypeOperatorCallImpl.transformChildren(IrTypeOperatorCallImpl.kt:75)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoidKt.transformChildrenVoid(IrElementTransformerVoid.kt:288)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.transformChildrenVoid(IrElementTransformerVoid.kt:283)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.transformChildren(IrElementTransformerVoid.kt:25)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitExpression(IrElementTransformerVoid.kt:112)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitTypeOperator(IrElementTransformerVoid.kt:214)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitTypeOperator(IrElementTransformerVoid.kt:215)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitTypeOperator(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.expressions.impl.IrTypeOperatorCallImpl.accept(IrTypeOperatorCallImpl.kt:68)
	at org.jetbrains.kotlin.ir.expressions.IrExpression$DefaultImpls.transform(IrExpression.kt:28)
	at org.jetbrains.kotlin.ir.expressions.impl.IrExpressionBase.transform(IrExpressionBase.kt:24)
	at org.jetbrains.kotlin.ir.declarations.impl.IrVariableImpl.transformChildren(IrVariableImpl.kt:93)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoidKt.transformChildrenVoid(IrElementTransformerVoid.kt:288)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.transformChildrenVoid(IrElementTransformerVoid.kt:283)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.transformChildren(IrElementTransformerVoid.kt:25)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitDeclaration(IrElementTransformerVoid.kt:46)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitVariable(IrElementTransformerVoid.kt:87)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitVariable(IrElementTransformerVoid.kt:88)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitVariable(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.declarations.impl.IrVariableImpl.accept(IrVariableImpl.kt:86)
	at org.jetbrains.kotlin.ir.declarations.IrDeclaration$DefaultImpls.transform(IrDeclaration.kt:42)
	at org.jetbrains.kotlin.ir.declarations.impl.IrDeclarationBase.transform(IrDeclarationBase.kt:27)
	at org.jetbrains.kotlin.ir.expressions.impl.IrBlockBodyImpl.transformChildren(IrBlockBodyImpl.kt:49)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoidKt.transformChildrenVoid(IrElementTransformerVoid.kt:288)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.transformChildrenVoid(IrElementTransformerVoid.kt:283)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.transformChildren(IrElementTransformerVoid.kt:25)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitBody(IrElementTransformerVoid.kt:93)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitBlockBody(IrElementTransformerVoid.kt:99)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitBlockBody(IrElementTransformerVoid.kt:100)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitBlockBody(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.expressions.impl.IrBlockBodyImpl.accept(IrBlockBodyImpl.kt:40)
	at org.jetbrains.kotlin.ir.expressions.IrBody$DefaultImpls.transform(IrBody.kt:24)
	at org.jetbrains.kotlin.ir.expressions.IrBlockBody$DefaultImpls.transform(IrBody.kt)
	at org.jetbrains.kotlin.ir.expressions.impl.IrBlockBodyImpl.transform(IrBlockBodyImpl.kt:26)
	at org.jetbrains.kotlin.ir.declarations.impl.IrFunctionBase.transformChildren(IrFunctionBase.kt:77)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoidKt.transformChildrenVoid(IrElementTransformerVoid.kt:288)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.transformChildrenVoid(IrElementTransformerVoid.kt:283)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.transformChildren(IrElementTransformerVoid.kt:25)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitDeclaration(IrElementTransformerVoid.kt:46)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitFunction(IrElementTransformerVoid.kt:55)
	at androidx.compose.plugins.kotlin.compiler.lower.ComposableCallTransformer.visitFunction(ComposableCallTransformer.kt:205)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitSimpleFunction(IrElementTransformerVoid.kt:58)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitSimpleFunction(IrElementTransformerVoid.kt:59)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid.visitSimpleFunction(IrElementTransformerVoid.kt:24)
	at org.jetbrains.kotlin.ir.declarations.impl.IrFunctionImpl.accept(IrFunctionImpl.kt:89)
	at org.jetbrains.kotlin.ir.declarations.IrDeclaration$DefaultImpls.transform(IrDeclaration.kt:42)
	at org.jetbrains.kotlin.ir.declarations.impl.IrDeclarationBase.transform(IrDeclarationBase.kt:27)
	at org.jetbrains.kotlin.ir.declarations.impl.IrFileImpl.transformChildren(IrFileImpl.kt:71)
	at org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoidKt.transformChildrenVoid(IrElementTransformerVoid.kt:288)
	at androidx.compose.plugins.kotlin.compiler.lower.ComposableCallTransformer.lower(ComposableCallTransformer.kt:197)
	at org.jetbrains.kotlin.backend.common.LowerKt.lower(Lower.kt:66)
	at org.jetbrains.kotlin.backend.common.phaser.PhaseBuildersKt$makeIrModulePhase$1.invoke(PhaseBuilders.kt:235)
	at org.jetbrains.kotlin.backend.common.phaser.PhaseBuildersKt$makeIrModulePhase$1.invoke(PhaseBuilders.kt:228)
	at org.jetbrains.kotlin.backend.common.phaser.AbstractNamedPhaseWrapper$runBody$1.invoke(CompilerPhase.kt:128)
	at org.jetbrains.kotlin.backend.common.phaser.CompilerPhaseKt.downlevel(CompilerPhase.kt:24)
	at org.jetbrains.kotlin.backend.common.phaser.AbstractNamedPhaseWrapper.runBody(CompilerPhase.kt:127)
	at org.jetbrains.kotlin.backend.common.phaser.AbstractNamedPhaseWrapper.invoke(CompilerPhase.kt:105)
	at org.jetbrains.kotlin.backend.common.phaser.CompositePhase.invoke(PhaseBuilders.kt:29)
	at org.jetbrains.kotlin.backend.common.phaser.CompilerPhaseKt.invokeToplevel(CompilerPhase.kt:42)
	at org.jetbrains.kotlin.backend.jvm.JvmLower.lower(JvmLower.kt:288)
	at org.jetbrains.kotlin.backend.jvm.JvmBackendFacade.doGenerateFilesInternal$backend_jvm(JvmBackendFacade.kt:91)
	... 37 more


e: java.lang.IllegalStateException: Backend Internal error: Exception during code generation

All I did was update this repo: https://github.com/Zhuinden/compose-simple-stack-experiment to dev04 and then remove

unaryPlus

from before where it was still there, and boom compilation exception in compiler 🤔

codeslubber

01/30/2020, 4:32 AM

Finally got my project to compile!! now a nutty thing is happening with my stepper. On first render things look fine: but then when I click + I get this:

Ian Warwick

01/30/2020, 9:24 AM

I managed to get my playground app working but hitting this now

e: org.jetbrains.kotlin.util.KotlinFrontEndException: Front-end Internal error: Failed to analyze declaration Mapper
File being compiled at position: (21,1) in /Users/ian.warwick/Documents/sdev/memset/router/src/main/java/com/citizenwarwick/memset/router/Mapper.kt
The root cause java.lang.OutOfMemoryError was thrown at: unknown
	at org.jetbrains.kotlin.resolve

Wondering if its because I am offline, will try restart maybe some java process holding to much mem?

camkadev

01/30/2020, 10:19 AM

Functions which invoke @Composable functions must be marked with the @Composable annotation

any workaround to change data (outside Composable) placed inside state?

Ian Warwick

01/30/2020, 11:19 AM

Not sure what the purpose of

key

is?

for (user in users) {
    key(user.id) { UserPreview(user = user) }
}

The docs don't really explain why you would use it 🤔 or I am not reading them properly

Ian Warwick

01/30/2020, 2:04 PM

Should we be using

ModelList

in our models? I found it was the only way to detect changes in a list but not sure if its for use in

@Model

annotated classes 🤔

amar_1995

01/30/2020, 3:09 PM

I am calling suspend function to retive data from server and then insert that data inside room db. But I am getting this wierd error

2020-01-30 20:25:18.750 21058-21058/com.amar.modularnewsapp E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.amar.modularnewsapp, PID: 21058
    java.lang.NullPointerException: Attempt to invoke virtual method 'int java.lang.Number.intValue()' on a null object reference
        at com.amar.modularnewsapp.repository.ArticleRepo$$loadMoreData$Continuation.invokeSuspend(Unknown Source:14)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
        at kotlinx.coroutines.ResumeModeKt.resumeUninterceptedMode(ResumeMode.kt:46)
        at kotlinx.coroutines.internal.ScopeCoroutine.afterCompletionInternal(Scopes.kt:32)
        at kotlinx.coroutines.JobSupport.completeStateFinalization(JobSupport.kt:310)
        at kotlinx.coroutines.JobSupport.tryFinalizeSimpleState(JobSupport.kt:276)
        at kotlinx.coroutines.JobSupport.tryMakeCompleting(JobSupport.kt:807)
        at kotlinx.coroutines.JobSupport.makeCompletingOnce$kotlinx_coroutines_core(JobSupport.kt:787)
        at kotlinx.coroutines.AbstractCoroutine.resumeWith(AbstractCoroutine.kt:111)
        at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:46)
        at kotlinx.coroutines.DispatchedTask.run(Dispatched.kt:241)
        at android.os.Handler.handleCallback(Handler.java:883)
        at android.os.Handler.dispatchMessage(Handler.java:100)
        at android.os.Looper.loop(Looper.java:214)
        at android.app.ActivityThread.main(ActivityThread.java:7356)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:492)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:930)

Mate

01/30/2020, 8:43 PM

kapt still can't be used together with compose? I tried 0.1.0-dev04 still gets

e: java.lang.NoSuchMethodError: org.jetbrains.kotlin.codegen.state.GenerationState$Builder.isIrBackend(Z)Lorg/jetbrains/kotlin/codegen/state/GenerationState$Builder;

https://issuetracker.google.com/u/1/issues/143232368 https://youtrack.jetbrains.com/issue/KT-34583

codeslubber

01/31/2020, 1:19 AM

Why do the release notes tell you

wraps

is deprecated for combining `Modifier`s but then the docs say unary is temporary?

Klaas Kabini

01/31/2020, 4:00 AM

I have updated my project from 0.1.0-dev03 to 0.1.0-dev04 including updating to new API changes that comes with 0.1.0-dev04 and now I am getting the following error. It was working fine on 0.1.0-dev03 prior to this update. Does anyone has an idea of what might be thee root cause of this error?

java.lang.IllegalStateException: Backend Internal error: Exception during code generation
Element is unknownThe root cause java.util.NoSuchElementException was thrown at: androidx.compose.plugins.kotlin.compiler.lower.ComposableCallTransformer.irComposableExpr(ComposableCallTransformer.kt:1362)
	at org.jetbrains.kotlin.codegen.CompilationErrorHandler.lambda$static$0(CompilationErrorHandler.java:35)
	at org.jetbrains.kotlin.backend.jvm.JvmBackendFacade.doGenerateFilesInternal$backend_jvm(JvmBackendFacade.kt:93)
.............
Caused by: java.util.NoSuchElementException: Collection contains no element matching the predicate.
	at androidx.compose.plugins.kotlin.compiler.lower.ComposableCallTransformer.irComposableExpr(ComposableCallTransformer.kt:1362)
	at androidx.compose.plugins.kotlin.compiler.lower.ComposableCallTransformer.visitBlock(ComposableCallTransformer.kt:252)
...................

Joseph Cheng

01/31/2020, 4:59 AM

Hi, I try to implement color selector on the button background. Any API I can use so far? The first thought I can use is

PressIndicatorGestureDetector

, like

Ripple

to customize one.

<?xml version="1.0" encoding="utf-8"?>
<selector xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:state_pressed="true"
          android:color="#ffff0000"/> <!-- pressed -->
    <item android:state_focused="true"
          android:color="#ff0000ff"/> <!-- focused -->
    <item android:color="#ff000000"/> <!-- default -->
</selector>

molikto

01/31/2020, 5:10 AM

Hello, I am reading the source code of compose, can I ask a question, what's the purpose of "androidx.compose.frames.Frame"?

camkadev

01/31/2020, 9:48 AM

i try to run sample with Constraints but without luck because Tag modifier hidden somewhere, can't import them, any idea?

amar_1995

01/31/2020, 10:22 AM

Purpose and difference of Key and Pivotal ?

Ian Warwick

01/31/2020, 11:10 AM

Hey composers, wrote about my experience so far https://medium.com/@fluxtah/jetpack-compose-is-getting-great-fast-735d97b88e98?source=friends_link&sk=90b2c13eaa496e818533fd491ec4884d

❤️ 2

☝️🏻 1

Hackdiod

01/31/2020, 11:38 AM

Hello! Do you now, how use Center item for few elements. I have Row>Column*2>Text*4, but Row>Column*2>Center>Column>Text*4 it works incorrectly. I think use Center to each text is the wrong approach.

amar_1995

01/31/2020, 12:56 PM

I updated my project from dev03 to dev04 and get this error.

java.lang.ClassCastException: androidx.compose.GroupStart cannot be cast to androidx.ui.foundation.ScrollerPosition

It was working fine in dev03. Can anyone help me to resolve this error and why this is occuring ??

carbaj0

01/31/2020, 3:56 PM

is there any plan for this component? https://material.io/components/bottom-navigation/