Hi is anyone having any good resources to read about the internals of the jetpack viewmodel? i was checking some logs and observed onClear is getting called before onDestory of Activity, I was expecting it to be called after onDestroy as per the diagram in docs

2021-05-24 00:41:39.235 22590-22590/com.example.myapp D/******* on stop >>>>: ON-STOP
2021-05-24 00:41:39.237 22590-22590/com.example.myapp D/******* on cleared  view-model>>>>: ON-CLEARED
2021-05-24 00:41:39.238 22590-22590/com.example.myapp D/******* on destroy >>>>: ON-DESTROY

Hello ! Does anyone know how to programmatically restart app in single Activity architecture?

Hello, Good morning everybody. Im curious about 2 solutions convert 

dp

 to 

px

Solution 1:

fun Int.dpToPx(context: Context): Int {
    return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, this.toFloat(), context.resources.displayMetrics).toInt()
}

Solution 2:

fun Int.dpToPx() = (Resources.getSystem().displayMetrics.density * this + 0.5f)

so Which once is correct for multiple screen? Thanks.

Hi guys, I'm new to the kotlinlang slack so I'm not sure if what I send is what I should send in this channel (if it's not please forgive me). I'm trying to put the following jetpack-compose code in a separate gradle module called

ui_components

(android library)

/**
 * Display a vertical list of [OutlinedTextField]
 */
@Composable
fun Form(fields: List<FormField>) {
    LazyColumn(content = {
        items(fields) { item ->
            OutlinedTextField(
                value = item.mutableState.value,
                onValueChange = { item.mutableState.value = it },
                label = { Text(text = stringResource(id = item.label)) },
                isError = item.isError(item.mutableState.value)
            )
        }
    })
}

However, when I compile the logs show me the following error:

e: org.jetbrains.kotlin.codegen.CompilationException: Back-end (JVM) Internal error: Couldn't inline method call 'items' into
local final fun androidx.compose.foundation.lazy.LazyListScope.<anonymous>(): kotlin.Unit defined in com.xxx.xxx.ui_components.Form
{
        items(fields) { item ->
            OutlinedTextField(
                value = item.mutableState.value,
                onValueChange = { item.mutableState.value = it },
                label = { Text(text = stringResource(id = item.label)) },
                isError = item.isError(item.mutableState.value)
            )
        }
    }

Am I doing something wrong here? Because individually the module compile (so no dependency missing, I guess) and without the dependency to

ui_components

the app compiles. Would be great if you can explain me, thanks in advance! 🙏

navigation component question: I have fragments A,B,C I want to have a shortcut of going from A to C, but also have a way to popup from C to B what is the recommended way to do this?

I just updated my app from kotlin-gradle-plugin:1.4.32 to 1.5.10. When I compiled, the following extension method no longer compiles. If I roll back to 1.4.32, it compiles again. (I've inlined some stuff to make it clearer so no need to point out the redundant lambdas. I just want to understand why it worked before, but doesn't now.) If I convert the property to a function, it also works (but i'd prefer to keep it a property). Code:

val UByteArray.utf8:String
	get() {
		val index = this.indexOf(0u)
		val cleaned = if (index == -1) {
			{ this }()
		}
		else {
			{ this.sliceArray(0 until index) }()
		}
		return cleaned.toByteArray().toString(Charsets.UTF_8)
	}

Error Message:

com.android.tools.r8.errors.b: Field name '$this_<get-utf8>' cannot be represented in dex format.

Currently we are using RxView to handle throttle clicks inside app and we have utility functions to subscribe on click listeners, we never unsubscribe from them. Is there an easy way to do so? or similar?

fun throttledClick(
        targetView: View,
        completionMethod: () -> Unit,
        throttleWindow: Long = DOUBLE_CLICK_THROTTLE_WINDOW
    ) {
        RxView.clicks(targetView)
            .throttleFirst(throttleWindow, MILLISECONDS)
            .subscribe {
                completionMethod.invoke()
            }
    }

Does kotlin REPL work for the JDK 9+?

Hi all. I recently upgrade my app to support data binding. so no more findViewById. just binding.view. I now want to move to a MVVM using ViewModels, so that I can move to LiveData. not sure (1) do both MVVM and LiveData at the same time or separately? (2) How does one begin to implement ViewModel from the old XML findViewById/binding way of doing things? Thanks all

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Hi all! Has anyone ever used `LifecycleObserver`s for running

suspend

functions or collecting

Flows

via

lifecycleOwner

-> scope?

I am trying to extend the AppCompatSeekBar to draw labels below the tick marks (e.g. 0 20 40 60 80 100). I have overriden the onDraw method to draw the labels on the Canvas but the labels are not showing. Can someone look at the code snippet in this thread and tell me what is it that I may be doing wrong.

Tell me please. Is it possible to somehow connect the cache with the Room database so that the data is loaded at the start of the application. I want to have a list with data at the start. So far, there is only one idea - to make two lists. I think this is bad.

if (errorMessage != null) {
    if (model.iconEnd == null) {
        model.iconEnd = InputField.Icon.ERROR
    } else {
        if (model.iconEnd != InputField.Icon.ERROR)
            model.icon = InputField.Icon.ERROR
    }
} else {
    if (model.iconEnd == InputField.Icon.ERROR) {
        model.iconEnd = null
    }
    if (model.icon == InputField.Icon.ERROR) {
        model.icon = null
    }
}

Is it possible to simpligy that code?

Hey everybody, What's the recommended approach for using Paging 3 and Room with Clean Architecture? Since the domain layer is Java or Kotlin only, my repository or usecases can't return a

PagingSource

and implementing it in the presentation layer is far from ideal.

I recently came across a simplified version of NetworkBoundResource. I was wondering how I could trigger a refresh (through user interaction, when pressing a button) if the flow fails and emits an error. Or is this inline function not the right approach?

Hey everybody, Can anyone please suggest me to work on an android app project that can impress my interviewers.( please help me...I'm not getting any ideas😣😣)

Hello, good morning everybody. I have implement 

*Modular Android* App *Architecture*

 , so I would like to discuss these two solutions: • Problems: ◦ Target : 

Module A

 send Event to show 

Dialog

 on the screens and exclude a some screens. ◦ Features divided into separate modules. ◦ Example Requirement: Class SocketService in

Module A

get events from server in Application class , we use ActivityLifecycleCallbacks to get

Current Activity

, We do not display dialog on Search Screens, Map Screen, … etc ( 2 cases : several screens or large screens should not show dialog) • Solution 1: ◦ Create an Interface

DoNotShowDialog

in

Common Module

◦ You will implement this interface to prevent to display

Dialog

in each modules/Activity class • Solution 2: ▪︎

Module A

use activity.javaClass.simpleName to compare with array of strings ▪︎ Example :

arrayListOf("SearchActivity", "MapActivity").contains(this.javaClass.simpleName)

Which solution will you choose? Thanks.

Hi all, I have an issue with use both Dagger2 and Hilt in my project. I post this in Stackoverflow , please help me.

hey, i am currently playing around with jetpack compose on android. since my experience with android is very beginner level (tbh i am a jvm backend developer trying to write my first android app 😄)  i am wondering how to avoid 

android.os.NetworkOnMainThreadException

i already figured out this is because i just call an http client (which is blocking) in the main activity (main/ui thread) as you can see on the screenshot. what do i need to do to make my http call with my client of choice work? stackoverflow was saying something about AsyncTasks but the answers has been very old and looked pretty different from my jetpack compose code 😄 I found solutions like: https://stackoverflow.com/a/13136668/10562333 that would just deactivate the restriction but that feels wrong to me. From what I understood so far I would need to do the call in a background thread instead of the main thread. Can I do this by wrapping my call in a coroutine and if so how? What would be the state of the art way to tackle this problem? (bearbeitet)

Hi, what is the difference between

val obj : Object = Object()

and

val obj: Object get() = Object()

?

I am trying to test an in-memory Room db which has suspend functions but the dao functions don't seem to be running in runBlocking. And tests fail.

@RunWith(AndroidJUnit4::class)
class SomeDaoTest {

  private lateinit var database: AppDatabase
  private lateinit var someDao: SomeDao

  @get:Rule
  var instantTaskExecutorRule = InstantTaskExecutorRule()

  @Before
  fun createDb() = runBlocking {
    val context = InstrumentationRegistry.getInstrumentation().targetContext
    database = Room
      .inMemoryDatabaseBuilder(context, AppDatabase::class.java)
      // needed to run @Transaction block
      .setTransactionExecutor(Executors.newSingleThreadExecutor())
      .build()
    someDao = database.someDao()

    someDao.insertAll(dummy1, dummy2)
  }

  @After
  fun closeDb() {
    database.close()
  }

  @Test
  fun testDeleteAll() = runBlocking {
      val someData = someDao.getData().getOrAwaitValue()
      someDao.deleteAll()
      assertEquals(0, someData.size)
    }

Any help on how I should do it or how to troubleshoot it would be nice.

The option to *I*mport .JAR/.AAR Package from the New Module wizard has been removed.

Hello guys, any tips how to create Library like Picasso, Glide, Retrofit... so I can use it for other project ? thank you

Hi. I have a question about resources in on-demand feature modules. Please check thread.

Hi everyone, How can I validate an input for a function with lint check? For instance if a function should accept only integers >= 0 how can I put a lint check in the parameter?

Hey i am trying to add space between two words and append in a string builder. Showing in text view its not working and if check in logs it's showing perfectly. Does any one how to fix this?

val list = mutableListOf(
        "1. Log in Google account\n",
        "2. Scroll to the page\n",
        "3. Tap disconnect from account to logout"
    )
    val content = StringBuilder()
    list.forEach{ string->
        content.append(string.replaceFirst(" " , "\t"))
    }
    System.out.print("string >> $content")
    list_string.text = content

As you see it fine in logs