#NotKotlin Which slack workspace is popular for android related queries? Android Chat or Android United?

Hi, Im trying out

Apollo3

for my Android GraphQL client calls

binding.button.setOnClickListener( View.OnClickListener {

})

binding.button.setOnClickListener {

}

Hey guys I am confused why I was able to skip the parenthesis on the 2nd example. The method takes a functional interface, but not a function, so how am I allowed to use the passing trailing lambda syntax here?

I have a

LiveData

of type

MutableLiveData<MutableList<User>>

. I have an issue. If I update the

value

by another

MutableList<User>

the changes are emitted to the observers. However, if I simply add other elements to the

MutableList<User>

, that is already initialised in the

LiveData

, the changes are not emitted. Here is what I am doing...

//other codes 
private val _users: MutableLiveData<MutableList<User>> = MutableLiveData<MutableList<User>>()

init {
    _users.value = mutableListOf<User>()
}

val uiScope = CoroutineScope(Dispatchers.Main + Job())

fun loadUsers(){
    uiScope.launch{
        // this works perfectly
        _users.value = fetchUsers() as MutableList<User>
        // this doesn't work... no idea why
        _users.value.addAll(fetchUsers())
    }
}

suspend fun fetchUsers(): List<User>{
    return withContext(<http://Dispatchers.IO|Dispatchers.IO>){
        //fetch users asynchronously
    }
}

This is just an emulation of the actual program. That actual code is not that trivial.

Hi. Is it possible to use some kotlin-based bridges to C++ instead of JNI?

"data": [
    {
      "player_id": 2497,
      "firstname": "Jay-Alistaire Frederick",
      "lastname": "Simpson",
      "birthday": "1988-12-01",
      "age": 32,
      "weight": 85,
      "height": 180,
    },
    {
      "player_id": 2570,
      "firstname": "Simranjit",
      "lastname": "Singh Thandi",
      "birthday": "1999-10-11",
      "age": 21,
      "weight": null,
      "height": null,
    }]

Hi i want to replace value of "weight" to 0 if its null from backend. How to do it in Data Class ? Any solution

I was trying to be clever with compareTo: override:

override fun compareTo(other: ValveSpan): Int {
    val fields = listOf(ValveSpan::begin, ValveSpan::end, ValveSpan::userTitle)
    val comparisons = fields.asSequence().map { field -> field(this).compareTo(field(other)) }
    return comparisons.firstOrNull { n -> n != 0 } ?: 0
}

Basically an arbitrary number of accessors, work through them lazily until i get to a non zero return and return that. But the compiler complains because:

Type mismatch.
Required: {Duration & String}
Found: {Comparable{Duration & String}> & Serializable}

my begin and end accessors do indeed return Durations and the userTitle does indeed return a String. I'm not entirely clear on what the compiler is not happy about here though. it seems like its figuring it out kind of, but not all the way. or there's some stupid syntax error that will only finally embarssingly occur to me finally after pressing send...

what's the idiomatic way to create a Set (immutable) from a collection mapping operation? The following works, but seems kind of round about:

val beginEdges: Set<Duration>
    get() = emptySet<Duration>() + spans.asSequence().map({ span -> span.begin })

setOf() takes varargs, but I'm not aware of a pythonesque ability to ** an iterable argument to varargs...

Hello folks. Is there a way to avoid MutableStateFlows posting the same value when the screen is rotated like what we have with SingleLiveEvent version of LiveData? I'm using this guy right here:

private val _errorStateFlow = MutableStateFlow<State<Error>>(InitialError)
    internal val errorStateFlow: StateFlow<State<Error>>
        get() = _errorStateFlow

Since it is an Error StateFlow, everytime it posts something, i show a SnackBar on the screen but i just want to do this one time for each time the error occurs. Any thoughts on it? Appreciate ya 👍

has the

Duration

API always been experimental? I swear I used it years ago and it wasn't. Am I making this up? 😛

I’m currently still using lots and lots of LiveData in my project. In fact, I just added even more LiveData. Now, I have skipped frames on some devices (which are older devices with older OS versions) during testing. I’m not 100% certain it is because of the LiveData, or if I accidentally introduces a bug along the way. In either case, could I assume a performance improvement when switching to Kotlin Flows? I know LiveData does still a lot on the main thread under the hood, so I would assume the main thread can be freed from computations by switching to Flow?

I orginally wrote an app in crossplatform framework (mistakes were made) and I've converted it to a kotlin jetpack compose app. Well... the main activity file structure was

org.kivy.android.PythonActivty

. Do I have to keep that naming convention for my main activity when I upload to google play? Or can that be changed between versions?

I have what I feel may be silly questions but I can't find a good reference anywhere. I'm making an SDK to be used by Android. In the SDK I'm exposing server endpoints and also doing some behind the scenes UDP broadcast listening. The SDK will be consumed by Java but written in Kotlin. Few questions: 1. In general, should libraries and SDKs be doing behind-the-scenes threading? For instance, I'd like my SDK to start listening for UDP events on a background thread on init. Should the multi-threading be handled explitcitly be the client of the code? 2. If I were to do multiple threads behind the scenes, Is there any way to run code in a coroutine/thread and then have the results post to the main thread without coupling the SDK with Android (requiring context)? 3. If an SDK were to offer an asynchronous API using callbacks for Java consumption and Flow for Kotlin, what is a clean way to dynamically include bindings for one or the other based on dependencies pulled in? (e.g. `implementation("mySDK-core") and implementation("mySDK-ktx")? Any docs or references on SDK or library design in general would be greatly apprecaited. Thanks in advance!

A couple years ago when I first starting learning Kotlin, porting an iOS Swift app, there wasn't a real comparable idiom to the Swift Enums which can capture values. I'm curious what the general approach now days for expressing something like the following Swift idiom in Kotlin?

enum ValveRunInterval {
    case future(start:Date, plan:Plan)
    case active(interval:DateInterval, plan:Plan)
    ...
}

I could use a little abstract/two subclass triad to express this. Not sure what the rules are when combining data classes and inheritance. Is there a better/different way?

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Hello, is it ok to pass data from Repositories to RemoteDataSource in MVVM?

hi all - i have a bundle provided during a notification payload. i want to convert this into a

data class

that the bundle is expected to conform to. is there any out of the box way to do this? i’m sure it could be done with a code gen library, just not sure if it’s been done before

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Why is

ViewModelProvider.Factory

not a

fun interface

? This would allow you to pass a lambda instead.

Disclaimer: Not 100% Kotlin related I was looking at the

Bluetooth permissions

docs and there is stated:

<manifest ... >
<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<!-- If your app targets Android 9 or lower, you can declare
     ACCESS_COARSE_LOCATION instead. -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
...
</manifest>

I'm wondering: When I follow this advice I end up declaring both permission FINE and COARSE, while I can restrict the use of COARSE:

<uses-permission-sdk-23 android:name="android.permission.ACCESS_COARSE_LOCATION"
        android:maxSdkVersion="28" />

But can I configure FINE_LOCATION so that it's only declared when API is >28? I mean isn't it a problem when I have both permission declared although I only need one of them at the same time? Same goes for the new permission BLUETOOTH_CONNECT/SCAN that is only needed on API level 31. I'm also wondering why FINE_LOCATION is stucked out on the New Bluetooth permissions in Android 12 page. Isn't it better to declare FINE_LOCATION like the other

legacy

permissions:

<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"
    android:maxSdkVersion="30" />

This permission is still needed on API level 29 or lower.

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Hi how do I make the java folder a root directory? when I created a module

base-persistence

only

unit test folder

and

ui test

are the defaults so I created a root folder or directory but everytime I create a sub folder it creates another new directory. Eg: In

com.metromart.runner_persistence

I want to create a sub directory called base but instead it creates another folder,

com.metromart.runner_persistence.base

.

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Hi, I have an issue in my unit tests where the LiveData does not dispatch the value to the observer registered using

LiveData.observeForever

. Does anyone has an idea as to what might be causing that?

Hi, I want to build an app with which you can create events like google calendar but only for the current day. I imagine a vision like when you select one day view in google calendar. Also probably need the dynamic size of the events because they must look different when are for 5 minutes and when for 1 hour. Generally, an experience like google calendar. What is the best solution in your opinion - recyclerView or there is something better?

Never use vars in a data class. Only val. With immutable objects a shallow copy is equivalent to a deep copy!

@everyone please help me. I have this error that path doesn't exist actually. Have a look and guide me.

Hello, I'm working on launching my app from a URL. I have the intent-filter set up in my manifest:

<activity
			android:name=".MyTargetActivity"
			android:screenOrientation="portrait">

			<intent-filter android:autoVerify="true">
				<action android:name="android.intent.action.VIEW" />

				<category android:name="android.intent.category.DEFAULT" />
				<category android:name="android.intent.category.BROWSABLE" />

				<data
					android:host="my.host.com"
					android:scheme="https" />
				<data
					android:host="my.host.com"
					android:scheme="http" />
			</intent-filter>
		</activity>

I've created the intent from the URL:

val url: HttpUrl = HttpUrl.Builder()
			.scheme("https")
			.host("<http://my.host.com|my.host.com>")
			.addPathSegment("invite")
			.addQueryParameter("voucher", voucherContents)
			.build()
		val sendIntent: Intent = Intent().apply {
			action = Intent.ACTION_SEND
			putExtra(Intent.EXTRA_TEXT, url.toString())
			type = "text/plain"
			toUri(0)
		}
		val shareIntent = Intent.createChooser(sendIntent, url.host)
		startActivity(context, shareIntent, null)

This pops up a chooser window where I can select an app or copy to clipboard. I choose the latter and then open up an app such as Slack or Sheets or something and paste it in. When I click the URL link I just pasted, it opens MyTargetActivity successfully, but it's in the app that opened it rather than a new application. How do I get it to launch as a standalone application? (I've also written the server part and gotten that working. I can rummage that up if needed.)