_uiState.value = uiState.value.copy() don't cause recompose There is some unresolved situation that happens with my code, my target is to change the property of an item in the "devices" list (update a boolean), The change should cause recompose of the view, but that doesn't happen, In addition, I can see that the item indeed changes with the debugger, but it also causes to add an additional item(an old copy without the included change) to show up in my list. Is there any idea how I was wrong with the new value assignment? The ViewModel private val...

Kotlin: user input into list I'm trying to create an app in Android Studio, where the user needs to input multiple names that are going to be stored in a list. I also wish to show the list to the users with ListView. Right now my approach is to have an EditText container where the user can input text, and then with the press of a button it would add it to the list "AllPlayersHidden". From there it would update the adapter, and then the ListView. Here's the main functional snippet: // List of players that is...

Autocomplete textview in fragments I want to create an autoCompleteTextView in a fragment but the Array adapter is bringing an error saying that 'none of the following function can be called with the arguments supplied'. So how should I use the array adapter in a fragment class? override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) val frequencyArray = ArrayList() frequencyArray.add("Daily") frequencyArray.add("Weekly") frequencyArray.add("Monthly")...

Can't connect kotlin to mySql even after adding the jdbc driver Im trying to connect kotlin to mySql but i've followed alot of tutorials and codes and then i receive that error and this is my code : No suitable driver found for jdbc:mysql://localhost:3306/mysql import java.sql.DriverManager import java.sql.Connection import java.sql.SQLException fun main() { Test.connection() } object Test { @JvmStatic var con: Connection? = null val url = "jdbc:mysql://localhost:3306/mysql" val username = "admin" val password = "123456" fun...

Testing custom exceptions in Kotlin with JUnit I have the following class data class CarDefects( private val _carModel: CarModel, private val _affectedYearsOfIssue: List, private val _defectCode: String ) { init { validateDefectCode(_defectCode) } } Validating function fun validateDefectCode(defectCode: String) { val pattern = Pattern.compile("^[a-zA-Z0-9-]*\$") val m = pattern.matcher(defectCode) if (defectCode.length !in 4..4) { throw InvalidDefectCodeException(defectCode, "Defect code...

Using MediatorLiveData to return if two LiveDatas are true Say I have two LiveData events, eventPlayerChose and eventOppChose, and I want to use MediatorLiveData eventRoundFinish to signal that both LiveDatas are true. Is this the best way to do so or is there a cleaner solution? private val _eventPlayerChose = MutableLiveData() val eventPlayerChose: LiveData get() = _eventPlayerChose private val _eventOppChose = MutableLiveData() val eventOppChose: LiveData get() = _eventOppChose // a round finishes when both players choose private val...

Kotlin flow map - make emit even if the value is same I want to know the kotlin flow flatMap working with jetpack compose I am having a flow for search and i am calling the api each time the search value changes. var search = MutableStateFlow("") And to call api var allItems = search.flatMapLatest{query-> flow{ emit(repository.getAllItems(query) } } It works perfectly fine , but excpet in one scenario. When the value of search is already "" an empty string, and i try to refresh the page , the code inside flatmap is not working...

How to access a function ,written in a fragment, in an activity I have created a function in a fragment that gets data from the fragment's UI. I would want to access it in my main Activity so as to store the data in cloud firestore This is the function in the fragment override fun onViewCreated(view: View, savedInstanceState: Bundle?) { super.onViewCreated(view, savedInstanceState) fun getData(){ var dairyMealStock: Int = view?.findViewById(R.id.et_dairy_meal_stock)?.text.toString().toInt() var dairyMealDuration: Int =...

Why is the no lateinit block in Kotlin? The following code is valid Kotlin code: abstract class A { protected lateinit var v: X abstract fun f(): X class SubA : A() { override fun f(): X { return SubX() } init { v = f() } } } It defines an abstract class which has a lateinit var field and an abstract method that sets the value of that field. The reason behind this is that that method may be called later again, and its behavior should be defined in the...

Type mismatch: inferred type is String but Int was expected , Kotlin Task :app:compileDebugKotlin FAILED Type mismatch: inferred type is String but Int was expected

How to parse the different type of json When I call an api with specific parameter, I get a json like this: { “name”:“my name”, “family”:”my family” }, { “name”:“my name1”, “family”:”my family1” } But when I call same api with different parameter I get same JSON but with the different type for example an empty array : [] How can create a data model for this type of response in kotlin?

Android + Kotlin + Hilt: Cannot @Inject in a non activity class I recently started learning Hilt, and for now it's giving me more headaches than happiness, but I like challenges, so let's go to the point. I'm having plenty of problems understanding how to inject in non activity classes, for example to inject a Context or any other class. Most of my non activity classes were objects (singleton) so far, but as I wasn't able to inject into an object I decided to convert them to classes. I'm trying to inject with field injection, because if I use constructor...

Kotlin - Why can't I pass this method directly into the constructor, why do I need to use a lambda? I just started to learn Kotlin yesterday, so brace yourself for a potentially stupid question. class MyCustomViewAdapter(private val callback: (position: Int) -> Unit) : RecyclerView.Adapter() { ... } When I try to initialize this class, I need to pass in a callback parameter to receive events. MyCustomViewAdapter({ position -> onClickFlowerCallback(position)}) // this works MyCustomViewAdapter(onClickFlowerCallback) // this doesn't work? private fun onClickFlowerCallback(position:...

Why doesn't isAppearanceLightStatusBars affect on Status bar content color programmatically? I've tried to change the color of status bar content using isAppearanceLightStatusBars: override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_splash_screen) WindowCompat.setDecorFitsSystemWindows(window, false) val controller = ViewCompat.getWindowInsetsController(window.decorView) controller?.isAppearanceLightStatusBars = true } it doesn't change anything, but when i change it in...

What is the relationship between non-blocking I/O and Kotlin coroutines? What is the relationship between Kotlin coroutines and non-blocking I/O? Does one imply the other? What happens if I use blocking I/O? How does this affect performance?

Java vs Kotlin from IOS pov I’m an IOS developer, i decided to learn android development but there are two major languages, Java and Kotlin. From IOS development pov , is java to kotlin like objective-c to swift or is it something different. Moreover, apple developer provides all documentation for frameworks for IOS development, is there an official website like that for android development

Unable to multiply due compile error in kotlin Beginner question - Any idea why my code won't compile? I based it on a code given in this codelab and the given code compiles just fine. Any help is greatly appreciated :) <a href="https://developer.android.com/codelabs/basic-android-kotlin-training-tip-calculator?continue=https%3A%2F%2Fdeveloper.android.com%2Fcourses%2Fpathways%2Fandroid-basics-kotlin-unit-2-pathway-1%23codelab-https%3A%2F%2Fdeveloper.android.com%2Fcodelabs%2Fbasic-android-kotlin-training-tip-calculator#3" rel="nofollow...

I want to give an exception to the first character in inputType of editText with Kotlin I want to make sure that the filter does not apply only the first letter in the numberPassword of the editText. Please give me an answer on what to do. android:inputType="numberPassword" ex -******* -> -3******

OEM Permission Manger I want more informations about OEM permission in android application and how to implement in Automobile AVD and what methods used in OEM permission to use in android automotive AVD

Implementing Flood Fill Algorithm in Kotlin import java.util.Queue import java.util.LinkedList fun explore(row: Int, column: Int) { val length1 = minefield.size val length2 = minefield[0].size if (displayedMinefield[row][column] == "/") return val queue: Queue = LinkedList() queue.add(listOf(row, column)) while (!queue.isEmpty()) { val (i, j) = queue.first queue.removeFirst() if (i < 0 || i >= length1 || j < 0 || j >= length2) { continue } else { if...

sequence concatadapter based on data type is it possible to use concatadapter based on data type. normal implementation of concatadapter is val concatadapter = listOf(firstAdapter, secondAdapter, thirdAdapter) while trying this code, for (nums in 0..15) { if (nums % 2 == 0) { concatAdapter.add(firstAdapter) } else { concatAdapter.add(secondAdapter) } } the first "firstAdapter" and "secondAdapter" will be display. But the next "firstAdapter" and "secondAdapter" is not displayed. is there...

Will the operation of collect from Flow cost many system resources when I use Compose with Kotlin? The SoundViewModel is a ViewModel class, and val listSoundRecordState may be used by some modules in the App. In Code A, I invoke fun collectListSoundRecord() when I need to use the data listSoundRecordState. But fun collectListSoundRecord() may be launched again and again because of Jetpack Compose recomposition, I don't know if it will cost many system resources? In Code B, I launch private fun collectListSoundRecord() in init { }, collectListSoundRecord() will be launched only one time,...

How can I handle java.io.EOFException? The error came up in the QR Scan Fragment that I created, when I finished scan, the error said D/StompClient: Socket closed with error Below are the list of error:- java.lang.Exception: java.io.EOFException at ua.naiksoftware.stomp.provider.OkHttpConnectionProvider$1.onFailure(OkHttpConnectionProvider.java:84) at okhttp3.internal.ws.RealWebSocket.failWebSocket(RealWebSocket.java:570) at okhttp3.internal.ws.RealWebSocket$1.onResponse(RealWebSocket.java:211)...

How to count unique csv/parquet rows? Is there a better algorithm for counting unique rows in csv/parquet than writing to HashMap or reading one row and iterating through whole file(if file is big)?

How to make certain part of an activity change depending on the day of the week? ANDROID STUDIO I am using a HorizontalScrollView as a container, inside it I have a button for each day of the week (Monday, Tuesday..., Friday) I want that depending on the day of the week when opening the application it automatically scrolls there, that is, today it is Monday the button that appears as an option is "MONDAY", if it is Wednesday the first option that appears is WEDNESDAY. <a href="https://i.stack.imgur.com/BQpWJ.png" rel="nofollow noreferrer">HorizontalScrollView, contains the different...

Can i use an interface type as constructor parameter in Koltin Coming from Java, I define two interfaces for triangles: interface TriangleA { val side: Double val corner1: Double val corner2: Double } interface TriangleB { val side1: Double val side2: Double val side3: Double } Then I define an adapter class that accepts a TriangleB and exposes a TriangleA class TriangleBAdapter(triangleB:TriangleB):TriangleA{ override val side: Double get() = this.triangleB.side override val corner1: Double...

kotlinOptions.useIR = true causes error after upgrade to Kotlin 1.7.10 I received a notification from android Studio to update my app to Kotlin 1.7.10. (all is working well at Kotlin 1.6.21) When I did that, I started receiving an error for the line kotlinOptions.useIR = true (I previously put this in about a year ago when I removed apply plugin: 'kotlin-android-extensions' which I was told at the time was bad, and at the same time added in buildFeatures { viewBinding = true } ) The error I receive for the useIR line is:

No such property:...

Draw a circle in a fixed area on the mapbox map. || Kotlin I've created an app I've used geofence I want. Show a circle on the mapbox with the same radius as the geofence. The problem is that the circle is displayed and the size of the circle changes as the map is zoomed.

Spotify AUTHENTICATION SERVICE UNKNOWN_ERROR kotlin android I am trying authenticate user with spotify app and spotify auth API (implementation 'com.spotify.android:auth:2.0.1') followed the steps mentioned in Spotify SDK github sample my code: Added in gradle(app.module) defaultConfig { manifestPlaceholders = [redirectSchemeName: "appname", redirectHostName:"spotify_login_callback"] } // Fragment/Activity val CLIENT_ID = "7bf56252cd644b339cc97df5b4d7eeee" val AUTH_TOKEN_REQUEST_CODE = 0x10 val AUTH_CODE_REQUEST_CODE = 0x11 var mAccessToken: String?...