Android use case unit test Here is my use case code interface - interface ItemUseCase { fun performItemAction(action: ItemAction): LiveData } Here is the implementation - class ItemUseCaseImpl( private val dataRepository: DataRepository ) : ItemUseCase { override fun performItemAction(action: ItemAction) = liveData { emit(Result.Loading) emit(dataRepository.performDataAction(action)) } } I am new in writing unit tests. So I need help with - 1) What all I can test in my use...

NavigationView clickable SubMenu In my application I am programmatically populating my NavigationView menu with something like val menu = navigation.menu menu.setGroupCheckable(MENU_GROUP, true, true) val subMenu = menu.addSubMenu(MENU_GROUP, 0, 0, "New group") subMenu.add(0, 0, 0, "item 1").apply { isCheckable = true } subMenu.add(0, 1, 1, "item 2").apply { isCheckable = true } subMenu.add(0, 2, 2, "item 3").apply { isCheckable = true } subMenu.add(0, 3, 3, "item 4").apply { isCheckable = true } val subMenu1 =...

how to create a new variable every time inside a for a loop in kotlin I have a for loop that creates a cardView for every time it loops, then it uses setOnClickListener for every view with different extras , the problem is only the last loop parameters is being set to every created card, here is my code : for (finalItem1 in finalList1) { thePoints.clear() theSteps.clear() theIcons.clear() val step1 = "${getString(R.string.from_your_location)} \n ${getString(R.string.move_to)} \n...

I can't import coroutines into kotline code I am trying to delay a task by 1 second using coroutines but when I try importing kotlinx.coroutines.* it says unresolved reference.

kotlin integer in einer funktion zurück geben wie kann ich einen Integer Wert zurück geben und ihn mit println() in der main ausgeben? // Eingabe durch Spieler und Überprüfung fun spieler_eingabe(): String { while (true) { println("er geht wieder raus") var eingabe_korrekt = false while (!eingabe_korrekt) { println("Bitte Zahl von 1 - 9 eingeben ") val eingabe = readLine()!! var spielzug = eingabe if (eingabe == "1") { return spielzug } else if (eingabe == "2") {...

Freemarker error: java.lang.NoClassDefFoundError: freemarker.core.TextBlock I use freemarker for generate html report in kotlin on android. When i process template i got java.lang.NoClassDefFoundError: freemarker.core.TextBlock I google error and I found this error is because Java was unable to find that class but according to this page , doc said Freemarker have no dependency and i only include Freemarker version 2.3.29 jar file as library in my android project and...

Kotlin flatMapTo does not compile I want to flat map a Collection of Sets to a single Set. I have the following code which does not compile in IntelliJ IDEA. I can't tell why: listOf(HashSet()).flatMapTo(HashSet()) { it.iterator() as Iterator } There is a very confusing error message on the lambda in the end which says: Type mismatch. Required: (kotlin.collections.HashSet /* = java.util.HashSet /) → Iterable Found: (kotlin.collections.HashSet / = java.util.HashSet */) → Iterator But they are both completely the...

How to enable CORS in Kotlin HTTP Server that uses JAX-RS? I created a kotlin web application using this tutorial: https://kotlinlang.org/docs/tutorials/httpservlets.html I have an endpoint that I wanna hit from my react app, something like: fetch('http://localhost:8086/userInfo?cookie='+this.state.userToken) .then((response) => response.json()) .then((responseJson) => { //do stuff }) .catch((error) => {...

Exception in thread "main" java.lang.NoClassDefFoundError: kotlin/KotlinPackage & Caused by: java.lang.ClassNotFoundException: kotlin.KotlinPackage When I try to add IntArrays in my codes, the Android Studio gives me these errors: "C:\Program Files\Android\Android Studio\jre\bin\java.exe" "-javaagentC\Program Files\Android\Android Studio\lib\idea_rt.jar=50719C\Program Files\Android\Android Studio\bin" -Dfile.encoding=UTF-8 -classpath...

Android Kotlin how to implementation AlarmManager I want to implement my service that checks and sends notifications when the condition is met. This service must work when the user uses the application, when the application is running in the background and when the phone is in sleep mode. I learned that you have to use the Manager's alarm. Unfortunately, the Service doesn't work as it should - sometimes it doesn't send notifications about the time it was supposed to. Can anyone tell me what I'm doing wrong? ForegroundService class...

My generic function for Retrofit interface creation get compiler error: inferred type is Class<T>? but Class<T!> was expected I am using Retrofit in my Android (kotlin) project. I created my interface: interface StudentsInterface { @GET("foo/bar/{id}") suspend fun getStudent(@Path("id") myId: Int) } I created a MyClient class in which I defined a generic function for creating endpoint service out from any interface like above code defined: class MyClient() { @Inject lateinit var retrofit: Retrofit // this is my generic function fun createService(interfaceClazz: Class?): T { //...

How button with setOnClickListener() does unfinished job when other button is pressed? If I press button which is set to do job on click and I press other button immidiately while 1st button didn't finish his job, will 1st button finish his job or will be interupted in Kotlin?

How to change newValue in OnPreferenceChange? I have got a Preference with the key "base_url" with an onPreferenceChangeListener. The problem is that I want to change wrong input directly in the onPreferenceChange but it does not save. For example: Input is google.at it should add https:// to the URL. class SettingsFragment : PreferenceFragmentCompat() { override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey: String?) { setPreferencesFromResource(R.xml.settings_pref, rootKey) val editURLPreference:...

Class in class inheritance I try to do this, but in Kotlin. I have done that: class MainActivity : AppCompatActivity() { lateinit var adapter: NewsRecViewAdapter var newsItems: ArrayList = ArrayList() override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main)...

setcontentview() crash multipul nav graphs android kotlin hi i am trying to start a new activity with a second navhost, my code crashes on onsetcontentview() i suspect it crashes from improper use of navigation hosts main activity: class MainActivity :AppCompatActivity(){ override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) val navController=this.findNavController(R.id.nav_host_fragment_main) NavigationUI.setupActionBarWithNavController(this,navController)...

How to solve latency issue in quiz application? I have array with more elements than posted here. I show only 2 in post but there are 10 showGreen variables, 10 additional threads, 10 "TextViews" and 10 isGreenBackgroundShouldAppear functions. As you see, when answer is correct, TextView1 or TextView2 becomes green on ACTION_DOWN and sets random image in image_view thus preparing next question. The problem is that if I use 10 threads which separately set value of answer for every TextView every 500ms, if user press correct answer TextView...

Android kotlin Arraylist of objects get specific value I have ArrayList and i want to get him some specific object values and insert them to another ArrayList, but I can't get the specific values val listA = ArrayList() this list contains some users with their id,name, and email so i need to get all user's whose names are john and id,email will be any value

Unresolved reference on RecyclerView I'm able to retrieve the data from Firebase but when I try to load it into the groupie adapter, the recyclerview activity is not loading, and shows the following error "Unresolved reference: None of the following candidates are applicable because of receiver type mismatch....", I am I missing dependency?? This is my activity code, under to the fetchUser method is where I get the error: import android.os.Bundle import android.util.Log import androidx.appcompat.app.AppCompatActivity import...

Optional generic parameters in Kotlin Here's the current problem I'm trying to solve, we have the following interface in Kotlin: interface Parent where Entity : Any { fun run(params: Params): Result } The issue here is that sometimes I don't want to pass any params to the interface so I end up passing Unit as the type parameter and the overriding class ends up looking like this: class Child : Parent { override fun run(params: Unit): String { ... } } End Goal: It would be nice to add some abstraction in order to...

Dagger 2: multi-module project, inject dependency but get "lateinit property repository has not been initialize" error at runtime Dagger version is 2.25.2. I have two Android project modules: core module & app module. In core module, I defined for dagger CoreComponent , In app module I have AppComponent for dagger. CoreComponet in core project module: @Component(modules = [MyModule::class]) @CoreScope interface CoreComponent { fun getMyRepository(): MyRepository } In core project module, I have a repository class, it doesn't belong to any dagger module but I use @Inject annotation next to its constructor:...

What is the correct way to use ViewModelProvider with my current ViewModel? My error seems to be while initializing the ViewModelProvider within my "QuotesActivity" class. The app compiles fine, but the update for the quote on screen does nothing when clicking the submit button. I walked slowly through all my code in the other classes and everything looks fine. I figured the ViewModelProvider is where I am messing up. package com.example.mvvmprep.ui.quotes import androidx.appcompat.app.AppCompatActivity import android.os.Bundle import...

Prevent JPanel subcomponents from being displayed twice I have a JFrame containing a JPanel. This JPanel has some more Components in it, like JLabel, JTextField, JLabel, and a JFileChooser. These components are displaying properly where they should be, but they are also displaying at position (0, 0) in the window underneath what should be there. Whichever one was last focused is displayed on top: <a href="https://i.stack.imgur.com/tz9Yf.png" rel="nofollow noreferrer">(Image) The JFileChooser is displayed as a separate window, but also displayed...

How to apply random list of numbers for selection from array to select image? How to make list of random numbers and use it to set image from array? val randomValues = List(15) { Random.nextInt(0, 5) } var array = intArrayOf(R.drawable.cat1,R.drawable.cat2,R.drawable.cat3,R.drawable.cat4,R.drawable.cat5) imageView.setImageResource(array[randomValues]) I'm getting Type mismatch on randomValues in imageView.setImageResource(array[randomValues]). Required: Int and Found: List >int< (I changed "

How to use Java code in a Kotlin-based app? I want to use Chris Banes PhotoView (https://github.com/chrisbanes/PhotoView) to insert a zoomable image into my app, as described in this Youtube video: The only difference is that my MainActivity file is in Kotlin, not Java. How can I get this to work anyway?

Google MapView implements OnMapReadyCallback with Kotlin I use a EmptyActivity and want put a MapView in MainActivity, I think I need implements OnMapReadyCallback, This is my code. package com.example.myapplication import android.os.Bundle import androidx.appcompat.app.AppCompatActivity import com.google.android.gms.maps.OnMapReadyCallback class MainActivity : AppCompatActivity(), OnMapReadyCallback{ override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState)...

Sharing recyclerview item ID with another fragment I'm trying to send the nightID of the recyclerview item that was clicked with another fragment so I can query the correct item from the database. How can I pass this ID to another fragment? Dashboard Fragment val adapter = CounterAdapter(CounterListener { nightId -> dashboardViewModel.onCountClicked(nightId) })

Kotlin Jar Error: Exception in thread "Timer-0" StorageException: 401 Unauthorized Overview I'm having an issue when attempting to migrate a Kotlin project from an older to a newer machine and run both the Main method and a built .jar file. Expected Run existing local .jar file from Kotlin project on existing MacBook Pro (MBP). Clone Kotlin project from GitHub repository into local IntelliJ project on new MBP. Build .jar on new MBP. Run .jar on new MBP. Host .jar on Google AppEngine instance. Observed Running .jar on existing MBP works as expected. Running main method...

Java/Kotlin callback syntax - do I really need 2 callback definitions after conversion to Kotlin? I have a problem that has been challenging me for a few days with no resolution (more directly, no resolution I feel is correct). The issue is around callbacks, Java implementation vs Kotlin implementation I have this Java method: public void setOnSelectionChange(MapControlUpdate mapMenuControl) { this.mapControlUpdate = mapMenuControl; } private MapControlUpdate mapControlUpdate; public interface MapControlUpdate { void onSelectionChange(MAP_TYPE mapType); } Using the above...

How to restrict instantiation of inner class only inside outer in Kotlin? Having inner & outer classes I want to restrict instantiation of inner only by the scope of outer class. How can I achieve this in Kotlin ? Java provides it in a very easy way. But is seems that in Kotlin I can't access private field even from inner class. Java: class Outer { Inner inside = new Inner(); class Inner { private Inner() {} } } Outer outer = new Outer(); Outer.Inner outsideInner = outer.new Inner(); // 'Inner()' has private access in 'Outer.Inner'...

Please help translating Android Studio Kotlin to Java Code class MainAdapter : RecyclerView.Adapter() { var list: List = arrayListOf() var tracker: SelectionTracker? = null init { setHasStableIds(true) } override fun onBindViewHolder(holder: ViewHolder, position: Int) { val number = list[position] tracker?.let { holder.bind(number, it.isSelected(position.toLong())) } } What does tracker?.let translate to? And also what's the equivalent of init in Java? I've been stuck for a long...