Kotlin Stream usage I have a code like below items.forEach { item -> request += getDetails(item.propertyId, item.destinationIds) count++ if( count == bulkSize) { save(request) request = "" count = 0 } } if(!request.isEmpty()) { save(request) } How can I use streaming api to make the code less verbose ?

How to work with progress bar while importing data to database? For my case, I need to import a lot of data from a text file into database. While importing data I would like to show some progress bar in order to let the user know. I would like to know how to implement progressive bar in my case. For now I can import data and get the total lines. This is the current code private fun importDialog(type: Int,context: Context) { val builder=AlertDialog.Builder(this) val inflater=this.layoutInflater val...

Guides and tips for programming in Kotlin Me and my friend are planning to create an app (which we have a general idea of how it should look like) in kotlin and as of now we have learnt some basic kotlin. We also have some reasonable experience with java and python and were wondering where we could find good guides and starting problems in order for us to get a better idea on how it works and how we should set about with our project. Simple links should suffice.

Is a std extensions to insert or update kotlin mutable list which use Comparator? I have a list of complex objects and I want to merge this list with new one. But if in new one has same object (based on passed comparator) then element should be replaced otherwise added at end of list in order. I wrote a extension function which do the job but I'm looking for more efficient way (and more elegant) like some combination of already existing extensions. fun MutableList.insertOrUpdate(items: List, comparator: Comparator): List { val out = mutableListOf() val toInsert...

How to get rid of the value using a Gson TypeAdapter? I have a json string that looks as follows: { "SomeStringProperty": { "value":"StringValue"}, "SomeIntProperty": { "value": 1}, "SomeBooleanProperty": {"value": true} } How do I map it to the following object data class PoJo(val SomeStringProperty: String,// val SomeIntProperty: Int,// val SomeBooleanProperty: Boolean)

【MPAndroidChart】How to remove bottom space in radarchart? I use MPAndroidChart. https://github.com/PhilJay/MPAndroidChart I added RadarChart to the layout file. However, I couldn't remove bottom space of RadarChart if the chart is triangle shape. If the chart shape is square or pentagon, the bottom space is OK. This picture is seen in Layout Inspector. I saw this answer. <a...

Any thing similar to Mapview in Android studio? Are there any methods similar to Mapview that I can use. I don't want the Google Text in Map view, and the text can not be removed. So anything that I can use other than Mapview.

Should abstract classes have implementation in Kotlin In Java, I'm use to seeing abstract classes without any implementation. I can't remember, but I don't think it's even possible to include implementation details. But in Kotlin, I have seen abstract classes contain implementation details. What I don't understand is that the Kotlin docs clearly state: An abstract member does not have an implementation in its class <a href="https://kotlinlang.org/docs/reference/classes.html" rel="nofollow...

Can / will Kotlin contracts express erased type implications? I would like to tell the compiler that if a function returns, one of its parameters is of a given type. Contracts seems to give me that power, but does not work when I want to signal an otherwise erased type. @ExperimentalContracts fun List.isListOfInt(): Boolean { contract { returns(true) implies (this@isListOfInt is List) } return TODO("some way that I know") } This fails because this@isListOfInt is List does not compile - Cannot check for instance of erased type:...

Dagger 2: AuthModule doesn't have a @Subcomponent.Builder or @Subcomponent.Factory, which is required when used with @Module.subcomponents I'm having a subcomponent module using dagger 2. @Subcomponent(modules = arrayOf(LoginPageActivityModule::class)) class AuthModule { @Provides internal fun provideAuthDataManager(appDataManager: AppDataManagerImpl): AuthRepository { return AuthRepository(appDataManager) } } I want to add it inside another module - @Module(subcomponents = arrayOf(AuthModule::class)) class LoginPageActivityModule { @Provides internal fun provideLoginDataManager(appDataManager:...

Firestore writing continuously even though it is contained within a setOnClickListener I am using Firestore to write data but it seems like data is being written continuously before i even call the function or even before i navigate to the Activity where this code is contianed. Below is the: buyerbid_selectleading.setOnClickListener { prevselref = FirebaseFirestore.getInstance() prevselref.collection("winning_bid").document(dealid) .addSnapshotListener { value, task -> if (task != null) {...

Kotlin coroutines Mutex owner usage What is the expected usage of owner in a kotlinx.coroutines.sync.Mutex? From what I understand a Mutex.withLock will make any calling coroutine after the first (witch locked the mutex), await until it is unlocked, and then hold the lock themselves. So, what could be causing a java.lang.IllegalStateException: Already locked by [..]? Note, that I am always using the same owneron its withLock calls, as per: abstract class Cache( private val cacheMutex = Mutex() override suspend...

How to support Multiple Screen Size In Android min api 26 and target Sdk 28 I create an android app min sdk 26 and target Sdk 28 with Kotlin , I want to know how To Support Multiple Screen Size ? I have seen the following Url :https://developer.android.com/training/multiscreen/screensizes#TaskUseWrapMatchPar, I try to use the constraint layout with wrap_content and match_parent but still not get the result.I just use the hard-coded sizes only...

Dynamically add Drawer and navigation view in kotlin The app has no XML,programmatically creating layouts so,I need code for drawer and navigation view for hamburger menu in main activity

Does Kotlin optmize the creation of lambdas in the JVM? I have a code that looks like the following: infix fun Option.valueIs(value : T): Pair Boolean,Set> { val function = {this.selectedValue == value} val parents = setOf(this) return Pair(function, parents) } My question is if Kotlin will always create an anonymous object in val function = {this.selectedValue == value} in the JVM every time that this extension function is called or if it has some sort of optimization to reuse it if this and value are the same.

Context in Singleton This is not a duplicate of Singleton with context in Android I have a singleton class that stores context below. class Preferences private constructor(private val context: Context) { private lateinit var tinyDB: TinyDB init { tinyDB = TinyDB(context) } companion object { private var sInstance: Preferences? = null fun getInstance(context: Context):...

android status bar transparent in light theme I want to have a transparent statusBar in the light style like this I tried this code: if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) { this.window.apply { clearFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS) addFlags(WindowManager.LayoutParams.FLAG_DRAWS_SYSTEM_BAR_BACKGROUNDS) decorView.systemUiVisibility = View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN...

Kotlin - Creating consecutive fragments adds the data in the wrong fragment I have this piece of code: val fm = supportFragmentManager val container = R.id.details this@CampusActivity.runOnUiThread(Runnable { fm.beginTransaction() .add( container, DetailCard.newInstance("Contacts", contacts, action.contactCardList) ).commit() fm.beginTransaction() .add( container, DetailCard.newInstance("About", about, action.aboutCard) ).commit() }) I am trying to create new instances of...

How to get new data after data change in SQLite using viewmodel? How to get new data after data change in SQLite using viewmodel ? FavoriteViewModel.Kt class FavoriteViewModel(application: Application) : AndroidViewModel(application) { private var favoriteEventList = MutableLiveData() init { favoriteEventList = getFavoriteEvent(application) } fun getFavorite(): LiveData = favoriteEventList private fun getFavoriteEvent(context: Context): MutableLiveData { val favoriteList = MutableLiveData() val favorites:...

How to include whastapp app in the intent action_call Here is my function fun getActionIntent(uri : String?) { val phoneIntent = Intent(Intent.ACTION_VIEW) phoneIntent.data = Uri.parse("tel:$uri") phoneIntent.setPackage("com.whatsapp") ctxt.startActivity(Intent.createChooser(phoneIntent, "Send Sms")) } I just get Phoneand Skype app in my chooser. I want whatsapp to be add to the list.

Creating a Kotlin Native Background Dispatcher for Coroutine I'm currently trying to write a dispatcher for iOS, to run Http requests in the background. My current attempt is the following object: val runCoroutineDispatcher: CoroutineContext = NsQueueDispatcher object NsQueueDispatcher: CoroutineDispatcher(){ override fun dispatch( context: CoroutineContext, block: Runnable ){ dispatch_async( dispatch_get_global_queue( NSNumber(double =...

Delaying Kafka Streams consuming I'm trying to use Kafka Streams (i.e. not a simple Kafka Consumer) to read from a retry topic with events that have previously failed to process. I wish to consume from the retry topic, and if processing still fails (for example, if an external system is down), I wish to put the event back on the retry topic. Thus I don't want to keep consuming immediately, but instead wait a while before consuming, in order to not flood the systems with messages that are temporarily unprocessable....

ViewModel not updating with data change So, this is my first time using architecture components in Android. I'm trying to create a ViewModel that will keep returning the latest location which can be used by UI elements. I've created a viewModel like this: class LocationViewModel(application: Application) : AndroidViewModel(application) { val currentLocation = MutableLiveData() init { val ctx = getApplication().applicationContext val fusedLocationProvider =...

Dokka not creating any documents in Android Studio I have successfully installed Dokka but after Make Project its not creating any documents. I have tried building APKs or debugging but no improvement. Also mentioned guidance document at dokka git link did not work. My project gradle file: buildscript { ext.kotlin_version = '1.3.50' ext.dokka_version = '0.10.0' repositories { google() jcenter() } dependencies { classpath 'com.android.tools.buildG3.5.3' classpath...

StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect) I'm working with creating REST service with spring boot. I have a model "DeliveryArea" where are child entities "DeLiveryConditions". I implemented bidirectional @OneToMany using hibernate and spring-data-jpa for convenient working with this entities. What's problem: I try to update parent entity with collection of child entities, but get this stack trace: org.springframework.orm.ObjectOptimisticLockingFailureException: Object of class...

Which of the information provided about Kotlin data types are correct? Question: Select all correct statements about data types. A-Every variable has a type. B-The type determines the name of a variable. C-The type restricts possible values of a variable. D-The type of a variable declared with the var keyword can be changed.

Received this `Error:Internal error: (java.lang.ClassNotFoundException) com.google.wireless.android.sdk.stats.IntellijIndexingStats$Index` I'm getting this error while trying to run a github project. Copied everything correctly but while trying to run this project on Emulator or Mobile i'm getting this error. Error:Internal error: (java.lang.ClassNotFoundException) com.google.wireless.android.sdk.stats.IntellijIndexingStats$Index java.lang.ClassNotFoundException: com.google.wireless.android.sdk.stats.IntellijIndexingStats$Index at java.net.URLClassLoader.findClass(URLClassLoader.java:381) at...

Generating Swagger/OpenAPI views in Micronaut when using Kotlin only The official docs at https://micronaut-projects.github.io/micronaut-openapi/latest/guide/index.html only describe how to add the -Dmicronaut.openapi.views.spec=... compiler flag to the JavaCompile Gradle task: tasks.withType(JavaCompile) { options.fork = true options.forkOptions.jvmArgs

Flutter - Get data with an Event Channel from Kotlin to Dart I have the following problem that I am already working on for over 20 hours: I want to use an Event Channel to get a data stream from the Spotify SDK. On the native side, I can automatically display the status of a current song by subscribing to my PlayerState. My goal is to be able to access this data stream with my Flutter app. On the native side I can output the data flow without problems. But I also want to be able to access this data in my Flutter App. The problem is that I do not get...

Checking if user is close to the location Problem about user location My app takes a user input such as a rotation or something of a shake and then uses that to open the app that is assigned to the action. However, I also want to implement location notification. Say I select Starbucks as the shake app, then the user can input 2 stores close to their house. Whenever my "lat" and "longs" are like 100m away from registered coordinates I want to issue a notification saying this place is close by. I have implemented all the stuff till...