RecyclerView does not bind data to ViewHolder unless it is notified I'm trying to implement the RecyclerView with data binding. The RecyclerView worked properly when I used findViewById to retrieve the widgets. But, if I use RecyclerView with data binding, the data are not bound to the ViewHolder. MainActivity.kt package com.example.wifilogger import android.os.Bundle import android.os.Handler import androidx.appcompat.app.AppCompatActivity import androidx.databinding.DataBindingUtil import androidx.recyclerview.widget.LinearLayoutManager import...

smoothScrollTo(position) scrolls to bottom instead of targeted position in RecyclerView My vertical RecyclerView (looking like a simple list) in Kotlin scrolls neatly to the next element when I press a button. 👍🏻 However when the next element is off screen (for example because in the meantime the user scrolled to a different position with a gesture) the problem is that this doesn't work anymore. Instead, it automatically scrolls all the way to the bottom of the RecyclerView. Any idea how to fix that? I'd appreciate it! Thanks in advance for your efforts. I'm overriding...

Why Navigation Graph IDs are not listed in R.id? I'm new to Android Navigation Component and I think I have everything ready for using it but when I try to navigate to another fragment using an action or a fragment id, the ids generated in the navigation graph xml file are not listed in R.id, so I can't use them to navigate. This is the code I'm trying to execute: view.findNavController().navigate(R.id.action_mainFragment_to_addFragment) This is my nav_graph.xml file (autogenerated): As you can see, the ids...

Return POJO from Room Database using joined data I have an entity, lets call is Cinema. Cinema has a few attributes such as name, rating e.t.c.. The Cinema also however has sections 1,2,3..n. To make things simpler through the application I have made a POJO called CinemaSection which contains the combined information of both, so that I may refer to CinemaSection.rating. I've designed it this way to conform to database normalization. I do not want this POJO to be an entity, I simply wish to assemble the POJO using the joined data between...

OnBindViewHolder on update autoScroll to top After the adapter submitList to the DiffUtil, onBindViewHolder is called and for some reason it always scroll the list to the top. I tried every single one of the answers in SO regarding autoscroll on updating list in the recyclerview but can't solve the issue. i.e. RecyclerView: Disable scrolling caused by change in focus <a...

Fill non mutable list with item creation function In Kotlin a non mutable list can only be filled with items via its varargs constructor. Let's say I want to write a function where the caller can specify an item creation function and a number of item: fun toList(count: Int, create: (Int) -> V): List { return listOf( // here I want to call the create function count times ) } To add the items to the list I have to call the function count times. How can I do this in Kotlin?

How to use Storage Access Framework with MediaMuxer if Android API level less than 26 I'm creating a file to recording via Android MediaMuxer, and I want to store this file in any folder I specified in the removable SD card (Not only in the /Android/data/data/application). I can use SAF (Storage Access Framework) to achieve it if the Android API level is above 26. var fd: FileDesciptor? = null for (permission in activity.contentResolver.persistedUriPermissions) { if (permission.uri.path == "path/to/file") { val docFile = DocumentFile.fromTreeUri(activity,...

Is it possible to extend a base class in a data class without overriding parameters? I have a simple inheritance tree in my Kotlin project, where a base class is extended by a data class. I cannot declare construction of my data class without overriding the parameters from the base class I've noticed that this would work if I wasn't extending in a data class: open class Base( val first: String, val second: String ) class Child( first: String, second: String, val third: List ) : Base(first, second) This is what I ended up with currently: open class...

Why Unit tests with coroutines delay() fails? I have this piece of code I do want to test loadSession() and testLoadSession() is testing method I have SuccessActivationCodeRepository for unit test and observeForTesting is extension function you can see I have added longer delay in the unit test but it doesn't help it return null for sessionData, How can I fix this? fun loadSession(activationCode: ActivationCode) { viewModelScope.launch { delay(START_DELAY) when (val result =...

Only safe or non null assserted kotlin message I'm trying to run an app on mine phone and i'm keep getting this problem with my project pledase help me with this thank youOnly safe or non null assserted calls are allowed on a nullable receiver type of arraylis register_btn.setOnClickListener { val email = email_registersscreen.text.toString() val password = password_registerscreeb.text.toString() Log.d("MainActiviy", "Email is:" + email) Log.d("MainActivity", "Password:$password") //Firebase Authentication user with...

java.lang.IllegalStateException: Task is not yet complete (Using Cloud Storage with Coroutines) My main activity (UserHomePage) hosts a Navigation Drawer with Navigation Header. I am trying to load data into the Navigation Header using Kotlin Coroutines. The main activity code goes like this: class UserHomePage : AppCompatActivity() { private lateinit var binding: com.newwebtools.maun.databinding.ActivityUserHomePageBinding private lateinit var headerBinding: NavHeaderMainBinding private lateinit var appBarConfiguration: AppBarConfiguration private lateinit var toolbar: Toolbar...

How to display dialog while thread is at sleep in kotlin I'm trying to show a progress bar dialog while a loop process is running. fun verifySensor(template: String) { //Load progress bar managerCallback.startLoading() val raw = template.decodeHex().toByteArray() var index = 0 while (index < raw.size) { val chunkSize: IntRange = if (index + 19 > raw.lastIndex) { IntRange(index, raw.lastIndex) } else { IntRange(index, index + 19) } val chunkList = raw.slice(chunkSize)...

How to optimize code with kotlin coroutines? Here is my code for each item I open new coroutine ,but the problem is that I want to optimize it and do some limitation let's say to have 5 coroutines , I know there is a solution with Coroutines Action ,but I don't know how can I introduce them here. Any help could be useful uiScope.launch { val infoItem = fetchItems(item.query) infoItems.add(infoItem) itemsMutableData.postValue(infoItems) } } override suspend fun fetchItems(query: String): Response{...

How to Mimic youtube bottom navigation behavior with android navigation component I'm trying to achieve navigation experience identical to youtube's bottom navigation using android navigation component. It seems like there is no easy way of doing it, at least not built into the library. I've already tried playing with NavOptions when navigating to the desired location. navController.navigate(it.itemId, null, NavOptions.Builder() .setPopEnterAnim(R.anim.nav_default_pop_enter_anim) .setPopUpTo(it.itemId, false) .setLaunchSingleTop(true) .build()) Assuming I have...

Serve kotlin multiplatform javascript from ktor I have set up a multi-module gradle project with a common module and a ktor module. The common module is a kotlin multiplatform library. I would like to be able to serve the javascript files generated from the common library from the ktor server, when I run it from Intellij. Currently ktor is set up to serve resources as static content: static("/static") { resources() } The ktor module has a dependency on the common module: dependencies { compile project(':common')...

java.io.IOException: There are no more files Android Gradle I am trying to run a clean build using the gradlew using TeamCity for CI/CD. I have BuildAgent to run it with what I believe to have all the necessary sdks, and everything installed. The Build Agents are running in a container. Additionally, the TeamCity server is on a Windows 10 VM. I try to run a clean build and it runs a few tasks, but then says: java.io.IOException: There are no more files I also got this error running it another time: Task annotationscompileKotlin FAILED...

Require a possibly nullable generic to be not null In Kotlin I'm able to write a function which takes a generic possibly nullable argument from a super class - let's call it Person - and returns the exact same type like this: fun identity(arg1: V): V = arg1 val p1: Person? = identity(null) // works fine val p2: Person = identity(Person()) // works fine val p3: Person = identity(null) // does not work Is it also possible to write a function like the one above which takes a second argument of type V which must not be null? I think about...

What is the naming convention for resource files in Android when using kotlin languge? Kotlin has introtuced synthetic import in Android development so we don't have to call finViewById like we used in Java. The naming convention for resource files is based on underscore '_' between the words like "textview_mainactivity_cancel" The problem is when I use synthetic import in my classes, the variables names of resource files breaks my naming convention that is CamelCase. So why should I do? Should I maintain the naming convention of the resource files or CamelCase naming...

JsonArray to Kotlin data class using Retrofit and GsonConverterFactory(Expected BEGIN_OBJECT but was BEGIN_ARRAY) I'm trying to load quotesJson file from github(https://github.com/JamesFT/Database-Quotes-JSON/blob/master/quotes.json). I'm new to retrofit and all of this, so I just tried following and understanding a tutorial(<a href="https://android.jlelse.eu/android-networking-in-2019-retrofit-with-kotlins-coroutines-aefe82c4d777" rel="nofollow...

How can I improve readability of this Kotlin code? I want to improve this code in Kotlin, it seems too redundant It should be possible with .forEach and Lambda's, but I don't know how Can anyone help please? val Point1 : List = topleft .split(",") .map { it .trim() .toDouble() } val Point2 : List = topright .split(",") .map { it...

Sharing context between springboot applications I am trying to create a fairly weird setup with one process running multiple ports. For example I want GET localhost:8080/hello to respond with world and GET localhost:8081/hello to respond with universe I want them to be the same process, which complicates things slightly. So I managed to get this working by creating 2 SpringBootApplication classes and starting these on separate ports like this fun startWorld() { var config = HashMap() config.put("server.port", "8080")...

Coroutine Scope, Suspend and withContext inquiries I have 3 snippet below Just scope launch fun main() = CoroutineScope(Dispatchers.IO).launch { runMe() } fun rumMe() = doSomething() scope launch with suspend fun main() = CoroutineScope(Dispatchers.IO).launch { runMe() } suspend fun rumMe() = doSomething() scope launch with suspend and withContext fun main() = CoroutineScope(Dispatchers.IO).launch { runMe() } suspend fun rumMe() = withContext(Dispatchers.Default) { doSomething() } I see them being launch in a...

Admob Rewarded Video Ad automatically closed without user action I have added Admob rewarded ads in my app. As i was showing 3-4 ads per day, in my recent update, i restricted user to see whole ad to claim gift. i.e. if user cancels ad, he need to see it again. On the second day of releasing update, i received reviews from some users that ad closes without clicking on close button and as ad is not completed, it says user to see ad again. Eventually i knew that it will create a problem with my AdMob account so i made changes that user will not be able to...

Primitive properties initialization in Kotlin I have immutable Int property which value is caclulated in the constructor.Something like this: class MyClass { val myProperty:Int init{ //some calculations myProperty=calculatedValue } } But this code won't compile.Compiler says Property must be initialized or be abstract.I can't initialize it as it's value will be known only after class instantiation.Looks like kotlin forces me to have the property mutable.Is this the only way?

Android InAppBillingV3 purchased and check if the item was purchesed I'm programming an Android app that's free. With an InApp purchase you can unlock additional features once. I am using InAppBillingV3 to use this. Im am creating the billing processor in my activity try { bp = BillingProcessor(this,"...",this) bp!!.initialize() } catch(e:Exception) { Log.e(Utils.LOG_TAG, e.message, e) } And I purchase my item fun purchaseProversion () : Boolean { try { if(inAppServiceAvailable()) { return...

Running a simple hello world from the console after installing IntelliJ IDEA I have installed IntelliJ IDEA on my mac and wrote the simplest Kotlin program fun main(args : Array){ println("Hello") } I can run it from the IDE environment. (It prints Hello of course) My question: How can you run this from the console? What I have done: I tried to call java simplekt.class but I got Error: could not find or load main class simplekt.class I tried java simplekt but then I got an exception in thread main java.lang.NoClassDefFoundError I tried to use kotlin...

Increment a field through with the set() method in batch operations in Android Firestore I have a collection which holds documents that has only a single field named "likeCount". I want to increment this when someone hits the like button from my android app. The thing is, when a post is liked for the first time, I want to create a new document for that post. If it has already been liked, a simple increment would be enough. Adding to this, I am performing this through a batch operation as I have to update another collection as I am doing this In my corresponding iOS app I wrote...

Adding group for bean validation, group not being set I'm using Kotlin and Spring to build a simple Web API. On one of the API endpoints I want to check whether the code field is null on POST requests but on all other requests such as GET the code field should be there. Where the request comes in here I have added the group: @Validated(CreateRequest::class) override fun create(request: DRequest, responseClass: KClass) : DResponse { return send(request, responseClass) } My RWithCode interface is as follows: interface RWithCode: A, B {...

Validating beans in Spring with Kotlin, group not being set on the class I'm using Kotlin and Spring to build a simple Web API. On one of the API endpoints I want to check whether the code field is null on POST requests but on all other requests such as GET the code field should be there. Where the request comes in here I have added the group: @Validated(CreateRequest::class) override fun create(request: DRequest, responseClass: KClass) : DResponse { return send(request, responseClass) } My RWithCode interface is as follows: interface RWithCode: A, B {...

How to resolve Android unit test from throwing an exception NullPointerException at androidx.arch.core.executor.DefaultTaskExecutor.isMainThread I'm attempting to write a simple unit that observes a livedata object, however when I attempt to observe that object I always get this exception: java.lang.NullPointerException at androidx.arch.core.executor.DefaultTaskExecutor.isMainThread(DefaultTaskExecutor.java:74) at androidx.arch.core.executor.ArchTaskExecutor.isMainThread(ArchTaskExecutor.java:116) at androidx.lifecycle.LiveData.assertMainThread(LiveData.java:442) at...