I want to declare an Array of type String that returns for me : Array<String>? not Array<String?> I am creating an AsyncTaskLoader I override in my Main Activity this function: override fun loadInBackground(): Array? { return OpenWeatherJsonUtils.getSimpleWeatherStringsFromJson(this@MainActivity, jsonWeatherResponse) } Note that this function cannot accept any type except: Array? and in my OpenWeatherJsonUtils.getSimpleWeatherStringsFromJson function, I have this code: @Throws(JSONException::class) fun getSimpleWeatherStringsFromJson(context: Context, forecastJsonStr: String): Array? {...

How to convert JSON date to string in Kotlin within my recyclerview adapter? The JSON data I am returning is a string in numbered format (YYYY-MM-DD) and I am wanting my app to display this as ex.(January 1, 2020) depending on which JSON date I query. Given the date formatting options in java and kotlin are based off integers, I am unsure of the most efficient way to convert the numbered string to a character string when...

Android AdMob's test ads not loading I wanted to add ads to my applications, so I started with an empty app that uses the sample app id from admob to test the ads. Well, the ads won't load. You can see the whole app's code and the log below. I don't know what did I mess up, I followed the getting started guide, but the only result I got is... "I/Ads: Ad failed to load : 0". AndroidManifest.xml ... ... activity_main.xml MainActivity.kt package com.csakitheone.adtest import...

Kotlin "Do not concatenate text displayed with setText. Use resource string with placeholders. " I want to set texts: Station 1, Station 2, Station 3... If I have code like this (frame is of type ScrollView) I get the warning: "Do not concatenate text displayed with setText. Use resource string with placeholders." for(i in 1..10){ frame.stationTextView.text = "Station $i" } If, however I do this, I don't get the warning. for(i in 1..10){ val str = "Station $i" frame.stationTextView.text = str } The second example seems redundant to me, but the warning is gone. Which one is...

No cached version of org.jetbrains.kotlin:kotlin-gradle-plugin:1.4.10 available for offline mode I am using android studio 4.0 and whenever i create a new project offline(without access to internet) it gives me this error and I haven't access to internet most of times. I tried toggling offline mode button and everything but again I need to have access to internet for complete build. Is there any solution to this or you need to have access to internet when build you project? I used to use Java for android app development and could build project offline too. but I have migrated to Kotlin...

How to mock a usecase in Android I am trying to Mock a usecase but I am new to this so not sure how to do it. I was thinking use case should return the FLOrderCompleteResponse so I tried to mock it but is definitely not right @PerApp class FLlingCompleteUseCase @Inject constructor( private val FLOrderRepository: FLOrderRepository ) : UseCase() { private lateinit var FLOrderId: String private var fetchFLOrderInResponse: Boolean? = null private lateinit var body: FLOrderWrapper fun execute(...

Use Kotlin coroutines for real time Firestore updates When fetching one-time data from Firestore, I can remove callbacks using the kotlinx-coroutines-play-services library: Using callbacks firestore.collection("Users") .document(userId) .get() .addOnSuccessListener { snapshot -> // Handle snapshot } .addOnFailureListener { exception -> // Handle exception } Using await() and coroutine try { val snapshot = firestore.collection("Users") .document(userId) .get().await() // Handle...

Annotations with arguments @field:Size(max = 100) not working on data class - KOTLIN I have a data model class in Kotlin where javax validations with arguments are not working. My model class: data class Data( @field:Size(max = 100, message = "Message must be less than 100 characters") val message: String? = null ) However, if I put something like @field:JsonIgnore without any parameters. The constraints do get implemented. My service class has @Validated/ @Valid annotations

Android kottlin - how ot create a property delegate for toolbar backbutton press I have a fragment that has a toolbar and i currently set the back button listen like this: with(myToolBarView) { (activity as AppCompatActivity).setSupportActionBar(this) setNavigationOnClickListener { requireActivity().onBackPressed() } } but when i have other fragments this code gets repeated all the time. so i wish i could do something like this: myToolBarView by backButtonDelegate(this) but the problem is for one, the view wont be ready until after onCreateView gets called. So i'll get...

Displaying a math problem consisting of two integers and a random operator I'm currently trying to write a program in kotlin to generate a random math problem, which consists of two random integers and a random operator. I have to then tell the user that the answer is wrong or correct, and display the answer if wrong. I'm new to kotlin, so I'm a little stuck right now. fun ranNumsAndProbs(a: Int, b: Int, op: String): Int { var firstNumA: Int = Random.nextInt(-100..100) // for add and subtract, the int is between -100 and 100 var secondNumA: Int =...

Issue with room database android I want to insert some value that i got from my transaction into Room database . I use the Insert method to save data into room database and also @query to get all data from database . But the problem is that the data not saved and when i switch between my screens there is no sign of data . Code : my table @Entity (tableName = "credit") data class Credit( @PrimaryKey(autoGenerate = true) val id : Int? , var credittext: Long ) my Dao : //credit table dao...

onDragListener with data binding in Android Studio The onDragListener without parameters works properly app:onDragListener="@{() -> viewModel.dragListenerFive()}" fun dragListenerFive():Boolean{ return true } but just as this one doesn't work, because I need the dragEvent object, and that's where I can't, someone knows how it's done?

Keeping Layout Parameters While Drawing Bitmaps To Canvas I have a custom view in which I draw incoming bitmaps to canvas in onDraw method: canvas.drawBitmap(bitmap, null, cameraRectangle, null) Each time I receive a new Bitmap (i.e. frame), I pass it to onDraw method and call invalidate(). My problem is as I call invalidate(), my previously set layout parameters also got invalid and their values are set to their initial values. How can I keep my layout parameters persistent while drawing a new bitmap on every draw? Thanks in advance!

Android Studio doesn't recognize Kotlin keywords After updating Studio to 4.0.1, along w/ AGP 4.0.1, Gradle 6.1.1 and upgrading Kotlin to 1.4.0, I can't get the Kotlin files to highlight (.java works just fine) the keywords in Studio. Some keywords like class, fun, val get recognized and yet others like import, internal, init, override don't get recognized I'm not sure what plugin I'm missing so, any pointers would be helpful. Also, any time I try to run the app in debug mode, I see the following error E/netmgr: qemu_pipe_open_ns62 Could...

Can't access a Firebase node to retrieve a channel list for app I have code that should update the list and then notifyDataSetChanged() to the list adapter once all of the nodes related to the channel in my Firebase Database is deleted, except after deleting the channel node under /channellist does not get deleted, and my subsequent child listener for /channellist is not able to access data under the ref.child("/channellist/$channelname"). So for some reason I can't access /channellist. <a href="" rel="nofollow...

Kotlin &amp; Spring MVC - HTTP Status 400 - Null I have a Kotlin @RestController, and I would expect it to return 400 - Bad Request in a situation where a null is passed for a @RequestParam argument. Example: @RestController class Api() { @PostMapping("endpoint") fun endpoint(@DateTimeFormat(iso = DATE) @RequestParam date: LocalDate) { //do something } } If I were to make a request to "POST - /endpoint?date" I a 500 - Internal Server Error with the following (shortened) body: { "timestamp": "2020-09-14T203938.102+0000",...

How can i sum value in room database android I want to know that how can i sum value in the room database . Let say i have insert this value (10,000) in the room database and i want to insert new value to database (20,000) and i want the new value to be sum with old value not replace it . how can i do that .? example of code : Database Table : @entity class sum ( id : int , value : Long ) Dao : @insert (onConflict = OnConflictStrategy.REPLACE) suspend fun insert (model :sum) what shoud i use instead of above insert ....

kotlin.Collections doesn't seem to be imported. "listOf" marked in red while in other proyect is working fine My problem is that I can't use the method "listOf" even I was using it a while ago. I don't know what I did. In other proyect the method is working fine. I suspected the issue was related with dependencies, but then I realized the method belongs to "kotlin.Collections" which belongs to Kotlin Standard Library and this library seems to be imported in the background. Sorry for my english. Please help!

Function to take picture from my app keeps crashing the app I am trying to implement a an intent to launch the camera app, take a picture and store a full size image. I am following Google documentation [here][1] but the App crashes each time I tap the "take Picture" button with the following error: E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.pickmytrash, PID: 7023 java.lang.IllegalArgumentException: Failed to find configured root that contains...

400 error after successfully refreshing Oauth 2 Token using Retrofit2 / Kotlin in Android This is the code I have for the refreshing token in an android app using kotlin ad retrofit 2. The gradle : implementation "com.squareup.retrofit2retrofit2.9.0" implementation "com.squareup.retrofit2converter moshiretrofit:2.9.0" And Authenticator is : class OAuthAuthenticator( private val refreshTokenService: Repository, private val sessionManager: SessionManager ) : Authenticator { @Synchronized override fun authenticate(route: Route?, response:...

Formatting Date that comes as a String using DataBinding I am using the following code to format a Date (that comes as a String from the service) and trying to bind it into the view using DataBinding but I am receiving the following exception when trying to build the solution "java.lang.reflect.InvocationTargetException" I have a class Util.kt that has the following code to format the date: @RequiresApi(Build.VERSION_CODES.O) @BindingAdapter("android:formatDate") fun formatDate(date : String?, view : TextView){ var formatter =...

NoSuchElementException java.lang.Scanner I have no idea what the error is, I am having a hard time adapting to this language, any help thank you very much. Error: Exception in thread "main" java.util.NoSuchElementException at java.base/java.util.Scanner.throwFor(Scanner.java:937) at java.base/java.util.Scanner.next(Scanner.java:1594) at java.base/java.util.Scanner.nextInt(Scanner.java:2258) at java.base/java.util.Scanner.nextInt(Scanner.java:2212) at Packing.(Packing.kt:100) at PackingKt.main(Packing.kt:7)...

Fist Button Click missed after screen initialised with Rxjava kotlin class I am using RxJava with Kotlin in my Android Application. to avoid multiple continues clicks on a button i handled like below with Rxava by using throttleFirst method. compositeDisposable = new CompositeDisposable(); @OnClick(R.id.f1rst_button) fun onFirstButtonClick(view: View) { Log.d("capture click event started") compositeDisposable.add(RxView.clicks(view).throttleFirst(500, TimeUnit.MILLISECONDS, AndroidSchedulers.mainThread()) .subscribe {...

Run Gradle-built App Continuously (as server daemon) even after logoff Gradle noob here. I am running a Kotlin application server-side (Ubuntu 20.04), built with Gradle. I can run it fine using: sudo sh gradlew run And even: sudo sh gradlew run & But as soon as I log out of the server, the app stops. How do I keep the app running as a server daemon continuously? How can I start it back up automatically after the server boots? I can probably hack something together with bash scripts, but I want to know what the industry standard way of doing this is.

Can I embed a Perl project alongside an Android project in Android Studio? I need to run a Perl script (main.pl) from my Android app. I came across perl-android-apk project which seems just what I need. It comes as an eclipse project and you can build what you need from this base. The problem is that I need this inside my own project. So my question is how can I incorporate this inside my own project? I am open to other suggestions about running a Perl script on Android too - however, the Perl interpreter needs to be contained in my APK. From <a...

Is there a Kotlin functon for finding the index of an element in the vector? In python, I can use index to find the index of an element, such as: # vowels list vowels = ['a', 'e', 'i', 'o', 'i', 'u'] # index of 'e' index = vowels.index('e') print('The index of e:', index) # index of the first 'i' index = vowels.index('i') print('The index of i:', index) Is there an equivalent function in Kotlin ?

TextView is hidden in form activity when beside spinner that has not been selected I have form activity that consists of some indicator. But my textview is hidden when spinner that has not been selected Like this I must click edittext in above so that the textview is visible like this This is my code class AddSengonProductActivity : AppCompatActivity(), CoroutineScope { companion object {...

Does anyone know how to fix Android Studio 4.0.1 problem in augmented reality? I already tried installing all the dependencies and installed and uninstalled the Google SceneForm Tools (Beta) plugin and I have not managed to get the *. Sfb * file through the * Import SceneForm asset * It generates the following error and I have not been able to solve it, the attached images are part of a single error so the union of them is only One error, it is too big. java.lang.NoSuchMethodError:...

Problem with suspend function in Kotlin coroutine I am following this video to use Kotlin coroutine : , at 9:30 in the video. But when I write the similar code, it doesn't behave like i expected: WalletDao.kt interface WalletDao { @Query("SELECT * FROM wallet LIMIT 1") suspend fun getFirstWallet(): Wallet } Repository.kt class Repository private constructor(appContext: Context) { private...

Filter recyclerview list in kotlin only works the first time problem I have a problem with filtering recyclerview list with barcode scanner. It works the first time when i scan, but every next scan returns a empty list. I logged everything and the problem is that it filters original list from main activity only on first scan, and the new filteredList on every other scan. Can someone tell me hoe to properly use original list and its copies when using Filterable? Here is code from my adapter class MyAdapter (var listOriginal: ArrayList) :...