Analog of raf.seek(pos) I wanna find analog of raf.seek(pos) method from java. Need to find page by number in text file (book's page). val raf = RandomAccessFile(file, "r") raf.seek(pageNumber * PAGE_SIZE) raf.read(bytePage) I don't like my version. It's too javish. Wanna find other way. W/o byte array maybe.

how to display rating value that is stored in database as number of stars in Kotlin i add rating data to firebase database without problem here it is Now i want get it and display rating in my rating bar Here is my code Rating database reference ratingReference=FirebaseDatabase.getInstance().getReference("Rating") Getting data from database private fun getFoodRating(foodID: String) { var query: Query=ratingReference.orderByChild("foodId").equalTo(foodID)...

Kotlin deprecated annotation replaces this with class name I have a method fun logError(message: String) and I want to replace it with a new method, which accepts sender object i.e. fun logError(sender: Any, message: String). If I make it like this: @Deprecated( message = "Use method with sender instead.", replaceWith = ReplaceWith("Logger.logError(this, message)")) Then in place, when I replace it - I'm getting it like this Logger.logError(Logger, message), which is not what was intended, how can I preserve this when...

Problem launching corda jar: newAtomicIntegerFieldUpdater I've tried to launch (like in this question) corda standalone jar and encountered a problem: internal.DriverDSLImpl.genericDriver - Driver shutting down because of exception java.lang.NoSuchMethodError: io.netty.util.internal.PlatformDependent.newAtomicIntegerFieldUpdater(Ljava/lang/Class;Ljava/lang/String;)Ljava/util/concurrent/atomic/AtomicIntegerFieldUpdater; at...

Error : problem in get data from php page with volley in kotlin android i have an android app that must recieving data from a web service. this is my kotlin code: class Main22Activity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main22) tv_button.setOnClickListener { getUsers() } } fun getUsers() { // Instantiate the RequestQueue. val queue = Volley.newRequestQueue(this) val url: String =...

Launching coroutines from a suspended function Given we have a suspending function but this is not a CoroutineScope, how can we launch other coroutines such that those are associated with the current scope of whatever runs this suspending function?

How do you get rid of superfluous casts to implemented interface? Let's say I have an interface public interface ICardSuit { /**short name*/ public String getName(); /** the colour of this card*/ public ICardColour getColour(); } that I decide to implement with an enum: public enum CardSuit implements ICardSuit { HEART{ @Override public ICardColour getColour() { return CardColour.RED; } }, SPADE{ @Override public ICardColour getColour() { return...

IntentService/Service - Keep running even if the application is terminated - Android I'm implementing an IntentService to download a PDF file, it shows a notification to the user on downloadStart and keep updating progress during this process, the service is working fine and the progress is updated correctly, the problem is as soon as i remove my app from "Recents" the download stops without even showing an error. Here's my DownloadService class : class DownloadService : IntentService("DownloadService") { lateinit var downloadNotification : DownloadNotification...

Kotlin: Generic Parameter on Classes and how they are resolved My question is in the following example, why does the kotlin compiler not know the real type of 'fromParam'? open class S(val param : R) class A : S(B()) class B fun test(value : S, param : R) { when(value) { is A -> { val fromClass : B = value.param val fromParam : B = param //

Android Architecture Components and sectioned RecyclerView Hi all dear android developers im new to android, i started android developing with the android-room-with-a-view-kotlin demo, it works good and no have any problem, but i want to add section headers in recyclerview by first letters. i can create a sectioned recyclerview (multi type content recyclerview like <a...

Why is this Kotlin class property not public? I've got an app that is regularly using classes written in Kotlin which are accessed by other classes and their methods written in Java. I had the following class in Java: public class MyDataClass { public String color; public String action; } I've decided to move it to Kotlin: class MyDataClass { var color: String = "" var action: String = "" } Upon recompiling, I'm now getting the following error message: /myPath/MyApp.java:[93,20] color has private access in...

Corda jar launching: Address already in use: bind error I have perfectly working Corda app in Kotlin - it launches and works normally when launched from IDE But when I try to build it as jar file, it crashes with the following error INFO: Booting SSHD INFO 11, 2019 82827 PM org.crsh.ssh.SSHPlugin init INFO: Booting SSHD INFO 11, 2019 82828 PM org.crsh.ssh.term.SSHLifeCycle init INFO: About to start CRaSSHD INFO 11, 2019 82828 PM org.crsh.ssh.term.SSHLifeCycle init INFO: About to start CRaSSHD INFO...

How to use setter for this Kotlin class property? I have the following class coded in Kotlin: class MyClass { var color: String = "" var action: String = "" val owners = Array(1) {Owner()} class Owner { var userId: String = "" var userName: String = "" } } ...and I'm accessing it Java: MyClass myObject = new MyClass(); myObject.setColor("blue"); myObject.setAction("throw"); ...and I'd like to be able to set the owner. I'm not sure how, though. If it were an object that was coded in Java with public...

Why the *Async naming convention for functions returning Deferreds? Intellij has an inspection (i.e. lint check) that tells you functions that return Deferred should be named something ending in Async. Naming conventions like these make sense to me in dynamically typed languages. But Kotlin has such a nice type-checker and ecosystem of tooling, so why rely on the convention? Especially because Kotlin coroutines bake <a...

android.view.ContextThemeWrapper cannot be casted to android.app.Activity I have a scenario in which I'm supposed to inject a Class into my recycler view .Inorder to inject my dagger class I need to get hold of context .so I wrote the following code in my recycler view class Components.getFrom(parent.getContext()).inject(this); Inside theDepComponent I have an inject method in which this particular recycler view is also added When I run the code I am getting this error android.view.ContextThemeWrapper cannot be cast to target.dagger.HasComponent I have...

Koin 1.0.2 Room Database I'm using koin 1.0.2 to manage dependencies injection but it's not working with room database, it's returning can't create definition for single... Here is my code: @Database(entities = [UserEntity::class], version = 1, exportSchema = false) abstract class UserDatabase : RoomDatabase() { abstract fun userDao(): UserDao companion object { private var INSTANCE: UserDatabase? = null fun getInstance(context: Context): UserDatabase { if (INSTANCE == null)...

Deserialize array based polymorphic json in Jackson I have a json array that contains child objects: [ ["t", 1, 2, 3], ["o", "a", "b"] ] Where "t" and "o" are keys, and other elements in array are data values. And I want to deserialize this array to classes using these models @JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.PROPERTY) @JsonSubTypes( JsonSubTypes.Type(value = T::class, name = "t"), JsonSubTypes.Type(value = O::class, name = "o") ) @JsonFormat(shape = JsonFormat.Shape.ARRAY) sealed class A data...

Update RecyclerView UI after SyncAdapter changes data in Kotlin I need to refresh my RecyclerView after the SyncAdapter finish a task, When I click some item from my RecyclerView I send the data to a Webserver, my server returns some data and save it in a local db (Anko db), this works fine, but I need to update the UI items when the data is save in a local DB. What is the best way to do this? That's my RecyclerViewAdapter: class TableRecyclerViewAdapter(private val tableList: List) : RecyclerView.Adapter() { override fun...

Load resource file (json) in kotlin js Given this code, where should I place the file.json to be able to be found in the runtime? // path: src/main/kotlin/Server.kt fun main() { val serviceAccount = require("file.json") } I tried place it under src/main/resources/ without luck. I also use Gradle to compile kotlin to js with kotlin2js plugin.

Can I split mapIndexed work from kotlin collection in multiple threads? I'm struggling a bit finding a solution for my app problem. My app is generating chart with a million of points, and for this works I'm saving a string with all points separeted by an blank space on the room database. That being said, i'm loading this String of points, splitting it nad using mapIndex to put a index on all of them, like this: val map = mutableMapOf() signal.split(" ").mapIndexed { index, signal -> signal.toFloatOrNull()?.let { floatSignal ->...

Callback Listener is always null I can't figure it out why listener in class PageFragment > getChapterLink function is always null. I already set the listener in pageFragment. It took me so long debugging this code but I can't fix it anymore. Please help me. Thanks. class ReaderFragment : Fragment() { private fun setPageRedirection() { val pageFragment = PageFragment() pageFragment.setChapterHrefCallbackListener(object: ChapterHrefCallback { override fun getChapterLink(href: String) {...

Firebase cloud function gets triggered twice. First time 'error', second time 'ok' Just trying to impletment Stripe Payment into my Android App. The trouble i have is that my cloud function is triggered twice when i enter a credit card in my app. the first trigger returns an "error" status and the second trigger returns an "ok" status Here is the code i use to save the Stripe token to my firebase realtime database: if (cardToSave != null) { stripe.createToken( cardToSave,...

Realm: How to tell if a field is nullable via DynamicRealm? Does DynamicRealm offer a way to determine if a field is nullable on a kotlin RealmModel subclass? For example, given the following realm models: open class IntObj( var i: Int = 1 ): RealmObject() open class NullIntObj( var i: Int? = null ): RealmObject() If I fetch a dynamic realm object representation of each type and try to determine the field type of parameter "i" via dynamicRealmObj.getFieldType("i"), they both return "INTEGER". Is there a way I can determine the...

permanent RotationAnimation with Kotlin :-) For my application project, I planned a welcome activity that allows the user to choose a group of countries. For that I have two buttons, the first one will allow a CardView containing 4 TextViews to rotate by 90 °, until the TexView of the country group is readable (the other Textviews will be oriented differently). The code below works for a Texview, but my problem is the permanent effect of the rotation. I added the line: rotateanimation.setFillAfter (true) that works well, but...

when convert Java to Kotlin, com.android.dex.DexIndexOverflowException: method ID not in [0, 0xffff]: 65536 in android studio After I had convert a java file to Kotlin, I got a error 'com.android.dex.DexIndexOverflowException: method ID not in [0, 0xffff]: 65536' But, It only happen 'make Project'. If I had ran 'debug app', It was good(no problem). In fact 1) use Multidex Setting for Google Guide 2) I checked Android Studio 3.2 and 3.0x 3) If I do not convert Java to Kotlin, It will do not make the problem. Sorry my poor English. I am gonna wait answers.

Expecting a class body when trying to create an instance of Fotoapparat OK so I'm trying to use the Fotoapparat library (link) and honestly I'm getting slightly confused but trying to work it out. This is the basic initialization according to the documentation: val fotoapparat = Fotoapparat( context = this, view = cameraView ) Now view is expecting an item of type CameraRenderer. I think the right approach (not sure though tbh) is as follows: val cameraView = object :...

Android - TimingLogger doesn't print log In my application i need to use time logger. when i try to log using time logger it doesn't print anything. Even though i used this command in the android terminal adb shell setprop log.tag.MyTag VERBOSE doesn't makes any change. TimingLogger logger = new TimingLogger("MyTag", "methodA"); logger.addSplit("WORK A") But none works right ? any idea how to handle this please

Trying to work with RetrofitClient and subscribe, having trouble with Kotlin I am trying to set up a user registration and login, and have been following a tutorial on youtube () I am also transitioning from java to kotlin while learning android programming vs just desktop, so a lot of new stuff for me. Anyways, code im tring to replicate: compositeDisposable.add(iMyService.loginUser(email,password)...

Kotlin Android Studio Warning "Do not concatenate text displayed with setText. Use resource string with placeholders." I made a simple program to learn about concatenation in android studio with Kotlin. So, I tried to get a string value from resources in strings.xml as shown below and concatenate with a value I got warning "Do not concatenate text..." as shown below By replacing resultView.text = getString(R.string.txt.show, " ") + result.format(2)...

Bottomnavigationview not working when turn off permission and go back to app If I go to manually turn off phone permissions that app will be restart. Bottomnavigationview did not respond when the application restart was completed. Pressing button will not change the Fragment. But the Fragment at that time were restored.