Haw to pass Firebase data in RecyclerView to second Activity Second Activity class BookDescription : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_book_description) var books = intent.getParcelableExtra("String") as Book Glide.with(this).load(books.imageUrl).into(bookImg1) nameTxt1.text = books.name autorTxt1.text = books.name } } Adapter class class Adapter(private val context: Context) : RecyclerView.Adapter() { private var datalist =...

How to use flow binding I try to handle clicks on my buttons and send action to viewModel private fun subscribeUI() { lifecycleScope.launch { binding.loginButton .clicks() .onEach { } .map { Action.WelcomeAction.SelectLogin } .collect { viewModel.actions.offer(it) } binding.homeButton .clicks() .onEach { } .map { Action.WelcomeAction.SelectHome } .collect {...

Android Kotlin: Illegal State Exception when checking if MediaPlayer is playing I am designing a simple Android application that shows a list of the user's system ringtones. When a user selects a ringtone, that ringtone is played for 5 seconds to give the user a sample of the alarm's sound. However, on the second time that the user selects a ringtone, the entire application crashes, yielding the following error: E/AndroidRuntime: FATAL EXCEPTION: main Process: com.example.alarmsampletest, PID: 24509 java.lang.IllegalStateException at...

Null Pointer Exception received when I'm trying to implement Manual Dependency Injection in Android So I was learning Manual Dependency Injection from the Android Developers documentation to implement a simple saving mechanism using the Room database library. However, it has been causing the NullPointerException in the Container class: 2021-03-15 071208.370 23721-23721/com.arpansircar.Practice.dependencyinjectionpractice E/AndroidRuntime: FATAL EXCEPTION: main Process:...

What does this mean when creating a MutableList? <Todo> This is a very noobie question, I apologise. So I'm just learning Kotlin, coming from JavaScript and while following a tutorial I saw this: MutableList I understand a MutableList interface but what is ? as in what is it called (e.g parameter, inheritance) so that I can find out more about what it means in the documentation, because to me i havent seen something like it (looks like XML?) A link to where it is it explained would be fine, thanks in advance.

Kotlin coroutines Unresolved reference: onComplete The previous functions are executed, but the following functions report "Unresolved reference" @WorkerThread @JvmSynthetic @SuspensionFunction suspend inline fun ApiResponse.request( noinline onStart: suspend () -> Unit = {}, noinline onSuccess: suspend ApiResponse.Success.() -> Unit = {}, noinline onFailure: suspend ApiResponse.Failure.Failure.() -> Unit = {}, noinline onException: suspend ApiResponse.Failure.Exception.() -> Unit = {},...

unable to compile the following kotlin file using $ kotlinc hello.kt -include-runtime -d hello.jar I wrote a code fun main(args:Array) { println("Hello world"); } when i used the command in cmd kotlinc hello.kt -include-runtime -d hello.jar it shows an error while compiling Java HotSpot(TM) 64-Bit Server VM warning: Options -Xverify:none and -noverify were deprecated in JDK 13 and will likely be removed in a future release. exception: java.lang.ArrayIndexOutOfBoundsException: Index 11026 out of bounds for length 11026 at...

How to get the Contact list of phone programmatically in Android 11? I'm building the Android program to get the contact list. Currently, the app is working on Android 10(Q). In order to get the contact list, I used the following code fun selectContact() { if (contactList != null && contactList!!.size < 5) { val intent = Intent(Intent.ACTION_PICK).apply { type = ContactsContract.CommonDataKinds.Phone.CONTENT_TYPE } if (intent.resolveActivity(packageManager) != null) { startActivityForResult(intent,...

How to test in ktor while using environment variables? I am using the PostgreSQL database in my Ktor Project. I saved JDBC_URL, JDBC_DRIVER..., in system environment variables of Intellij Idea. fun hikari(): HikariDataSource{ val config = HikariConfig() ****config.driverClassName = System.getenv("JDBC_DRIVER")*********** ****config.jdbcUrl = System.getenv("JDBC_DATABASE_URL")************* config.maximumPoolSize = 3 config.isAutoCommit = false config.transactionIsolation = "TRANSACTION_REPEATABLE_READ" val password...

Initialize an array after it's created in Kotlin? I have a Building class that represents an array of Room objects. Each room has some properties which are irrelevant for now. I am getting the rooms from user input like this: First-line is the number of rooms. The next n lines give information about the rooms in this format: "[room index] [room properties...]". The index of each room ranges from 0 to n -1. Example input: 3 0 [room 0 properties: a, b] 2 [room 2 properties: x, y] 1 [room 1 properties: u, v] which should create the object:...

how to shorten lines in kotlin var etxtUserName: EditText? = null var etxtContact:EditText? = null var etxtPassword:EditText? = null As you can see etxtUserName, etxtContact and etxtPassword is EditText. So, I want to add them in a line. Like we did in Java. EditText etxtUserName,etxtContact,etxtPassword; Is there any way to do same thing in Kotlin. Here what I tried var etxtUserName,etxtContact,etxtPassword: EditText? = null error : Property getter or setter expected

ExpandableListView alongside regular menu items, inside a navigation drawer, not showing up properly For my setup I use: One main activity with many fragments Data binding A navigation graph A navigation drawer What I Want I want to use a ExpandableListView as the actionLayout source for a menu item. I will put this menu item inside a regular menu. I will point my navigation drawer to use this menu via the app:menu attribute to populate itself. I want to use a ExpandableListView alongside regular menu items, and so as an action layout. My Problem The ExpandableListView shows up in the...

Kotlin - Why Does Type Inference Fail Consider the following example: data class Foo(val value: T) data class Bar( val value: Foo, val x: Foo? = null, val y: Foo? = null, val z: Foo? = null ) class Test { init { Bar(value = Foo(BigDecimal.ZERO), x = Foo(1234)) Bar(value = Foo(BigDecimal.ZERO), y = Foo("ab")) Bar(value = Foo(BigDecimal.ZERO), z = Foo(Unit)) Bar(value = Foo(BigDecimal.ZERO), z = Foo(Unit)) Bar(value = Foo(BigDecimal.ZERO), z = Foo(Unit)) } } This...

Unable to import os.log in Kotlin Multiplatform I am trying to implement kotlin multiplaform logger. During the implementation of iOS architecture, I couldn't import os.log to use os_log. How could I do this or what else can I use to log in iOS in Kotlin Multiplatform project?

My Notification Channel is not being created Whenever I send a notification through fcm. It says it will use the default from manifest or the android app, I also have mentioned my channel in manifest as default. It just says that the channel is not created by the app. Log says W/FirebaseMessaging: Notification Channel requested (message_notification) has not been created by the app. Manifest configuration, or default, value will be used. This is my onMessageReceived function. override fun onMessageReceived(p0: RemoteMessage) {...

How to correctly fix an error while initializing Interstitial ads? I have a singleton class for loading and displaying ads object AdmobProvider { var countLoadAds = 0 lateinit var mInterstitialAd: InterstitialAd private val adRequest = AdRequest.Builder().build() fun init(activity: Activity) { MobileAds.initialize(activity) initInterstitial(activity) } private fun initInterstitial(context: Activity) { mInterstitialAd = InterstitialAd(context) if (!SubscriptionProvider.hasSubscription()) {...

How to observe three data using SwitcpMap? I have a switch map which listen for an ID mainly, then i listen for some data by using that id, now i need to listed for another data by using that id so i have to expand the SwitchMap to observe two live data instead of one.. How can i achieve that? Now my code looks like this: Transformations.switchMap(corpoViewModel.getIdTestata()) { id -> idTestata = id corpoViewModel.getCorpo(id.toInt()) }.observe(viewLifecycleOwner, { articoli -> ... // doing stuff...

Facing Some issue with the layout alignment while replacing FrameLayouts ehn required [closed] I am facing some issue with the layout alignment. My Structure is like: FragmentExploreJunction.kt is the first file which is loaded in the layout and under that comes the FragmentSelectServiceStation.kt, and the same way FragmentSelectServiceStation consists of FragmentCurrentLocationView.kt and FragmentSelectServiceView.kt . And I am trying to replace the FrameLayout in the FragmentExploreJunction with FragmentSelectServiceStation and the same way I am trying to do it with...

No type arguments expected for interface Callback in kotlin val apiInterface: ApiInterface = ApiClient().getApiClient()!!.create(ApiInterface::class.java) ?: val call: Call? = apiInterface.signUp(username, contact, password) call.enqueue(object : Callback() { fun onResponse(call: Call?, response: Response) { val value: String = response.body().getValue() val message: String = response.body().getMassage() if (value == "success") { Toast.makeText(this@SignUpActivity, message,...

ResultSet containing EnumSet produces Table doesn't exist I have an Enum like enum class AmenitiesEnum { POOL, PETS_ALLOWED // shortened list, for demo purpose only } This Enum gets included in a class that then gets persistent in a MySQL database. @Entity @Table(name = "hotels") class Hotel ( @Id @GeneratedValue(strategy= GenerationType.AUTO) override val id: Int? = null, override val name: String, @Enumerated(EnumType.STRING) val rating: RatingsEnum?, @OneToMany(mappedBy = "hotel", cascade = [CascadeType.ALL]) val rooms : List = ArrayList(),...

Kotlin extension for lessThan on nullable types please see answer https://stackoverflow.com/a/57503610/835883 I was searching for a comparator on nullable types. i created this extension but then i learned that it does not guarantee all cases. This extension may have a issue: lets take a look at a specific example: fun Long?.isLessThan(other: Int?) = this != null && other != null && this < other isLessThan if this returns true, that would mean number X is less than Y, but if...

android google maps detect double tap I want to detect double tap on google maps when and add marker I set setOnMapClickListener and set a time when is tap but when I tap twice a setOnMapClickListener is called only one time

How to transform LiveData&lt;List&lt;T&gt;&gt; into LiveData&lt;T&gt;? I have been working with RxJava for a long time and I recently swapped to a project that is using LiveData and I'm trying to implement a flatMap function that emits each of the elements of a list instead of the whole list. I wrote an extension function like this: fun LiveData.flatten(): LiveData { return Transformations.switchMap(this) { MediatorLiveData().apply { for (element in it) { this.value = element } } } } However while...

Android bottom navigation with keeping fragment states I am working on an educational Android app in which the user can practise solving some tasks. I currently have around 20 tasks, and each has its own fragment. To navigate I use the navigation component and a navigation graph. Now I would like to implement a bottom navigation bar shown only in the tasks (not in the menu part of the app), from which the user can open some tools he/she can use to solve the task, and some help text that describes the method of solving the task. The intended...

call retrofit for all visible items in recyclerview Using room and paging library with MVVM. What i am trying to achieve is to call retrofit to get some data for every visible item in recycler view and then update the view accordingly. For now what i have achieved is to just implement the paging library and show data accordingly. What i can do is to get the pagedlist and get data for whole list and update the view Or i can call api for every list item. We don't want the user to wait a lot to see the updated data on the visible item class...

How do I correctly handle exceptions within 'use' block? I want a Closeable resource to auto-close itself, but at same time I want to be able to handle any possible exception. Consider the following piece of code. val opcPackage: OPCPackage URI.create(document.fileUrl).toURL().openStream().use { opcPackage = OPCPackage.open(it) // it = InputStream! } In case of exception, the InputStream will auto-close itself thanks to the use block. However, the execution flow will be interrupted. I still want to handle such exception and do something with...

From kotlin to Java, issue on kotlin generics I'm doing the code migration from java to kotlin and I have some problem with generics. This is an example explaining my doubts: import java.util.* import kotlin.collections.HashMap interface MyGenerics{ fun produce():T fun publish(toPublish:T):String } class MyImplementation:MyGenerics{ override fun produce(): Boolean { return true } override fun publish(toPublish: Boolean): String { return "test" } } class RegistrationClass{ private val workers = HashMap()...

Loading vcard of multiuserchat via jid throws bad request error in smack with openfire I am fetching VCard for group chat . but receiving ecception and my app is getting crash. Can u suggest where it was going wrong or any direction ? Caused by: org.jivesoftware.smack.XMPPException$XMPPErrorException: XMPP error reply received from test3@conference.openfire.chats.com: XMPPError: bad-request - modify at org.jivesoftware.smack.StanzaCollector.nextResultOrThrow(StanzaCollector.java:268) at...

Trying to redirect to a Activity from a Fragment Today i'm trying to open a new activity from a fragment. My goal is that the button on my XML linked to my fragment redirects me to an Activity allowing the creation of a client. This is my Fragment --> Client package com.madera.kotlin.Controller.Home.ui.chantier import android.os.Bundle import android.view.LayoutInflater import android.view.View import android.view.ViewGroup import android.widget.Button import android.widget.TextView import androidx.fragment.app.Fragment import...

Flow - pause/resume flow In RxJava there is the valve operator that allows to pause (and buffer) a flow and resumes the flow again (and also emit the buffered values as soon as it's resumed). It's part of the rx java extensions (https://github.com/akarnokd/RxJavaExtensions/blob/3.x/src/main/java/hu/akarnokd/rxjava3/operators/FlowableValve.java). Is there...