Does an actor or channel need to be managed (closed/terminated) when encapsulated by another object like TextWatcher? I would like to implement a DebounceTextWatcher. I intend to use an actor to consume text changes and debounce on a specified time interval and subsequently forward events to an external consumer. The code would look as follows: class DebounceTextWatcher( delayMs: Long = DebounceTextWatcher.DEFAULT_TIMER_DELAY_MS, handler: (text: String) -> Unit ) : TextWatcher { private val channel = GlobalScope.actor { debounce(delayMs).consumeEach(handler) } override fun...

Android Room Kotlin - Query in background thread - return value problem I have converted a sample program from Java/SQLite to Kotlin/Room. I am struggling to implement queries with return values in a background thread. This has been asked but I could not get it to work. I have read answers to similar questions but some are deprecated, or some solutions seem complex for something that should be trivial. I am really stumped in coming up with a simple solution when I need to use the return value of the query. (Everything works as it should if I force doing...

Data binding - access individual properties contained in LiveData Is there a way to do something like this with LiveData and data binding? ViewModel has this property: val weather: LiveData What I'm trying to do in the layout: Is this possible in any way or do I have to split the object contained in LiveData into multiple ones for each property of the contained object?

Kotlin: How to simplify this filter firstNorNull call chain? I got a warning from Android Studio: Call chain on collection type may be simplified. val hit = hits.filter { val trackable = it.trackable trackable is Plane && trackable.isPoseInPolygon(it.hitPose) }.firstOrNull() ?: return

Are functional collection types available in Kotlin? Are functional collection types available in Kotlin? Something like immutable Queue or Stack in Scala? If not, is there any good library out there which provides functional collection types to Kotlin (based on Kotlin's Any) ?

kotlin recyclerview data not showing Our question is how to show Parent and Child data from two SQLite DB tables? We have two tables that are added to two ArrayLists childList and parentList Here are the Model Class's for each class ModelParent { var idD:Int = 0 var dept:String = "" var fkD:Int = 0 var children: List? = null } class ModelChild { var idI:Int = 0 var item:String = "" var fkI:Int = 0 } We have two Adapters for each table and will post that code We are able to iterate through the two ArrayList with...

ArCore Sceneform: Play .mp4 video when detect image When I find an image, I want to place a text and a video above it. The text view is placed on the scene but the video is not, it is just added to my main layout in the middle. I'm using the component VideoView, I'm not sure that's the problem override fun onCreate(savedInstanceState: Bundle?) { (....) arFragment!!.arSceneView.scene.addOnUpdateListener { this.onUpdateFrame(it) } arSceneView = arFragment!!.arSceneView } private fun onUpdateFrame(frameTime:...

Kotlin Type Mismatch for a function return a string import java.util.UUID fun UuidGenerator() { val id = UUID.randomUUID().toString(); return id.replace("-", "") } ^^^ UuidGenerator.kt Just try to build a simple UUI generator function so I can import it into a class and use it to generate random string of 32 characters, but keep getting type mismatch.

AlertDialog gets reshown on orientation change Code for question on Github I have a app which is using fragments + viewmodels. In one fragment I need to present a list of options to the user when they hit a button. I'm doing this using an AlertDialog builder and it works to solve that problem. But if I open the application, hit the button to show the alertdialog, dismiss the dialog, and then rotate the phone to trigger a teardown/buildup the alertdialog get's...

I want set up an app bar but failed, how to solve that problem? https://developer.android.com/training/appbar/setting-up I just follow this instruction, but the toolbar doesn't show on my screen, and there's an error

Accessing public download files onActivityResult Android 28 So I've recently upgraded a project that was working just fine and it now has a bug now that it is compiling with build tools 28, for the latest version of Android. So I have always used this PathUtil to get the file path I needed from an implicit intent to get file selection from the user. I'll share a link to the code that I am using for a long time now below. PathUtil It's just a utility...

Deploy Failed : Kotlin Spring Boot app on the Google App Engine I am trying to deploy my spring boot kotlin application on google cloud app engine with maven, but I am getting this strange error. Failed to execute goal com.google.cloud.toolsappengine maven plugin1.2.1:deploy (default-cli) on project 'project_name': Execution default-cli of goal com.google.cloud.toolsappengine maven plugin1.2.1:deploy failed: Non zero exit: 1 -> Full Stack Trace org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal...

Identifying fake accounts based on IP address or email Some users on a discussion board create multiple accounts to act as multiple people, although every user should have a single account. In this way, a number of accounts on the discussion board are fake. How to implement solution for identifying and grouping the fake users in java (or Kotlin) based on either email or IP. For example if users have either the same email or IP address, they are likely the same person. Users A and B share emails but C doesn’t share either email or IP, they...

Cannot find the getter for attribute ImageView while using Databinding in kotlin I am trying to learn data binding with Kotlin and I was able to implement it successfully for edit text and text views. After that I am trying to use it for Image Views. I am currently trying to give an option to users to choose their profile picture by clicking on the imageview. This code works properly but when I try to set the image to the view using data binding adapter , I get the following error. Found data binding errors. ****/ data binding error ****msg:Cannot find the getter...

In Android Webview window open work just one time My Website(use laravel) call window.open method on this code window.open('My_URL','_blank'); and my Android Webview open new window on dialog. code is override fun onCreateWindow(view:WebView, isDialog:Boolean, isUserGesture:Boolean, resultMsg:Message):Boolean { // set dialog webview val dialog = Dialog(context) dialog.requestWindowFeature(Window.FEATURE_NO_TITLE) dialog.setContentView(R.layout.activity_webview)...

Synthetic of kotlin extensions does not work when I import Android-ktx in gradle I'm trying to test some android jetpack features in my project, I already have the navigation working. When I tried to import android-ktx and migrate my dependencies to androidx I managed to synchronize the gradle successfully, but I lost access to my button through synthetic. Anyone have any idea what it can be? My Gradle: apply plugin: 'com.android.application' apply plugin: 'kotlin-android' apply plugin: 'kotlin-android-extensions' android { compileSdkVersion 28 defaultConfig...

Sms BroadCastReceiver Leaks Memory I have a registration screen using mobile, when user signs up using mobile number, an otp is send and i listen to that otp so that user don't have to manually feed the otp But when listening to that otp i get an memory leak. Here is my code for listening to sms class SmsReceiver : BroadcastReceiver() { private var bundle: Bundle? = null private lateinit var currentSMS: SmsMessage private var otp: String? = null override fun onReceive(context: Context?, intent: Intent?) {...

Kotlin - Type mismatch: required: Context found: Context? I tried to make a PopupMenu override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) menu_btn.setOnClickListener { var menu: PopupMenu? menu = PopupMenu(this.context, it) menu.inflate(R.menu.card_menu) menu.setOnMenuItemClickListener { when(it.itemId) { R.id.menu_modify -> { Toast.makeText(context, "Modify", Toast.LENGTH_LONG).show() true }...

How to use a bit to store a config in Kotlin? For example, to store config1-8 to config var config1 = false var config2 = false var config3 = false var config4 = false var config5 = false var config6 = false var config7 = false var config8 = false var config = 0 if config is var config1 = false var config2 = false var config3 = false var config4 = false var config5 = false var config6 = false var config7 = false var config8 = true then config is 1 if config is var config1 = false var config2 = false var config3 = false var...

Why my viewpager's all tabs shows same data? I am new to android, just a beginner in kotlin. I have android app with tab layout and viewpager. There are two tabs when i try to show the data in tabs, both tabs to show me the same data in stands of different one.what i made a mistake please guide me. here is the to call the setuppager: val incomingTransactionsObserver = Observer { if (it != null) { viewPager = findViewById(R.id.viewpager); setupViewPager(viewPager!!, it, INCOMING) tabLayout =...

Change activity data on Firebase onMessageReceived I have MainActivity where I want to show received messages count number and change that number dinamically when new notification will receive. How to achieve that?

How to remote/control Android camera and microphone using Java or Kotlin I want to create an application which enable to control Android camera and microphone but I don't know how. For example, I want to control to device that login to the same gmail account or the same id. Do you have any concept or example implementation dear?

Gradle sync failed in android due to kotlin I am not using kotlin in my program, it was working fine unless I update the target version from 26 to 28. I don't know a bit about kotlin. whenever i am trying to sync the gradle files it gives an error : org.jetbrains.kotlin.gradle.KotlinGradleModel.getImplements()Ljava/util/List; Why it is happening so ? My gradle file is : apply plugin: 'com.android.application' android { compileSdkVersion 28 defaultConfig { applicationId "com.example.pr20020897.dms"...

Custom annotation for null into Kotlin JVM My goal: writing a custom field annotation that throws an exception if null is set to a nullable variable. data class Contact ( @RequiredAttribute var name: String?, var number: String? ) So if I do something like val contact = Contact(null, "test") it should end up with an exception with a message like Attribute name can't be set as null. My question: is this possible to achieve? I never wrote a custom annotation in Java or Kotlin, so I'm quite noob on this field.

Populate a RecyclerView with rxkotlin: The Recyclerview stay empty Here is a kotlin activity which should display a list of events (from sample.json) class TalksActivity : AppCompatActivity(), TalkAdapter.Listener { private val TAG = TalksActivity::class.java.simpleName private var mCompositeDisposable: CompositeDisposable? = null private var mAdapter: TalkAdapter? = null private var disposable: Disposable? = null private val mapper = createMapper() override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState)...

Enums in kotlin I want to access the keys for an item in enum class enum class Events { REFER_AND_EARN { val key: String = "Refer and Earn" val source: String = "Source" }, REFILL_PAST_MEDICINE_CLICK { val key: String = "Refill Past Medicine Click" val source: String = "Source" val pointOfInitiation: String = "Point of initiation" } } Like for the above enum class can I access source like this??...

Retrofit HEAD must use Void as Response Type in Kotlin I have the following API method defined: @HEAD(""test/{name}) fun checkTitle(@Path("name") name: String): Single I then want to unit test a successful response on this HEAD request but can't figure out how to instantiate a Void object in Kotlin. whenever(mockService.checkTitle(any())) .thenReturn(Single.just(Response.success(VOID NEEDS TO BE HERE))) repo.checkTitle("tester") .test() .assertError(ValueTaken::class.java) If I change the api call response to return Unit, it...

How to create a Kotlin "hollow" jar env for faster deployment Situation: Coding Kotlin 1.3 EAP in IntelliJ, deploying to a raspberrypi using maven. Works great! ...except the fat jar is really big (contains all of kotlin 1.3, maven dependencies, and my app) and takes a long time to transfer over the network every time I want to do a...

JSON integration: Room architecture (many-to-many) with Relation, Embedded or TypeConverter? I am looking to find the most efficient way to use this kind of data: I have the following JSON (simplified for the example): { "organizations": [{ "id": 1, "name": "Orga One" }, { "id": 2, "name": "Orga Two" }], "forms": [{ "id": 10, "name": "Form 10", "organizationsId": [ 1, 2 ] }, { "id": 11, "name": "Form 11", "organizationsId": [ 2 ] } ] } I would like...

Kotlin garbage collect strong referenced lambda MainActivity.kt: class MainActivity : AppCompatActivity() { private val printers = Printers() private val strongObject = object: Item { override fun print(): Int { return Log.e("MainActivity", "strongObject") } } private val strongSAM = { Log.e("MainActivity", "strongSAM") } override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) val...