RecyclerView Multiple ViewHolders ItemDetailsLookup My recyclerview (for chatview) loads views correctly but when i tap a view it throws cast exception: ViewHolderReceived cannot be cast to ViewHolderSent ViewHolders: class ViewHolderReceived(val view: View) : RecyclerView.ViewHolder(view) { fun getItemDetails(): ItemDetailsLookup.ItemDetails = object : ItemDetailsLookup.ItemDetails() { override fun getPosition(): Int = adapterPosition override fun getSelectionKey(): Long? = itemId...

white backgroud for png Image in android studio I'm trying to show some png images on RecyclerView, the images has transparent background but it show white background when run on device !!. I tried to add android:background="@android:color/transparent" to ImageView, but still white I use Picasso to load the image on ImageView, like that Picasso.get() .load(newpath) .into(itemView.imgMCat)

Calling RecycleView within onBindViewHolder I set "setOnClickListener" within "OnBindViewHolder", so when I click an item, I'll do somethings. But when I click an item, it gives an error like below, java.lang.IllegalStateException: holder.itemView.myAdsRecycleView must not be null The line which gives error is below, holder.itemView.myAdsRecycleView.layoutManager = myLinearLayout What can be the problem? itemview and array seems doesn't null? override fun onBindViewHolder(holder: adsViewHolder, position: Int) {...

Kotlin Spring WebMvcTest Mockk Has anyone encountered the issue where @MockkBean does not seem to actually work or at least the stubs are not coming through? The simple example: @RunWith(SpringRunner::class) @WebMvcTest(controllers = [WidgetController::class]) class WidgetTest { @Autowired private lateinit var mockMvc: MockMvc @MockkBean private lateinit var widgetService: WidgetService @Test fun test() { val value = objectMapper.readValue(something())) every {...

Why does Kotlin need to design 'also' keyword? I think that Code A is equivalent to Code B, I can't understand why Kotlin need to design 'also' keyword. It make programmer puzzle. Code A val list = mutableListOf().also { it.add(1) } Code B val list = mutableListOf().apply { add(1) }

How to retrieve messages from a service in an AlertDialog Android Kotlin I have implemented a barcode scanning program which grabs barcodes from a barcode scanning service. Within this program I occasionally open a dialog box with an editText field for additional information, I would like to know how I could get the service to send the barcode to this alertDialog. When this alertDialog is closed the barcode should then be sent to the open activity again. Here is how I Send/Retrieve the messages class SomeActivity : AppCompatActivity() { /* variables to...

How to combine Completable with Single in RxJava I'm building an application that is caching data from the internet, when the phone is offline it will show the offline items(this functionality works as intended). Now I have a difficulty to include a refresh option(I will basically will delete the items that I have in the cache and try to fetch more recent items). I have two problems: I'm not sure how to combine Completable with Single it gives me an error none of the following functions can be called with the arguments supplied I'm not...

How to Safe Cast within a Try-Catch Block I'm trying to draw on a Canvas object but I'm getting a smart-cast compilation error. I think I need to safe cast but I'm not sure how to. Usually, when I need to safe cast, I use this format: fun functionName() { if (propertyName is ClassName1) { val variableName2 = propertyName as ClassName1() propertyName.memberFunction() } } But it doesn't work well with the working code (I might have shown too much but I want you guys to understand the context): import...

Retrieve Google assigned Image of a selected location similar to Google Calendar I want to set an imageView in my app to obtain the image of the location set similar to that of Google Calendar. An example of how Google Calendar is shown below where I have selected Petronas Twin Towers, and it automatically sets the image set on Google as the background. Which API is required to do the same?

How to assign Json Array into spinner list? I have a JSON sample list as below and I tried to put this into my spinner:- [{"occupation_id":0,"occupation_name":"Teacher"},{"occupation_id":1,"occupation_name":"Business Owner"}] When I tried to apply these code:- val jsonArray = JSONArray(jsonString) var list = ArrayList() var x = 0 while (x < jsonArray.length()) { var jsonObject = jsonArray.getJSONObject(x) list.add(Occupation(...

How to set the selected item highlighted in Alert Dialog? Is there any way to high-light the selected item in alertdialog? In my case I added two items to the alertdialog, and I want to set the clicked item as high-lighted. My current approach is that I can only high-light one item but not user interactive.Here is my approach- lateinit var dialog: AlertDialog val listItems=arrayOf("English", "Thai") var selectedElement= 0 val builder=AlertDialog.Builder(this) builder.setTitle("Choose Language")...

TTS engine on android doesn't work with certain characters I have a problem with the text to speech engine in android using Kotlin. It won’t work for languages with Latin-based scripts such as Swedish or German if the text contains a character outside of the basic Latin characters that are used in English (i.e. diacritics). So for example it will say "man" with no problem but refuse to say "män" (and any text it appears in). I figured that it must have something to do with the text encoding if TTS engines that are meant to deal with these...

How to fix connection error while fetching API? Kept crashing whenever trying to authenticate I am doing a project that includes different modules that can sign in with different department to take logical test, and training etc etc. However the API of the database and test is fetching from a REST API. Currently i am facing problem connecting to the API "Security Policy" Error whenever i try to authenticate. Hence, now i am trying to connect to a localhost to test what is the problem and i cannot connect too. I am beginning to wonder is it my code problem or connection problem....

How to create a Modal Bottom Sheet with a custom layout? So I have a Material Bottom Sheet that expands to extend time on the timer. I would like to create a transparent background and block the background until the sheet is dismissed. I understand that a Modal Bottom Sheet will do this but I can not figure out how to set the custom layout. Here is my layout for the bottom sheet: This is called inside my main activity layout:...

Colouring individual triangles in a TriangleMesh through texture map is inaccurate The problem I am having is that I want to color complex models (+4k triangles) without having to split the models up into many TriangleMesh objects. From my understanding this can only be done through mapping the colors onto an image and then calculate the texture coordinates of each color pixel in the image. Which I have done below: val uniqueColors = colors.toHashSet() val colorTexCoordsMap = HashMap() val atlas = WritableImage(uniqueColors.size, 1)...

Sometime duplicate message receive and send suddenly in a socket I'm having problems with a simple java socket client: the connection is established properly and both server and client receive and send data. But some time message receiving and sending 2 or 4 times. I have used following library [https://github.com/socketio/socket.io-client-java]

iterate enum internal values in kotlin I know there was a similar question . For me, the enum is as below: enum class Gender (val s:String) { Female("female"), Male("male") } How can i iterate the Gender enum and get "female" or "male"?

corda scheduling event issue how to fix this issue even i am doing same did in github samples. net.corda.core.internal.TransactionDeserialisationException: Failed to deserialise group OUTPUTS_GROUP at index 0 in transaction: net.corda.core.contracts.TransactionState (erased) -> data(net.corda.core.contracts.ContractState) -> com.heartbeat.HeartState: Requested interfaces must consist only of methods that start with 'get': net.corda.core.contracts.SchedulableState.nextScheduledActivity

Kotlin CoroutineScope can't cancel in android views For example,this view.When the onDetachedFromWindow invoke the scope is cancelled,but the launched job is still active. class TestView : FrameLayout,CoroutineScope { val TAG = "TestView" override val coroutineContext: CoroutineContext get() = Dispatchers.Main + Job() constructor(context: Context) : super(context) constructor(context: Context, attrs: AttributeSet?) : super(context, attrs) { launch { while (true) { Log.i(TAG,"is in...

How do i manage resources in Kotlin ? Trying to make the setUp function static to run once not before every test I want to run the setUp function only once, not before every test from the class. I've tried to make the setUp funtion static but i get an error - unresolved reference If i make activityRule in the BaseClass static(with companion object) i dont get that error but when i run the test i get that context is null. Every time i try to use context.findViewById i get that context.findViewById must not be null //Base Class @RunWith(AndroidJUnit4::class) @LargeTest open class BaseTest {...

Android No view found for id when using toolbar button when i click to toolbar button, galleryFragment should open thats what i want to do. But i got these error: java.lang.IllegalArgumentException: No view found for id 0x7f080051 (com.example.myapplication:id/container) for fragment GalleryFragment{e255e88 (923e67b6-0b21-4fac-acf1-f85b79a3311a) id=0x7f080051} My button id is: shop you can see my codes in onOptionsItemSelected function. do you have any ideas about it? this is my MainActivity: package com.example.myapplication class...

Code is running succesfully in real device but mockito wanted but not invoked I am getting mockito wanted but not invoked. I don't know what to do cause Im new here :). by the way when I run the code in real device its okay. Wanted but not invoked: observer.onChanged(true); TestClass @RunWith(MockitoJUnitRunner::class) class LoginViewModelTest { var loginViewModel: LoginViewModel? = null @get:Rule val instantTaskExecutorRule = InstantTaskExecutorRule() @Mock lateinit var observer: Observer @Mock...

onClick not triggering associated function - kotlin I can't understand why my onClick handler isn't working on this particular case. I want to make a CardView clickable, using databinding. I've seen a lot of code for onClickListener, but i decided to use this pattern, as described in the Android doc. I have a class, named Recipe(), which contains 3 elements : an ID, a Title and an URL. The ultimate goal of this click handler is to navigate to a new fragment, passing the ID as a parameter to display new elements. I'll later get the ID in the...

Bluetooth device will be disconnected shortly in android I want to make a connection with a Bluetooth device gamepad shortly(less than 2 seconds) device will be discounted. I have 2 activities, which in the first one I will scan for devices and pair with them and then I want to establish Rfcomm which will give an error and stop, I don't want to read or send any data because I Handel gamepad in the second activity with using on key-pressed-down and up callbacks. fun connect(device: BluetoothDevice) { eventListener.onConnecting()...

Does read code help me to learn to programming? How much helps read code from other programmers for learning programming. While I love to read code, when I try to write I come no further.

Android: How to unit test Observable concatMap compose with mockK I need to unit test an Observable with concatMap and then compose. I'am using RxJava and mockk library. I've been trying to use two separetes every statements to mock the results. But when i call first every { remoteLocalInteractor.isServerConfigurationEmpty() .compose(schedulerProvider.ioToMainObservableScheduler()) } returns Observable.just(true) and then every { remoteLocalInteractor.isServerConfigurationEmpty() } returns Observable.just(true)...

Kotlin WebView File upload There are a few same question here on the Stack Overflow, but with no answer and if yes it's in Java not in Kotlin. I have simple WebView app written in Kotlin, that opens my web application. Everything is ok, but I have a problem with file upload through HTML form. I figured out how to open FileChooser, but when I choose a file, input is still with no value. Have you ever had the same problem? Below is my code: override fun onCreate(savedInstanceState: Bundle?) {...

Additional restrictions for kotlin compiler using contracts I'm trying to implement addition restrictions for kotlin compiler: fun main() { val list = listOf(1) val bigList = listOf(3) list.second() } fun List.second(): Int { require(size > 1) return this[1] } My expectation is that compilation will fail in this case. Is it possible to implement using contracts? Appreciate for any help.

Transform a List of One Type To Another I have a list of type A. I want to turn it into a list of type B. fun publish(listOne: List<A>) { val result: List = } Class B looks like this. It has a constructor that if you pass A then it will copy the variables and make a new instance of B. class B(name: String ....) { constructor(a: A) { // copies the values of a then creates an instance. } } How can I use this constructor to make a new list of type B? Normally I would traverse the entire list of and make a...

Android periodic location updates using workmanager I am using a WorkManager as follows - class LocationWorker( ctx: Context, params: WorkerParameters ) : CoroutineWorker(ctx, params), KoinComponent { private val locationDataRepository: LocationDataRepository by inject() override suspend fun doWork(): Result { return try { locationDataRepository.triggerLocationUpdates() Result.success() } catch (e: Exception) { Result.failure() } } } I trigger the Worker as -...