Unsucceedable cast when declaring CheckBoxPreference After declaring a CheckboxPreference in my activity for my app's settings, a warning appears for as in the line 'val mCheckBoxPreference = findPreference("preference_a") as CheckBoxPreference'. What should be done so that the cast does succeed? This cast can never succeed app_preferences.xml fragment class class MySettingsFragment : PreferenceFragmentCompat(), Preference.OnPreferenceChangeListener { override fun onCreatePreferences(savedInstanceState: Bundle?, rootKey:...

custom attribute DataBinding I have following to set custom attribute databinding in kotlin : object BindingsAdapter { @JvmStatic @BindingAdapter("imageUrl") fun bindImage(imageView: ImageView, url: String?) { val options = RequestOptions() .centerCrop() Glide.with(imageView.context) .load("${MovieViewHolder.BASE_BACKDROP_PATH}$url") .apply(options) .into(imageView) } } And my item.xml :...

"Fire and forget" with structured concurrency and coroutines I have a little endpoint that looks like this val numbers = it.bodyAsString.parseJsonList() processedNumbers = numberService.process(numbers) GlobalScope.launch { sqsService.sendToSqs(processedNumbers) } it.response.setStatusCode(204).end() The reason why I use GlobalScope is because the producer does only need the acknowledge after the numbers have been processed so I am trying to do a fire and forget in a parallel track to be able to immediately respond to the producer What would be...

Retrofit Multipart Complex Object [ { “id”: "string", "images": [ null ], "quantity": 0, “description": "string" }, { “id”: "string", "images": [ null ], "quantity": 0, “description": "string" } ] How can we send the object (like above) using Multipart request in Retrofit. Thank you in advance. i.e an array of objects having images list in it.

How can I read Kotlin documentation I am beginer with Kotlin, I am readig the official Documentation My problem is that not sure how can I interpretate the documentation, by ex: inline fun T.let(block: (T) -> R): R How should read this?

Create TypeAdapterFactory for data binding ObservableField I am using the ObservableField for data binding and I would like to deserialize with GSON. class Foo: Observable { var bar: ObservableField? = null } If I don't provide a TypeAdapter, GSON will try to deserialize as an object instead of a string. My type adapter factory and type adapter: class ObservableFieldTypeAdapterFactory: TypeAdapterFactory { override fun create(gson: Gson, type: TypeToken): TypeAdapter? { if (type.rawType != ObservableField::class.java) {...

Android array of arrays with string as index I'm looking for something that is surely very simple, but I don't know the best way to do it. I could have 2 arrays of strings (that I don't know size at start), containing something like: down[0]:"file1" down[1]:"file2" ... up[0]:"file3" up[1]:"file4" ... But I'd like them in the same array like: array["down"][0]:"file1" array["down"][1]:"file2" array["up"][0]:"file3" array["up"][1]:"file4" And insert data with: array[mykey].put(filename); And loop through the data with: for...

Create copy of generic array with new size Is it possible in Kotlin to create a copy of a generic array with new size if I already have an instance of that array and pass a construction method for its items? I think about something like this: fun resize(arr: Array, newSize: Int, creator: (Int) -> T): Array { ... } Obviously I cannot call Array(newSize) { i -> creator(i) } because the type T is not known at compile time. For efficicy reasons I do not want to use an inline function with a reified type. I also cannot use the...

custom attribute DataBinding I have following project in Github : https://github.com/Ali-Rezaei/TMDb-Paging, at the current moment it has a bind method to set image for an imageView and set color for title_background view : <a href="https://github.com/Ali-Rezaei/TMDb-Paging/blob/master/app/src/main/java/com/sample/android/tmdb/ui/MovieViewHolder.kt" rel="nofollow...

Android WiFiManager enableNetwork returning false TO BE CLEAR: The most likely part of the code which has the problem is the connect function, which you can find in the code block. PERMISSIONS: I've been tasked to create a part of an app where the user will be able to see a list of scanned WiFi access points (ScanResult), be able to select one, and, if it requires auth be presented with a screen where they enter the PSK. After entering the PSK, the system will attempt to connect to the access point by first creating and configuring...

Accessing class variables from a Kotlin coroutine I've encountered an odd issue here(new to Kotlin and coroutines). I am modifying a class variable in the function getMovies. In the launch block I get a JSON which I then run through GSON and get a mutable list of movie info entries. You can see 2 longToasts from Anko which displays a Toast, but the first one displays 20 and the other one 0. Why is that? Android Studio doesn't throw any errors and I am referencing the same moviesList variable. I tried numerous blogs and instructions on the...

Switching fragments using onClickListener I have a "home page" in my app that looks like the following import android.os.Bundle import android.support.v4.app.Fragment import android.view.LayoutInflater import android.view.View import android.view.ViewGroup import kotlinx.android.synthetic.main.activity_home.* class HomeActivity: Fragment() { override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { val view: View = inflater.inflate(R.layout.activity_home,...

Determine which of two possible result objects has been returned I have a Result sealed class that I use to represent a response from an api. In fragments, I use this to parse the response: activity?.onResult(response?.result, onSuccess = { // Act on successful response }, onValidationError = { // Act on errored response }) Now, in my tests, I would like to test the response and run asserts on if it's a successful response, or an error response (and what type of response). If I have a variable like response: Result = someResponse returned, is...

Java/Kotlin application using mysql hangs on ConnectionImpl$NetworkTimeoutSetter I've been having issues with hanging ever since I started using MySQL instead of flat files. I used to have it freeze basically daily from what as far as I've been able to figure out was concurrent inserts between multiple server instances, so my very dirty fix for that was locking on a file. That solved it, but now I'm having a new issue where there's a hang on ConcurrentImpl$NetworkTimeoutSetter#run. app//com.mysql.jdbc.ConnectionImpl$NetworkTimeoutSetter.run(ConnectionImpl.java:5534)...

How to register a deserializer for a generic field I am trying to register a custom date deserializer. Without generics: open class ConcreteDateBox { @SerializedName("value") var value: Date? = null } I could do this: GsonBuilder() .registerTypeAdapter(Date::class.java, MYDateDeserializer()) .create() .fromJson(json, ConcreteDateBox::class.java) However, I have the following generic class: open class Box { @SerializedName("value") var value: T? = null } My extended classes parameterizes on Date: class DateBox:...

Unsupported method: IdeaModuleDependency.getDependencyModule() error when migrating project to Kotlin Gradle DSL I am getting a very uninformative error when I try to build my project after migrating from Gradle Groovy DSL to Kotlin DSL in IntelliJ IDEA. Unsupported method: IdeaModuleDependency.getDependencyModule(). The version of Gradle you connect to does not support that method. To resolve the problem you can change/upgrade the target version of Gradle you connect to. Alternatively, you can ignore this exception and read other information from the model. I'm using the gradle 5.0 wrapper so...

custom attribute databinding in Kotlin I have a bind method to set image for an imageView and set color for title_background view : https://github.com/Ali-Rezaei/TMDb-Paging/blob/master/app/src/main/java/com/sample/android/tmdb/ui/MovieViewHolder.kt I want to use custom attribute databinding instead as follow : object BindingsAdapter { @JvmStatic...

How to handle in app notifications from service class and display it in toast or snackbar I'm developing an android app which needs to display an in-app notification like facebook.The problem is I dont know how to implement it via service

MainActivity not launching when run I am developing a simple login and register android app and everything have been coded and no errors were issued. The app can be ran successfully and all, but, the screen doesn't show the launcher activity. Like, it only shows up and then immediately close the app. I hope someone can catch what I am trying to say here. Also, I'm 100% sure that i have registered the activities on the manifest file.

Is there a way to open a file from a non-activity class in Kotlin on Android? I have a non-activity Kotlin class in my app. Since it doesn't have any visual stimulus for the user, I did not make it into an activity. The class pulls a list from a file, which I put in the res/raw folder. According to the Android docs, I use openRawResource(), which requires a Context. Other similar questions in Java show a variable being declared as a variable, but when I do this in Kotlin, it tells me that the variable _context must be initialized. This is my code so far: val...

In kotlin QR Code scan from image which is picking from the gallery, working fine via camera but not with gallery image? In kotlin, It is a good response, when we capture image from camera, but if i want to scan qr code from image which we are selecting from gallery, it does not work. i apply the same code, with same logic i implemented in camera capturing image code. Select image from gallery does not work. Please help me. Thank you in advance. the code is, which i am implementing when i got imagepath of gallery. It always goes to exception part because it does not load the image. if (requestCode ==...

Android Studio Kotlin Passing Intents multiple times and global array? I have 3 activities: Home Add Ticket Ticket summary Add ticket issuer At Home, it will show a ListView of all the tickets added from "Add Ticket". When user submit details they entered in "Add Ticket" activity, they will be brought to "Ticket summary". When user clicks on "add issuer", he will be brought to "Add ticket issuer" activity where he can add more information. After submitting, he will be brought back to "Ticket Summary" activity that shows the original data along with the new...

Swagger, Kotlin, Spring Boot and javadoc I have a project with Spring Boot + Kotlin, and I want use Swagger to make the documentation. The problem, I don't want repeat the document usen Javadoc and Swagger Annotations. I show "enunciate" that use javadoc to generate data for swagger, but it does not work with Kotlin, only with java. Using dokka I can genarate javadoc json data, but I don't know how use it for swagger. Any ideas?

Spring Boot Jersey Validation for Integer value in DTO data class RunBody(val type: String, @field:NotNull @field:Positive val duration: Int?, @field:NotNull @field:Positive val distance: Int?) This is the current code for my DTO object. When the correct json is sent in the request body it is deserialized into this data object. My question is, is there an easy way to validate that a valid integer is sent Ex. '1' and not an...

Hiding Kotlin Operator overloading function in java I have a library that I'm developing for kotlin users, and I'm also kinda supporting Java. One of my functions is 'add' It looks similar to this open fun add(element: T, position: Int = elements.size) { elements.add(position, element) if (!updateUi) return if (isUiThread()) notifyItemInserted(position) else throw uiThreadException } Which is great, to make it a bit cooler I added an Operator overloading function for the spoken 'add' function which looks like this open...

Rx Exception Handling Fail I'm using RxJava with a retrofit to make API calls, By using RxJava methods like flatMap and map I'm making API calls as well as performing DB operations in room database on the background thread. My implementation is perfect and working fine if there is no error, but In the case when I got an error or any exception while performing DB Operation, Application getting crashed due to following Rx error. The exception was not handled due to missing onError handler in the subscribe() method...

Passing complex objects as a parameter in Android's Navigation Architecture Component I've been looking for some time to android architechture components and lately to the Navigation component. I'm trying to pass as a parameter an object, so the next fragment can retrieve that data, but to do so I'm required to do one of two things: Pass it through a Bundle, which will make me implement the Parcelable interface to that object. Use the "Safeargs" plugin which I've tried and it looks like behind the hood makes use of Bundles and requires the implementation of the Parcelable...

WeakReference getter returns null I use MVVM architecture, but at one point I pass clicklistener into ViewModel. I do it in Fragment onCreate - i pass listener to ViewModel and wrap it in WeakReference object and store in ViewModel as a field. private var weakRefListener: WeakReference? = null private val listenerViewModel = object : ClickListener { override fun onClicked(id: Long) { weakRefListener?.get()?.onClicked(id) } } /* called in Fragment */ fun setClickListener(clickListener: ClickListener) {...

How to programmatically change seekbar time and enable full screen in youtube iframe api using webView? val frameVideo = " \n" + " \n" + "var player;\n" + "function onYouTubeIframeAPIReady()\n" + "{player=new YT.Player('playerId',{events {onReady:onPlayerReady}})}\n" + "function onPlayerReady(event){player.playVideo();}\n" + "\n" + "\n" + "...

Sliding Up Panel (Java to Kotlin) How can I display panel states of SlidingUpPanel in Kotlin? I want to use https://github.com/umano/AndroidSlidingUpPanel library, following this tutorial: http://www.devexchanges.info/2015/05/making-sliding-up-panel-like-google.html and the result should look like this: <a...