I am new to Kotlin language. Can anyone help how to add two total value that is displayed on different onClickListener? var addQuantity = 0 // counter variable // button_two on clickListener button_two.setOnClickListener{ val laptopTwo =500.60 val total_price_two:Double addQuantity = addQuantity + 1 total_price_two =( addQuantity * laptopTwo).toDouble() resultDisplayText.text=total_price_two.toString() //displays the result in TextView } // button_three on clickListener button_three.setOnClickListener{ val laptopThree=400.00 val total_price_three:Double addQuantity = addQuantity + 1 total_price_three...

get name of file in android kotlin I have an Extention function in file with the name StringEx.kt. StringEx.kt package com.example fun String.addUnderline(): String { return "_" + this + "_" } how can get the name and package of the file("StringEx.kt") in other class? for example: println(StringEx:class.name) // print com.example.StringEx

How to access ProgressBar from another layout from RecyclerView's adapter? [Kotlin] I'm trying to access ProgressBar in a activity_history.xml from my Adapter. I tried findViewById but it doesn't seem to work. What am I doing wrong? Thanks for help in advance! Adapter's code: class MyAdapter : RecyclerView.Adapter(){ override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder { val layoutInflater = LayoutInflater.from(parent.context) val moodInflater = layoutInflater.inflate(R.layout.mood_layout, parent, false) return...

Kotlin generic type mismatch Is it possible to accept subclass of a class in generics? It works in Java but unfortunatelly I don't know how to make it work in Kotlin. Simplified problem: open class Food class Meat : Food() interface Animal { fun eat(food : T) } class Dog : Animal { override fun eat(food: Meat) { // Dog eats meat } } lateinit var pet : Animal fun setAnimal(animal: Animal) { pet = animal // DO NOT COMPILE } I would like to method setAnimal() accept all of the animals, no...

How to create new string from old string in kotlin i have created a new string inviteToken from old string inviteCode using replace but the value of inviteToken is not passing in startmeet function. (deepLink?.getQueryParameter("inviteCode")?.substringBefore("?inviteToken=","") + deepLink?.getQueryParameter("inviteCode")?.replace("inviteCode","inviteToken") ).let {startMeet(it)} on passing the string values in function startmeet. Its showing error: No value pass for parameter inviteToken this is the code for startmeet: private fun...

When it is appropriate / not appropriate to use the dependency injection like Hilt I am bit confused that is it Mandatory to use dependency injection in project, if yes when to use and what are the benefit, does companion/static do not provide such reusability

Need Calendar Instance only date (not time) and compare with date String in Kotlin as it lags I need only date from Calendar Instance not the time. Whenever i used calendar object it returns the date with time. val calendar = Calendar.getInstance() calendar.time. // Mon Nov 09 114129 GMT 2020 I change this by using SimpleDateFormat SimpleDateFormat("dd/MM/yyyy").format(date) 09/09/2020 I am creating calendar so i have huge amount of data in list. I am adding data at specific date. So I am comparing dates with string date. My string date Format is look like this :- 20/05/2020 So...

Gradle, error: module not found: kotlin.logging These are my dependencies in build.gradle.kts: implementation("io.github.microutilskotlin logging1.7.8") implementation("org.slf4jslf4j api1.7.29") Then in module-info.java: requires kotlin.logging; All the rest works fine with the...

Android: Room can't access member variable when using getter I am trying to access a member variable of my entity which is defined with a custom getter inside my query. My problem is, that I can't access the setter in my @Query() when I declare my variable as a val. Does this have to do with the fact, that there is no backing property when using val? Entity @Entity(tableName = "products") data class ProductCacheEntity( @PrimaryKey(autoGenerate = true) val id: Int, val name: String = "", val price: Float = 0F, val...

Why I need HasAndroidInjection to inject an inner Fragment? I have an Activity called Activity1, then inside has a Fragment1 all have the @ContributeAndroidInjection and then if my Activity2 wants to inject Fragment1 Why I need to implement HasAndroidInjector and do the @Inject lateinit var androidInjector: DispatchingAndroidInjector override fun androidInjector(): AndroidInjector = androidInjector to be able to use a Fragment that is already with @ContributeAndroidInjection ? If I remove this two lines it says : RunTimeException:Unable to resume...

Micronaut Controller returns HTTP 200 even if Flowable method annotated with custom Authorization Annotation returns FORBIDDEN I have method in my MICRONAUT Controller and annoted with Custom Authorization annotation which should return FORBIDDEN(in testing) but returning 200 with empty body. @Controller("/demo") @ExecuteOn(TaskExecutors.IO) open class SampleController(private val service: Service) { @Get(value = "/") @CustomAuthorization open fun sam(@QueryValue("no") no: List): Flowable { return service.getNo(no) } } Here CustomAuthorization has intercept method to...

findViewById() unresolved reference in codelabs Good day, y'all! Today I was doing the Google Codelabs for Kotlin. I'm trying to use findViewById() in a function but it shows as an unresolved reference. I bet it's a fairly easy problem but I can't figure it out. this is my code class MainActivity : AppCompatActivity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) findViewById(R.id.done_button).setOnClickListener { addNickname(it) } } } private...

How to change the default image loaded in a TextView with Spanned via Html.fromHtml(text) I have a news section on my app that loads some piece of news from my website and some of them contains images, so I load them from the internet. But while the image is not loaded, there is a green square that only disappears when the image loads. Image not loaded: Then image loaded: I want to make that green square invisible. For...

Is there any solution for caching objects in android? Reading about programming Android using Kotlin I came to this section : Cache Data in Android Here is the code by Google example: // @Inject tells Hilt how to create instances of this type // and the dependencies it has. class UserRepository @Inject constructor( private val webservice: Webservice, // Simple in-memory cache. Details omitted for brevity. private val userCache: UserCache ) {...

ViewPager with more than 3 Tabs I am trying to implement more than 3 tabs in my app with fragments. In FragmentPagerAdapter ,there is one method getItem that returns Frgament so my question is what the logic should we use to shorten the code because it will be so messy when we return all the fragments which may be 10 or more than that here is my PagerAdapter class PageAdapter(fragmentManager: FragmentManager, private val tabCount: Int) : FragmentPagerAdapter(fragmentManager, tabCount) { override fun getCount() = tabCount...

How can I get data from firebase to data model? I'm quite new at Kotlin. I have data class which hold image urls named testModel. I need to add data to model from firebase with that code: Here my data model: class testModel(val imageLinks: List) private val dbRef = FirebaseDatabase.getInstance().reference.child("categories").child("1").child("top") fun readDataFromFirebase(){ dbRef.addValueEventListener(object : ValueEventListener { override fun onDataChange(dataSnapshot: DataSnapshot) { var list = ArrayList()...

Dynamic Feature Module is not available for download I try to download my dynamic module on demand. I shared my app through Internal app sharing and when I press button to download module I get error: Split Install Error(-2): A requested module is not available(to this user/device, for the installed apk)... When I run my app from Android Studio activity in dynamic module opens and everything works fine. That's how I download dynamic module (I do it in Fragment) private fun startDownloading() { val splitInstallManager =...

How to load data class that include MutableList<Uri> from SharedPreference? I'm trying to use SharedPreference and error occur when i load data. I think the problem is that my data class include MutableList, but i don't know how to handle it. This is my loadData function. When i see the log, it just show 2020-11-04 231233.418 15720-15720/kr.co.ddophi.autochangingwallpaper D/log: data load 1 2020-11-04 231233.420 15720-15720/kr.co.ddophi.autochangingwallpaper D/log: data...

Getting a String resource from the secondary language file when this language is not selected I have two languages in my application, English and Arabic. and in the string resource files I have an array called "employment_array". I want to be able to grab this array from the language that is not selected. for example: if the user is using English language I want to grab the array from the Arabic String file. I'm using the code below, but it is grabbing the array from the file of the selected language. val employmentPositions: Array = resources.getStringArray(R.array.employment_array)

kaptDebugKotlin error after added kotlin-kapt I have an error after added kapt to my gradle. The problem is one of my dependencies, I get error: static import only from classes and interfaces. Do you have any clue? e: C:\Users\admin\.gradle\caches\transforms-2\files-2.1\88ef629ce0fbea1ad07555e8e347bc4a\jetified-mapbox-android-sdk-9.5.0-sources.jar(com/mapbox/mapboxsdk/geometry/LatLng.java)15 error: static import only from classes and interfaces import static com.mapbox.turf.TurfConstants.UNIT_METRES;

ViewHolder gets a null reference for a custom view when used in a RecycleView adapter I have the following RecycleView adapter: class PageViewerAdapter(val context: Context, private val pages: List) : RecyclerView.Adapter() { override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ViewHolder { val inflater = LayoutInflater.from(context); val view = inflater.inflate(R.layout.page_viewer_card, parent, false) return ViewHolder(view) } override fun onBindViewHolder(holder: ViewHolder, position: Int) {...

Is there a simple way of getting my phone current location on Kotlin? Currently, I'm developing an app on Kotlin using OSM, so I need to get my current location by clicking a button on the screen. Googling my question leads me to some huge Java solutions which use LocationListener and I cant rewrite it to Kotlin for some reason. And the second question is: if there's any way to refine my location marker by clicking button? I need very high accuracy getting my position and i need to get my location again if I move away for some distance.

kotlin Data Store var value: String = "" fun getValue(key: String, lifecycleOwner: LifecycleOwner): String { val data = dataStore.data.map { pre -> pre[preferencesKey(key)] } data.asLiveData().observe(lifecycleOwner, Observer { value = it ?: "noData" Log.i("MONO", "A | $value") }) return value } return log data is true but in return value data is null

Only loading the new messages I am working on a chat app connected to firestore. I am trying to load all messages and also listen for new messages. This loads all messages but my problem is that it loads the whole list every time I add a new message. Is there any good way to fix this? Thanks private fun listenForMessages() { val db = FirebaseFirestore.getInstance() db.collection("messages/").addSnapshotListener { snapshot, e -> if (snapshot != null) { for (document in...

How do i retrieve the selected GIFs URL and upload to Firebase Storage (Messaging App). Using onGifSelected I'm using the GIPHY UI SDK for Android so I can send gifs to users in my messenger app. I want to get the url and upload to my firebase storage. Here's my activity Activity: override fun onGifSelected(media: Media, searchTerm: String?, selectedContentType:...

Android Lint : Kotlin Dispatchers unresolved reference but compilation working I have already tried invalidating caches. Clean build and rebuild project also done. But I still keep getting unresolved reference for : Dispatchers, launch, withContext, delay, ... But CoroutineScope isn't marked as unresolved reference, the import kotlinx.coroutines.* isn't marked as unknown and the project is compiling (it has been working for months, it is not a recent project). Android studio : 4.0.1 Settings > Languages & Frameworks > Kotlin : Current kotlin plugin version :...

Deserializing 2d array in kotlinx.serialization I am quite new to Kotlin but and I have successfully used Kotlin serialization on many cases - works out of the box even for nested classes, mutableLists etc. However I struggle with two dimensional arrays. My class: import kotlinx.serialization.* @Serializable data class Thing(val name:String) @Serializable data class Array2D(val width:Int, val height:Int, var arrayContents:Array = Array(1){Array(1){null} }){ init{ arrayContents =...

Write a program that reads a three-digit number(923), reverses the order of its digits, and outputs a new number(329) in Kotlin? import java.util.Scanner fun main() { val scanner = Scanner(System.in) } I know there is possibility of using String.reversed() but the exercise is part of Integers in action so I need to solve it only with integers.

Can't show items by sections correctly in recyclerview in kotlin I am relatively new in kotlin and I would like to know how I can display items by sections, like this: showing data in sections . I have two services, one returns the list of section names and the other returns the items for each section. So far I did the following, the view is like this: and in my adapter I did the following, where I pass a list of sections to the adapter and for each one...

Android error: cannot write code_item after gradle upgrade I recently assumed an Android app that has a very old gradle configured (distribution 3.3.3 plugin 2.2.3). I got the ok to upgrade it to 4.10.2 (plugin 3.3.2). In the most part the upgrade was ok. I had to include a bunch of rules in the proguard file. Recently I'm getting the following (or similar) error everytime I build in release: Execution failed for task 'appFinalizeRegularRelease'. Exception occurred while writing code_item for method...