Is There a Best Way to Chunk a String from the last element to first Is there a good or best way to add some leading zeros for the string chunk that don't have an appropriate number of digits. At the code below I want to split a string where each chunk is composed of 4 digits. To add some leading zeros to a string I use this approach: val text = "1010111".reversed() // 1110101 | len: 7 .chunked(4) { // [1110, 101 *this element only gets 3 digits] val sb = StringBuilder(it) val rem = it.length % 4 /* [1110, 1010 -> now this element have a same...

Fragment Observing ViewModel Property fails on reentering the Activity I have an activity with a fragment that observes the Activity's viewmodel. Everything works fine the first time. When the activity is destroyed, if the user comes back to the Activity, when the activity posts a value to the viewmodel, the fragment observer is never notified. Again, it works the first time and as long as I never destroy the Activity. What am I doing wrong? ACTIVITY private lateinit var viewModel: TowPayViewModel override fun onCreate(savedInstanceState: Bundle?) {...

How to add multiple events in one button Kotlin? I want to pick and upload image from gallery with one button in the same time for Firebase. But the first when i clicked the button it picked up image and the second time when i clicked it uploads. How can i fix it that when i clicked it should be go to gallery and save to Firebase Storage idgir.setOnLongClickListener { if (ContextCompat.checkSelfPermission( this, Manifest.permission.READ_EXTERNAL_STORAGE )...

java.lang.NullPointerException at com.Awwray.awwray.MessageChatActivity$onCreate$2.onDataChange error is on line 73

How to make between activities animation like a books My question is the same as the title. So how can I do? I have uploaded a video for you to watch. Please help me. Thank you :) Video: CLICK HERE

Best kotlin Guide What’s the best tutorial guide to follow online to start coding in kotlin from scratch

How to show pop up on icon long-click in Jetpack Compose Within the Settings app of Android a handy popup appears whenever I long-click on the vertical dots on the top-right corner of the screen. Can this useful feature be launched using Jetpack Compose? Nothing happens when the code below is used. @Composable fun IconMoreVert() { var showMenu by remember { mutableStateOf(false) } IconButton(onClick = { showMenu = !showMenu }) { Icon(...

Using of map or Max by in kotlin I am solving a leet code problem. I found one question in leetcode, which are below You are given an m x n integer grid accounts where accounts[i][j] is the amount of money the i​​​​​​​​​​​th​​​​ customer has in the j​​​​​​​​​​​th​​​​ bank. Return the wealth that the richest customer has. A customer's wealth is the amount of money they have in all their bank accounts. The richest customer is the customer that has the maximum wealth. Example 1: Input: accounts = [[1,5],[7,3],[3,5]] Output: 10...

Kotlin JSON deserialization with nested class discriminator I want to use a class discriminator in Kotlin to get polymorphic deserialization of JSON messages. The problem is that the class discriminator in my messages is nested one level deep: { "header": { "message_type": "FooBar" } "data": {...} } The contents of data depend on message_type. If message_type were one level higher, this would...

Is it safe update to latest kotlin version while using Compose in a project? I have read about some people having compiler problems when they update to the latest version of Kotlin while using Jetpack Compose in a project. I currently learning Compose and Android Studio is offerring me to update to Kotlin 1.7.0, but I´m not sure that if I do, it will still working. I'm using AS Chipmunk and a regular Compose project (not the material 3 one).

Dagger2. How to use multibinding with supporting of assisted injection? I have an interface PaymentProvider: interface PaymentProvider { fun pay(amount: Double): Boolean } Here is different implementations: class PayPalPayment @AssistedInject constructor( private val payPalRepo: PayPalRepository, @Assisted private val paymentData: PaymentData ): PaymentProvider { @AssistedFactory interface Factory : PaymentProviderFactory override fun pay(amount: Double): Boolean { // some code } } class CreditCardPayment( private...

How to fix **error: cannot find symbol** when importing kotlin package into MainApplication.java for Android in React Native app? I'm building a react native app that uses the react-native-vision-camera by Mrousavy (https://github.com/mrousavy/react-native-vision-camera) and I'm trying to create a frame processor plugin, following this guide <a href="https://mrousavy.com/react-native-vision-camera/docs/guides/frame-processors-plugins-android" rel="nofollow...

Touch to focus not getting the accurate focus area I am using Camera2 API for my app to communicate to camera device of android device, Then I'm trying to make a touch to focus feature unfortunately the focus area is not accurate. I was tried different work around and suggestions in google but I can't get the right focus area when I touch the screen. Is there anyone here make this feature working smoothly using kotlin? here's the snippet of my code the calculate the focus area val sensorArraySize: Rect? =...

What is the simple way to add a left icon to each line, in an alert list dialog using Kotlin? In my Android (write in kotlin) App I have an alert dialog with a similar structure like this. The list of items is injected from a json, but for this question I made the code more simple.

var items = mutableListOf()

items.addAll(listOf("line 1", "line 2", "line 3", "line x"))

val builder = android.app.AlertDialog.Builder(this@aplicacion)

var items2=items.toTypedArray()

with(builder)

{

setItems(items2) { dialog, i ->

var...

For accessing data from api ,by retrofit. in android ,not able to link with service class apiInterfac which i have created TO access api by Retrofit , Retrofit builder object i am able to use retrofitbuilder object , connect url , build butnot able to attach my service class apiInterface which i have created . private fun getmydata() { lateinit var myAdapter: RecyclerAdapter val retrofitBuilder = Retrofit.Builder() .addConverterFactory(GsonConverterFactory.create()) .baseUrl(myuri) .build(); var api : apiInterface =...

Change an image of a called composable in Jetpack compose A question, maybe a little basic since I am in an early learning phase. If I want to change the image of a composable when calling it, how would I do it? I know that this is possible with Int and Strings thanks to the parameters that I define in the original function, but how would it be done in the case of images? @Composable fun ComposableTest(exampleText:String){ Column() { Image ( painter = painterResource(R.drawable.sample_image), contentDescription...

Fragment inflate not intended xml file I have a problem that EditSleepPressureFactorFragment inflates other xml file fragment_sleep_record.xml. But my intention is to inflate fragment_edit_sleep_pressure.xml. A Spinner having an id "year_spinner" is in fragment_edit_sleep_pressure.xml but binding!!.yearSpinner code occure unsolved refference. And binding!!.startSleepYear code cause no error. "start_sleep_year" id is in fragment_sleep_record.xml. How I solve this problem? EditSleepPressureFragment.kt import android.os.Bundle...

Android custom view attributes not being applied to view I am working on a paint app, and I have created a custom view called ColorSwitcherView which holds the primary/secondary color state: package com.therealbluepandabear.pixapencil.customviews.colorswitcherview import android.annotation.SuppressLint import android.content.Context import android.graphics.* import android.util.AttributeSet import android.view.MotionEvent import android.view.View import androidx.core.content.ContextCompat import com.therealbluepandabear.pixapencil.R class...

How can I call object/function inside an if-else statement in Kotlin I have a library that assigned me to integrate it GuardianSdk.getInstance().hasDuplicateUserKey(userName(), object : GuardianResponseCallback { override fun onSuccess(result: ResultResponse) { Log.i(TAG, "Result code : " + result.rtCode) } override fun onFailed(errorResult: ErrorResult) { Log.e(TAG, "Error code : " + errorResult.errorCode) } }) I...

androidx.Biometrics library - setOnCancelListener for cancellation signal not working, onAuthenticationError being called randomly Here's what I'm experiencing - I call the biometrics function as soon as the app launches. So, as soon as the prompt is displayed, the onAuthenticationError gets called. Don't know why, but seems useful in solving the issue. The listener in cancellationSignal doesn't get called when I press the prompt's cancel button. touching outside the prompt dismisses the prompt. But, not without calling the onAuthenticationError function again. The device I am using is a Huawei nova 3 with android 9.0. I...

Classes, Initializer block and Constructor in Kotlin I am a newbie to kotlin and I'm struggle to understand the relationship between initializer block, primary constructor and secondary constructor. I saw some video on youtube discussing about them but I am still confuse. Is the body in the class same as the body of constructor and what are the sequence for them to execute? What are the differences between the primary constructor and secondary constructor. Furthermore, how is the this works?

How will usage of kapt(Kotlin Annotation Processing Tool) while kapt being in maintenance mode alters my project? I think kapt will not work when I use it in my project while it is in maintenance mode. Because when I use it in my project it throws me this error appkaptDebugKotlin task failed. appkaptReleaseKotlin task failed. , and I think there is nothing wrong in my codes and I have tried different ways and I am pretty sure that this error due to kapt because error only occurs when I use kapt in my project.

How can I add an animation to an item when it is selected in a LazyRow or Column in Jetpack Conpose? I am trying to make it so that the item in a LazyRow clips to the center of the screen, and if it is in the center is becomes larger while the items next to it return to the original size. Below is an example

kotlin arrayadapter Error none of the following functions can be called with the arguments supplied I have a ListView and I am trying to use an array to fill in the list view. But I am getting the following error: None of the following functions can be called with the arguments supplied. I have tried some alternatives, but they didn't work. Does someone have any suggestions? This is my code import android.os.Bundle import android.view.LayoutInflater import android.view.View import android.view.ViewGroup import android.widget.ArrayAdapter import androidx.fragment.app.Fragment import...

Android - Detecting when a view's constraints have been fully resolved/loaded I have quite a complex problem to do with Android views, I am creating a paint application, and I have two views: a transparent background view and the pixel art board. For both views, I want the height and width to be calculated off of the distance between view A and B: Instead of calculating the distance between these two views, I simply 'constraint' a view in the middle like so, and then extract its height by...

How can I start dynamic rendering on canvas and stop or change the rendering when the onTouchEvent event occurs? There is a separate View class that implements rendering on canvas and listening for onTouchEvent events. How can they be run in different coroutines or threads, but so that events can stop or change rendering? class CustomView( context: Context, attributesSet: AttributeSet? ) : View(context, attributesSet) { ... private val pointer=... var x = false override fun onDraw(canvas: Canvas) { super.onDraw(canvas) while(true){...

The problem of saving data in the database and closing the program quickly after execution I have a layout that has two EDITETEXT and they should be filled and saved in the database by pressing the save button Everything is correct, but when I write the button code, the program runs and quickly exits the program (And that there is no mistake) If I want to say complete, it means: everything is correct until I want to use the database :| code main activity: enter codeclass MainActivity : AppCompatActivity() { private lateinit var adapter: Adapter private lateinit var...

How can I create widget with timer? I am working on one application with has a widget functionality So I have designed a widget but tried with timer. widget is working on background after kill the app.so can you guide me to set current time on my widget.

Creating recyclerview with variable height of item as per the content text with swipeable feature How to create a recyclerview with items having variable height as per the length of content text like the below image. Recyclerview also supports swipeable items. Expected Actual My layout...

passing array to functional interface but get (Array&lt;out TypeVariable(T)&gt;) -&gt; Array&lt;out TypeVariable(T)&gt;? type mismatch val changeFirstElement = VarargsFunction { ss: Array -> ss[0] = ss[0]!! + " world" ss } val params = arrayOf("hello") } fun interface VarargsFunction { fun apply(vararg t: T): Array? } I get this following exception: Type mismatch: inferred type is (Array) -> Array? but (Array) -> Array? was expected Any suggestion why is this exception and how to resolve it? Thanks Playground link https://pl.kotl.in/kBwQZlCZj