What is the difference Job.Cancel vs Scope.Cancel in coroutines? I have been exploring coroutines and I am quite surprised to see that cancel called on Job does not actually cancel the job while cancel called on scope cancels the coroutines launched from the scope immediately. Can anyone explain this? Job cancel example. /** * This never stops */ @Test fun coroutineTest7() = runBlocking { val job = launch(Dispatchers.IO) { var count = 0 while(true){ if(isActive){...

How to edit the text of a textView using viewbinding? I am new to kotlin and android and I just started getting into using viewbindings. Im trying to make this locations app and when setting the date through a datepickerdialog, when i try to edit the text of a textview with a binding its giving me errors. Can someone help me? private fun displaySelectedDate(timestamp : Long){ binding?.etDate?.text = format.format(timestamp)

reuse the same set of routes in multiple paths with Javalin so I am trying to refactor my route definitions in Javalin to be a little more DRY. So I have the same set of actions performed at different hierarchies. I have a company, an application, and a environment and for each of these, I've split into separate routes that use the same controller action in Javalin. Currently, it looks a little something like this: app.routes { path("api/") { path("company/{companyId}") { path("application/{applicationId}") {...

converting to coroutines for geting data for a RecyclerView my code was val cursor = getApplication().contentResolver.query( asksContract.CONTENT_URI, projection, null, null, sortOrder ) dbCursor.setValue(cursor!!) // Update on different thread And I changed it to viewModelScope.launch(Dispatchers.IO) { val cursor = getApplication().contentResolver.query( TasksContract.CONTENT_URI, projection, null, null, sortOrder ) dbCursor.setValue(cursor!!) } I think this is correct, no need to postValues as ime no longer in the main...

Android Developer kotlin playground code error fun birthdayGreeting(name: String): String { val nameGreeting = "Happy Birthday, $name!" val ageGreeting = "You are now 5 years old!" return "$nameGreeting\n$ageGreeting" } No main method found in project. Can someone explain how to solve this, I've just started taking this code labs. thanx in advance.

Why my app crashes after recreating and switching to the dark mode? I have an app that crashes after recreating. I'm trying to implement dark mode in the app, so when app theme follows the system's and I'm switching modes in device's settings while app is open, my app crashes in any fragment that was inherited from MainFragment. It switches great in other fragments(i.e. IndependentFragment), problem is only with the Main because of the toolbar manager(i suppose). If I call 'recreate()' in any of MainFragment's inheritors the app crashes too, so I don't think...

Pass safearg to navigation drawer How to pass safe args to fragment from navigation Drawer? I've found only how to pass them with actions, but I want possibility to navigate to fragmentB from all other fragments using navigation drawer. But I need to pass userId/email in the specific fragmentB.

multiple linedataset label didn't show MPChart Android I'm trying to show the label of my LineDataSet, but it didn't show on my android chart. It should be 4 labels at the bottom, with 4 different colors and names. I simply the code so I can post it here Here is my code : val chartLineDataSet = LineDataSet(arrayData, "Phasa A") chartLineDataSet.mode = LineDataSet.Mode.CUBIC_BEZIER chartLineDataSet.color = Color.RED chartLineDataSet.circleRadius = 5f chartLineDataSet.lineWidth = 2f...

Field Variable Not Persisting I am learning Kotlin. I am from a Java background, so some of my coding style may reflect that. So I have written a Spring Boot application. I have written a class like this: class CISCODeviceAdapter(private val deviceConnectionDetails: DeviceConnectionDetails) : DeviceAdapterBase { private val logger = LoggerFactory.getLogger(javaClass) private val transactionID : String = "" private var sshConnection : SSHConnection? = null . . . . override fun...

interpreter of commands received via sms I would like to know if it is possible to create an android application that interprets commands, received via sms or email, and performs actions such as taking photos, recording a sound, sending a photo, playing a sound or saving the phone book in a file. Can you recommend some examples?

Mapping to Flow and using it as a List<Item> Im using retrofit and fetching data from news api. I wanted to use flows so I do this in repository: fun getTopArticles(): Flow { return flow { val topArticles = apiService.getTopHeadlinesArticles().articles .map { article -> Article( title = article.title, content = article.content ) } emit(topArticles) }.flowOn(Dispatchers.IO)...

Android wait for service callback with coroutines I wan't to connect to a service inside a texture view. The connection can be cut off if the service crashes. For this case a new connection needs to be established. On every onSurfaceTextureAvailable I check if the service is still alive and running. If not i try to reconnect to the service. Due that multiple things happen in this view I have to wait till the service is connect and can then continue. I would like to solve it with blocking coroutines like this: suspend fun bindServiceAndWait()...

How to loop using Mustache in my ktor kotlin android project I am making an android application where the android device act as the server and you can connect to it through your browsers in other devices using the default IP address. I have bee able to get to the spot where my the .hbs(which is the template for creating a html page) displays all data. When I pass single data like String, Int, Bool from the backend to this .hbs page, I can get them and display it to the to the .hbs Nut when I try to pass a list or arraylist, nothing displays and I cant...

WorkManager List&lt;OneTimeWorkRequest&gt; in series I am working on a file upload Worker that will send a potentially large list of files. Currently I have it sending a single file with a progress observer for both the foreground and the notification. This seems to work well with a single file, once I enqueue multiple jobs or enqueue the manager with a list of work requests they all run in parallel. As per the <a href="https://developer.android.com/topic/libraries/architecture/workmanager/how-to/chain-work" rel="nofollow noreferrer">chaining...

Type mismatch: inferred type is unit but int is expected kotlin Im trying to get multiple types of return (Int and Boolean) but i can only seem to get one at a time: fun isValidPositions(p1: Int, p2: Int, pairs: List):Boolean{ if(p1 !in 0..9 || p2 !in 0..9 ){ println("Posições inválidas") }else if (p1 == p2){ println("Posições inválidas") }else if(pairs.get(p1) != '_' || pairs.get(p2) != '_' ) println("Posições inválidas") return true } then in my funcion main i have this: val first = readPosition("primeira")...

Vibration on button click not working in Android Studio I want to add vibration functionality to my app and just wanted to get started with a simple vibration, I tried lots od turtorias but none of them seemed to work @SuppressLint("NewApi") override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.activity_main) val timer_button = findViewById(R.id.timer_button) val timer_text: EditText = findViewById(R.id.time_text) val vibrator =...

Trying to notify adapter that item added after getting data from fire store inside MainActivity I have snapShot listener to document added that calls a function inside a fragment that supose to set and update the adapter of item that stored in fire store mFireStore.collection(Constans.BOARDS) .whereArrayContains(Constans.ASSIGNED_TO,FireStore().getCurrentUid()) .orderBy("timeStamp", Query.Direction.DESCENDING) .addSnapshotListener { value, e -> Log.d("MainActivity","board listener") if (e != null) {...

How to send data from Activity to Fragment using Interface and without the transaction? I want to send the data from MainActivity to Fragment but i don't want to pass the data in the arguments when i am making the transaction to the fragment like below: val bundle = Bundle() bundle.putString("name", name) val fragment = BlankFragment(this) fragment.arguments = bundle supportFragmentManager.beginTransaction().replace(R.id.fragmentView, fragment).commit() I want to pass the data from the activity to the fragment using the interface. I am able to send the data from the...

How to add only the required number of inputs in an array in Kotlin? My question is: How to add only the required number of inputs in an array in Kotlin? Input Format The first line of input will contain a single integer, the number of test cases. Then the test cases follow. Each test case consists of 2 lines of input. The first line of input of each test case contains a single integer, N, which is the total number of problems that the person has added to his to-do list. The second line of input of each test case contains N space-separated integers (eg: d1,...

Android Studio NFC reading data, removal of the prefix en I'm working on an nfc scanner and have come across a problem. When displaying tag data, the prefix "en" appears, for example: enKeyboard. I would like it to display Keyboard itself. How can I do this? The code below: override fun onTagDiscovered(tag: android.nfc.Tag?) { val test = findViewById(R.id.test) val mNdef = Ndef.get(tag) if (mNdef != null) { val mNdefMessage = mNdef.cachedNdefMessage val firstRecord = mNdefMessage.records[0]...

Why is "contains" or "in" not working in Kotlin I'm currently working on a project with different functions. One of the functions is supposed to take a map and a string as inputs, then compare the items in the map and string and create a new map with matching items. This function is not working because "containsKey" always returns false. "in" always returns fault. I tried substituting the map with a mutable List and got the same results. I tried this same code on kotlin playground, link; <a href="https://pl.kotl.in/zZm1Smz3Z" rel="nofollow...

Kotlin Ktor TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 I'm having trouble with implementing TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 in Kotlin using the Ktor CIO lib. Basically, I'm trying to implement the EEBUS SHIP Protocol in Kotlin JVM, and as the Documentation states: "The TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256 cipher suite, as specified in RFC 5289, MUST be supported." (row: 563). Reading the Ktor docs i found: <a...

making an array of ID’s from an array of names I am making a food recognition app, for this app i get an array of recognized ingredients from this array I want to create an array of the integer ID’s of the corrosponding images. For example lets say i have val ingredients = arrayOf(apple, banana) From this I want to create the array val images = arrayOf(R.drawable.apple, R.drawable.banana) I am looking for a way that I can generate this Array of images from the Array of ingredients. I have tried every type of loops, commands everything....

how to create a code entry input style jetpack compose Im using jetpack compose and kotlin, what I need to create a textinput for a sms code that looks like the one on the image, it should just accept 5 numbers, the thing is that I dont know how to make it look like this, that one number per line, tried to do 5 separate inputs but its not that smooth, is therea way to do this with only one text input?

How to run kotlin code with root privilege? I'm using this library to get root access https://github.com/topjohnwu/libsu I can run bash code with root privilege; Initialization: class MainActivity : ComponentActivity() { companion object { init { //here goes static initializer code Shell.enableVerboseLogging = BuildConfig.DEBUG Shell.setDefaultBuilder( Shell.Builder.create()...

Android Messaging Style notification -Add icon from image url - Person.Builder I am using Person Object to build chat app notifications like gmail. So i have created the person object. But i want to set icon from a image url coming from server an not from drawable resource. I am using Coil library for loading images . The below code is working fine, By default the android generates the icon with the first letter passed to the title. So, How can i show the image coming from server as a url in...

How to split viewmodel or build master viewmodel with small viewmodels? I have one pretty big complicated ViewModel and I want to split it or build it with few smaller ViewModels held in one master ViewModel that could be re lifecycle. Below I want to show how I make my ViewModels in general (please do not laugh, this is my first Android ViewModel). I'm not using DataBinding, just ViewBinding. class AssignUserTagToInventoryItemViewModel() : ViewModel() { private val UserTag = "MyApp" + this.javaClass.simpleName init { Log.d(UserTag, "Class init...

How can I assert if a function does or does not call its parent? I'm trying to write a unit test for a RecyclerView adapter. The twist is that I'm using DiffUtil and returning payload diffs, which calls onBindViewHolder(holder: ViewHolder, position: Int, payloads: List instead of (well, in addition to) the normal onBindViewHolder(holder: ViewHolder, position: Int). Based on this tutorial the main part is: override fun...

Moshi Json / Kotlin - Empty String to Null (for numerical properties) I have a model class containing Long and Int properties and I am using Moshi Library to parse a json string into this class. data class Adjust ( var appId: String?, var clicks: Long?, var count: Int?) If I parse a json like this {"appId":"1", "clicks":""}, I get an error Expected a long but was at path $.clicks Same thing happens for the Int field. What can I do short of adding two custom adapters so that the blank strings are parsed as null and do not error out? The custom...

Firebase Kotlin -How to Monitor Storage Upload Tasks for Resume and Error Issues Using Swift, I use the following code to monitor a storage upload, if it fails, I can run a switch on the StorageErrorCode to figure out what happened. If it pauses, I can resume the task using task?.observe(.resume, handler .... How can I do the same for both in Kotlin? Swift: var uploadTask: StorageUploadTask? func uploadPhotoToStorage() { let storageRef = Storage.storage().reference().child("...") uploadTask = storageRef.putFile(from: photoUrl, metadata: metadata, completion: {...