saving private RSA key I have a messaging app, in order to secure the users messages i first encrypt the message with an AES key then i encrypt that AES key with the other user's known public RSA key and send the AES key with the message. when the key arrives at the other user he decrypts that key with a private RSA key saved on the phones database. I've learned when trying to upload the app to google play that this is an unsafe way of storing the the private RSA key. I've tried storing the key pair in a KeyStore...

Kotlin: tailrec makes suspend fun never ends I'm learning how to make coroutines work with Java libraries using CompletableFuture. Below is my code: // x invokes y invokes z invokes Java client suspend fun x(i: Int, client: FakeJavaClient): Int { fun z(k: Int): Int { println("z: $k") return client.query(k).get() } tailrec // with 'tailrec', the code never terminates suspend fun y(j: Int): Int { val ret = z(j) if (ret > 10) { return ret } return y(j + 1)...

Get internal Memory size free/total/Available Hello i'm try to get device total and free internal memory size using below method. but its returning me wrong values: fun totalMemory(): Long { val statFs = StatFs(Environment.getRootDirectory().absolutePath) return (statFs.blockCount * statFs.blockSize).toLong() } fun freeMemory(): Long { val statFs = StatFs(Environment.getRootDirectory().absolutePath) return (statFs.availableBlocks * statFs.blockSize).toLong() } fun busyMemory(): Long { val statFs =...

Not able to open keyboard when edittext is focused and also not able to close keyboard manually in kotlin android I am using kotlin and making tablet app in that I want to close keyboard manually in fragment but I am not able to do it, also keyboard not appears when edittext is focused

How to force initializing a Context in Application Class before testing with Mockito This is my Application Class class MainApplication : MultiDexApplication() { init { INSTANCE = this } companion object { lateinit var INSTANCE: MainApplication private set val applicationContext: Context get() { return INSTANCE.applicationContext } } override fun onCreate() { super.onCreate() } } And in my test I have to read a live location coming from here in my CurrentCityViewModel: class...

invalidateOptionsMenu not triggering onPrepareOptionsMenu() From the main activity I'm simply trying to change the title of an item of a "basic menu" (drawer layout, navigatonView, menu.xml, setNavigationItemSelectedListener in the activity etc..) at runtime ( minSdkVersion 23,targetSdkVersion 29). Basically there's a variable in shared preferences referring to the "logged user" and I would like to set that string as the title of the item or restore the default item title (stored in string.xml) if the user is "disconnected". As suggested in others...

Remove element from mutable list - removeIf private var cardsList: MutableList? = null val condition = Predicate { it.id() == cardId } cardsList?.toMutableList()?.removeIf(condition) getNavigator()?.initRecycleView(cardsList) I have one element in list; I have verified the id to be the same as cardId. When I run the above code i expect that after removeIf is called, the cardsList() will be empty, but it still has one element. removeIf - returns true when called with codition. I don't get it.

android - html to pdf with kotlin webview and PdfDocument() I'm trying to get PDF from HTML file using WebView and PdfDocument. First tried showing html in layout - works. private fun createDocument(uri: Uri) { val document = PdfDocument() val pageInfo = PageInfo.Builder(595, 842, 1).create() val page = document.startPage(pageInfo) val rect = Rect() rect.set(0, 0, 595, 842) val view = TextView(this) view.text = "ANY TEXT" //formatting output...

Sonar Kotlin Object 0% coverage In my project I created an object to hold some Constants to be used along the project modules, for example, Success/Error messages, but when I run the Sonar scan, it reports the file with 0% coverage. I tried to test the constants values to check if Sonar would see that as covered, but it didn't, actually it does show the object Messages {} as not covered, not the lines inside: How can I cover it with tests so...

Problem with JacksonXmlElementWrapper on Kotlin I'm trying to parse a XML file using Jackson and Kotlin on Android Studio. In particular, I want to run the code from the following test case in jackson-module-kotlin: https://github.com/FasterXML/jackson-module-kotlin/blob/master/src/test/kotlin/com/fasterxml/jackson/module/kotlin/test/github/Github153.kt...

RecyclerView Kotlin, unable to add recycler widget to layout I'm trying to implement RecyclerView in Kotlin. Following guides but getting an error right after launch "My Application keeps stopping" Basically I just added Recycler widget to my layout. Nothing else changed from template empty activity starter project.

Lateinit property has not been initialised? In my code I have declared the variable as lateinit var but when I ren the test which I have written is giving the error as "lateinit property has not been initialized". What is this? If somebody can explain then please do.

setCancelable(false) on Alert dialog does not work, when back button is clicked I have an alert dialog, I want to make non cancellable, if the user clicks back button on the device, the dialog is gone. how do i stop it from doing that. I have added setCancelable(false) but it is not working. Any thoughts on how to fix this please Here is my code. override fun onCreateDialog(savedInstanceState: Bundle?): Dialog { app.bus.post(ScreenDimEvent(false)) val builder = AlertDialog.Builder(activity) val inflater = activity!!.layoutInflater...

Modify textView in a fragment from MainActivity using SharedPreferences (Kotlin) I have an issue with a project in Kotlin. I need to modify textViews in fragments but I cannot access those textView. The error I receive back is: java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.example/com.example.example.MainActivity}: java.lang.IllegalStateException: emailSettingsText must not be null In my MainActivity (where the fragment is) I tried this: emailSettingsText.text = sharedPreferences.getString("EMAIL", "") I tried also to create a var in...

how to convert java code with interface to kotlin, Hi I am trying to convert this code to Kotlin. but unable to Ide could not automatically convert it alertDialog.setOnKeyListener(new DialogInterface.OnKeyListener() { @Override public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) { // Prevent dialog close on back press button return keyCode == KeyEvent.KEYCODE_BACK; } }); Interface interface OnKeyListener { /** * Called when a key is dispatched to a dialog. This allows...

getting private key from keystore in PKCS8 format so in my app i encrypt my data with AES key and encrypt that key with an RSA pair. i then save that pair to the KeyStore. when retrieving the private key from the KeyStore i need to format it to PKCS8 how ever i cannot format the private key because you cannot access private key encoded from key store. is there a way to generate the pair in PKCS8 format? or maybe a workaround in order to format the private key without accessing the encoded? generating the keys: fun...

why kotin can not deduce a type when using infix? class DATA public fun add1(t1T,t2T): List = listOf(t1, t2) public infix fun T.add2(t2:T): List = listOf(this, t2) fun printData(list: List) { println("Hello World!") } fun main(args: Array) { printData( add1(DATA(), DATA()) ) printData( DATA() add2 DATA()) //why this line can not compile？ } As the above code shows, when I using infix function, the type can't be deduced properly, and produced a compile error, why kotlin does not support this?

Sharing with android and kotlin I want to implement sharing functionality that allows the user to share a url via text message, facebook, email, etc. Is there a share sheet functionality in kotlin/android as there is in ios?How can I access that using kotlin code?

ViewPager with two tabs and a shared recyclerview So, I have a viewpager with two tabs, each tab needs its own set of data, so I have done this in order to send two different lists to the viewpager container, and then place this list in a shared recyclerview which each tab will display So , this how I send the data to the adapter val allProducts = completeProductList val productsList = mutableListOf() val drinksList = mutableListOf() for (product in allProducts) { if...

Does the scope handles the exception silently under the hood? I have the following snippet for testing purposes; fun main() { val myScope = CoroutineScope(Dispatchers.Default) + Job() myScope.launch { val job = async { delay(1000) throw RuntimeException("shiiiet") } try { job.await() } catch (ret: RuntimeException){ throw RuntimeException("yooo!") } } try { Thread.sleep(5000) } catch(e: Exception){ } println("wohoooo!") } I thought...

How to have image to prevent sensitive content like bank app in kotlin? I wondered how to have an image in background to prevent sensitive content in kotlin like https://i.stack.imgur.com/Ivim7.jpg?s=256 I tried this, but it's not working getWindow().setFlags(WindowManager.LayoutParams.FLAG_SECURE, WindowManager.LayoutParams.FLAG_SECURE);

Class Intent in AndroidStudio not recognized when starting an activity I´m currently trying to start another activity by pressing a button, but it gives me this error: None of the following functions can be called with the arguments supplied: public constructor Intent(p0: Context!, p1: Class!) defined in android.content.Intent public constructor Intent(p0: String!, p1: Uri!) defined in android.content.Intent The code I´m using worked previously on the project, but right now it doesn´t. My code is this, and fails when pressing help_button: import...

In Kotlin how to use the method getTime() The Kotlin documentation https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.js/-date/get-time.html says that there exists a method getTime(). But do not tell which module to import to use it. I would greatly appreciate to get this information.

How to create custom Kotlin coroutine dispatcher worked on my ThreadPoolExecutor? In the process of migration to Kotlin, the question arose. We already have some ThreadPools for different reasons. How to execute coroutine on existed ThreadPool? For exampe this code : suspend fun fetchMedia(): Flow { return withContext(Dispatchers.IO) {...} } How to replace Dispatchers.IO to my own ThreadPoolExecutor ?

How to test event listener in android I am new in kotlin and unit testing I want to write unit test cases on below mentioned code snippet but not getting how to test event listener which is getting set from a method I have the following structure within my Android app which I'm trying to write a unit test for: Model Class object ConnectingContextModel{ var state: BaseState? = null private val TAG = "UIMainContext" /* Connectivity Wrapper Instance*/ var wrapperObject: UIStateMachineWrapper =...

Jackson JsonIgnore does not work in kotlin I am rewriting Java Spring application to Kotlin Spring application. All works fine except API request to openweather. To store DTO in database there is id field alongside with cityId retrieved from API (it is called id there). For some reason @JsonIgnore does not work for DTO id field. build.gradle // plugins id 'org.springframework.boot' version '2.2.4.RELEASE' id 'io.spring.dependency-management' version '1.0.9.RELEASE' id 'java' id 'war' id 'maven' id...

Set view style programmatically Kotlin I searched for many answers but didn't find any working solution. I wonder if there is some possibility to set Edittext style programmatically. In my situation, I have one layout which is included and used in two different places and beside the place where it is included need to use a different style. 1 true 0.5 first_activity.xml second_activity.xml custom_layout.xml

Open recently downloaded PDF from Android push notification I'm prompting the user to download the PDF file in the device storage and then sending a notification that will open that file using the same Uri returned in the OnActivityResult() method. But it seems that the new Intent can't open this Uri, when I click on the notification nothing happens. Here's the code: private fun firePushNotification() { val intent: Intent if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) { intent = Intent(Intent.ACTION_VIEW).apply {...

How do I change the state of one of a row of buttons in jetpack compose with kotlin? I have a list items and for each element in the list a button with the index of the element in the list. One element in the list contains another list with some data, but that is not relevant here. When I press one button, I want to change the state of selectedButton and turn the selected button yellow. With my current code the label of a different button changes when I press a button. I hope someone can lead me to a good solution for this. I use Android Studio 4.1 Canary 2 and I know...

Duplicate class kotlin classes kotlin version 1.3.70 Error while adding MoshiPack Library in kotlin latest version 1.3.70 to gradle.build application Moshi pack implementation 'com.daveanthonythomas.moshipackmoshipack1.0.1' Error Message Duplicate class kotlin.reflect.KClasses found in modules jetified-kotlin-reflect-1.1.1.jar (org.jetbrains.kotlinkotlin reflect1.1.1) and jetified-kotlin-stdlib-1.3.70.jar (org.jetbrains.kotlinkotlin stdlib1.3.70) any Suggestions how to solve this issue or any other library i can use in kotlin so i...