Pass data between fragment viewmodels Let me just say up front that this is more of a "structural" question, and I'm not asking anybody to write code; I'm just trying to figure out how I should be structuring my application. I'm using Android's DrawerLayout/NavigationView for my app. This means that MainActivity is the host for all my fragments. I currently have three fragments (in reality it's many more, but they are more or less exactly like these three fragments, just for different sets of data). ListFragment...

Android, RecyclerView touch listener not triggered In my RecyclerView I need to implement a long touch listener for trigger some logic when a user press on a item of the list. I code in Kotlin. First, to do that I create this interface interface TouchListener { fun onLongTouch(view: View, position: Int) } Then I implement the RecyclerView.OnItemTouchListener class RecyclerTouchListener(context: Context, recycleView: RecyclerView , private val touchListener: TouchListener?) : RecyclerView.OnItemTouchListener { private var...

How To Get CDATA Inside A XML Node - Kotlin I'm parsing an XML and my code works fine except for a node which contains Ngày 23 tháng 1 – 2018, hãng tin công giáo Á châu Ucanews loan tin]]> This is my code in Kotlin that I use to get content in each node private fun getTextNodeValue(elem: Node?): String { try { var child: Node? if (elem != null) { if (elem.hasChildNodes()) { child = elem.firstChild while (child != null) {...

OpenCV: multiply Mat with Scalar in Kotlin on Android I'm writing an Android App, using the Camera API 2. It takes 3 pictures in burst mode with different exposure values and merges them with OpenCV. By merging I mean the Mertens algorithm, which is available in the Photo module. In order to save the result as a image on the device, I need to multiply it with a scalar. If I don't do it the resulting image is black. fun multiply(src: Mat, scalar: Scalar): Mat { val scalar = Scalar(255.0,255.0,255.0) val dest = Mat()...

kotlin: extension methods and null receiver In lombok extension method obj.method() is a syntax sugar for SomeUtil.method(obj). It allows for obj be null. Kotlin extensions methods are resolved statically so I assume it's the same syntactic sugar, bit when I wrote fun Any.stringOrNull() = this?.toString() i got warning about unnecessary safe call on non-null receiver. does it mean i can't call extension functions on null objects like with lombok?

Select blocks of time with MaterialDateTimePicker I want to show a clock where only a selected blocks of times can be selected. For example: I want the clock to only let me select times from 09:00 to 10:00 or from 12:00 to 12:30 or from 14:00 to 18:00. All hours outside those ranges should not me selectable. Using MaterialDateTimePicker I was able to set a array of selected times: val time = TimePickerDialog.newInstance(timeSet,...

RecyclerView inside NestedScrollView does not give correct visible item position I have a RecyclerView inside a NestedScrollView and I'm trying to get the position of the last visible list item during scroll events using. The following code allows me to reliably detect scroll events: val recyclerView = nestedScrollView.getChildAt(0) as RecyclerView val layoutManager = recyclerView?.layoutManager as? LinearLayoutManager nestedScrollView.setOnScrollChangeListener { v: NestedScrollView?, scrollX: Int, scrollY: Int, oldScrollX: Int, oldScrollY: Int -> val...

Android list widget and item click not working I know this question has been asked many times, but I tried almost every solution and nothing worked for me.. So I guess I didn't understood something maybe. Here is the point, I have a home screen widget, a list one, and as usual, I want each item to open the activity when clicked. I see a lot of answers with toast and broadcasts, but I want it to open an activity. The thing is, the click doesn't work. Here is what I've done: The widget_info.xml The Provider class...

Caused by: java.lang.IllegalArgumentException: Parameter specified as non-null is null: method kotlin.jvm.internal.Intrinsics.checkParameterIsNotNull Hi I am trying to pass the object from one activity to another activity in android in kotlin. I made parcelable class using @Parcelize data class ItemsItem( ): Parcelable SearchRepositoryActivity.kt val intent = Intent(this@SearchRepositoryActivity, RepositoryDetailActivity::class.java) val bundle = Bundle() bundle.putParcelable("repoItem", repo) intent.putExtra("myBundle", bundle) startActivity(intent) RepositoryDetailActivity.kt override fun onCreate(savedInstanceState: Bundle?) {...

How do I get the sums for all elements of two lists in Kotlin? In Kotlin I have two lists: val x: List = listOf(1,2,3,4,5,6) val y: List = listOf(2,3,4,5,6,7) How do I get: val z: List = 3,5,7,9,11,13 without using loops?

Marque widget/view for android I want to create a full-featured view in Android which can be updated by itself in specific period of time, based on some configurations. I have inherit my view from RelativeLayout and I put a TextView in the layout automatically, then by posting a handler, update the TextView margins to move the text inside the RelativeLayout. The code of the custom view is (I removed unnecessary lines): import android.annotation.SuppressLint import android.content.Context import android.os.Handler import...

How I can set visibility for view to some time? I have ugly method. The problem of this method is that i use handler twice. I have textViewTitle (visibility = View.GONE) and I should to show my view with a delay 1 sec and after 5 sec set visibility = gone back. How I can do it? private fun mechanics() { Handler().postDelayed({ textViewTitle.visibility = View.GONE }, 2000) someActions() Handler().postDelayed({ textViewTitle.visibility = View.VISIBLE someActions() ,1100) }

HtmlUnit Doesn't Recognize Valid CSS So, I just started using HtmlUnit (literally just now), and I've already run into an error. I have some simple code: fun getPage() { val page: Page = WebClient().getPage("http://htmlunit.sourceforge.net") } However, it throws an extremely long error: WARNING: CSS error: 'http://htmlunit.sourceforge.net/css/apache-maven-fluido-1.5.min.css' [9:90176] Error in declaration. '*' is not allowed as first char of a property. Jan 24, 2018 41458 PM...

Cannot compile test programs using IDEA Kotlin multiplatform (experimental) I'm evaluating Kotlin on IDEA, using the multiplatform option, which is marked as experimental (and using Gradle). I can develop and run shared, JVM and JS code OK, but my problem is compiling test programs for execution under TestNG. Running the :compileTestKotlinCommon task, both from IDEA and from a console, it clears and re-generates the expected output directory (build/classes/kotlin/test/..., but only puts kotlin_metadata files in there. Before I get into posting configuation details,...

Kotlin: check if a nullable value is valid in an if statement Ideally, I think the commented-out if statements make more sense, at least to me. I mean, if someone asks me if null is bigger than 0, than I would answer no. Or if null is true, then also no. But those did not work as I expected, and throw compilation errors. So, I have changed those like below. But those do not look good or concise. Is there a better way to handle these? class Result(val code:Int) { } fun getResult():Result? { return null; } fun main(args: Array) { var result =...

Using Kotlin classes from jar built with kotlin-maven-plugin I've built a Java/Kotlin hybrid lib using kotlin-maven-plugin (v 1.2.21). The lib is actually a Spring Boot app (v 1.5.9 Now, when I declare it as a dependency in another project I face strange issues : - My IDE (Intellij) is able to find the classes I need : auto-completion proposes me the classes, and I have no error - But when I try to build my application, I get compilation errors, saying the packages (and therefore the class) I am trying to import don't exist. When I expand the jar in...

Add load animation to custom dialog in kotlin I want to add load animation to custom dialog, I was able to do it in java but I m having issue to do the same in kotlin it gives me the below error E/AndroidRuntime: FATAL EXCEPTION: main android.util.AndroidRuntimeException: requestFeature() must be called before adding content at com.android.internal.policy.impl.PhoneWindow.requestFeature(PhoneWindow.java:229) at com.android.internal.app.AlertController.installContent(AlertController.java:234) at...

Sorted Array List Object In Kotlin Let's say I have an array list of BaiGiangModel which I need to sort by title first. I was able to sort it using this code list.sortWith(compareBy({it.title})) However, the result is not perfect. Instead of getting 9 Number in front of 10 Number order, I get 10 Number then 9 Number. Everything else is fine. Any suggestions? Below is my array list. var list= ArrayList() val model1 = BaiGiangModel("10 Number","www.one.com") val model2 = BaiGiangModel("9 Number","www.two.com")...

How to create Kotlin Annotation Nested Class In java one can create something like public @interface MyAnnotation { enum AnnotationOption { ONE, TWO, THREE } AnnotationOption value(); } Without creating a package called MyAnnotation, is there an equivalent in Kotlin as annotation classes cannot have a body? Potentially something like annotation class MyAnnotation(val value: MyAnnotation.AnnotationOption) enum class MyAnnotation.AnnotationOption { ONE, TWO, THREE }

how to item select background color in android override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) { val item: DaywiseEvents = mList!!.get(position) mClickListener = listner if (item != null) { when (item!!.type) { DaywiseEvents.CALENDAR_TYPE -> (holder as DayViewHolder).mTitle.setText(item.calendar) DaywiseEvents.EVENT_TYPE -> { (holder as EventViewHolder).mTitle.setText(item.event?.eventTitle) val...

Does Kotlin's "@Parcelize" work with non data classes? I have simple data classes. I mean, they are data classes logically, but not data class, because I need inheritance and other constructors. They only have fields (of basic types Int?, String?, or List?, etc), and constructors. I need to pass them (all of their fields need to be passed) from Activity to Activity, so I need to make them parcellisable (or is there a better way?). I first created them as data class and just added @Parcelize. Even though there was a warning and red line that said...

how can I convert Bitmap to String, String to bitmap in kotlin i try to write the code i used to use in java .. but did not work in kotlin .. // in java public String BitMapToString(Bitmap bitmap){ ByteArrayOutputStream baos=new ByteArrayOutputStream(); bitmap.compress(Bitmap.CompressFormat.PNG,100, baos); byte [] b=baos.toByteArray(); String temp=Base64.encodeToString(b, Base64.DEFAULT); return temp;} how can i convert from bitmap to String in kotlin ?

how to add multiple transaction in CollectSignaturesFlow I have finished building of two transaction using Transaction builder with two different state and contract respectively in single flow. Now Am trying to add those transaction to CollectSignaturesFlow to get counterparty signatures. But I couldn't.

Lint considers Kotlin MutableMap.forEach() as java.util.Map.forEach() I am using Kotlin's MutableMap in my Android project. And trying to do some action per item. So here is my code. private val uris: MutableMap = mutableMapOf() // ... Fill the items here ... uris.forEach { // Do some Action } Everything just works fine at runtime, but my CI build fails with below lint error: MyActivity.kt142 Error: Call requires API level 24 (current min is 16): java.util.Map#forEach [NewApi] shopIcons.forEach { ~~~~~~~ I know...

Getting unresolved reference error in Kotlin Android Library Project I am getting unresolved reference error in Kotlin Android Library project. 1.) standard_kotlin_lib.jar --> contains: Kotlin classes, META-INF/standard_kotlin_lib.kotlin_module 2.) A.aar --> compiles only standard_kotlin_lib.jar file. After compilation, inside generated A.aar file’s classes.jar: META-INF/standard_kotlib_lib.kotlin_module is missing, infect whole META-INF is missing 3.) B.aar --> compiles A.aar. Here, kotlin source code importing classes define in...

Kotlin scope functions with vs extension run From what I've learned, it seems like extension function T.run and with have kind of the same purpose of creating the possibility to group multiple calls on the same object, returning lambda's last object as its result. T.run() has the advantage of applying check for nullability before using it. (as this article points it out) What are the...

Spring webflux bean validation mono I am trying to use bean validation in Webflux. This is what I have so far: @PostMapping("contact") fun create(@RequestBody @Valid contact: Mono) : Mono { return contact.flatMap { contactRepository.save(it) } .doOnError{ Error("test") } } The The validation doesn't work... I would expect that the Error("test") would be shown... Does someone has a working example(Java or Kotlin)?

cannot set colors css tornadofx I am just playing with examples of TornadoFX, but I cannot reproduce the following https://github.com/edvin/tornadofx/wiki/Type-Safe-CSS, more precisely: backgroundColor += hoverColor Doesn't compile for me, it says type mismatch, required Paint, found CSSRule Neither can I set the borderColor +=box(dangerColor), I also have a type mismatch <a href=""...

Kotlin vs Swift. Which one best for Mobile App Development? [on hold] Kotlin and swift both are modern languages and also provide some features which are not supported by the old languages. But which one is better, Kotlin or Swift?

How we define the id in kotlin without any use of third party library? In java, we used to define the id by using findviewbyid. I am Wondering how we can define the id in kotlin without any use of third party library.