Android

Issue #555 Synthetic properties generated by Kotlin Android Extensions plugin needs a view for Fragment/Activity to be set before hand. In your case, for Fragment, you need to use view.btn_K in onViewCreated override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { super.onCreateView(inflater, container, savedInstanceState) val view = inflater.inflate(R.layout.fragment_card_selector, container, false) view.btn_K.setOnClickListener{} // access with `view` return view } Or better, you should only access synthetic properties in onViewCreated override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?...

Issue #497 Synthetic properties generated by Kotlin Android Extensions plugin needs a view for Fragment/Activity to be set before hand. In your case, for Fragment, you need to use view.btn_K in onViewCreated override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? { super.onCreateView(inflater, container, savedInstanceState) val view = inflater.inflate(R.layout.fragment_card_selector, container, false) view.btn_K.setOnClickListener{} // access with `view` return view } Or better, you should only access synthetic properties in onViewCreated override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?...

Issue #472 Build error view Use convenient code from Omnia To make view height dynamic, pin UILabel to edges and center import UIKit final class ErrorMessageView: UIView { let box: UIView = { let view = UIView() view.backgroundColor = R.color.primary view.layer.cornerRadius = 6 return view }() let label: UILabel = { let label = UILabel() label.styleAsText() label.textColor = R.color.darkText label.numberOfLines = 0 return label }() override init(frame: CGRect) { super.init(frame: frame) setup() } required init?...

Issue #466 iOS View Controller -> View Model | Logic Handler -> Data Handler -> Repo Android Activity -> Fragment -> View Model | Logic Handler -> Data Handler -> Repo

Issue #431 Use AdMob with Firebase https://firebase.google.com/docs/admob/android/quick-start build.gradle buildscript { repositories { google() jcenter() } dependencies { classpath 'com.google.gms:google-services:4.3.2' } } app/build.gradle class Version { class Firebase { static def analytics = "17.2.0" static def ads = "18.2.0" } } dependencies { implementation "com.google.firebase:firebase-analytics:$Version.Firebase.analytics" implementation "com.google.firebase:firebase-ads:$Version.Firebase.ads" } apply plugin: 'com.google.gms.google-services' Manifest.xml <manifest> <application> <!-- Sample AdMob App ID: ca-app-pub-3940256099942544~3347511713 --> <meta-data android:name="com.google.android.gms.ads.APPLICATION_ID" android:value="[ADMOB_APP_ID]"/> </application> </manifest> MyApplication.kt class MyApplication: Application() { override fun onCreate() { super....

Issue #397 We recommend that, rather than disabling the preview window, you follow the common Material Design patterns. You can use the activity’s windowBackground theme attribute to provide a simple custom drawable for the starting activity. styles.xml <style name="LaunchTheme" parent="Theme.AppCompat.NoActionBar"> <item name="android:windowBackground">@drawable/launch_background</item> </style> Set android:theme="@style/LaunchTheme" to activity element AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.onmyway133.whatsupintech"> <uses-permission android:name="android.permission.INTERNET" /> <application android:name=".MyApplication" android:allowBackup="true" android:icon="@mipmap/ic_launcher" android:label="@string/app_name" android:roundIcon="@mipmap/ic_launcher_round" android:supportsRtl="true" android:theme="@style/AppTheme"> <activity android:name=".features.main.MainActivity" android:label="@string/app_name" android:theme="@style/LaunchTheme"> <intent-filter> <action android:name="android....

Issue #396 Use app:headerLayout <com.google.android.material.navigation.NavigationView android:layout_width="wrap_content" android:layout_height="match_parent" android:id="@+id/navigationView" android:fitsSystemWindows="true" android:layout_gravity="start" app:menu="@menu/drawer_menu" app:itemIconTint="@color/title" app:itemTextColor="@color/title" app:headerLayout="@layout/navigation_header" /> navigation_header.xml <?xml version="1.0" encoding="utf-8"?> <androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent" xmlns:app="http://schemas.android.com/apk/res-auto"> <androidx.appcompat.widget.AppCompatImageView android:layout_width="0dp" android:layout_height="wrap_content" android:src="@drawable/icon" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" app:layout_constraintBottom_toBottomOf="parent"/> </androidx.constraintlayout.widget.ConstraintLayout>

Issue #383 Right click res -> New -> Android Resource Directory, select anim and name it anim Right click res/anim -> New -> Android Resource file, name it bounce <?xml version="1.0" encoding="utf-8"?> <set xmlns:android="http://schemas.android.com/apk/res/android"> <translate android:fromYDelta="0" android:toYDelta="-100" android:repeatCount="infinite" /> </set> We have to set repeatCount in xml, setting in code does not work !! val bounce = AnimationUtils.loadAnimation(context, R.anim.bounce) bounce.repeatMode = Animation.REVERSE bounce.duration = (1000..2000).random().toLong() imageView.startAnimation(bounce)

Issue #382 import android.content.Context fun Int.toDp(context: Context?): Int { if (context != null) { val scale = context.resources.displayMetrics.density return (this.toFloat() * scale + 0.5f).toInt() } else { return 0 } } val set = ConstraintSet() set.setMargin(imageView.id, ConstraintSet.RIGHT, rightMargin.toDp(150)) Read more https://stackoverflow.com/questions/5255184/android-and-setting-width-and-height-programmatically-in-dp-units

Issue #381 From API < 17, there is ViewCompat.generateViewId() For API 17, there is View.generateViewId() Note that to use ConstraintSet, all views under ConstraintLayout inside xml must have unique id val imageView = ImageView(context) imageView.id = View.generateViewId() imageView.setImageResource(resId) constraintLayout.addView(imageView) val set = ConstraintSet() set.clone(constraintLayout) set.connect(imageView.id, ConstraintSet.RIGHT, ConstraintSet.PARENT_ID, ConstraintSet.RIGHT) set.applyTo(constraintLayout)

Issue #380 Downloadable fonts https://developer.android.com/guide/topics/ui/look-and-feel/downloadable-fonts Android 8.0 (API level 26) and Android Support Library 26 introduce support for APIs to request fonts from a provider application instead of bundling files into the APK or letting the APK download fonts. The feature is available on devices running Android API versions 14 and higher through the Support Library 26 Before Select File -> New -> Folder -> Assets Folder to create src/main/assets/fonts al myTypeface = Typeface....

Issue #379 interface Api { @GET("topstories.json?print=pretty") suspend fun getTopStories(): List<Int> @GET("item/{id}.json?print=pretty") suspend fun getStory(@Path("id") id: Int): Item } class Repo { fun api(): Api { return Retrofit.Builder() .baseUrl("https://hacker-news.firebaseio.com/v0/") .addConverterFactory(MoshiConverterFactory.create()) .build() .create(Api::class.java) } } class ViewModel(val repo: Repo): ViewModel() { val items = MutableLiveData<ArrayList<Item>>() suspend fun load() { try { val ids = repo.api() .getTopStories() .take(20) val items = ids.map { repo.api().getStory(it) } this.items.value = items.toCollection(ArrayList()) } catch (e: Exception) { this....

Issue #378 After having a generic RecyclerView, if we want to show multiple kinds of data in Fragment, we can use generic. We may be tempted to use interface or protocol, but should prefer generic. class FeedFragment() : Fragment() { override fun onActivityCreated(savedInstanceState: Bundle?) { super.onActivityCreated(savedInstanceState) val mainViewModel: MainViewModel = ViewModelProviders.of(activity!!).get(MainViewModel::class.java) mainViewModel.resId.observe(viewLifecycleOwner, Observer { when (it) { R.id.gitHub -> { handleGitHub() } R.id.hackerNews -> { handleHackerNews() } R.id.reddit -> { handleReddit() } R....

Issue #370 Define response model import com.squareup.moshi.Json data class Response( @field:Json(name="data") val data: ResponseData ) data class ResponseData( @field:Json(name="posts") val posts: Posts ) data class Posts( @field:Json(name="edges") val edges: List<Edge> ) data class Edge( @field:Json(name="node") val node: Item ) data class Item( @field:Json(name="id") val id: String, @field:Json(name="name") val name: String, @field:Json(name="url") val url: String, @field:Json(name="tagline") val tagline: String, @field:Json(name="featuredAt") val featuredAt: String, @field:Json(name="votesCount") val votesCount: Int, @field:Json(name="commentsCount") val commentsCount: Int, @field:Json(name="thumbnail") val thumbnail: Thumbnail ) data class Thumbnail( @field:Json(name="url") val ur: String ) Here is the query...

Issue #367 https://api.github.com/search/repositories?sort=stars&order=desc&q=language:javascript,java,swift,kotlin&q=created:>2019-08-21 interface Api { @GET("https://api.github.com/search/repositories") suspend fun getTrendingRepos( @Query("sort") sort: String, @Query("order") order: String, @Query("q") qs: List<String> ): Response } class Repo { fun api(): Api { return Retrofit.Builder() .baseUrl("https://api.github.com/") .addConverterFactory(MoshiConverterFactory.create()) .build() .create(Api::class.java) } } class ViewModel(val repo: Repo, val dateProvider: DateProvider): ViewModel() { val items = MutableLiveData<ArrayList<Item>>() suspend fun load() { try { val order = "desc" val sort = "star" val formatter = SimpleDateFormat("YYYY-MM-dd") val qs = listOf( "language:javascript,java,swift,kotlin", "q=created:>${formatter....

Issue #366 Code uses Retrofit 2.6.0 which has Coroutine support app/build.gradle implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.2.0-alpha01" implementation "com.squareup.moshi:moshi:$Version.moshi" implementation "com.squareup.retrofit2:retrofit:$Version.retrofit" implementation "com.squareup.retrofit2:converter-moshi:$Version.retrofit" Api.kt import retrofit2.http.GET interface Api { @GET("api/articles") suspend fun getArticles(): List<Article> } Repo.kt import retrofit2.Retrofit import retrofit2.converter.moshi.MoshiConverterFactory class Repo { fun get(): Api { return Retrofit.Builder() .baseUrl("https://dev.to") .addConverterFactory(MoshiConverterFactory.create()) .build() .create(Api::class.java) } } ViewModel.kt import androidx.lifecycle.ViewModel import androidx.lifecycle.liveData import kotlinx.coroutines.Dispatchers class ViewModel(val repo: Repo): ViewModel() { val articles = liveData(Dispatchers.Main) { emit(repo.get().getArticles().toCollection(ArrayList())) } } Article....

Issue #363 ViewModels a simple example https://medium.com/androiddevelopers/viewmodels-a-simple-example-ed5ac416317e Rotating a device is one of a few configuration changes that an app can go through during its lifetime, including keyboard availability and changing the device’s language. All of these configuration changes cause the Activity to be torn down and recreated The ViewModel class is designed to hold and manage UI-related data in a life-cycle conscious way. This allows data to survive configuration changes such as screen rotations....

Issue #359 app/build.gradle implementation "org.koin:koin-core:$Version.koin" implementation "org.koin:koin-androidx-scope:$Version.koin" implementation "org.koin:koin-androidx-viewmodel:$Version.koin" MyApplication.kt import android.app.Application import org.koin.android.ext.koin.androidContext import org.koin.android.ext.koin.androidLogger import org.koin.androidx.viewmodel.dsl.viewModel import org.koin.core.context.startKoin import org.koin.dsl.module class MyApplication: Application() { var appModule = module { single { MyRepo() } viewModel { MyViewModel(get()) } } override fun onCreate() { super.onCreate() startKoin { androidLogger() androidContext(this@MyApplication) modules(appModule) } } } MyFragment.kt import org.koin.androidx.viewmodel.ext.android.viewModel val viewModel: MyViewModel by viewModel()

Issue #358 app/build.gradle implementation "androidx.lifecycle:lifecycle-livedata-ktx:2.2.0-alpha01" import androidx.lifecycle.ViewModel import androidx.lifecycle.liveData import kotlinx.coroutines.Dispatchers class MainViewModel : ViewModel() { val repository: TodoRepository = TodoRepository() val firstTodo = liveData(Dispatchers.IO) { val retrivedTodo = repository.getTodo(1) emit(retrivedTodo) } } Use coroutines with LiveData https://developer.android.com/topic/libraries/architecture/coroutines The liveData building block serves as a structured concurrency primitive between coroutines and LiveData. The code block starts executing when LiveData becomes active and is automatically canceled after a configurable timeout when the LiveData becomes inactive....

Issue #357 generic/Adapter.kt package com.onmyway133.generic import android.view.LayoutInflater import android.view.View import android.view.ViewGroup import androidx.recyclerview.widget.RecyclerView abstract class Adapter<T>(var items: ArrayList<T>): RecyclerView.Adapter<RecyclerView.ViewHolder>() { abstract fun configure(item: T, holder: ViewHolder) fun update(items: ArrayList<T>) { this.items = items notifyDataSetChanged() } override fun getItemCount(): Int = items.count() override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder { val view = LayoutInflater .from(parent.context) .inflate(viewType, parent, false) return ViewHolder(view) } override fun onBindViewHolder(holder: RecyclerView.ViewHolder, position: Int) { configure(items[position], holder as ViewHolder) } } class ViewHolder(view: View): RecyclerView....