yongjhih

class MyViewModel(private val sharedPreferences: SharedPreferences) : ViewModel {
  var isAdult by sharedPreferences.isAdult

  init {
    println(isAdult) // null
    isAdult = true
    println(isAdult) // true
    isAdult.value = false
    println(isAdult) // false

yongjhih

/**
 * Interface representing a read-only property with a value
 *
 * Usage:
 *
 * ```
 * val doubleValue by propertyOf(1).map { it * 2 }.map { it * 2 }
 *
 * doubleValue // 4
 * ```

yongjhih

inline fun <reified T : View> ViewGroup.childrenByType(): Sequence<T> = descendantsBreadth.filterIsInstance<T>()

val ViewGroup.descendantsBreadth: Sequence<View>
    get() = sequence {
        val queue: Queue<View> = LinkedList()
        [email protected] { child -> queue.offer(child) }

        var child = queue.poll()
        while (child != null) {
            yield(child)

yongjhih

inline fun <reified T> Any.getDeclaredFieldValue(fieldName: String): T =
    javaClass.findDeclaredField(fieldName).run {
        if (!isAccessible) isAccessible = true
        get(this@getDeclaredFieldValue) as T
    }

inline fun <reified T> Any.getDeclaredFieldValueOrNull(fieldName: String): T? =
    try { getDeclaredFieldValue(fieldName) }
    catch (e: NoSuchFieldException) { null }
    catch (e: SecurityException) { null }

yongjhih

    private val childHelper by lazy { NestedScrollingChildHelper(this).apply {
        //isNestedScrollingEnabled = false
    } }

    init {
        isNestedScrollingEnabled = true
    }
    
    override fun setNestedScrollingEnabled(enabled: Boolean) {
        return childHelper.setNestedScrollingEnabled(enabled) // Caused by: java.lang.NullPointerException: Attempt to invoke interface method 'java.lang.Object kotlin.Lazy.getValue()' on a null object reference

yongjhih

class NestedScrollingChildImpl(val view: View) : NestedScrollingChild3 {
    private val childHelper by lazy { NestedScrollingChildHelper(view) }

    override fun setNestedScrollingEnabled(enabled: Boolean) {
        return childHelper.setNestedScrollingEnabled(enabled)
    }

    override fun isNestedScrollingEnabled(): Boolean {
        return childHelper.isNestedScrollingEnabled
    }

yongjhih

import androidx.compose.foundation.BorderStroke

/*
 * Copyright 2020 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0

yongjhih

@RequiresApi(Build.VERSION_CODES.M)
fun View.scrollChanges() = callbackFlow {
    val listener = View.OnScrollChangeListener { v, scrollX, scrollY, oldScrollX, oldScrollY ->
        trySendBlocking(Quintuple(v, scrollX, scrollY, oldScrollX, oldScrollY))
    }
    setOnScrollChangeListener(listener)
    awaitClose { setOnScrollChangeListener(null) }
}

fun ViewTreeObserver.scrollChanges() = callbackFlow {

yongjhih

fun <T : Any> Class<T>.getDeclaredFieldOrNull(name: String): Field? =
        tryOrNull { getDeclaredField(name) }

@Suppress("SpreadOperator")
fun <T : Any> Class<T>.getDeclaredMethodOrNull(name: String, vararg parameterTypes: Class<*>): Method? =
        tryOrNull { getDeclaredMethod(name, *parameterTypes) }

@Suppress("SpreadOperator")
fun <T : Any> Class<T>.getDeclaredConstructorOrNull(vararg parameterTypes: Class<*>): Constructor<T>? =
        tryOrNull { getDeclaredConstructor(*parameterTypes) }

yongjhih

@JvmName("getActivityInternal")
internal tailrec fun Context.getActivity(): Activity? =
    this as? Activity
    ?: (this as? ContextWrapper)?.baseContext?.getActivity()

val Context.activity: Activity? get() = getActivity()

val View.activity: Activity? get() = context.getActivity()