adam-arold

interface Component {
   val children: Iterable<Component>
   fun requestFocus()
   fun clearFocus()
}

class MyComponent(
       override val children: Iterable<Component>,
       val drawSurface: DrawSurface) : Component {

adam-arold

class MyComponent(
       val children: Iterable<Component>, // 1
       internal val drawSurface: DrawSurface) { // 2

   fun requestFocus() {
   }

   fun clearFocus() {
   }

adam-arold

class MyComponent(
       val children: List<MyComponent>, // 1
       internal val drawSurface: PixelGraphicsImpl) { // 2

   fun requestFocus() {
   }

   fun clearFocus() {
   }

adam-arold

class MyComponent(
       val isFocused: Boolean,
       val children: List<MyComponent>,
       val drawSurface: PixelGraphicsImpl) {

   fun requestFocus() {
   }

   fun clearFocus() {
   }

adam-arold

class Tile

fun writeTile(tile: Tile) =
    println("Tile: $tile")

writeTile(Tile())

adam-arold

class Tile:
  pass

def write_tile(tile: Tile):
  print("Tile: " + str(tile))

write_tile(Tile())

adam-arold

public final class SomeClass {
   // $FF: synthetic field
   static final KProperty[] $$delegatedProperties = new KProperty[]{(KProperty)Reflection.mutableProperty1(new MutablePropertyReference1Impl(Reflection.getOrCreateKotlinClass(SomeClass.class), "someValue", "getSomeValue()Ljava/lang/String;"))};
   @NotNull
   private final ReadWriteProperty someValue$delegate = NotNullVarKt.notNull();

   @NotNull
   public final String getSomeValue() {
      return (String)this.someValue$delegate.getValue(this, $$delegatedProperties[0]);
   }

adam-arold

class SomeClass {

    var someValue: String by notNull()
}

adam-arold

public fun <T : Any> notNull(): ReadWriteProperty<Any?, T> = NotNullVar()

adam-arold

class NotNullVar<T : Any> : ReadWriteProperty<Any?, T> {
    private var value: T? = null

    public override fun getValue(thisRef: Any?, property: KProperty<*>): T {
        return value ?: throw IllegalStateException("Property ${property.name} should be initialized before get.")
    }

    public override fun setValue(thisRef: Any?, property: KProperty<*>, value: T) {
        this.value = value
    }