Lamartio

/*
 *    Copyright 2019 Danny Lamarti
 *
 *    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
 *
 *    Unless required by applicable law or agreed to in writing, software

Lamartio

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(LinearLayout(this).layout(User.observable) {

            layout.orientation = LinearLayout.VERTICAL
            layout.gravity = Gravity.CENTER

            +textView {

Lamartio

+textView {
    text = "This is plain text"
    bind { user -> text = "${user.name}: ${user.age}" } // User is the argument
    bind { text = "$name: $age" } // User is the this-pointer
}

typealias Observer<T> = T.(T) -> Unit

Lamartio

open class BindableLayout<T, V : ViewGroup>(
        layout: V,
        private val observable: Observable<T>
) : Layout<V>(layout) {

    init {
        layout.addOnAttachStateChangeListener(DisposableOnAttachStateChangeListener {
            observable.subscribe(observers)
        })
    }

Lamartio

open class BindableLayout<T, V : ViewGroup>(layout: V) : Layout<V>(layout) {

    private val observers = Observers()

    fun bind(observer: Observer<T>) {
        observers.add(observer)
    }

    private inner class Observers : ArrayList<Observer<T>>(), Consumer<T> {

Lamartio

data class User(val name: String = "Danny", val age: Int = 27) {

    companion object {

        fun asDataSource(): Observable<User> =
                Observable
                        .interval(1, TimeUnit.SECONDS)
                        .scan(User()) { user, _ -> user.copy(age = user.age + 1) }
                        .observeOn(AndroidSchedulers.mainThread())

Lamartio

LinearLayout(this) layout {
 // ...
}

infix fun <V : ViewGroup> V.layout(block: Layout<V>.() -> Unit): V =
        also { Layout(it).run(block) }

class Layout<V : ViewGroup>(val layout: V) : ViewManager by layout, ViewParent by layout {}

Lamartio

LinearLayout(this) layout {
    +textView {
        text = "Hello world"
    }
}

val Layout<*>.textView: TextView get() = TextView(context)
val Layout<*>.button: Button get() = Button(context)

Lamartio

LinearLayout(this) layout {
    +TextView(context) {
        text = "Hello world"
    }
}

class Layout<V : ViewGroup>(val layout: V) : ViewManager by layout, ViewParent by layout {
    
    // ...

Lamartio

LinearLayout(this) layout {
    +TextView(context).apply {
        text = "Hello world"
    }
}

class Layout<V : ViewGroup>(val layout: V) : ViewManager by layout, ViewParent by layout {

    val context = layout.context