sample of a strongly typed layout dsl for android results in http://i.imgur.com/KS7KLR6.png

01 - iota dsl sample.scala

package iota.sample

import android.os.Bundle
import android.support.v7.app.AppCompatActivity
import android.graphics.drawable.Animatable
import android.widget._
import android.view.ViewGroup.LayoutParams._
import iota._

class MainActivity extends AppCompatActivity { self =>
    lazy val views = ViewTree.inflateF(this, Main) {
        case "progress.pb1" =>
            this.make[ProgressBar](android.R.attr.progressBarStyleSmall)
        case "progress.pb2" =>
            this.make[ProgressBar](android.R.attr.progressBarStyleHorizontal)
    }
    case class ProgressBars(
        container: LinearLayout,
        pb1: ProgressBar,
        pb2: ProgressBar,
        pb3: ProgressBar
    ) extends ViewTree[LinearLayout] {
        container.setOrientation(LinearLayout.VERTICAL)
        pb2.setIndeterminate(true)
        pb2.matchWidth().marginLeft(16.dp).marginRight(16.dp)
    }
    case class Main(
        container: LinearLayout,
        text: TextView,
        image: ImageView,
        progress: ProgressBars,
        ok: Button,
        cancel: Button
    ) extends ViewTree[LinearLayout] {
        container.setOrientation(LinearLayout.VERTICAL)

        private[this] val buttons = nest[LinearLayout](ok, cancel) {
          ok.lp(WRAP_CONTENT, WRAP_CONTENT, 1)
          cancel.weight(0.5f)
        }
        buttons.lp(MATCH_PARENT, WRAP_CONTENT)
        buttons.marginBottom(8.dp).marginLeft(8.dp).marginRight(8.dp)

        text.matchWidth().marginTop(8.dp).marginLeft(8.dp)
        text.setText(s"Hello world, from ${TR.string.app_name.value}")
        text.setTextAppearance(self, android.R.style.TextAppearance_Large)

        image.lp(MATCH_PARENT, 256.dp, 1) // can set weight in ctor or separate
        image.weight(1)
        image.setImageResource(R.drawable.waving_scala_android)
        ok.setText("Ok")

        cancel.setText("Cancel")
    }
    override def onCreate(savedInstanceState: Bundle): Unit = {
        super.onCreate(savedInstanceState)
        setContentView(views.container)
        views.ok.onClick {
            views.text.setText("I am OK!")
            views.image.getDrawable match {
              case a: Animatable => a.start()
              case _ => // not animatable
            }
        }
        views.cancel.onClick {
            views.text.setText("I have been stopped!")
            views.image.getDrawable match {
              case a: Animatable => a.stop()
              case _ => // not animatable
            }
        }
    }
}

02 - comparable-layout.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
    <TextView
        android:layout_height="wrap_content"
        android:layout_width="match_parent"
        android:layout_marginLeft="8dp"
        android:layout_marginTop="8dp"
        android:textAppearance="?android:textAppearanceLarge"
        android:id="@+id/text"
        android:text="Hello world ...."/>
    <ImageView
        android:layout_height="256dp"
        android:layout_width="match_parent"
        android:layout_weight="1"
        android:id="@+id/image"
        android:srcCompat="@drawable/waving_scala_android"
    <LinearLayout
        android:orientation="vertical"
        android:layout_height="wrap_content"
        android:layout_width="wrap_content">
      <ProgressBar
          style="@android:style/Widget.ProgressBar.Small"
          android:layout_width="wrap_content"
          android:layout_width="wrap_content"/>
      <ProgressBar
          style="@android:style/Widget.ProgressBar.Horizontal"
          android:indeterminate="true"
          android:layout_width="wrap_content"
          android:layout_width="wrap_content"/>
      <ProgressBar
          android:layout_width="wrap_content"
          android:layout_width="wrap_content"/>
    </LinearLayout>        
    <LinearLayout
        android:layout_marginBottom="8dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_height="wrap_content"
        android:layout_width="match_parent">
      <Button
          android:layout_width="wrap_content"
          android:layout_width="wrap_content"
          android:layout_weight="1"
          android:id="@+id/ok"
          android:text="Ok"/>
      <Button
          android:layout_width="wrap_content"
          android:layout_width="wrap_content"
          android:layout_weight="0.5"
          android:id="@+id/cancel"
          android:text="Cancel"/>
    </LinearLayout>
</LinearLayout>