Android for Beginners : Cookies Kotlin Code

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#B388FF"
    android:orientation="vertical"
    tools:context=".MainActivity">

    <ImageView
        android:id="@+id/android_cookie_image_view"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"
        android:scaleType="centerCrop"
        android:src="@drawable/before_cookie" />

    <TextView
        android:id="@+id/status_text_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginLeft="16dp"
        android:layout_marginRight="16dp"
        android:layout_marginTop="16dp"
        android:text="I'm so hungry"
        android:textColor="@android:color/white"
        android:textSize="34sp" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="16dp"
        android:text="EAT COOKIE"
        android:onClick="eatCookie" />

</LinearLayout>

MainActivity.kt

package com.example.android.cookies

import android.support.v7.app.AppCompatActivity
import android.os.Bundle
import android.view.View
import android.widget.ImageView
import android.widget.TextView

class MainActivity : AppCompatActivity() {

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
    }

    /**
     * Called when the cookie should be eaten.
     */
    fun eatCookie(view: View) {
        // TODO: Find a reference to the ImageView in the layout. Change the image.
        val androidCookieImageView = findViewById<ImageView>(R.id.android_cookie_image_view) as ImageView
        androidCookieImageView.setImageResource(R.drawable.after_cookie)

        // TODO: Find a reference to the TextView in the layout. Change the text.
        val statusTextView = findViewById<TextView>(R.id.status_text_view) as TextView
        statusTextView.text = "I'm so full"

    }
}