Chrome Custom Tabs example in Kotlin

ChromeCustomTabsActivity.kt

package com.thejakeofink.chromecustomtabs

import android.content.ComponentName
import android.graphics.Color
import android.net.Uri
import android.os.Bundle
import android.support.customtabs.CustomTabsClient
import android.support.customtabs.CustomTabsIntent
import android.support.customtabs.CustomTabsServiceConnection
import android.support.customtabs.CustomTabsSession
import android.support.v7.app.AppCompatActivity
import android.widget.Button

/**
 *  This example is using the Chrome Custom Tab Support Library
 *  make sure to include:
 *  compile 'com.android.support:customtabs:<version_number e.g. 23.1.1>'
 *  in your build dependencies
 */
class ChromeCustomTabsActivity : AppCompatActivity() {

    val CUSTOM_TAB_PACKAGE_NAME = "com.android.chrome";


    private var mCustomTabsServiceConnection: CustomTabsServiceConnection? = null
    private var mClient: CustomTabsClient? = null
    private var mCustomTabsSession: CustomTabsSession? = null

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

        mCustomTabsServiceConnection = object : CustomTabsServiceConnection() {
            override fun onCustomTabsServiceConnected(componentName: ComponentName, customTabsClient: CustomTabsClient) {
                //Pre-warming
                mClient = customTabsClient
                mClient?.warmup(0L)
                mCustomTabsSession = mClient?.newSession(null)
            }

            override fun onServiceDisconnected(name: ComponentName) {
                mClient = null
            }
        }

        CustomTabsClient.bindCustomTabsService(this, CUSTOM_TAB_PACKAGE_NAME, mCustomTabsServiceConnection);

    }

    override fun onResume() {
        super.onResume()

        val google = findViewById(R.id.google_btn) as Button
        val vivint = findViewById(R.id.vivint_btn) as Button
        val geek = findViewById(R.id.geek_btn) as Button
        val ksl = findViewById(R.id.ksl_btn) as Button
        val parallax = findViewById(R.id.parallax_btn) as Button

        google.setOnClickListener {
            loadCustomTabForSite("http://google.com")
        }

        vivint.setOnClickListener {
            loadCustomTabForSite("http://vivintsky.com", resources.getColor(R.color.vivint_orange));
        }

        geek.setOnClickListener {
            loadCustomTabForSite("http://www.dividendgeek.com", resources.getColor(R.color.colorPrimary));
        }

        ksl.setOnClickListener {
            loadCustomTabForSite("http://www.ksl.com", resources.getColor(R.color.colorAccent))
        }

        parallax.setOnClickListener {
            loadCustomTabForSite("http://matthew.wagerfield.com/parallax/", Color.RED);
        }

    }

    fun loadCustomTabForSite(url: String, color: Int = Color.BLUE) {
        val customTabsIntent = CustomTabsIntent.Builder(mCustomTabsSession)
                .setToolbarColor(color)
                .setShowTitle(true)
                .build()

        customTabsIntent.launchUrl(this, Uri.parse(url))


    }
}