MainActivity.kt

package org.example.tortotrulo

import android.content.Intent
import android.net.Uri
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.webkit.WebView
import android.webkit.WebViewClient
import androidx.core.content.ContextCompat
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

    //a WebViewClient that accepts all www.cake.co URLs and displays them, but relegates
    //other URLs to the system's default browser
    private class CakeWebViewClient : WebViewClient() {
        override fun shouldOverrideUrlLoading(view: WebView?, url: String?): Boolean {
            if (Uri.parse(url).host == "www.cake.co") {
                //false for all URLs under the cake.co host, these will open in app
                return false
            }

            //external link, launch another Activity that handles URLs
            if (view?.context != null) {
                Intent(Intent.ACTION_VIEW, Uri.parse(url)).apply {
                    ContextCompat.startActivity(view.context,this,null)
                }
            }
            return true
        }
    }

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

        //use a WebViewClient that opens all cake.co URLs in the view,
        //but opens external web content elsewhere (e.g. Chrome)
        webview.webViewClient = CakeWebViewClient()

        //enable JS for functionality like Follow/Signin to work
        webview.settings.javaScriptEnabled = true

        //load some cake.co content
        webview.loadUrl("https://www.cake.co/")
    }
}