MainActivity WebView

import ...

class MainActivity : AppCompatActivity() {
    private val URL = "https://mydomain.com/"
    private val DOMAIN = "mydomain.com"
    private var doubleBackToExitPressedOnce = false

    @SuppressLint("SetJavaScriptEnabled")
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        webView.settings.javaScriptEnabled = true
        webView.settings.domStorageEnabled = true
        val SDK_INT = Build.VERSION.SDK_INT
        if (SDK_INT > 16) {
            webView.settings.mediaPlaybackRequiresUserGesture = false
        }

        webView.webChromeClient = object : WebChromeClient(){
            // Popup permissions for cam + mic
            override fun onPermissionRequest(request: PermissionRequest) {
                runOnUiThread {
                    request.grant(request.resources)
                }
            }
        }

        WebView.setWebContentsDebuggingEnabled(true)
        webView.webViewClient = object : WebViewClient() {
            override fun onPageStarted(view: WebView?, url: String?, favicon: Bitmap?) {
                super.onPageStarted(view, url, favicon)
                webView.visibility = View.VISIBLE
                progressBar.visibility = View.GONE
            }

            override fun shouldOverrideUrlLoading(view: WebView, url: String): Boolean {
                if (AppUtils.checkInternetConnection(this@MainActivity)) {
                    if (url.startsWith("mailto:")) {
                        val mailTo = MailTo.parse(url)
                        val intent = Intent(Intent.ACTION_SEND)
                        intent.putExtra(Intent.EXTRA_EMAIL, arrayOf(mailTo.to))
                        intent.putExtra(Intent.EXTRA_TEXT, mailTo.body)
                        intent.putExtra(Intent.EXTRA_SUBJECT, mailTo.subject)
                        intent.putExtra(Intent.EXTRA_CC, mailTo.cc)
                        intent.type = "message/rfc822"
                        startActivity(intent)
                        view.reload()
                        return true

                    } else if (!url.contains(DOMAIN)) {
                        val intent = Intent(Intent.ACTION_VIEW, Uri.parse(url))
                        startActivity(intent)
                        return true
                    } else {
                        view.loadUrl(url)
                        return true
                    }
                } else {
                    return false
                }
            }
        }

        if (savedInstanceState == null) {
            webView.loadUrl(URL)
        }
    }

    override fun onSaveInstanceState(outState: Bundle) {
        super.onSaveInstanceState(outState)
        webView.saveState(outState)
    }

    override fun onRestoreInstanceState(savedInstanceState: Bundle) {
        super.onRestoreInstanceState(savedInstanceState)
        webView.restoreState(savedInstanceState)
    }

    override fun onBackPressed() {
        if (webView.canGoBack()) {
            webView.goBack()
        } else {
            if (doubleBackToExitPressedOnce) {
                super.onBackPressed()
                return
            }

            this.doubleBackToExitPressedOnce = true
            Toast.makeText(this, "Please click BACK again to exit", Toast.LENGTH_SHORT).show()
            Handler().postDelayed({ doubleBackToExitPressedOnce = false }, 2000)
        }
    }
}