Convert a Website into an Android App with WebView

package com.example.webviewapp;

import android.annotation.SuppressLint;
import android.content.ActivityNotFoundException;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.webkit.WebChromeClient;
import android.webkit.WebResourceError;
import android.webkit.WebResourceRequest;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.ProgressBar;
import android.widget.Toast;

import androidx.activity.EdgeToEdge;
import androidx.activity.OnBackPressedCallback;
import androidx.appcompat.app.AppCompatActivity;
import androidx.core.graphics.Insets;
import androidx.core.view.ViewCompat;
import androidx.core.view.WindowInsetsCompat;

/** Shows a website inside the app, like a mini browser locked to one site. */
public class MainActivity extends AppCompatActivity {
    // Change this to your own website.
    private static final String HOME_URL = "https://codelab-x.com/";

    WebView webView;
    ProgressBar progress;

    @SuppressLint("SetJavaScriptEnabled") // the site is ours, so JavaScript is safe to allow
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        EdgeToEdge.enable(this);
        setContentView(R.layout.activity_main);
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main), (v, insets) -> {
            Insets bars = insets.getInsets(WindowInsetsCompat.Type.systemBars());
            v.setPadding(bars.left, bars.top, bars.right, bars.bottom);
            return insets;
        });

        webView = findViewById(R.id.webview);
        progress = findViewById(R.id.progress);

        WebSettings webSettings = webView.getSettings();
        webSettings.setJavaScriptEnabled(true);
        webSettings.setDomStorageEnabled(true); // many modern sites need local storage

        webView.setWebViewClient(new MyWebClient());
        // WebChromeClient reports loading progress for the bar at the top.
        webView.setWebChromeClient(new WebChromeClient() {
            @Override
            public void onProgressChanged(WebView view, int newProgress) {
                progress.setProgress(newProgress);
            }
        });

        // After a rotation, restore the page the user was on instead of starting over.
        if (savedInstanceState == null || webView.restoreState(savedInstanceState) == null) {
            webView.loadUrl(HOME_URL);
        }

        // Back goes back through the web pages first, and only leaves the app at the first page.
        getOnBackPressedDispatcher().addCallback(this, new OnBackPressedCallback(true) {
            @Override
            public void handleOnBackPressed() {
                if (webView.canGoBack()) {
                    webView.goBack();
                } else {
                    setEnabled(false);
                    getOnBackPressedDispatcher().onBackPressed();
                }
            }
        });
    }

    private class MyWebClient extends WebViewClient {
        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            progress.setVisibility(View.VISIBLE);
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            progress.setVisibility(View.GONE);
        }

        @Override
        public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
            Uri url = request.getUrl();
            // Pages on our own site stay inside the app.
            if (url.getHost() != null && url.getHost().endsWith(Uri.parse(HOME_URL).getHost())) {
                return false;
            }
            // Everything else (other sites, mail, phone links) opens in the right app.
            try {
                startActivity(new Intent(Intent.ACTION_VIEW, url));
            } catch (ActivityNotFoundException e) {
                Toast.makeText(MainActivity.this, R.string.no_app, Toast.LENGTH_SHORT).show();
            }
            return true;
        }

        @Override
        public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
            if (request.isForMainFrame()) {
                Toast.makeText(MainActivity.this, R.string.offline, Toast.LENGTH_LONG).show();
            }
        }
    }

    @Override
    protected void onSaveInstanceState(Bundle outState) {
        super.onSaveInstanceState(outState);
        webView.saveState(outState);
    }
}