Edit the MainActivity.java file (Creating HTML5 Android WebApp)

The next step is to edit MainActivity.java file. Copy and paste this code to your MainActivity, but remember keep your package name unchanged, my package name is “com.thirteenov.lightweightnotetaker” so you must your own package name as it is your unique app identifier.

package com.thirteenov.lightweightnotetaker;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.Window;
import android.view.WindowManager;
import android.webkit.WebChromeClient;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class MainActivity extends AppCompatActivity {

    WebView browser;

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        requestWindowFeature(Window.FEATURE_NO_TITLE);
        getWindow().setFlags(
                WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN
        );

        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        browser = findViewById(R.id.webview);
        browser.setWebChromeClient(new WebChromeClient());
        browser.getSettings().setJavaScriptEnabled(true);
        browser.getSettings().setDomStorageEnabled(true);
        browser.getSettings().setAllowFileAccessFromFileURLs(true);
        browser.getSettings().setAllowUniversalAccessFromFileURLs(true);
        browser.getSettings().setMediaPlaybackRequiresUserGesture(false);

        browser.loadUrl("file:///android_asset/index.html");

        browser.setWebViewClient(new WebViewClient() {
            public boolean shouldOverrideUrlLoading(WebView viewx, String urlx) {
                if(!urlx.contains("http")){
                    viewx.loadUrl(urlx);
                    return false;
                }else{
                    Intent intent = new Intent(Intent.ACTION_VIEW, Uri.parse(urlx));
                    startActivity(intent);
                    return true;
                }
            }
        });
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        WebView browser = findViewById(R.id.webview);
        if ((keyCode == KeyEvent.KEYCODE_BACK) && browser.canGoBack()) {
            //if Back key pressed and webview can navigate to previous page
            browser.goBack();
            // go back to previous page
            return true;
        }
        else
        {
            finish();
        }
        return super.onKeyDown(keyCode, event);
    }
}