Android: How can i show progress bar while loading data into WebView?

Question

How can I show the progress bar while loading data into my webview? My code :

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    this.requestWindowFeature(Window.FEATURE_PROGRESS);
    getWindow().setFeatureInt( Window.FEATURE_PROGRESS, Window.PROGRESS_VISIBILITY_ON); 
    this.setProgressBarVisibility(true);
    setContentView(R.layout.layout_article);
    WebView webview = (WebView) findViewById(R.id.webView);
    final Activity activity = this;
    webview.setWebChromeClient(new WebChromeClient() {
        public void onProgressChanged(WebView view, int progress) {
            activity.setProgress(progress * 100);
        }
    });

    webView.loadUrl("http://google.com");
}

Answer 1

public class MainActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        final ProgressBar progress = (ProgressBar) findViewById(R.id.progress);

        WebView webView = (WebView) findViewById(R.id.webview);
        webView.getSettings().setJavaScriptEnabled(true);
        webView.setWebViewClient(new WebViewClient() {
            @Override
            public boolean shouldOverrideUrlLoading(final WebView view, final String url) {
                return false;
            }

            @Override
            public void onPageStarted(final WebView view, final String url, final Bitmap favicon) {
                progress.setVisibility(View.VISIBLE);
                super.onPageStarted(view, url, favicon);
            }

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

        webView.loadUrl("http://google.com");
    }
}

And R.layout.activity_main:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="match_parent"
     android:layout_height="match_parent">

    <WebView
        android:id="@+id/webview"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

    <ProgressBar
        android:id="@+id/progress"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:visibility="gone"
        android:layout_centerInParent="true"/>
</RelativeLayout>