Implementation of WebViewClient that can be used to monitor/show/hide progress

ProgressChromeClient.java

import android.annotation.TargetApi;
import android.graphics.Bitmap;
import android.webkit.WebResourceError;
import android.webkit.WebResourceRequest;
import android.webkit.WebView;
import android.webkit.WebViewClient;

/**
 * Extension of {@link WebViewClient} that can update caller about changes in the loading progress
 *
 * @author milan
 */
public class ProgressChromeClient extends WebViewClient {
    private final ProgressListener progressBar;

    public ProgressChromeClient(ProgressListener progressBar) {
        this.progressBar = progressBar;
    }

    @Override
    public void onPageStarted(WebView view, String url, Bitmap favicon) {
        super.onPageStarted(view, url, favicon);
        progressBar.showProgress(view, -1);
    }

    @Override
    public void onPageFinished(WebView view, String url) {
        super.onPageFinished(view, url);
        progressBar.hideProgress(view);
    }

    @SuppressWarnings("deprecation")
    @Override
    public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
        super.onReceivedError(view, errorCode, description, failingUrl);
        progressBar.hideProgress(view);
    }

    @TargetApi(android.os.Build.VERSION_CODES.M)
    @Override
    public void onReceivedError(WebView view, WebResourceRequest request, WebResourceError error) {
        super.onReceivedError(view, request, error);
        progressBar.hideProgress(view);
    }
}

ProgressListener.java

import android.webkit.WebView;

/**
 * Interface to be implemented by callers that requires to listen to progress changes
 *
 * @author milan
 */
public interface ProgressListener {
    /**
     * Invoked when progress needs to be shown
     *
     * @param view     that needs an update
     * @param progress value
     */
    void showProgress(WebView view, int progress);

    /**
     * Invoked when progress needs to be hidden
     *
     * @param view that needs an update
     */
    void hideProgress(WebView view);
}

usage.md

Set a WebViewClient with WebView.setWebViewClient and you are free to use any kind of progress views

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.webkit.WebView;
import android.widget.ProgressBar;

import com.milanix.view.ProgressChromeClient;
import com.milanix.view.ProgressListener;

/**
 * Fragment to display a web page with a progress
 *
 * @author milan
 */
public class WebPageFragment extends Fragment implements ProgressListener {
    protected WebView webView;
    protected ProgressBar progressBar;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        webView.setWebViewClient(new ProgressChromeClient(this));
    }

    @Override
    public void showProgress(WebView view, int progress) {
        progressBar.setVisibility(View.VISIBLE);
    }

    @Override
    public void hideProgress(WebView view) {
        progressBar.setVisibility(View.GONE);
    }
}