Are WebViewClient and WebChromeClient mutually exclusive?

Question

From this great explanation about the differences between WebViewClient and WebChromeClient it seems that if you use one, you shouldn't be using the other (for the same WebView object).

Is my understanding correct?

If not, when would one use both WebViewClient and WebChromeClient for the same WebView object?

Is there an example of a situation where only use both WebViewClient and WebChromeClient for the same WebView object would accomplish a certain goal?

Solution 1

You certainly can use both, they just have different functions. Setting your own custom WebViewClient lets you handle onPageFinished, shouldOverrideUrlLoading, etc., WebChromeClient lets you handle Javascript's alert() and other functions.

Just make your own class, for example:

public class MyWebChromeClient extends WebChromeClient {
    //Handle javascript alerts:
    @Override
public boolean onJsAlert(WebView view, String url, String message, final android.webkit.JsResult result)  
{
  Log.d("alert", message);
  Toast.makeText(context, message, 3000).show();
  result.confirm();
  return true;
};
...

and / or

public class MyWebViewClient extends WebViewClient {
@Override
    //Run script on every page, similar to Greasemonkey:
public void onPageFinished(WebView view, String url) {
        view.loadUrl("javascript:alert('hi')");
    }
...

Just override the functions described in the documentation, then set your client in onCreate with:

webview.setWebViewClient(new MyWebViewClient());
webview.setWebChromeClient(new MyWebChromeClient());

Solution 2

You can use both clients simultaneously. It is useful as both of them provides different functionalities.

For example, if you would like to:

• follow redirects in web view rather than opening available browser

and

• trace the loading progress

which are impossible with just one of the clients you can do the following:

WebView webView = (WebView) findViewById(R.id.web_view);
webView.setWebViewClient(new WebViewClient());
webView.setWebChromeClient(new WebChromeClient() {
    @Override
    public void onProgressChanged(WebView view, int newProgress) {
        super.onProgressChanged(view, newProgress);

        // Your custom code.
    }
});

As the default implementation of shouldOverrideUrlLoading(WebView, String) method can be use as-is for above mentioned case - there is no need to override it unless you would like other behavior.

Comments

[ef2011]

I really meant an example of a situation, not code. :) Accepting unless a better answer comes along.

[user1207504]

@ef2011: Say u want to load a page containing a video into your webview. BUT the page is secured by an htaccess file. So,to authenticate u need to use setWebViewClient and overide its onReceivedHttpAuthRequest() method with ur credentials. Then u want to play the video.... but turns out the video doesnt play! Maybe its controlled via JS. Or it needs a plugin. So, in order to make full use of the content and better JS support you ALSO need to setWebChromeClient(). The way I see it: setWebViewClient for basic HTTP browser stuff, setWebChromeClient for content-related operations and support.

[Chandranshu]

I agree with @ef2011. This comment is more clarifying than the code example above.

[Tomasz Dzieniak]

Maybe is a bit late, but I've provided another use case. :)

[Kifayat Ullah]

I wonder why the Android team not document these things in a simple, clear and understandable way.

[Maseed]

Why WebView is so slow in response and loading contents? Any suggestions or hacks?