How to listen for a WebView finishing loading a URL?

@ian this is not 100% accurate. If you have several iframes in a page you will have multiple onPageFinished (and onPageStarted). And if you have several redirects it may also fail. This approach solves (almost) all the problems:

boolean loadingFinished = true;
boolean redirect = false;

mWebView.setWebViewClient(new WebViewClient() {

    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String urlNewString) {
        if (!loadingFinished) {
            redirect = true;
        }

        loadingFinished = false;
        webView.loadUrl(urlNewString);
        return true;
    }

    @Override
    public void onPageStarted(WebView view, String url) {
        loadingFinished = false;
        //SHOW LOADING IF IT ISNT ALREADY VISIBLE  
    }

    @Override
    public void onPageFinished(WebView view, String url) {
        if (!redirect) {
           loadingFinished = true;
            //HIDE LOADING IT HAS FINISHED
        } else {
            redirect = false; 
        }
    }
});

UPDATE:

According to the documentation: onPageStarted will NOT be called when the contents of an embedded frame changes, i.e. clicking a link whose target is an iframe.

I found a specific case like that on Twitter where only a pageFinished was called and messed the logic a bit. To solve that I added a scheduled task to remove loading after X seconds. This is not needed in all the other cases.

UPDATE 2:

Now with current Android WebView implementation:

boolean loadingFinished = true;
boolean redirect = false;

    mWebView.setWebViewClient(new WebViewClient() {

        @Override
        public boolean shouldOverrideUrlLoading(
                WebView view, WebResourceRequest request) {
            if (!loadingFinished) {
               redirect = true;
            }

            loadingFinished = false;
            webView.loadUrl(request.getUrl().toString());
            return true;
        }

        @Override
        public void onPageStarted(
                WebView view, String url, Bitmap favicon) {
            super.onPageStarted(view, url, favicon);
            loadingFinished = false;
            //SHOW LOADING IF IT ISNT ALREADY VISIBLE  
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            if (!redirect) {
               loadingFinished = true;
                //HIDE LOADING IT HAS FINISHED
            } else {
                redirect = false; 
            }
        }
    });

I am pretty partial to @NeTeInStEiN (and @polen) solution but would have implemented it with a counter instead of multiple booleans or state watchers (just another flavor but I thought might share). It does have a JS nuance about it but I feel the logic is a little easier to understand.

private void setupWebViewClient() {
    webView.setWebViewClient(new WebViewClient() {
        private int running = 0; // Could be public if you want a timer to check.

        @Override
        public boolean shouldOverrideUrlLoading(WebView webView, String urlNewString) {
            running++;
            webView.loadUrl(urlNewString);
            return true;
        }

        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            running = Math.max(running, 1); // First request move it to 1.
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            if(--running == 0) { // just "running--;" if you add a timer.
                // TODO: finished... if you want to fire a method.
            }
        }
    });
}

Extend WebViewClient and call onPageFinished() as follows:

mWebView.setWebViewClient(new WebViewClient() {

   public void onPageFinished(WebView view, String url) {
        // do your stuff here
    }
});