JavaFX stop opening URL in WebView - open in browser instead

Question

The embedded WebView browser I am using needs special handling for particular URLs, to open them in the native default browser instead of WebView. The actual browsing part works fine but I need to stop the WebView from displaying that page as well. I can think of several ways to do it but none of them work. Here is my code:

this.wv.getEngine().locationProperty().addListener(new ChangeListener<String>() {
    @Override
    public void changed(ObservableValue<? extends String> observable, String oldValue, String newValue)
    {
        Desktop d = Desktop.getDesktop();
        try
        {
            URI address = new URI(observable.getValue());
            if ((address.getQuery() + "").indexOf("_openmodal=true") > -1)
            {
                // wv.getEngine().load(oldValue); // 1
                // wv.getEngine().getLoadWorker().cancel(); // 2
                // wv.getEngine().executeScript("history.back()"); // 3
                d.browse(address);
            }
        }
        catch (IOException | URISyntaxException e)
        {
            displayError(e);
        }
    }
});

A bit more info about what happens in each of three cases

1. Loading the previous address

wv.getEngine().load(oldValue);

This kills the JVM. Funnily enough, the page opens fine in the native browser.

# A fatal error has been detected by the Java Runtime Environment:
#
#  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x000000005b8fef38, pid=7440, tid=8000
#
# JRE version: 7.0_09-b05
# Java VM: Java HotSpot(TM) 64-Bit Server VM (23.5-b02 mixed mode windows-amd64 compressed oops)
# Problematic frame:
# C  [jfxwebkit.dll+0x2fef38]  Java_com_sun_webpane_platform_BackForwardList_bflItemGetIcon+0x184f58
#
# Failed to write core dump. Minidumps are not enabled by default on client versions of Windows
#
# An error report file with more information is saved as:
# C:\Users\Greg Balaga\eclipse\Companyapp\hs_err_pid7440.log
#
# If you would like to submit a bug report, please visit:
#   http://bugreport.sun.com/bugreport/crash.jsp
# The crash happened outside the Java Virtual Machine in native code.
# See problematic frame for where to report the bug.

2. Cancelling the worker

wv.getEngine().getLoadWorker().cancel();

Does nothing, the page loads in both the WebView and native browser.

3. Using history.back()

wv.getEngine().executeScript("history.back()");

Same as above, no effect.

4. Reacting to Stage changes instead

I have also tried to instead of looking the locationProperty of WebEngine, listen on chenges for stateProperty of the Worker and fire the same opening code if newState == State.SCHEDULED. There was no difference in result from previous method (apart from not actually being able to use #1).

---

Update

The code I'm using now still crashes the JVM:

this.wv.getEngine().locationProperty().addListener(new ChangeListener<String>() {
    @Override
    public void changed(ObservableValue<? extends String> observable, final String oldValue, String newValue)
    {
        Desktop d = Desktop.getDesktop();
        try
        {
            URI address = new URI(newValue);
            if ((address.getQuery() + "").indexOf("_openmodal=true") > -1)
            {
                Platform.runLater(new Runnable() {
                    @Override
                    public void run()
                    {
                        wv.getEngine().load(oldValue);
                    }
                });
                d.browse(address);
            }
        }
        catch (IOException | URISyntaxException e)
        {
            displayError(e);
        }
    }
});

---

Workaround

Ok I managed to make it work by tearing down the webview and rebuilding it.

this.wv.getEngine().locationProperty().addListener(new ChangeListener<String>() {
    @Override
    public void changed(ObservableValue<? extends String> observable, final String oldValue, String newValue)
    {
        Desktop d = Desktop.getDesktop();
        try
        {
            URI address = new URI(newValue);
            if ((address.getQuery() + "").indexOf("_openmodal=true") > -1)
            {
                Platform.runLater(new Runnable() {
                    @Override
                    public void run()
                    {
                        grid_layout.getChildren().remove(wv);
                        wv = new WebView();
                        grid_layout.add(wv, 0, 1);
                        wv.getEngine().load(oldValue);
                    }
                });
                d.browse(address);
            }
        }
        catch (IOException | URISyntaxException e)
        {
            displayError(e);
        }
    }
});

Answer 1

There is another method for handling this.

You can add an event listener to the DOM elements and intercept it that way.

Example:

NodeList nodeList = document.getElementsByTagName("a");
            for (int i = 0; i < nodeList.getLength(); i++)
            {
                Node node= nodeList.item(i);
                EventTarget eventTarget = (EventTarget) node;
                eventTarget.addEventListener("click", new EventListener()
                {
                    @Override
                    public void handleEvent(Event evt)
                    {
                        EventTarget target = evt.getCurrentTarget();
                        HTMLAnchorElement anchorElement = (HTMLAnchorElement) target;
                        String href = anchorElement.getHref();
                        //handle opening URL outside JavaFX WebView
                        System.out.println(href);
                        evt.preventDefault();
                    }
                }, false);
            }

Where document is the DOM document object. Make sure this is done after the document has finished loading.

Answer 2

I finally found a working solution that worked for me:

import javafx.beans.value.ChangeListener;
import javafx.beans.value.ObservableValue;
import javafx.concurrent.Worker;
import javafx.scene.web.WebView;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.w3c.dom.events.Event;
import org.w3c.dom.events.EventListener;
import org.w3c.dom.events.EventTarget;
import org.w3c.dom.html.HTMLAnchorElement;

import java.awt.*;
import java.net.URI;

public class HyperLinkRedirectListener implements ChangeListener<Worker.State>, EventListener
{
    private static final String CLICK_EVENT = "click";
    private static final String ANCHOR_TAG = "a";

    private final WebView webView;

    public HyperLinkRedirectListener(WebView webView)
    {
        this.webView = webView;
    }

    @Override
    public void changed(ObservableValue<? extends Worker.State> observable, Worker.State oldValue, Worker.State newValue)
    {
        if (Worker.State.SUCCEEDED.equals(newValue))
        {
            Document document = webView.getEngine().getDocument();
            NodeList anchors = document.getElementsByTagName(ANCHOR_TAG);
            for (int i = 0; i < anchors.getLength(); i++)
            {
                Node node = anchors.item(i);
                EventTarget eventTarget = (EventTarget) node;
                eventTarget.addEventListener(CLICK_EVENT, this, false);
            }
        }
    }

    @Override
    public void handleEvent(Event event)
    {
        HTMLAnchorElement anchorElement = (HTMLAnchorElement) event.getCurrentTarget();
        String href = anchorElement.getHref();

        if (Desktop.isDesktopSupported())
        {
            openLinkInSystemBrowser(href);
        } else
        {
            // LOGGER.warn("OS does not support desktop operations like browsing. Cannot open link '{}'.", href);
        }

        event.preventDefault();
    }

    private void openLinkInSystemBrowser(String url)
    {
        // LOGGER.debug("Opening link '{}' in default system browser.", url);

        try
        {
            URI uri = new URI(url);
            Desktop.getDesktop().browse(uri);
        } catch (Throwable e)
        {
            // LOGGER.error("Error on opening link '{}' in system browser.", url);
        }
    }
}

Usage:

webView.getEngine().getLoadWorker().stateProperty().addListener(new HyperLinkRedirectListener(webView));

Answer 3

This worked for me as I had to generically trap any anchor with target="_blank". I had to work around the fact that the PopupFeatures callback has absolutely no useful context by asking the DOM for all elements under the pointer (e.g. :hover).

// intercept target=_blank hyperlinks
webView.getEngine().setCreatePopupHandler(
    new Callback<PopupFeatures, WebEngine>() {
        @Override
        public WebEngine call(PopupFeatures config) {
            // grab the last hyperlink that has :hover pseudoclass
            Object o = webView
                    .getEngine()
                    .executeScript(
                            "var list = document.querySelectorAll( ':hover' );"
                                    + "for (i=list.length-1; i>-1; i--) "
                                    + "{ if ( list.item(i).getAttribute('href') ) "
                                    + "{ list.item(i).getAttribute('href'); break; } }");

            // open in native browser
            try {
                if (o != null) {
                    Desktop.getDesktop().browse(
                            new URI(o.toString()));
                } else {
                    log.error("No result from uri detector: " + o);
                }
            } catch (IOException e) {
                log.error("Unexpected error obtaining uri: " + o, e);
            } catch (URISyntaxException e) {
                log.error("Could not interpret uri: " + o, e);
            }

            // prevent from opening in webView
            return null;
        }
    });