How can I get context menu from webview in Java FX?

Question

I would like to get default context menu items from javafx.scene.web.WebView object . Then I want to fire a menu item programmatically like :

table.getContextMenu().getItems().get(0).fire();

Is this possible ?

Answer 1

This is an XY problem . Per your comment:

Actually all I want to fire the "Open Frame in New Window" menu item.

So you don't actually need to access the WebView's context menu at all, you just want to open a frame from the document in a new window.

A WebView's WebEngine always stores an HTML document as an XML Document object. Once the WebEngine has finished loading the document, you can:

• search for frames using XPath
• examine each frame element's src attribute
• resolve the value of the src attribute against the URI of the original HTML document
• create a new WebView and load that new resolved URI in it

First, you must wait for the WebEngine to finish loading the document. The listener has to be added before you load the page:

    WebEngine engine = webView.getEngine();
    engine.getLoadWorker().stateProperty().addListener(
        (o, old, state) -> updateFrameList(state));
    engine.load(url);

// ...

private void updateFrameList(Worker.State loadState) {
    if (loadState == Worker.State.SUCCEEDED) {
        Document doc = webView.getEngine().getDocument();

Once you have the fully loaded document, you can use the javax.xml.xpath package to search for frames:

NodeList frames;
try {
    XPath xpath = XPathFactory.newInstance().newXPath();
    frames = (NodeList) xpath.evaluate("//*" +
        "[local-name() = 'frame'" +
        " or local-name() = 'FRAME'" + 
        " or local-name() = 'iframe'" + 
        " or local-name() = 'IFRAME']" + 
        "[@src]", doc, XPathConstants.NODESET);
} catch (XPathException e) {
    throw new RuntimeException(e);
}

Since the XPath expression starts with //* , it matches only elements, so it is safe to cast each result to a DOM Element in order to examine its destination:

URI docURI = URI.create(webView.getEngine().getLocation());

int count = frames.getLength();
for (int i = 0; i < count; i++) {
    Element frame = (Element) frames.item(i);
    URI frameLocation = docURI.resolve(frame.getAttribute("src"));
    // Show frameLocation in new window...
}

The easiest part of all is showing the frame's content:

WebView frameView = new WebView();
frameView.getEngine().load(frameLocation.toString());

Stage stage = new Stage();
stage.setTitle("Frame content");
stage.setScene(new Scene(new BorderPane(frameView)));
stage.show();

Here is a program that puts it all together:

import java.net.URI;
import java.util.Collection;
import java.util.Objects;

import javax.xml.xpath.XPath;
import javax.xml.xpath.XPathConstants;
import javax.xml.xpath.XPathFactory;
import javax.xml.xpath.XPathException;

import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.NodeList;

import javafx.application.Application;
import javafx.concurrent.Worker;
import javafx.geometry.Insets;
import javafx.geometry.Pos;

import javafx.stage.Stage;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.control.ComboBox;
import javafx.scene.layout.BorderPane;
import javafx.scene.layout.HBox;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;

public class FrameOpener
extends Application {
    private static class FrameInfo {
        final String name;
        final String uri;

        FrameInfo(String name,
                  String uri) {

            this.name = name;
            this.uri = uri;
        }

        @Override
        public boolean equals(Object obj) {
            if (obj instanceof FrameInfo) {
                FrameInfo other = (FrameInfo) obj;
                return Objects.equals(this.name, other.name) &&
                       Objects.equals(this.uri, other.uri);
            }
            return false;
        }

        @Override
        public int hashCode() {
            return Objects.hash(name, uri);
        }

        @Override
        public String toString() {
            return name;
        }
    }

    private ComboBox<FrameInfo> frameList;
    private WebView webView;

    @Override
    public void start(Stage stage) {
        String url;
        Collection<String> params = getParameters().getRaw();
        if (params.isEmpty()) {
            url = "https://docs.oracle.com/javase/10/docs/api/index.html" +
                "?overview-summary.html";
        } else {
            url = params.iterator().next();
        }

        frameList = new ComboBox<>();

        Label label = new Label("_Frame:");
        label.setMnemonicParsing(true);
        label.setLabelFor(frameList);

        Button showFrameButton = new Button("_Show frame");
        showFrameButton.setMnemonicParsing(true);
        showFrameButton.setOnAction(e -> showFrame());

        webView = new WebView();

        WebEngine engine = webView.getEngine();
        engine.getLoadWorker().stateProperty().addListener(
            (o, old, state) -> updateFrameList(state));
        engine.load(url);

        HBox framePane = new HBox(6, label, frameList, showFrameButton);
        framePane.setAlignment(Pos.BASELINE_CENTER);
        framePane.setFillHeight(true);
        framePane.setPadding(new Insets(12));

        Scene scene = new Scene(
            new BorderPane(webView, null, null, framePane, null));

        stage.setScene(scene);
        stage.setTitle("Frame Opener");
        stage.show();
    }

    private void updateFrameList(Worker.State loadState) {
        if (loadState == Worker.State.SUCCEEDED) {
            Document doc = webView.getEngine().getDocument();
            NodeList frames;
            try {
                XPath xpath = XPathFactory.newInstance().newXPath();
                frames = (NodeList) xpath.evaluate("//*" +
                    "[local-name() = 'frame'" +
                    " or local-name() = 'FRAME'" + 
                    " or local-name() = 'iframe'" + 
                    " or local-name() = 'IFRAME']" + 
                    "[@src]", doc, XPathConstants.NODESET);
            } catch (XPathException e) {
                throw new RuntimeException(e);
            }

            URI docURI = URI.create(webView.getEngine().getLocation());

            int count = frames.getLength();
            FrameInfo[] newFrameInfo = new FrameInfo[count];
            for (int i = 0; i < count; i++) {
                Element frame = (Element) frames.item(i);
                URI frameLocation = docURI.resolve(frame.getAttribute("src"));
                newFrameInfo[i] = new FrameInfo(
                    frame.getAttribute("name"), frameLocation.toString());
            }

            frameList.getItems().setAll(newFrameInfo);
            if (newFrameInfo.length > 0) {
                frameList.setValue(newFrameInfo[0]);
            }
        }
    }

    private void showFrame() {
        FrameInfo info = frameList.getValue();

        WebView frameView = new WebView();
        frameView.getEngine().load(info.uri);

        Stage stage = new Stage();
        stage.setTitle(info.name);
        stage.setScene(new Scene(new BorderPane(frameView)));
        stage.show();
    }
}