java - 检测 WebView 中的超链接悬停并打印链接

Question

我想从 WebView 添加悬停的超链接并将其显示在角落中。

我怎样才能实现？它应该像 Chrome 的功能:

Chrome 屏幕截图示例

包含许多链接的示例 WebView 代码:

import javafx.application.Application;
import javafx.scene.Group;
import javafx.scene.Scene;
import javafx.scene.control.ScrollPane;
import javafx.scene.web.WebEngine;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

public class core extends Application {
    @Override
    public void start(final Stage stage) {
        Scene scene = new Scene(new Group());

        final WebView browser = new WebView();
        final WebEngine webEngine = browser.getEngine();

        ScrollPane scrollPane = new ScrollPane();
        scrollPane.setContent(browser);

        webEngine.load("http://java2s.com");

        scene.setRoot(scrollPane);

        stage.setScene(scene);
        stage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

Answer 1

第一件事 - 您的 Scene 应该包含多个元素，而不仅仅是 ScrollPane。您需要一个 TextField 来显示超链接的内容，并且这两个 Control 应该放置在某种 Pane 上。 为了处理当鼠标滑过超链接时显示内容，您需要获取所有超链接类型的节点，然后向它们添加适当的监听器。

看看下面的代码，它实现了您想要实现的目标(它部分基于 'JavaFX WebView addHyperlinkListener' article from the 'Inspiration and Expression' blog ):

public class Main extends Application {

  @Override
  public void start(final Stage stage) {
    Scene scene = new Scene(new Group());

    final WebView browser = new WebView();
    final WebEngine webEngine = browser.getEngine();

    ScrollPane scrollPane = new ScrollPane();
    scrollPane.setContent(browser);

    TextField textField = new TextField();
    textField.setVisible(false);
    textField.setEditable(false);

    webEngine.getLoadWorker().stateProperty().addListener((observable, oldValue, newValue) -> {
      if (newValue == Worker.State.SUCCEEDED) {

        EventListener mouseOverEventListener = new EventListener() {
          @Override
          public void handleEvent(Event ev) {
            String href = ((Element) ev.getTarget()).getAttribute("href");
            textField.setText(href);
            textField.setVisible(true);
            textField.setPrefWidth(textField.getText().length() * 6); //
            System.out.println(href);
          }
        };

        EventListener mouseOutEventListener = new EventListener() {
          @Override
          public void handleEvent(Event ev) {
            textField.setVisible(false);
          }
        };

        Document document = webEngine.getDocument();
        NodeList nodeList = document.getElementsByTagName("a");
        for (int i = 0 ; i < nodeList.getLength() ; i++) {
          ((EventTarget) nodeList.item(i)).addEventListener("mouseover",mouseOverEventListener,false);
          ((EventTarget) nodeList.item(i)).addEventListener("mouseout",mouseOutEventListener,false);
        }
      }
    });

    String content = "http://java2s.com";
    webEngine.load(content);

    AnchorPane anchorPane = new AnchorPane();
    anchorPane.getChildren().add(scrollPane);
    anchorPane.getChildren().add(textField);
    AnchorPane.setBottomAnchor(textField, 0.0);
    AnchorPane.setLeftAnchor(textField, 0.0);

    scene.setRoot(anchorPane);
    stage.setScene(scene);
    stage.show();
  }

  public static void main(String[] args) {
    launch(args);
  }
}