How to hide scrollbars in the JavaFX WebView

问题

I'm trying to remove the scrollbars in a javafx webview. Search on forums, the suggestion is to make them invisible as follows:

browser.getChildrenUnmodifiable().addListener(new ListChangeListener<Node>() {
    @Override public void onChanged(Change<? extends Node> change) {
        Set<Node> deadSeaScrolls = browser.lookupAll(".scroll-bar");
        for (Node scroll : deadSeaScrolls) {
            scroll.setVisible(false);
        }
    }
})

However, I receive the following error:

"trait ListChangeListener is abstract; cannot be instantiated"

I can understand why its failing, but then again, why are people using this code with success? I'm using Eclipse and the code is surrounded in Scala code.

Thanks! S

回答1:

I wrote the scroll bar hiding code you refer to and posted it to a forum.

I tried it again using WinXPsp3, JavaFX 2.2b13, JDK7u6b14ea and it still works for me.

I have never tried accessing the code from Scala, so you may have run into some Java<->Scala interoperability issue. Java does not have traits, so the error you receive would appear Scala related. I added a Scala tag to your question, so maybe somebody with Scala expertise could help.

Here is a short, compilable test application I used to recheck the functionality.

import java.util.Set;
import javafx.application.Application;
import javafx.collections.ListChangeListener;
import javafx.collections.ListChangeListener.Change;
import javafx.scene.*;
import javafx.scene.web.WebView;
import javafx.stage.Stage;

// demos showing a webview which does not visibly display scrollbars.
public class NoScrollWebView extends Application {
  public static void main(String[] args) { launch(args); }
  @Override public void start(Stage primaryStage) {
    // show a doc in webview.
    final WebView webView = new WebView();
    webView.getEngine().load("http://docs.oracle.com/javafx/2/get_started/jfxpub-get_started.htm");
    primaryStage.setScene(new Scene(webView));
    primaryStage.show();

    // hide webview scrollbars whenever they appear.
    webView.getChildrenUnmodifiable().addListener(new ListChangeListener<Node>() {
      @Override public void onChanged(Change<? extends Node> change) {
        Set<Node> deadSeaScrolls = webView.lookupAll(".scroll-bar");
        for (Node scroll : deadSeaScrolls) {
          scroll.setVisible(false);
        }
      }
    });
  }
}

The best solution here, would probably be to provide a new WebView control skin which does not not have any controls in it - but that would likely be difficult until the WebView control is open sourced.

回答2:

The simplest way to do this is to provide a NoOp Skin for .scroll-bar components in your scene CSS file.

So, in the CSS enter something like:

.scroll-bar {
    -fx-skin: "org.acme.visual.NoOpScrollbarSkin";
}

and subclass SkinBase class:

public class NoOpScrollbarSkin extends SkinBase<ScrollBar,ScrollBarBehavior> {
    public NoOpScrollbarSkin(ScrollBar scrollBar, ScrollBarBehavior scrollBarBehavior) {
        super(scrollBar, scrollBarBehavior);
    }

    public NoOpScrollbarSkin(ScrollBar scrollBar) {
        super(scrollBar, new ScrollBarBehavior(scrollBar));
    }
}

EDIT: this example doesn't appear to work for WebView because of a cast to com.sun.javafx.scene.control.skin.ScrollBarSkin. Solution is not better than previous checking for node changes, one has to subclass ScrollBarSkin to override behavior.

回答3:

When setting up your WebView add this code:

engine.getLoadWorker().stateProperty().addListener(new ChangeListener<State>()
{

    public void changed(ObservableValue<? extends State> o, State old, final State state)
    {
        if (state == State.RUNNING || state == State.SUCCEEDED)
        {
            // System.out.println("Page: " + state + ": " + engine.getLocation());
            engine.executeScript("document.body.style.overflow = 'hidden';");
        }
    }

});

This code will remove the scrollbars of any web-page that is loaded in the WebView.

Unfortunately while the page is loading there might be a scrollbar for a short moment (if the webpage specified one in its markup).

回答4:

I was able to remove the scrollbars by adding the following css block to my global html stylesheet

body {
   overflow-x: hidden;
   overflow-y: hidden;
}

来源：https://stackoverflow.com/questions/11206942/how-to-hide-scrollbars-in-the-javafx-webview

标签

scala

webview

hide

javafx

scrollbars