How to use my trackpad for horizontal mousewheel scrolling in a Java AWT ScrollPane

问题

Like many modern mice and trackpads, my laptop supports vertical and horizontal scrolling. It's an addictive feature once you get used to it. I simply want my Java apps to support horizontal scrolling via the trackpad/mousewheel, but everywhere I search it seems that this is not possible in Java.

I really want someone to tell me that I'm somehow doing it wrong, this feature is already requested behaviour: http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=6440198

The inability to do this simple thing is actually a deal breaker for the app I'm working on. In fact, for any app I can envision! I've invested a bit of time in the Java backend, so I'd really like to find a solution for this seemingly simple thing.

Question is what could I do to implement this behaviour? Are raw OS level events even exposed to me by java, would I then need to write this from scratch?

import java.awt.*;

public class ScrollExample extends Canvas {

    public void paint(Graphics g) {

        g.setColor(Color.green);
        g.fillOval(0,0,400, 400);

    }

    public static void main(String[] args) {

        ScrollExample b = new ScrollExample();
        Frame f = new Frame ("Scroll Example");

        ScrollPane scroller = new ScrollPane (ScrollPane.SCROLLBARS_ALWAYS);
        scroller.add(b,"Center");
        f.setPreferredSize(new Dimension(500,500));
        f.add ("Center",scroller);
        f.pack();
        f.show();

    }

}

Swing example works with both horizontal and vertical scrolling

import java.awt.*;
import javax.swing.*;

public class ScrollExample extends JPanel { 

    public void paint(Graphics g) {

        super.paint(g);

        g.setColor(Color.green);
        g.fillOval(0,0,400, 400);

    }

    public static void main(String[] args) {

        JFrame f = new JFrame ("Scroll Example");
        ScrollExample p = new ScrollExample();
        p.setPreferredSize(new Dimension(1000, 1000));

        JScrollPane scroller = new JScrollPane(p,JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
        scroller.getHorizontalScrollBar().setUnitIncrement(10);
        scroller.getVerticalScrollBar().setUnitIncrement(10);

        f.setPreferredSize(new Dimension(500,500));
        f.add (scroller,BorderLayout.CENTER);
        f.pack();
        f.show();
    }
}

回答1:

This is supported by default in Swing although vertical scolling has priority over horizontal scrolling when both scrollbars are visible.

I would expect new development to be done in Swing not AWT.

Edit:

You should be able to use the Mouse Wheel Controller to customize the scroll speed. I've never tried it on horizontal scrolling, let me know if it works.

回答2:

The navigation events on my MacBookPro's trackpad are handled out of the box. Note there is a method on JScrollPane to enable wheel events: setWheelScrollingEnabled

来源：https://stackoverflow.com/questions/2843314/how-to-use-my-trackpad-for-horizontal-mousewheel-scrolling-in-a-java-awt-scrollp

标签

java

awt

mousewheel

scrollpane