Remove Arrows from Swing Scrollbar in JScrollPane

问题

I would like to remove the scrollbar arrow buttons from a scrollbar in a JScrollPane. How would I do this?

回答1:

class NoArrowScrollBarUI extends BasicScrollBarUI {


protected JButton createZeroButton() {
    JButton button = new JButton("zero button");
    Dimension zeroDim = new Dimension(0,0);
    button.setPreferredSize(zeroDim);
    button.setMinimumSize(zeroDim);
    button.setMaximumSize(zeroDim);
    return button;
}

@Override
protected JButton createDecreaseButton(int orientation) {
    return createZeroButton();
}

@Override
protected JButton createIncreaseButton(int orientation) {
    return createZeroButton();
}


@Override
protected void paintTrack(Graphics g, JComponent c, Rectangle trackBounds) {
    //own painting if needed
}

@Override
protected void paintThumb(Graphics g, JComponent c, Rectangle thumbBounds) {
    //own painting if needed
}

}

Removing buttons let space for then. I found make buttons zero as the simplest way.

回答2:

If you are using the basic version of JScrollBar, then it is probably rendering using the BasicScrollBarUI. I would suggest that you extend BasicScrollBarUI to create a custom UI class (like MyBasicScrollBarUI) . The buttons are protected variables in the superclass. So you need to override the installComponents() methods in the subclass and make sure that you do not add the buttons. See the below code snippet and hide the lines as suggested there.

protected void installComponents(){
    switch (scrollbar.getOrientation()) {
    case JScrollBar.VERTICAL:
        incrButton = createIncreaseButton(SOUTH);
        decrButton = createDecreaseButton(NORTH);
        break;

    case JScrollBar.HORIZONTAL:
        if (scrollbar.getComponentOrientation().isLeftToRight()) {    
            incrButton = createIncreaseButton(EAST);
            decrButton = createDecreaseButton(WEST);
        } else {
            incrButton = createIncreaseButton(WEST);
            decrButton = createDecreaseButton(EAST);
        }
        break;
    }
    scrollbar.add(incrButton); // Comment out this line to hide arrow
    scrollbar.add(decrButton); // Comment out this line to hide arrow
    // Force the children's enabled state to be updated.
scrollbar.setEnabled(scrollbar.isEnabled());
}

Then, in your code after you initialize a JScrollBar, you can call setUI() and pass in an instance of MyBasicScrollBarUI class.

Note: I havent tried this myself, but from the code it looks like it could work.

回答3:

It is not the most elegant way... but works for me

JScrollBar jsb = getHorizontalScrollBar();
        for(Component c : jsb.getComponents()) {
            jsb.remove(c);
        }

来源：https://stackoverflow.com/questions/1786886/remove-arrows-from-swing-scrollbar-in-jscrollpane

标签

java

swing

icons

jbutton

jscrollbar