Question

In a Swing-based Java application using Nimbus LookAndFeel I try to set the background color of my tooltips. So I created a subclass of JToolTip and used it in my components by overriding createToolTip(). Fine so far and the tooltip is shown correctly, but the background color does not change. The foreground color is set as expected.
When changing the LookAndFeel to e.g. Metal I can set colors as expected.

Here a small example with ability to switch between Metal and Nimbus. As yopu hopefully see, the background color of the button’s tooltip is only set when Metal is used.

import java.awt.Color;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JToolTip;

public class TooltipTestApp {

private static final String METAL_LOOK_AND_FEEL = "javax.swing.plaf.metal.MetalLookAndFeel";
private static final String NIMBUS_LOOK_AND_FEEL = "com.sun.java.swing.plaf.nimbus.NimbusLookAndFeel";
private static JButton button;
private static String usedLookAndFeel = NIMBUS_LOOK_AND_FEEL;

    public static void main(String args[]) {
        button = new JButton() {

            @Override
            public JToolTip createToolTip() {
                JToolTip toolTip = super.createToolTip();
                toolTip.setBackground(Color.BLACK);
                toolTip.setForeground(Color.RED);

                    return toolTip;
            }
        };

        button.addActionListener(new java.awt.event.ActionListener() {

            @Override
            public void actionPerformed(java.awt.event.ActionEvent evt) {
                TooltipTestApp.toggleLookAndFeel();
            }
        });

        button.setToolTipText("Some text");

        JFrame frame = new JFrame("TooltipTestApp");

        TooltipTestApp.toggleLookAndFeel();
        frame.add(button);
        frame.setSize(450, 100);
        frame.setVisible(true);
    }

    private static void toggleLookAndFeel() {
        try {
            if (usedLookAndFeel.equals(METAL_LOOK_AND_FEEL)) {
                usedLookAndFeel = NIMBUS_LOOK_AND_FEEL;
            } else {
                usedLookAndFeel = METAL_LOOK_AND_FEEL;
            }

            UIManager.setLookAndFeel(usedLookAndFeel);

            String lookAndFeelName = usedLookAndFeel.substring(usedLookAndFeel.lastIndexOf(".") + 1);
            button.setText("This is: " + lookAndFeelName);
        } catch (Exception ex) {
            ex.printStackTrace();
        }
    }
}

Answer 1

The following also works for the Metal LAF without overriding the createToolTip() method:

UIManager.put("ToolTip.background", Color.RED);

LAF’s can choose whether to use the UIManager properties or not. I have no idea if this will work with Nimbus.