How to change button text color and background color while button is pressed

Question

I'm trying to change the button background color and text (foreground) color while the mouse button is pressed, using Swing UI in Java. My main class is pretty simple and straightforward:

public class Main {


    public static void main(String[] args) {
        SynthLookAndFeel laf = new SynthLookAndFeel();
        try {
            laf.load(Main.class.getResourceAsStream("/styles.xml"), Main.class);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        try {
            UIManager.setLookAndFeel(laf);
        } catch (UnsupportedLookAndFeelException e) {
            e.printStackTrace();
        }

        JFrame frame = new JFrame("Not hello world");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        frame.setSize(300, 300);
        frame.setLocation(50, 50);
        frame.setLayout(new FlowLayout());

        frame.add(new JButton("Button 1"));
        frame.add(new JButton("Button 2"));
        frame.add(new JButton("Button 3"));

        frame.setVisible(true);


    }
}

the loaded XML Synth style file is following:

<synth>
    <style id="basicStyle">
        <font name="Verdana" size="16"/>
        <state>
            <color value="#eeeeee" type="BACKGROUND"/>
            <color value="#000000" type="FOREGROUND"/>
        </state>

    </style>
    <bind style="basicStyle" type="region" key=".*"/>

<style id ="button_style">
    <state value="PRESSED">
        <color value="#666666" type="FOREGROUND" />
        <color value="#aaaaaa" type="BACKGROUND" />
    </state>
</style>
<bind style="button_style" type="region" key="button"/>

But all I get is buttons that have black text and gray-ish backround, on the screen. When pressing the buttons, nothing happens:

Any way I can achieve such a behavior?

Answer 1

There are some issues in your Synth file:

1. It's not closed with </synth>

2. If you don't set opaque="true" in it, by default your JButton will be transparent (i.e. your background won't be visible).

3. I'm not entirely sure why, but for the foreground font color to change on state change you need to use TEXT_FOREGROUND instead of FOREGROUND key.

I changed some colors from your file as they weren't too visible, but your file should look something like:

<synth>
    <style id="basicStyle">
        <font name="Verdana" size="16" />
        <state>
            <color value="#eeeeee" type="BACKGROUND" />
            <color value="#000000" type="FOREGROUND" />
        </state>

    </style>
    <bind style="basicStyle" type="region" key=".*" />

    <style id="button_style">
        <opaque value="true" />
        <insets top="4" left="4" right="4" bottom="4" />
        <state>
            <color value="blue" type="TEXT_FOREGROUND" />
            <color value="#ffffff" type="BACKGROUND" />
        </state>
        <state value="PRESSED">
            <color value="white" type="TEXT_FOREGROUND" />
            <color value="#aaaaaa" type="BACKGROUND" />
        </state>
    </style>
    <bind style="button_style" type="region" key="button" />
</synth>