Swing には CSS スタイルはありません。ただし、Swing の後継である JavaFx2 を使用する場合は、CSS スタイルを利用できます。
Swing にまだ慣れていない場合は、JavaFX を検討することをお勧めします。最新の 1.7 バージョンの Java には、JavaFX 2.2 が組み込まれています。これには、CSS サポートとMedia Playerがあります。
もちろんSwingでも可能です。使用できるさまざまなアプローチがありますが、出発点として、ボタンを作成する方法を次に示します。このアプローチには Java 7 が必要ですが、代わりに JXLayer を使用すると、以前のバージョンの Java でも実行できます。ボタンは、2D ペイントと私がアクセスできるいくつかのアイコンの組み合わせです。お持ちのアイコンに変更するだけです。使用している画像に応じて、円のサイズが自動的に変更されます。
ボタンをクリックすると、ビープ音が鳴り、適切なテキストがコンソールに出力されます。一般的に言えば、JLayer は Swing アプリケーションのスタイリングに非常に役立ちます。

import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.geom.Ellipse2D;
import java.awt.geom.Rectangle2D;
import java.net.URL;
import java.util.logging.Logger;
import javax.swing.*;
import javax.swing.plaf.LayerUI;
/**
*/
public class MediaPlayer {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
JFrame frame = new JFrame("Media Clone");
MediaController mediaController = new MediaController();
frame.getContentPane().add(new MediaView(mediaController));
frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
frame.setMinimumSize(new Dimension(800, 450));
frame.setLocationRelativeTo(null); // Center
frame.pack();
frame.setVisible(true);
}
});
}
static class MediaView extends JPanel {
private MediaList mediaList;
private ButtonView buttonView;
private MediaController controller;
MediaView(MediaController controller) {
this.controller = controller;
createComponents();
makeLayout();
}
public void createComponents() {
mediaList = new MediaList();
buttonView = new ButtonView(controller);
}
public void makeLayout() {
setLayout(new BorderLayout());
add(mediaList);
add(new JLayer<>(buttonView, new GradientUI()), BorderLayout.NORTH);
}
}
static class MediaList extends JPanel {
private JTable mediaTable;
MediaList() {
createComponents();
makeLayout();
}
public void createComponents() {
String[] header = new String[]{"Song", "Artist"};
String[][] model = new String[2][2];
model[0][0] = "Hello";
model[0][1] = "World";
model[1][0] = "Goodbye";
model[1][1] = "Sunshine";
mediaTable = new JTable(model, header);
}
public void makeLayout() {
setLayout(new BorderLayout());
add(new JScrollPane(mediaTable));
}
}
static class GradientUI extends LayerUI<JComponent> {
@Override
public void paint(Graphics g, JComponent c) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
int height = c.getHeight();
int width = c.getWidth();
g2.setPaint(new GradientPaint(0, 0, new Color(136, 146, 155), 0, height, new Color(101, 108, 116)));
Rectangle2D area = new Rectangle(0, 0, width, height);
g2.fill(area);
super.paint(g2, c);
}
}
enum MediaAction {
PLAY, NEXT, PREVIOUS
}
static class MediaController {
private Toolkit toolkit = Toolkit.getDefaultToolkit();
public void execute(MediaAction mediaAction) {
toolkit.beep();
System.out.println(mediaAction.name());
}
}
static class ButtonView extends JPanel {
private static Logger log = Logger.getLogger(ButtonView.class.getName());
private JButton play;
private JButton next;
private JButton previous;
private RoundButtonUI playUI;
private ActionListener playActionListener;
private ActionListener nextActionListener;
private ActionListener previousActionListener;
private MediaController controller;
ButtonView(MediaController controller) {
this.controller = controller;
createComponents();
makeLayout();
createHandlers();
registerHandlers();
initComponent();
}
public void createComponents() {
play = new JButton();
next = new JButton();
previous = new JButton();
playUI = new RoundButtonUI();
}
public void createHandlers() {
playActionListener = createMediaAction(MediaAction.PLAY);
nextActionListener = createMediaAction(MediaAction.NEXT);
previousActionListener = createMediaAction(MediaAction.PREVIOUS);
}
private ActionListener createMediaAction(final MediaAction mediaAction) {
return new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
controller.execute(mediaAction);
}
});
}
};
}
public void registerHandlers() {
play.addActionListener(playActionListener);
next.addActionListener(nextActionListener);
previous.addActionListener(previousActionListener);
}
public void makeLayout() {
setLayout(new FlowLayout(FlowLayout.LEADING));
makeButtonRound(previous, "<<", "bullet_triangle_grey_shadow.png", "bullet_triangle_grey.png");
makeButtonRound(play, ">", "bullet_triangle_glass_grey128x128.png", "bullet_triangle_glass_grey128x128.png");
makeButtonRound(next, ">>", "bullet_triangle_grey_shadow.png", "bullet_triangle_grey.png");
add(new JLayer<>(previous, playUI));
add(new JLayer<>(play, playUI));
add(new JLayer<>(next, playUI));
}
public void initComponent() {
setOpaque(false);
}
private void makeButtonRound(final JButton toBeRounded, String fallback, String imageNormal, String imagePressed) {
toBeRounded.setOpaque(false);
toBeRounded.setFocusPainted(false);
toBeRounded.setBorderPainted(false);
toBeRounded.setContentAreaFilled(false);
toBeRounded.setBorder(BorderFactory.createEmptyBorder(5, 10, 5, 5));
URL normalURL = getClass().getClassLoader().getResource(imageNormal);
URL pressedURL = getClass().getClassLoader().getResource(imagePressed);
if (normalURL != null || pressedURL != null) {
final ImageIcon released = new ImageIcon(normalURL);
final ImageIcon pressed = new ImageIcon(pressedURL);
toBeRounded.setIcon(released);
toBeRounded.addMouseListener(new MouseAdapter() {
@Override
public void mousePressed(MouseEvent e) {
toBeRounded.setIcon(pressed);
}
@Override
public void mouseReleased(MouseEvent e) {
toBeRounded.setIcon(released);
}
});
} else {
toBeRounded.setText(fallback);
log.severe("Missing resources: " + imageNormal + " and " + imagePressed);
}
}
}
/**
* Shifts the image so it looks pressed down.
* Creates a circle around the icon, that varies in size depending on the supplied icon.
*/
static class RoundButtonUI extends LayerUI<JComponent> {
private static final int STROKE_WIDTH = 5;
@Override
public void paint(Graphics g, JComponent c) {
Graphics2D g2 = (Graphics2D) g.create();
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON);
ButtonModel buttonModel;
JButton b;
if (((JLayer) c).getView() instanceof JButton) {
b = (JButton) ((JLayer) c).getView();
buttonModel = b.getModel();
} else {
super.paint(g, c);
return;
}
int iconHeight = b.getIcon() != null ? b.getIcon().getIconHeight() : 60;
int iconWidth = b.getIcon() != null ? b.getIcon().getIconWidth() : 60;
Shape circle = new Ellipse2D.Double(STROKE_WIDTH, STROKE_WIDTH, iconHeight, iconWidth);
g2.setPaint(new GradientPaint(5, 5, new Color(222, 224, 230), 30, 55, new Color(187, 189, 199)));
g2.fill(circle);
g2.setPaint(new GradientPaint(15, 0, new Color(90, 97, 105), 15, 30, new Color(132, 142, 152)));
g2.setStroke(new BasicStroke(5));
g2.draw(circle);
if (buttonModel.isPressed()) {
g2.translate(1, 1);
}
super.paint(g2, c);
g2.dispose();
}
}
}