// -*- mode:java; encoding:utf-8 -*-

// vim:set fileencoding=utf-8:

// @homepage@

package example;

import java.awt.*;

import java.awt.event.ActionListener;

import java.awt.event.ComponentAdapter;

import java.awt.event.ComponentEvent;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

import java.awt.event.MouseListener;

import java.util.logging.Logger;

import javax.swing.*;

public final class MainPanel extends JPanel {

public static final Color DRAWER_BG = new Color(33, 37, 41);

public static final Color HOVER_COLOR = new Color(52, 58, 64);

public static final int DRAWER_WIDTH = 200;

public static final int DURATION = 400;

private final JPanel overlay = makeOverlay();

private final JPanel drawer = makeDrawer();

private final Timer timer = new Timer(10, e -> animate());

private DrawerPosition position = DrawerPosition.LEFT;

private long startTime;

private int startX;

private int targetX;

private boolean isOpen;

private MainPanel() {

super();

EventQueue.invokeLater(() -> {

initLayeredPane();

updateLayoutSizes();

});

add(makeControlBox());

setBackground(Color.GRAY);

setPreferredSize(new Dimension(320, 240));

}

private void initLayeredPane() {

JLayeredPane layeredPane = getRootPane().getLayeredPane();

// layeredPane.add(this, JLayeredPane.DEFAULT_LAYER);

layeredPane.add(overlay, JLayeredPane.PALETTE_LAYER);

layeredPane.add(drawer, JLayeredPane.MODAL_LAYER);

layeredPane.addComponentListener(new ComponentAdapter() {

@Override public void componentResized(ComponentEvent e) {

updateLayoutSizes();

}

});

}

private JPanel makeControlBox() {

JButton btnOpen = new JButton("Open Menu");

btnOpen.addActionListener(e -> toggleDrawer());

JRadioButton rbLeft = new JRadioButton("Left", true);

JRadioButton rbRight = new JRadioButton("Right", false);

ButtonGroup group = new ButtonGroup();

group.add(rbLeft);

group.add(rbRight);

ActionListener positionSwitcher = e -> {

position = rbLeft.isSelected() ? DrawerPosition.LEFT : DrawerPosition.RIGHT;

updateLayoutSizes();

};

rbLeft.addActionListener(positionSwitcher);

rbRight.addActionListener(positionSwitcher);

JPanel controls = new JPanel();

controls.setOpaque(false);

controls.add(btnOpen);

controls.add(rbLeft);

controls.add(rbRight);

return controls;

}

private JPanel makeOverlay() {

JPanel ov = new OverlayPanel();

ov.setVisible(false);

ov.addMouseListener(new MouseAdapter() {

@Override public void mousePressed(MouseEvent e) {

if (isOpen) {

toggleDrawer();

}

}

});

return ov;

}

private JPanel makeDrawer() {

Box menuContainer = Box.createVerticalBox();

menuContainer.setBackground(DRAWER_BG);

menuContainer.add(new NavButton("🏠 Dashboard"));

menuContainer.add(new NavButton("📩 Messages"));

menuContainer.add(new NavButton("📊 Analytics"));

menuContainer.add(new NavButton("⚙️ Settings"));

menuContainer.add(Box.createVerticalGlue());

menuContainer.add(new NavButton("🚪 Logout"));

JScrollPane scroll = new JScrollPane(menuContainer);

scroll.setBorder(BorderFactory.createEmptyBorder());

scroll.getVerticalScrollBar().setUnitIncrement(16);

scroll.getViewport().setBackground(DRAWER_BG);

JPanel dr = new JPanel(new BorderLayout());

dr.setBackground(DRAWER_BG);

dr.add(scroll);

// KeyStroke escape = KeyStroke.getKeyStroke("ESCAPE");

// dr.getInputMap(WHEN_IN_FOCUSED_WINDOW).put(escape, "closeDrawer");

// dr.getActionMap().put("closeDrawer", new AbstractAction() {

// @Override public void actionPerformed(ActionEvent e) {

// if (isOpen) {

// toggleDrawer();

// }

// }

// });

return dr;

}

private void updateLayoutSizes() {

Container contentPane = getRootPane().getContentPane();

Dimension d = contentPane.getSize(); // = this.getSize();

int w = d.width;

int h = d.height;

contentPane.setBounds(0, 0, w, h); // this.setBounds(0, 0, w, h);

overlay.setBounds(0, 0, w, h);

drawer.setBounds(isOpen ? getOpenX(w) : getClosedX(w), 0, DRAWER_WIDTH, h);

revalidate();

repaint();

}

private int getOpenX(int w) {

return position == DrawerPosition.LEFT ? 0 : w - DRAWER_WIDTH;

}

private int getClosedX(int w) {

return position == DrawerPosition.LEFT ? -DRAWER_WIDTH : w;

}

private void toggleDrawer() {

if (!timer.isRunning()) {

isOpen = !isOpen;

int w = getRootPane().getContentPane().getWidth();

startX = drawer.getX();

targetX = isOpen ? getOpenX(w) : getClosedX(w);

overlay.setVisible(isOpen);

startTime = System.currentTimeMillis();

timer.start();

}

}

private void animate() {

long elapsed = System.currentTimeMillis() - startTime;

double progress = Math.min(1d, (double) elapsed / DURATION);

double easedProgress = 1 - Math.pow(1 - progress, 3);

int currentX = (int) (startX + (targetX - startX) * easedProgress);

drawer.setLocation(currentX, 0);

boolean stop = progress >= 1d;

if (stop) {

timer.stop();

if (!isOpen) {

overlay.setVisible(false);

}

}

}

public static void main(String[] args) {

EventQueue.invokeLater(MainPanel::createAndShowGui);

}

private static void createAndShowGui() {

try {

UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());

} catch (UnsupportedLookAndFeelException ignored) {

Toolkit.getDefaultToolkit().beep();

} catch (ClassNotFoundException | InstantiationException | IllegalAccessException ex) {

Logger.getGlobal().severe(ex::getMessage);

return;

}

JFrame frame = new JFrame("Drawer Demo");

frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

frame.getContentPane().add(new MainPanel());

frame.pack();

frame.setLocationRelativeTo(null);

frame.setVisible(true);

}

}

enum DrawerPosition {

LEFT, RIGHT

}

class OverlayPanel extends JPanel {

@Override public void updateUI() {

super.updateUI();

setOpaque(false);

setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));

}

@Override protected void paintComponent(Graphics g) {

Graphics2D g2 = (Graphics2D) g.create();

g2.setColor(new Color(0, 0, 0, 140));

g2.fillRect(0, 0, getWidth(), getHeight());

g2.dispose();

}

}

class NavButton extends JButton {

public static final Color TEXT_COLOR = new Color(248, 249, 250);

private transient MouseListener mouseListener;

protected NavButton(String text) {

super(text);

}

@Override public void updateUI() {

removeMouseListener(mouseListener);

super.updateUI();

setContentAreaFilled(false);

setFocusPainted(false);

setBorderPainted(false);

setForeground(TEXT_COLOR);

setHorizontalAlignment(LEFT);

setFont(getFont().deriveFont(Font.PLAIN, 14f));

setBorder(BorderFactory.createEmptyBorder(10, 20, 10, 20));

setCursor(new Cursor(Cursor.HAND_CURSOR));

mouseListener = new MouseAdapter() {

@Override public void mouseEntered(MouseEvent e) {

setOpaque(true);

setBackground(MainPanel.HOVER_COLOR);

}

@Override public void mouseExited(MouseEvent e) {

setOpaque(false);

}

@Override public void mousePressed(MouseEvent e) {

setBackground(MainPanel.HOVER_COLOR.darker());

}

@Override public void mouseReleased(MouseEvent e) {

setBackground(MainPanel.HOVER_COLOR);

}

};

addMouseListener(mouseListener);

}

@Override public Dimension getMaximumSize() {

return new Dimension(MainPanel.DRAWER_WIDTH, 50);

}

@Override protected void paintComponent(Graphics g) {

if (isOpaque()) {

g.setColor(getBackground());

g.fillRect(0, 0, getWidth(), getHeight());

}

super.paintComponent(g);

}

}