Tetris/scr/tetris/NextBlockPanel.java

package tetris;

import javax.swing.*;
import java.awt.*;

public class NextBlockPanel extends JPanel {
    private Block nextBlock;
    private GamePanel gamePanel;
    private JLabel scoreLabel;
    private final ResourceManager resManager = ResourceManager.getInstance();

    public NextBlockPanel() {
        setPreferredSize(new Dimension(200, 600));
        setLayout(new BorderLayout());
        initUI();
    }

    public void setGamePanel(GamePanel gamePanel) {
        this.gamePanel = gamePanel;
    }

    private static final int[] SPEED_LEVELS = {800, 400, 200};

    private void initUI() {
        JPanel previewPanel = new JPanel() {
            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                if (nextBlock == null) return;

                int[][] shape = nextBlock.getShape();
                int startX = (getWidth() - shape[0].length * 30) / 2;
                int startY = (getHeight() - shape.length * 30) / 2;

                for (int i = 0; i < shape.length; i++) {
                    for (int j = 0; j < shape[i].length; j++) {
                        if (shape[i][j] == 1) {
                            int type = nextBlock.getType();
                            Image blockImage = resManager.getBlockImage(type);
                            if (blockImage != null) {
                                g.drawImage(blockImage, startX + j * 30, startY + i * 30, 29, 29, this);
                            }
                        }
                    }
                }
            }

            @Override
            public Dimension getPreferredSize() {
                return new Dimension(150, 150);
            }
        };
        previewPanel.setBorder(BorderFactory.createTitledBorder("下一个方块"));

        scoreLabel = new JLabel("得分: 0", SwingConstants.CENTER);
        scoreLabel.setFont(new Font("微软雅黑", Font.BOLD, 16));

        JPanel controlPanel = new JPanel(new GridLayout(4, 1, 0, 10));
        controlPanel.setBorder(BorderFactory.createEmptyBorder(20, 10, 20, 10));

        JComboBox<String> combo = new JComboBox<>(new String[]{"简单", "中等", "困难"});
        JButton restartBtn = new JButton("重新开始");

        combo.addActionListener(e -> {
            int index = combo.getSelectedIndex();
            gamePanel.setFallSpeed((index >= 0 && index < SPEED_LEVELS.length) ? SPEED_LEVELS[index] : 500);
            gamePanel.requestFocusInWindow();
        });

        restartBtn.addActionListener(e -> {
            gamePanel.newGame();
            updateScore();
            gamePanel.requestFocusInWindow();
        });

        controlPanel.add(scoreLabel);
        controlPanel.add(new JLabel("难度设置:"));
        controlPanel.add(combo);
        controlPanel.add(restartBtn);

        add(previewPanel, BorderLayout.CENTER);
        add(controlPanel, BorderLayout.SOUTH);

        setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10));
        revalidate();
    }

    public void setNextBlock(Block block) {
        nextBlock = block;
        repaint();
    }

    public void updateScore() {
        SwingUtilities.invokeLater(() -> scoreLabel.setText("得分: " + gamePanel.getScore()));
    }
}