从Java GUI中形状的用户JList选择中绘制随机大小的形状

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

public class ShapeDrawer extends JFrame {
    private JList<String> shapeList;
    private JPanel drawingPanel;

    public ShapeDrawer() {
        setTitle("Shape Drawer");
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // 创建形状选项列表
        DefaultListModel<String> shapeListModel = new DefaultListModel<>();
        shapeListModel.addElement("Circle");
        shapeListModel.addElement("Rectangle");
        shapeListModel.addElement("Triangle");
        shapeList = new JList<>(shapeListModel);

        // 创建绘图区域
        drawingPanel = new JPanel() {
            @Override
            protected void paintComponent(Graphics g) {
                super.paintComponent(g);
                // 绘制形状逻辑
                String selectedShape = shapeList.getSelectedValue();
                if (selectedShape != null) {
                    int width = (int) (Math.random() * 100) + 50;  // 随机生成形状的宽度
                    int height = (int) (Math.random() * 100) + 50; // 随机生成形状的高度
                    if (selectedShape.equals("Circle")) {
                        g.drawOval(50, 50, width, height);
                    } else if (selectedShape.equals("Rectangle")) {
                        g.drawRect(50, 50, width, height);
                    } else if (selectedShape.equals("Triangle")) {
                        int[] xPoints = {50, 50 + width, 50 + width / 2};
                        int[] yPoints = {50 + height, 50 + height, 50};
                        g.drawPolygon(xPoints, yPoints, 3);
                    }
                }
            }
        };

        // 监听形状选项的选择事件
        shapeList.addListSelectionListener(new ListSelectionListener() {
            @Override
            public void valueChanged(ListSelectionEvent e) {
                drawingPanel.repaint(); // 重新绘制形状
            }
        });

        // 创建布局并添加组件
        setLayout(new BorderLayout());
        add(new JScrollPane(shapeList), BorderLayout.WEST);
        add(drawingPanel, BorderLayout.CENTER);

        pack();
        setLocationRelativeTo(null);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                new ShapeDrawer().setVisible(true);
            }
        });
    }
}