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

public class DrawingPanelBefore extends JPanel implements MouseListener, MouseMotionListener {
    private Point startPoint;
    private Point endPoint;
    private String currentTool = "RECTANGLE"; // Beispielwerkzeug

    public DrawingPanelBefore() {
        addMouseListener(this);
        addMouseMotionListener(this);
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        if (startPoint != null && endPoint != null) {
            int x = Math.min(startPoint.x, endPoint.x);
            int y = Math.min(startPoint.y, endPoint.y);
            int width = Math.abs(startPoint.x - endPoint.x);
            int height = Math.abs(startPoint.y - endPoint.y);

            switch (currentTool) {
                case "RECTANGLE":
                    g.drawRect(x, y, width, height);
                    break;
                // Weitere Fälle für andere Werkzeuge
            }
        }
    }

    @Override
    public void mousePressed(MouseEvent e) {
        startPoint = e.getPoint();
    }

    @Override
    public void mouseReleased(MouseEvent e) {
        endPoint = e.getPoint();
        repaint();
    }

    @Override
    public void mouseDragged(MouseEvent e) {
        endPoint = e.getPoint();
        repaint();
    }

    // Leere Implementierungen für nicht genutzte Methoden
    @Override public void mouseClicked(MouseEvent e) {}
    @Override public void mouseEntered(MouseEvent e) {}
    @Override public void mouseExited(MouseEvent e) {}
    @Override public void mouseMoved(MouseEvent e) {}
}

public interface DrawingCommand {
    void mousePressed(int x, int y);
    void mouseDragged(int x, int y);
    void mouseReleased(int x, int y);
    void execute();
    void undo();
}

public class DrawRectangleCommand implements DrawingCommand {
    private Point startPoint;
    private Point currentPoint;
    private DrawingPanelAfter panel;

    public DrawRectangleCommand(DrawingPanelAfter panel) {
        this.panel = panel;
    }

    @Override
    public void mousePressed(int x, int y) {
        startPoint = new Point(x, y);
    }

    @Override
    public void mouseDragged(int x, int y) {
        currentPoint = new Point(x, y);
        panel.repaint();
    }

    @Override
    public void mouseReleased(int x, int y) {
        currentPoint = new Point(x, y);
        panel.addRectangle(startPoint.x, startPoint.y, Math.abs(x - startPoint.x), 
                                                       Math.abs(y - startPoint.y));
        panel.repaint();
    }
    
    // Vorheriger Zustand, z.B. eine Liste aller bisher gezeichneten Formen
    private DrawingPanelAfter panel;

    @Override
    public void execute() {
        // Zeichnen des Rechtecks
    }

    @Override
    public void undo() {
        // Entfernen des zuletzt gezeichneten Rechtecks
    }
}

public class DrawLineCommand implements DrawingCommand {
    private Point startPoint;
    private Point currentPoint;
    private DrawingPanelAfter panel;

    public DrawLineCommand(DrawingPanelAfter panel) {
        this.panel = panel;
    }

    @Override
    public void mousePressed(int x, int y) {
        startPoint = new Point(x, y);
    }

    @Override
    public void mouseDragged(int x, int y) {
        currentPoint = new Point(x, y);
        panel.repaint();
    }

    @Override
    public void mouseReleased(int x, int y) {
        currentPoint = new Point(x, y);
        panel.addLine(startPoint.x, startPoint.y, x, y);
        panel.repaint();
    }
}

import java.util.ArrayList;

public class DrawingPanelAfter extends JPanel implements MouseListener, MouseMotionListener {
    private DrawingCommand currentCommand;
    private ArrayList<Shape> shapes = new ArrayList<>();

    public DrawingPanelAfter() {
        setDrawingTool("LINE"); // Standardmäßig Linien-Werkzeug
        addMouseListener(this);
        addMouseMotionListener(this);
    }

    public void setDrawingTool(String toolType) {
        switch (toolType) {
            case "RECTANGLE":
                this.currentCommand = new DrawRectangleCommand(this);
                break;
            case "LINE":
                this.currentCommand = new DrawLineCommand(this);
                break;
            // Weitere Werkzeuge können hier hinzugefügt werden
        }
    }

    public void addRectangle(int x, int y, int width, int height) {
        shapes.add(new Rectangle(x, y, width, height));
    }

    public void addLine(int startX, int startY, int endX, int endY) {
        shapes.add(new Line2D.Float(startX, startY, endX, endY));
    }

    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D) g;
        for (Shape shape : shapes) {
            g2.draw(shape);
        }
    }

    @Override
    public void mousePressed(MouseEvent e) {
        currentCommand.mousePressed(e.getX(), e.getY());
    }

    @Override
    public void mouseReleased(MouseEvent e) {
        currentCommand.mouseReleased(e.getX(), e.getY());
    }

    @Override
    public void mouseDragged(MouseEvent e) {
        currentCommand.mouseDragged(e.getX(), e.getY());
    }

    // Leere Implementierungen für nicht genutzte Methoden
    @Override public void mouseClicked(MouseEvent e) {}
    @Override public void mouseEntered(MouseEvent e) {}
    @Override public void mouseExited(MouseEvent e) {}
    @Override public void mouseMoved(MouseEvent e) {}
}