drawingboard.java

java编写的最好的画图板程序

/*
 * DrawingBoard.java
 *
 * Created on April 29, 2005, 7:13 PM
 */

package hysun.draw;

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

/**
 *
 * @author hysun
 */
public class DrawingBoard extends JPanel implements 
                                MouseListener, MouseMotionListener {
    
    public static final int TOOL_LINE = 0;
    public static final int TOOL_RECT = 1;
    public static final int TOOL_OVAL = 2;
    public static final int TOOL_DIAMOND = 3;
    public static final int TOOL_PENCIL = 4;
    public static final int TOOL_ERASER = 5;
    public static final int TOOL_POLYGON = 6;
    
    public static final Stroke[] STROKES = new Stroke[] {
        new BasicStroke(1.0f),
        new BasicStroke(2.0f),
        new BasicStroke(5.0f),
        new BasicStroke(7.5f),
        new BasicStroke(10.0f)
    };
    
    public static final Stroke[] ERASER_STROKES = new Stroke[] {
        new BasicStroke(15.0f),
        new BasicStroke(20.0f),
        new BasicStroke(30.0f),
        new BasicStroke(50.0f),
        new BasicStroke(100.0f)
    };
    
    private ArrayList shapes;
    
    private IShape currentShape;
    
    private int tool;
    
    private int strokeIndex, eraserIndex;
    
    public DrawingBoard() {
        shapes = new ArrayList();
        tool = TOOL_LINE;
        currentShape = null;
        strokeIndex = 0;
        eraserIndex = 0;
        
        setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR));
        setOpaque(true);
        setForeground(Color.black);
        setBackground(Color.white);
        
        addMouseListener(this);
        addMouseMotionListener(this);
    }
    
    public void setTool(int t) {
        if (t < TOOL_LINE || t > TOOL_POLYGON)
            throw new IllegalArgumentException("Invaild Tool Specified!");
        tool = t;
    }
    
    public void setStrokeIndex(int i) {
        if (i < 0 || i > 4)
            throw new IllegalArgumentException("Invaild Weight Specified!");
        strokeIndex = i;
    }
    
    public void setEraserIndex(int i) {
        if (i < 0 || i > 4)
            throw new IllegalArgumentException("Invaild Size Specified!");
        eraserIndex = i;
    }
    
    public void clearBoard() {
        shapes.clear();
        repaint();
    }
    
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        int size = shapes.size();
        Graphics2D g2d = (Graphics2D) g;
        for (int i=0; i<size; i++) {
            ((IShape) shapes.get(i)).draw(g2d);
        }
    }
    
    public void mousePressed(MouseEvent e) {
        if (e.getButton() == MouseEvent.BUTTON1) {
            switch (tool) {
                case TOOL_LINE:
                    currentShape = new Line(this.getForeground(), 
                                STROKES[strokeIndex], e.getX(), e.getY());
                    break;
                case TOOL_RECT:
                    currentShape = new Rect(this.getForeground(), 
                                STROKES[strokeIndex], e.getX(), e.getY());
                    break;
                case TOOL_OVAL:
                    currentShape = new Oval(this.getForeground(), 
                                STROKES[strokeIndex], e.getX(), e.getY());
                    break;
                case TOOL_DIAMOND:
                    currentShape = new Diamond(this.getForeground(), 
                                STROKES[strokeIndex], e.getX(), e.getY());
                    break;
                case TOOL_PENCIL:
                    currentShape = new PolyLine(this.getForeground(), 
                                STROKES[strokeIndex], e.getX(), e.getY());
                    break;
                case TOOL_ERASER:
                    currentShape = new Eraser(this, ERASER_STROKES[eraserIndex], 
                                            e.getX(), e.getY());
                    break;
                case TOOL_POLYGON:
                    currentShape = new PolyGon(this.getForeground(), 
                                STROKES[strokeIndex], e.getX(), e.getY());
                    break;
            }
            shapes.add(currentShape);
            repaint();
        } else if (e.getButton() == MouseEvent.BUTTON3 && currentShape != null) {
            currentShape.processCursorEvent(e, IShape.RIGHT_PRESSED);
            repaint();
        }
    }
    
    public void mouseDragged(MouseEvent e) {
        if (currentShape != null) {
            currentShape.processCursorEvent(e, IShape.CURSOR_DRAGGED);
            repaint();
        }
    }
    
    public void mouseReleased(MouseEvent e) {
        if (e.getButton() == MouseEvent.BUTTON1 && currentShape != null) {
            currentShape.processCursorEvent(e, IShape.LEFT_RELEASED);
            currentShape = null;
            repaint();
        }
    }
    
    public void mouseClicked(MouseEvent e) {}
    public void mouseEntered(MouseEvent e) {}
    public void mouseExited(MouseEvent e) {}
    public void mouseMoved(MouseEvent e) {}
    
}