rectboundedshape.java

java编写的最好的画图板程序

/*
 * RectBoundedShape.java
 *
 * Created on April 29, 2005, 4:48 PM
 */

package hysun.draw;

import java.awt.*;
import java.awt.event.MouseEvent;

/**
 *
 * @author hysun
 */
public abstract class RectBoundedShape implements IShape {
    
    protected Color color;
    
    protected Stroke stroke;
    
    protected int startX, startY, endX, endY;
    
    protected RectBoundedShape(Color c, Stroke s, int x, int y) {
        color = c;
        stroke = s;
        startX = endX = x;
        startY = endY = y;
    }
    
    public void processCursorEvent(MouseEvent e, int t) {
        if (t != IShape.CURSOR_DRAGGED)
            return;
        int x = e.getX();
        int y = e.getY();
        if (e.isShiftDown()) {
            regulateShape(x, y);
        } else {
            endX = x;
            endY = y;
        }
    }
    
    /** 
     * Regulate the bounding rectangle to a square with ending point 
     * coordinate derived from the specified x, y.
     */
    protected void regulateShape(int x, int y) {
        int w = x - startX;
        int h = y - startY;
        int s = Math.min(Math.abs(w), Math.abs(h));
        if (s == 0) {
            endX = startX;
            endY = startY;
        } else {
            endX = startX + s * (w / Math.abs(w));
            endY = startY + s * (h / Math.abs(h));
        }
    }
    
}