radiushandle.java

开源（Open Source）项目JHotDraw的文档和源程序

/*
 * @(#)RadiusHandle.java 5.2
 *
 */

package CH.ifa.draw.figures;

import java.awt.*;
import CH.ifa.draw.framework.*;
import CH.ifa.draw.standard.*;
import CH.ifa.draw.util.Geom;

/**
 * A Handle to manipulate the radius of a round corner rectangle.
 */
class RadiusHandle extends AbstractHandle {

    private Point fRadius;
    private RoundRectangleFigure fOwner;
    private static final int OFFSET = 4;

    public RadiusHandle(RoundRectangleFigure owner) {
        super(owner);
        fOwner = owner;
    }

    public void invokeStart(int  x, int  y, DrawingView view) {
        fRadius = fOwner.getArc();
        fRadius.x = fRadius.x/2;
        fRadius.y = fRadius.y/2;
    }

    public void invokeStep (int x, int y, int anchorX, int anchorY, DrawingView view) {
        int dx = x-anchorX;
        int dy = y-anchorY;
        Rectangle r = fOwner.displayBox();
        int rx = Geom.range(0, r.width, 2*(fRadius.x + dx));
        int ry = Geom.range(0, r.height, 2*(fRadius.y + dy));
        fOwner.setArc(rx, ry);
    }

    public Point locate() {
        Point radius = fOwner.getArc();
        Rectangle r = fOwner.displayBox();
        return new Point(r.x+radius.x/2+OFFSET, r.y+radius.y/2+OFFSET);
    }

    public void draw(Graphics g) {
        Rectangle r = displayBox();

        g.setColor(Color.yellow);
        g.fillOval(r.x, r.y, r.width, r.height);

        g.setColor(Color.black);
        g.drawOval(r.x, r.y, r.width, r.height);
    }
}