arrowicon.java

来自「JAVA 工作指南 可以说是程序员必备的东西哦」· Java 代码 · 共 56 行

package components;

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

/* This class is used by CustomIconDemo.java. */
public class ArrowIcon implements Icon, SwingConstants {
    private int width = 9;
    private int height = 18;

    private int[] xPoints = new int[4];
    private int[] yPoints = new int[4];

    public ArrowIcon(int direction) {
        if (direction == LEADING) {
            xPoints[0] = width;
            yPoints[0] = -1;
            xPoints[1] = width;
            yPoints[1] = height;
            xPoints[2] = 0;
            yPoints[2] = height/2;
            xPoints[3] = 0;
            yPoints[3] = height/2 - 1;
        } else /* direction == TRAILING */ {
            xPoints[0] = 0;
            yPoints[0] = -1;
            xPoints[1] = 0;
            yPoints[1] = height;
            xPoints[2] = width;
            yPoints[2] = height/2;
            xPoints[3] = width;
            yPoints[3] = height/2 - 1;
        }
    }

    public int getIconHeight() {
        return height;
    }

    public int getIconWidth() {
        return width;
    }

    public void paintIcon(Component c, Graphics g, int x, int y) {
        if (c.isEnabled()) {
            g.setColor(c.getForeground());
        } else {
            g.setColor(Color.gray);
        }

        g.translate(x, y);
        g.fillPolygon(xPoints, yPoints, xPoints.length);
        g.translate(-x, -y);   //Restore graphics object
    }
}