GraphicsJLabel.java 文件源码

/**
 * Draws a black triangle-shaped shadow with the vertix in the middle of the
 * Rectangle <code> from</code> and the base centred in the middle of the
 * Rectangle <code>to</code>. The base width is determined by the parameter
 * <code>defaultWidth</code>. the base at <code>base</code>.
 *
 * @param vertix
 * @param base
 */
private void draw(Rectangle from, Rectangle to) {
    GraphicsJLabel label = this;
    EventQueue.invokeLater(new Runnable() {
        @Override
        public void run() {
            xx[0] = from.getX() + from.getWidth() / 2;
            yy[0] = from.getY() + from.getHeight() / 2;
            xx[1] = to.getX() + to.getWidth() / 2;
            yy[1] = to.getY() + to.getHeight() / 2;
            double alpha = atan(Math.abs((xx[1] - xx[0]) / (yy[1] - yy[0])));
            xx[2] = xx[1] + DEFAULT_WIDTH * cos(alpha);
            yy[2] = yy[1] + DEFAULT_WIDTH * sin(alpha);
            label.updateUI();
        }
    });

}