PlumNeedle.java 文件源码

/**
 * Draws the needle.
 *
 * @param g2  the graphics device.
 * @param plotArea  the plot area.
 * @param rotate  the rotation point.
 * @param angle  the angle.
 */
protected void drawNeedle(Graphics2D g2, Rectangle2D plotArea, Point2D rotate, double angle) {

    Arc2D shape = new Arc2D.Double(Arc2D.PIE);
    double radius = plotArea.getHeight();
    double halfX = plotArea.getWidth() / 2;
    double diameter = 2 * radius;

    shape.setFrame(plotArea.getMinX() + halfX - radius ,
                   plotArea.getMinY() - radius,
                   diameter, diameter);
    radius = Math.toDegrees(Math.asin(halfX / radius));
    shape.setAngleStart(270 - radius);
    shape.setAngleExtent(2 * radius);

    Area s = new Area(shape);

    if ((rotate != null) && (angle != 0)) {
        /// we have rotation houston, please spin me
        getTransform().setToRotation(angle, rotate.getX(), rotate.getY());
        s.transform(getTransform());
    }

    defaultDisplay(g2, s);
}