DialPointer.java 文件源码

/**
 * Draws the pointer.
 *
 * @param g2  the graphics target.
 * @param plot  the plot.
 * @param frame  the dial's reference frame.
 * @param view  the dial's view.
 */
@Override
public void draw(Graphics2D g2, DialPlot plot, Rectangle2D frame,
    Rectangle2D view) {

    g2.setPaint(this.paint);
    g2.setStroke(this.stroke);
    Rectangle2D arcRect = DialPlot.rectangleByRadius(frame,
            this.radius, this.radius);

    double value = plot.getValue(this.datasetIndex);
    DialScale scale = plot.getScaleForDataset(this.datasetIndex);
    double angle = scale.valueToAngle(value);

    Arc2D arc = new Arc2D.Double(arcRect, angle, 0, Arc2D.OPEN);
    Point2D pt = arc.getEndPoint();

    Line2D line = new Line2D.Double(frame.getCenterX(),
            frame.getCenterY(), pt.getX(), pt.getY());
    g2.draw(line);
}