DetachingArcThrobberUI.java 文件源码

private void paintArc(Graphics2D g,JComponent jc,float f,float w,float h,float multiplier,float angleOffset,float a) {
    float z = f*f*f*f;
    float r = f * w / 2f;
    float arcX = w/2f - r;
    float arcY = h/2f - r;
    float arcW = 2*r;
    float arcH = 2*r;
    float arcStart = (float)( multiplier*Math.sqrt(f)*360 + angleOffset );
    float arcExtent = (1-f)*(1-f)*360/3;

    Arc2D arc = new Arc2D.Float( arcX, arcY, arcW, arcH, arcStart, arcExtent, Arc2D.OPEN);
    g.setStroke(new BasicStroke(4*(1-z)));

    Color c = jc==null ? getDefaultForeground() : jc.getForeground();
    int alpha = (int)( 255*(1-f)*a );
    g.setColor(new Color( c.getRed(), c.getGreen(), c.getBlue(), Math.min(alpha, 255) ));
    g.draw(arc);
}