int length = getAnimationLength();
int half = length/2;
double scale = size.getHeight()/length;
int offset = 0;
// calculate the fade out part
if(state >= 0 && state < half) {
// draw the saved version of the old tab component
if(prev != null) {
g2.drawImage(prev,(int)size.getX(),(int)size.getY(),null);
}
offset = (int)((10-state)*scale);
}
// calculate the fade in part
if(state >= half && state < length) {
g2.setColor(Color.white);
offset = (int)((state-10)*scale);
}
// do the drawing
g2.setColor(Color.white);
Rectangle area = new Rectangle((int)(size.getX()+offset),
(int)(size.getY()+offset),
(int)(size.getWidth()-offset*2),
(int)(size.getHeight()-offset*2));
g2.fill(area);
