public void centreViewport() {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
final MoveCamera action = new MoveCamera();
action.setScrollPane(getScrollpane());
action.setPx(ORIGIN.getX()+page.getWidth()*IShape.PPC/2.);
action.setPy(ORIGIN.getY()+getVisibleBound().getHeight()/2.-IShape.PPC);
if(action.canDo())
action.doIt();
action.flush();
}
});
}