private void computeBackgrounds ( BoxNode root , Color currentbg ) { Color newbg = root . getBackgroundColor ( ) ; if ( newbg == null ) newbg = currentbg ; root . setEfficientBackground ( newbg ) ; root . setBackgroundSeparated ( ! newbg . equals ( currentbg ) ) ; for ( int i = 0 ; i < root . getChildCount ( ) ; i ++ ) computeBackgrounds ( ( BoxNode ) root . getChildAt ( i ) , newbg ) ; }
Computes efficient background color for all the nodes in the tree