question: public static final void centerChildToParent ( final Component parent , final Component child , final boolean bStayOnScreen ) { int x = ( parent . getX ( ) + ( parent . getWidth ( ) / 2 ) ) - ( child . getWidth ( ) / 2 ) ; int y = ( parent . getY ( ) + ( parent . getHeight ( ) / 2 ) ) - ( child . getHeight ( ) / 2 ) ; if ( bStayOnScreen ) { final Toolkit tk = Toolkit . getDefaultToolkit ( ) ; final Dimension ss = new Dimension ( tk . getScreenSize ( ) ) ; if ( ( x + child . getWidth ( ) ) > ss . getWidth ( ) ) { x = ( int ) ( ss . getWidth ( ) - child . getWidth ( ) ) ; } if ( ( y + child . getHeight ( ) ) > ss . getHeight ( ) ) { y = ( int ) ( ss . getHeight ( ) - child . getHeight ( ) ) ; } if ( x < 0 ) { x = 0 ; } if ( y < 0 ) { y = 0 ; } } child . setLocation ( x , y ) ; }
target:  Centers the child component relative to it's parent component