question: public static void optionClean ( ) { mDataList . clear ( ) ; mFile = null ; if ( mSlicingHandler != null ) { mSlicingHandler . setOriginalProject ( null ) ; mSlicingHandler . setLastReference ( null ) ; mSeekBar . setVisibility ( View . INVISIBLE ) ; mSurface . requestRender ( ) ; showProgressBar ( 0 , 0 ) ; } }
target:  Clean the print panel and delete all references