question: public static boolean extendDown ( Spannable text , Layout layout ) { int end = getSelectionEnd ( text ) ; int line = layout . getLineForOffset ( end ) ; if ( line < layout . getLineCount ( ) - 1 ) { int move ; if ( layout . getParagraphDirection ( line ) == layout . getParagraphDirection ( line + 1 ) ) { float h = layout . getPrimaryHorizontal ( end ) ; move = layout . getOffsetForHorizontal ( line + 1 , h ) ; } else { move = layout . getLineStart ( line + 1 ) ; } extendSelection ( text , move ) ; return true ; } else if ( end != text . length ( ) ) { extendSelection ( text , text . length ( ) ) ; return true ; } return true ; }
target:  Move the selection end to the buffer offset physically below the current selection end.