question: public void parseElement ( String tagName , Map < String , Object > attrs ) { if ( canvas == null && tagName . equalsIgnoreCase ( "GRAPH" ) ) { scale = mxUtils . getDouble ( attrs , "scale" , 1 ) ; canvas = createCanvas ( attrs ) ; if ( canvas != null ) { canvas . setScale ( scale ) ; } } else if ( canvas != null ) { boolean drawLabel = false ; if ( tagName . equalsIgnoreCase ( "VERTEX" ) || tagName . equalsIgnoreCase ( "GROUP" ) ) { drawVertex ( attrs ) ; drawLabel = true ; } else if ( tagName . equalsIgnoreCase ( "EDGE" ) ) { drawEdge ( attrs ) ; drawLabel = true ; } if ( drawLabel ) { drawLabel ( tagName . equalsIgnoreCase ( "EDGE" ) , attrs ) ; } } }
target:  Parses the given element and paints it onto the canvas.