this.drawingList = context.getDrawingList();
this.properties = context.getProperties();
this.undoMgr = context.getUndoMgr();
selectState = new SelectState(context);
lineState = new LineState(context);
rectState = new RectState(context);
ellipseState = new EllipseState(context);
polygonState = new PolygonState(context);
pencilState = new PencilState(context);
eraserState = new EraserState(context);