如何避免从组中拖放任何mxCell或顶点

Question

我的图表中有多个包含顶点的组。我要求顶点不应移出组或父级。尽管给出了增量坐标，我的所有组都会叠加在一个地方。可以做任何事情来解决这些问题吗？

mxGraph graph = new mxGraph();
Object parent = graph.getDefaultParent()
graph.beginModel().beginUpdate();
for(Object Card: CardList.size())
{
  int x=300;
  int y =300;
  Object vtx=graph.insertVertex(parent,null,"Side",x,y,20,10);//group Object
  graph.createGroupCell(new Object[] {vtx});
   // A recursive function callwhich creates vertices
     y= y+400;
  x=x+300;
}
mxGraphComponent graphComponent= new mxGraphComponent(graph);
graph.isRemoveCellsFromParent(false);
contentPane.add(graphComponent);
graph.endModel().endUpdate();
   }