How to invalid the diagram move OR set background image can move with node?

I need to create a house design like web application, so I need put a background image of house in div, then put some moveable node with image on it, to display as bed, desk and so on, and they can move optionally.

But when the mouse not point on the node, instead of point on other div space, click and move, all the node will move, and my div background image will not move together, I use the coordinate to locate the node, if I move all the node, the node coordinate will not matched to the background image.

Diagram has a Property allowMove, but it’s only for node, not for all node move.
So my problem is, how to invalid this all node move, or I can setting a background image which can move with all node.

What you’re seeing is the PanningTool operate. You can disable the panning tool:

myDiagram = $(go.Diagram, "myDiagram",
              {
                // other Diagram constructor initialization
                "panningTool.isEnabled": false
              });

But instead it may be better if you do not use a Backround image on the DIV for the room, but instead add a special go.Part to your Diagram that represents the room, that is an unselectable, unpickable object. That’s what the Kitten Monitor sample does:

http://gojs.net/latest/samples/kittenMonitor.html

  // the background image, a floor plan
  myDiagram.add(
    $(go.Part,  // this Part is not bound to any model data
      { layerName: "Background", position: new go.Point(0, 0),
        selectable: false, pickable: false },
      $(go.Picture, "http://upload.wikimedia.org/wikipedia/commons/9/9a/Sample_Floorplan.jpg")
    ));

Hi Simon, thanks for your help, it’s solved in both way.