As a part's unconnected port (shown by an X) comes close to a stationary port with which it is compatible, the dragged selection snaps so that those ports coincide. A custom DraggingTool, called SnappingTool, is used to check compatibility.
Dragging automatically drags all connected parts. Hold down the Shift key before dragging in order to detach a part from the parts it is connected with. These functionalities are also controlled by the custom SnappingTool.
Use the GraphObject.contextMenu to rotate, detach, or delete a node. If it is connected with other parts, the whole collection rotates.