In this picture the red (darker) links are intergraph links and the yellow (light) links are regular links.

Creating an Intergraph Link

Given that the intergraph link has an origin and a destination in different graphers, the question is in which grapher the link itself is stored.

To create an intergraph link, the code will look like this (assuming that the origin and destination variables have been created and added in different graphers):

IlvGraphic origin, destination;
IlvLinkImage link;

...

link = new IlvLinkImage(origin, destination, false);

IlvGrapher common = IlvGrapher.getLowestCommonGrapher(origin, destination);

common.addLink(link, false);

The IlvGrapher.addInterGraphLink static utility method allows you to directly add the link in the common parent grapher:

The code shown in the previous example is the equivalent to:

IlvGraphic origin, destination;
IlvLinkImage link;

...

link = new IlvLinkImage(origin, destination, false);

IlvGrapher.addInterGraphLink(link, false);

Accessing the Intergraph Link

Since an intergraph link is stored in the same way as other links in the grapher, it is also part of the list of all objects contained in this grapher returned by the getObjects method of the class IlvManager:

Nevertheless, calling the getInterGraphLinks method is much more efficient than traversing all objects of the grapher.

To distinguish an intergraph link from other objects in the grapher, you can use the following method of the IlvGrapher class:

This method returns true if the specified graphic object is a link stored in the grapher instance with the origin or the destination stored somewhere else. That is, if the graphic object is an intergraph link.

The difference between the methods getInterGraphLinks and getExternalInterGraphLinks is that the first method returns the intergraph links stored in a grapher with an origin or destination in another grapher, and the second method returns the intergraph links stored in another grapher but with the origin or destination in this grapher.

If the grapher has no subgraphers, the external intergraph links obtained by getExternalInterGraphLinks() are all links that are leaving or entering the grapher.

If the grapher has subgraphers, links whose origin or destination is not stored directly in the grapher, but are stored in a subgrapher are not included. In this case, links that are leaving or entering the nesting hierarchy of the grapher could be obtained by examining all external intergraph links of the subgraphers recursively. To help in this task the following convenience methods are supplied:

When a grapher is moved, it is possible that the grapher and all its nested subgraphers appear at a new location on the screen. The grapher displacement causes the shape of the following links to change:

Grapher A contains two graphers, B and D. Grapher B contains another grapher, C. The intergraph link from an object of C to an object of D is then stored in A.