At times, you may want some nodes of the graph to be “pinned” (that is, to stay in their current position when the layout is performed). You need a way to indicate the nodes that the layout algorithm cannot move. This makes sense especially when using a Semi-automatic layout (the method where the user fine tunes the layout by hand after the layout is completed) or when using an Incremental layout (the method where the graph and/or the position of the nodes is modified after the layout has been performed and then the layout is performed again).

Rogue Wave Views allows you to specify that a node is fixed using the method:

If fixed is IlTrue, it means that the node is fixed. To obtain the current setting for a node:

The default value is IlFalse.

To remove the fixed attribute from all nodes in the grapher, use the method:

You can read the current option using the method:

To indicate whether a subclass of IlvGraphLayout supports this mechanism, the following method is provided:

The default implementation returns IlFalse. A subclass can override this method in order to return IlTrue to indicate that this mechanism is supported.