Invalidation will happen on any scene change event or any selection event UNLESS any of these server tags are set.
ITEMTYPES This can be set to a list of item types that affect this list type. Changes to items of a different type will not invalidate lists of this type.
GRAPHS This can be set to a list of graph names that affect this list type. Changes different graphs will not invalidate lists of this type.
NOSELECTION This tag can be set to any value, and if set then item selection events will not invalidate lists of this type.
Different types of item lists can be created based on item list type servers. Each server gets passed an argument string and root item and is then required to generate a list matching those settings. The force interface allows clients to compute forces from positions and other element features.
SetArgument(LXtObjectID self, const char *arg)¶
When first created an item list type object will have the argument string and root item set to define the context for this list.
The “by-type” list will list all items matching a set of types. The types are given by whitespace delimited list of type names in the argument string. By default the type will test for subtypes but if the name is preceded by “=” then the type must match exactly.