PropertyHandle :: GetRelative - Get relative instance
The function returns an instance according to the relative position in a collection, which is restricted by a filter condition or a context selection handler. The position passed to the collection refers to the nth available instance. Instances skipped because of the filter condition are not counted.
Instances do have the type of the referenced property handle (collection type). The instance contains a pointer to a properly structured instance area.
You can use the !-operator or the GetData() function to check whether the instance refers to data or not.
Implementation details
- set_pos0_w
- Position in collection
The position of an instance in a collection depends on the selected index. if the collection is unsorted the position is the only way for accessing the instance.
For sorted collections the position is determined according to the instance key. If is a contradiction between position and key value the position will be ignored.
Special positions are
CUR_INSTANCE (-1) refers to the currently selected instance. If no instance is selected it refers to the first instance.
FIRST_INSTANCE (0) refers to the first instance in a collection according to the selected index (sort order).
FIRST_INSTANCE (0x7fffffff) refers to the last instance in a collection according to the selected index (sort order).
Default: AUTO