ObjectDBX SelectionSets

Is there a reason why Autodesk doesn't implement selectionsets in ObjectDBX, apart from the fact that there is no editor open? If a selection works at the database level, so what difference would it makes to have the editor opened or closed? TIA

 

Selection sets also filter based on the display list which is not
available in ObjectDBX.

 

Would that be the SelectOnScreen method? I don't know how the selection based on display list works, would you explain?

 

Right. Most forms of object selection (like crossing,
window, and so forth) operate on the display list,
which is only present for drawings open in the editor.

The way it works in simple terms, is that objects are
selected by searching the display list for vectors that
are crossing and/or within a selection range (window,
polygon, point, etc.). That's how AutoCAD determines
what object to select when you pick it with the mouse.

I've written ObjectARX code that can use selection sets
in ObjectDBX documents, but only with the "X" form of
object selection (e.g., acSelectionSetAll, which operates
by searching the database rather than the display list).

Unfortunately, doing that requires a few tricks, and is
only possible from ObjectARX.

 

I understand that in order to select a group of entities on the screen you need the editor. However, I still no see any reasons why they couldn't implement selectionsets like selectall or even selection by crossing or window. The ObjectDBX is a great way to extract information from your drawings without wasting time by loading them on the editor. I don't have the time or the tools to implement such functionality, but they sure have.

 

Those operations depend on the display list. Try using either of them in
VBA or VB with points that are not on the screen.

 

You are wright. But, wouldn't we benefit even if they could only implement the functionality of the acSelectionSetAll mode? I definitely would because most of my selections are of this type anyways.