Reference-only entities (plugin API v9): a scene-scoped, in-memory
designation for plugin-owned display geometry, plus HostNotification
dispatch to native plugins so they can re-mark on DocumentOpened.
Resolves the new DeltaSnapshot site in block_editor.rs.
Co-Authored-By: Claude Opus 5.5 <[email protected]>
Open the Edit Block Definition dialog when BEDIT is invoked without an active selection, listing candidate block definitions alphabetically while filtering layout records, anonymous blocks, and external references. Allow typing a new valid block name to start an empty block editor session that only commits to the drawing block table upon explicit save.
Preview the current unsaved block in a disposable drawing with independent history. Keep normal Draw tools available, append Close Test Block, and return to the original editor without saving. Guard persistence paths and handle refresh and parent-close lifecycle by stable document identity.
Create a new named definition from current session edits, restore the source checkpoint, and continue editing the copy with fresh local history. Add the name dialog and Save dropdown, clone supported owned metadata onto independent handles, and refuse unsupported relationships atomically.
In the Block Editor, BVSTATE makes a new visibility state, makes one
current, renames or deletes one; BVHIDE and BVSHOW hide or show the
picked objects in the current state (BVSHOW shows every object of the
block while they are picked). The first use makes the block dynamic.
The states are stored as the format keeps them: a
BLOCKVISIBILITYPARAMETER in the block's ACAD_ENHANCEDBLOCK evaluation
graph with its visibility grip and the grip's two location expressions,
the round-trip purge preventer, AcDbDynamicBlockTrueName /
AcDbDynamicBlockGUID / AcDbBlockRepETag on the definition and element
tags on each of its objects. The definition shows its first state; a
reference given another state gets its own evaluated *U copy, tagged
AcDbBlockRepBTag and linked back through AcDbBlockRepresentation /
AcDbRepData, so it shows that state and the other references do not
change. Saving the block drops erased objects from the states.
Checked: a block authored this way reads back with its states and
reference link from DWG and DXF, and the ODA converter accepts the DWG.
Closes#1566
Co-Authored-By: Claude Opus 5.5 <[email protected]>
