Implement the AutoCAD compatible HATCHTOBACK (HB) command and enhance the interactive DRAWORDER command pipeline with comprehensive verb selection and viewport entity picking.
Key implementations and architectural details:
1. HATCHTOBACK command execution
* Isolates entities belonging to the active layout block record or global space.
* Filters out entities residing on locked layers using an efficient hash set lookup.
* Records targeted delta undo operations on SortEntitiesTable objects (~100 bytes) rather than snapshotting full document structures.
* Performs granular draw depth cache invalidation via Scene::invalidate_draw_depth, preserving existing geometry tessellations and spatial indices.
* Emits localized user notifications when no qualifying hatch entities are found.
2. Interactive DrawOrderCommand state machine
* Supports preselected entities as well as interactive on demand selection gathering.
* Implements subverb selection supporting single character shortcuts (A for Above, U for Under, F for Front, B for Back) and case insensitive keyword parsing.
* Enables interactive reference object picking directly in the viewport via needs_entity_pick and on_entity_pick callbacks.
* Supports hexadecimal handle specification directly from the command line interface.
3. Ecosystem and system integration
* Bumps DEFAULT_ALIASES_VERSION from 2 to 3 to register the HB alias while preserving existing user overrides.
* Integrates HATCHTOBACK and HB into dynamic autocomplete registries.
* Adds localized message strings across all 20 Fluent translation catalogs.
* Corrects hatch boundary serialization flags to ensure outermost boundary rings consistently carry the external attribute.
Complete missing keys in the existing translations and add selectable Spanish, Brazilian Portuguese, Arabic, and Japanese resources.\n\nThe large compatibility catalogs for the new locales remain in progress.
- preserve command history colors after reopening
- remove collapsed command bar residue and split the unsaved prompt
- read system text when the drawing clipboard is empty
Refs #467
Refs #468
Refs #470
