Managers

Each manager owns one concern. Singleton pattern throughout. They live in src/lib/ts/managers/.

Overview

• Stores. General session-and-persistent values shared across components — view mode, decorations bitmask, solid flag, side-panel-open flag, forward face index, rotation-snap flag, editing-lock flag, scale, grid opacity, orientation, the all-parts list, the tick counter.
• Selection. The current list of selected parts. Empty list means nothing selected; one item means the selected part; two or more means multi-selection. Exposes a backwards-compatible "the only selected part" view for the many call sites that read single-selection semantics.
• Parts. The collapsed-rows set for the parts table, plus tree-walk helpers (tree order, ancestor-collapsed check, reveal helpers, hide-generation, reveal-generation, toggle-reveal). The collapsed-rows set is persistent.
• Scenes. Save and load the current scene to and from local storage. Library management — list saved scenes, switch active scene, reset library to defaults.
• History. The undo and redo stack. The engine snapshots the current scene before any mutation; undo and redo walk the stack.
• Preferences. Local-storage wrapper. Read, write, remove, clear by typed key. Plus two store builders (persistent and persistent_set) that back a writable with local storage.
• Status. The on-screen status strip. Shows transient messages ("cannot drag a center", and similar) at the bottom of the canvas.
• Versions. Library object version migration. Reads the saved-scene format version and rewrites old-format data into current format on load.

File layout

src/lib/ts/managers/
├── index.ts
├── History.ts
├── Parts.ts
├── Preferences.ts
├── Scenes.ts
├── Selection.ts
├── Status.ts
├── Stores.ts
└── Versions.ts

Singletons used by the rest of the app

Each manager exposes one singleton instance:

• stores — from Stores.ts
• selection — from Selection.ts
• parts — from Parts.ts
• scenes — from Scenes.ts
• history — from History.ts
• preferences — from Preferences.ts
• status — from Status.ts
• (the versions module is used at load time by scenes)

What is NOT in managers

Several other major orchestrators live elsewhere because they are tied to the canvas or to events:

• The renderer, the engine, the camera, the animation tick, and the scene-tree storage live under src/lib/ts/render/.
• The mouse routing, the hit-target detector, the canvas-side mouse handler, and the three-dimensional hit-test live under src/lib/ts/events/.
• The drag tool and the inline editors (dimension, angle, face label) live under src/lib/ts/editors/.

Dependencies between managers

• The history manager calls scene serialization on snapshot.
• The scenes manager reads and writes through the preferences manager.
• The parts manager reads the selection and writes to the selection (when collapsing a row that hides the selected part, the selection moves to the collapsed row).
• The stores manager exposes a tick counter that many other modules bump after mutation to nudge reactive readers.
• The versions module is used only at scene-load time, behind the scenes manager.

Citations

• The set of files in the managers folder: src/lib/ts/managers/ directory listing.
• The selection's list-shaped store and the backwards-compat single-selection view: src/lib/ts/managers/Selection.ts.
• The toggle-reveal moving the selection: src/lib/ts/managers/Parts.ts lines 144-163.
• The store-builder helpers backed by local storage: src/lib/ts/managers/Preferences.ts lines 132-143.