Editor State Model
An editor instance is a single authority over several state domains. Every piece of editor state belongs to exactly one domain, and the domain decides its full lifecycle: whether it is persisted, whether undo restores it, whether it replicates to collaborators, and whether it is shared across views or owned per view. Placing a field in the right domain is a contract, not a filing choice — most historical editor bugs (undo restoring the camera, remote edits polluting local undo, hover state leaking into saved files) are domain violations.
The domains
| Domain | Contents | Persisted | Undoable | Replicated | Scope |
|---|---|---|---|---|---|
| Content | The document: nodes, hierarchy, order, properties, scenes | yes | yes | yes (document sync) | document |
| Authoring context | Selection, active scene, content-edit mode, isolation | no | yes | as presence only | editor |
| View | Camera transform, zoom, viewport size | no | never | as presence only | per view |
| Interaction | Active gesture, hover, marquee/lasso, active tool, pointer, modifier state | no | never | no | per view |
| Collaboration | Remote cursors, remote selections, presence, ephemeral chat | no | never | remote-sourced | editor |
Two rows deserve emphasis:
- Authoring context is undoable but not persisted. Undoing a deletion must restore the selection that existed before it; but a saved file carries no selection. This asymmetry is deliberate and is the reason authoring context is a domain of its own rather than part of content or interaction.
- View state is never undoable. Undo never moves the camera. If a host wants "zoom to the undone change," that is a view policy applied after undo, not a property of history.
Mutation authority
The editor is the single mutation choke-point for content and authoring context. All changes — pointer gestures, commands, remote sync, agent actions — enter through one mutation vocabulary and are classified there. Nothing else writes to these domains. This single entry point is what makes history (every entry passes through it), sync (every local change can be broadcast), and render invalidation (every change can be classified) possible without heroics.
Interaction and view state, by contrast, are written freely by the input pipeline and view controllers; they carry no such ceremony because nothing downstream depends on observing their transitions.
Intent phases
Interactive edits pass through two phases:
- preview — a tentative change shown live during a gesture. A preview is visible in the rendered view but has not entered history and is not broadcast as a committed change. Replacing or discarding a preview leaves no trace.
- commit — the change becomes real: it enters history as one entry and is eligible for replication.
Every gesture that mutates content must declare which phase it is in; "committed on every mouse-move" is a spec violation (it floods history and sync), and "never committed" is a data-loss bug.
Views
One editor instance drives one document and N views. Each view owns its own view and interaction state; content, authoring context, and collaboration state are shared. A conforming implementation with a single hard-wired view must still keep the domains separate such that adding a second view is a host change, not an editor redesign.