Ludus editor interaction design

Status: target updated 2026-10-06. The current S1 shell and Qt/Wasm preview exist; the compact layout and full portable document transactions below are proposed. The initial S2 interactions implement bounded project history, focus preservation and scoped Save/Undo. GUI systems owns the engineering contracts; this document owns their user interaction. Existing functionality remains documented in the workspace guide.

Default workspace

Native: OS decoration + platform menu conventions
Browser: app container, without simulated OS title bar

Project / document / save state       Save   useful context actions   Search
+--------------------------------------------------+-------------------+
| Active document tabs                             | Inspector         |
|                                                  | when applicable   |
| Project settings / Configuration / Audio / World  |                   |
|                                                  | Document or       |
| Current authoring work has first claim on space   | session scope     |
+--------------------------------------------------+-------------------+
| Optional Output / Jobs: opened for useful details, otherwise collapsed|
+----------------------------------------------------------------------+
| Draft / operation / capability status                                |

The drawing describes roles, not fixed sizes or a promise of a particular viewport layout. Menus retain common commands, View tool windows and Window → Reset Window Layout. The context strip presents frequent actions for the current task; native-only actions do not consume a permanently disabled browser row. Advanced commands remain discoverable through stable menus and command search. Context menus and shortcuts provide faster access without being the only way to find an action.

Native windows retain OS decoration and macOS menu conventions. Browser windows use the website/application container without a second imitation title bar. Qt fonts, logical pixels and layout managers govern control sizing. A narrow container switches secondary panels to tabs/drawers, preserving the complete form through scrolling instead of clipping it. Show an Inspector only for an applicable selection; collapse empty diagnostics initially. A job/error indicator can reveal details without taking keyboard focus away from an edit.

Desktop panels may move, float and hide. View restores each named panel; Reset Layout restores access without discarding drafts, stopping Play or changing project data. Local preferences are versioned and bounded; corrupt/incompatible layout recovers to defaults. Exact app/Qt compatibility is checked before opaque Qt layout restoration. Do not load layout blobs from project files. A preferences write failure leaves document saves independent. Browser multiwindow behavior requires its own acceptance; floating native docks are not assumed there.

Existing project workflow

Creation asks for Name and a parent Location with Browse, previews the new folder, and uses Create Project. The native shared backend selects/prepares the associated engine and verifies staged configure/build/tests. An explicit Advanced override never falls back silently on failure. Opening checks setup without building or repairing it. Browser import/download is a separate capability; it does not create a working native project or run the compiler.

Native Close Project uses the existing settings/audio Save/Discard/Cancel and quiescence policy; owned work stops before close. Configuration has an independent offline draft that survives a project change. Quit considers its unsaved state. The current F1 shortcut list and shared action objects remain useful. Current Ctrl+S now follows the active Project Settings, Audio or Configuration work area. The full command catalogue and portable transaction model below remain pending; the workspace guide owns the implemented behavior and limits.

Proposed command and edit behavior

• One command catalogue supplies menu, strip, shortcut, search and automation intent. Validate current capability/target at dispatch. Unavailable commands explain a useful reason; hiding a strip item does not invent support.
• Focus routes text editing first, then committed document operations, then workspace commands. Platform Save/Open/Undo conventions use Ctrl or Command as appropriate. Viewport manipulation shortcuts never capture typing or IME.
• A field may contain an incomplete/invalid buffer. Show validation near it and preserve it while jobs or session snapshots arrive. Save validates pending buffers in scope; failure keeps them available. No heartbeat rebuilds a focused form or changes selection/scroll. Close counts pending edits as unsaved work.
• Drag/scrub begins a transient edit, previews it, and commits one Undo item on acceptance. Escape or lost capture cancels it. Multi-selection displays mixed values; focus alone changes nothing. Failed batch preparation changes nothing.
• Undo restores committed document content; text Undo first edits the focused temporary buffer. Undo back to saved content can be clean at a newer revision. Saving during another edit acknowledges only the captured snapshot.
• Labels name data, tooltips explain consequences, and status reports state. Document draft, live session and imported artifact scopes remain visible. Applying live values and copying them to a draft are distinct operations.
• Keep common actions visibly available; reduce cursor travel with contextual tools and stable ordering. Allow user customization without dynamically moving commands based on usage. Advanced options may be disclosed without hiding the next step of the main task.
• Ordinary validation and progress remain in the workspace. Use Save/Discard/ Cancel for loss of work and explicit confirmations for irreversible actions; frequent reversible edits rely on Undo. Cancellation says requested until the operation acknowledges or otherwise finishes.
• Form labels, panels and custom canvases expose names/roles and keyboard paths. Focus indication, errors, mixed state and dirty state use more than color. Shared semantic controls support light/dark, density, scale and contrast; a decorative theme cannot replace text and accessibility behavior.

Representative tasks and failure behavior

Task	Expected interaction	Failure behavior
Open native recent project	Select/open, or double-click	Existing path/setup diagnostics; no automatic repair/download
Edit project/document	Active task, edit, Save	Invalid buffer or save conflict preserves the draft; Build uses documented saved state
Browser round trip	Import, edit, download, reopen	Malformed/oversized admission retains current content; volatile storage/export limits stay explicit
Tune Play	Start, pause, inspect, apply to session	Stale revisions rejected; failed game process cannot overwrite source
Author audio	Select/create, edit, save, preview	Existing discard policy; native preview stops before game launch
Recover workspace	Window tool-window toggle or Reset Window Layout	Corrupt/incompatible preferences use useful defaults
Future asset import	Source, progress/result, optional cancellation	Last valid artifact retained; stale job cannot publish; actionable retry
Future scene transform	Select, preview, accept, Undo	Cancel/invalid target safely drops preview; resized-scene picking cannot select obsolete data
Future macOS authoring	Same operations with native menu/Command/text behavior	Host-specific capabilities and errors; engine Metal support alone does not qualify the editor

Evaluation

Use sketches to assess hierarchy and discoverability. Use runnable prototypes for efficiency, large models, text/IME, screen readers, renderer composition and failure recovery. Observe role-appropriate users doing the same realistic tasks without coaching; record completion, wrong turns, recovery and repeated-task cost. Preference is useful feedback but not a performance benchmark.

Current S1 tests cover action identity, panel recovery and preferences. They do not prove the new interactions. Verify keyboard-only, real text input, high DPI, light/dark, narrow browser container and actual native window-manager tasks. Offscreen images do not establish screen-reader behavior, Wayland/macOS/Windows input or rendered frames. Add focused-buffer, transaction, stale job and savepoint acceptance with the corresponding implementation slice.

The October 6 review records the actual Lightbown/Wihlidal/Nystrom excerpts and their effect. The historical October 4 task script remains useful for current native workflows; the GUI systems delivery gates qualify the new target.