# Editor Shell

The Stage-6 docking **shell** is the editor's host frame: the top menu bar,
the bottom status bar, the dockable panel area, the Preferences window, and
the wiring between every Stage-6 framework piece — command stack, project
system, settings, file watcher, and the
[module → editor extension API](editor-extensions.md).

Lives in [`oxide_editor::shell`](../editor/src/shell.rs) (the library) with
[`oxide-editor`](../editor/src/main.rs) (the binary) acting as glue: open a
window, run the egui paint pump, run the 3D viewport, hand events to the
shell. Splitting the shell into the library lets it be unit-tested without
spinning up a window.

## Layout

```
┌──────────────────────────────────────────────────────────────┐
│ File  Edit  View  Project  Modules  Help        ⚙ Prefs     │  ← menu bar
├────────────┬───────────────────────────┬────────────────────┤
│            │                           │                    │
│ Hierarchy  │        Viewport           │     Inspector      │
│            │                           │                    │
│            ├───────────────────────────┤                    │
│            │  Project │ Console        │                    │
│            │                           │                    │
├────────────┴───────────────────────────┴────────────────────┤
│ Reloaded 3 asset(s)                 modules: 0  undo: 2     │  ← status bar
└──────────────────────────────────────────────────────────────┘
```

Panels are dockable: drag a tab to re-dock, resize splits, or pop it out as a
floating window — provided by [`egui_dock`](https://docs.rs/egui_dock). The
default layout is built once in [`Shell::default_dock`]; persisting the user's
layout across restarts is a later refinement.

## What's wired to what

| Shell surface | Backing system |
|---------------|----------------|
| File menu → New / Open / Save / Recent / Quit | [`Project`](projects.md) + `RecentProjects` + `Shell::take_quit_request` |
| Edit menu → Undo / Redo (Ctrl+Z / Ctrl+Y) | [`CommandStack`](../editor/src/command.rs) |
| View menu → Show/Hide panel toggles | dock state |
| Project menu → Open project info | `EditorState::project` |
| Modules menu → module-contributed items | [`EditorExtensions`](editor-extensions.md) |
| Help → About | static info |
| Status bar → live hint (last action, errors) | `StatusLine` (timed TTL) |
| Status bar → module / undo counters | `EditorExtensions` + `CommandStack` |
| Preferences window → settings sections + module on/off | [`Settings`](settings.md) + `EditorExtensions` |
| File watcher (on project open) → `AssetServer::reload_path` | [`FileWatcher`](file-watching.md) |

## Commands and undo

`Edit` menu shows the labels of the next undo / redo entry; `Ctrl+Z` /
`Ctrl+Y` (also `Ctrl+Shift+Z`) drive them. The shortcut router is
[`Shell::try_consume_shortcut`] — same path the menu uses, so the unit tests
exercise the real flow.

The first wired commands ([`SetTransformCmd`], [`RenameCmd`]) live in
[`oxide_editor::commands`](../editor/src/commands.rs).
[`SetTransformCmd::merge`] coalesces consecutive edits to the same entity, so
a slider drag (or a future gizmo drag) is **one** undo entry instead of one
per frame.

Structural edits (spawn / despawn / reparent / change mesh) still bypass the
stack today — round-tripping a despawn through undo needs stable entity ids,
a Stage-7 design step alongside the gizmos.

## File watcher

[`Shell::open_project`] (or `create_project`) attaches a
[`FileWatcher`](file-watching.md) over the project's `assets/`, `scenes/`, and
`scripts/` directories (~150 ms debounce window). The shell's
[`frame_tick`](../editor/src/shell.rs) pumps events through
[`reload_changed_assets`](file-watching.md) each frame, so editing a file
externally hot-reloads any handle that was already loaded. Closing the
project tears the watcher down.

Backends that don't deliver events (some sandboxed CI environments) log a
warning and let the editor keep running — the watcher is best-effort.

## Module integration

Anything a module registers via the [extension API](editor-extensions.md) is
hosted by the shell with no editor-source edits:

- **Menu items** appear under the `Modules` top menu (shown only when at
  least one item is registered).
- **Panels** appear in the dock as `PanelKind::Custom(name)` tabs, rendered
  through the module's `FnMut(&mut egui::Ui)` closure.
- **Settings pages** + module on/off checkboxes are surfaced in the
  Preferences window's sidebar.
- **Component inspectors** (Stage 7+) will be looked up by reflection name
  when the Inspector encounters a selection holding that component.

Disabling a module in Preferences hides every contribution at once but keeps
it registered — re-enabling restores it instantly, no shell rebuild.

## Why a `Shell` library

A few reasons it lives in `editor/src/shell.rs` rather than `main.rs`:

- **Unit-testable behavior.** Shortcut routing, project open/close, recent
  list updates, command stack lifecycle — all exercised without a window.
  The maintainer's manual pass focuses on what tests *can't* prove: how the
  UI looks and feels.
- **Reusable in tests and future hosts.** A headless reproducer for a UI bug
  can drive the shell directly; an alternate front-end (web, embedded) could
  reuse it.
- **Separation of concerns.** The binary stays a thin runner — window event
  loop, 3D viewport, egui paint pump — while the shell owns editor state,
  layout, and the framework wiring.

## Viewport camera modes (Stage 7)

The viewport has two camera schemes; the active one is toggled with
**F** (the default binding for the `editor.camera.toggle_flythrough`
action) while the cursor is over the Viewport tab. Bindings live in
`EditorState::actions` ([`ActionMap`](input.md)) registered with editor
defaults at startup; the [Input Bindings](#input-bindings-preferences-page)
preferences page exposes them for remapping.

| Mode | Controls |
|------|----------|
| **Orbit** (default) | L-drag = orbit · R-drag = pan · scroll = zoom · click = pick |
| **Flythrough** | WASD = forward/back + strafe · QE = down/up · Shift = sprint · R-drag = look · scroll = adjust move speed · click = pick |

Toggling preserves pose: the new camera lands looking at the same view
the previous one was showing, so the scene doesn't snap.

## Input Bindings preferences page (Stage 7 piece 5)

The Preferences window's `input.bindings` section renders a rich page
listing every registered editor action — buttons, 1D axes, 2D axes — with
its current bindings. Each binding cell:

- Clicking it arms a **capture** for that slot. The page shows
  "Press a key…"; the next non-`Escape` key or mouse button press
  becomes the binding. `Escape` cancels.
- `✕` removes that binding.
- `+` (per direction or per action) starts an append capture so the user
  can add a binding without replacing one.
- `↺` (per action) restores that action to its code-defined defaults.
- A global **Restore all defaults** button at the top resets every
  action.

Edits flow through [`Shell`](../editor/src/shell.rs)'s
`try_complete_capture`, which mutates `EditorState::actions`, syncs the
new bindings into the `input.bindings` settings section via
`sync_action_overrides_to_settings`, and flips a `bindings_dirty` flag.
The host runner reads-and-clears the flag each frame and writes the
preferences file to `$XDG_CONFIG_HOME/oxide/editor.ron` (or
`$HOME/.config/oxide/editor.ron`). On startup the editor reads that
file, calls `Settings::import`, and `apply_action_overrides_from_settings`
layers the user's remap on top of the defaults — so a remap survives a
restart, and removing an action from code never breaks an old file
(unknown sections are silently skipped).

The page is intentionally a built-in Shell feature rather than going
through `EditorExtensions::add_settings_page`: it needs to mutate
`EditorState::actions` while a capture is in flight, which is more
direct from the Shell than through the extension API's `FnMut(&mut Ui)`
contract.

## What's not yet here

| Feature | Where it lands |
|---------|---------------|
| Native New/Open dialogs (`rfd` or similar) | Polish; the in-app text-path modals fill the gap today |
| ~~3D viewport with its own projection sized to the Viewport tab~~ | ✅ Landed in Stage 7 piece 6b: `FrameContext::viewport_rect` restricts the wgpu viewport and drives the projection aspect; `Viewport::pick` rebases the cursor to tab-local NDC. |
| Layout persistence across restarts | After settings sections are richer (Preferences-driven) |
| Inspector via reflection-keyed component editors | Stage 7 alongside the gizmos |
| Undo/redo for spawn/despawn/reparent | Stage 7 — needs stable entity ids |
| Console wired to a real log feed / Stage-10 terminal | Stage 10 |

[`Shell::default_dock`]: ../editor/src/shell.rs
[`Shell::try_consume_shortcut`]: ../editor/src/shell.rs
[`Shell::open_project`]: ../editor/src/shell.rs
[`SetTransformCmd`]: ../editor/src/commands.rs
[`SetTransformCmd::merge`]: ../editor/src/commands.rs
[`RenameCmd`]: ../editor/src/commands.rs
