nordisk/nornir

nornir viz — the Urðr-Threads master shell as a DECLARATIVE scene — design

Class: design · Function axis: f0 (the master shell as data) · f1 the shell builder · f2 NavState + render wiring · f3 the SceneHost that DRIVES the panes · f4 responsive + drawer · f5 observability + tests.

Strict: this file states only the shape we run. The scene lives in src/viz/shell_scene.rs; the render wiring + host live in src/viz/app.rs.

f0 — the master shell as DATA

nornir's egui shell (UrdrThreadsApp) is a real master/detail app: a top-bar tab strip, a right "Time machine" inspector, a bottom action-log, and a central active pane. Its master/detail LAYOUT is now described DECLARATIVELY as a [facett_app::scene::Scene] — a menubar + a tree of foldable/draggable/drawer panes

• nav routes — and rendered by facett_app::scene::render through facett-app's OWN primitives (Router / TabView / facett-menu). The scene reinvents nothing: it DRIVES the existing panes through this app's SceneHost impl.

What moved onto the scene (was hand-wired panels):

• the right SidePanel::right("detail") → the detail slot (a foldable pane on the DRAGGABLE master/detail split);
• the bottom TopBottomPanel::bottom("action_log") → the action_log slot (a foldable .drawer() that auto-collapses on a phone-class width);
• the central CentralPanel tab dispatch → the active_pane slot (rendered by draw_active_pane, preserving the S3c Tab::id() AccessKit id_salt).

What deliberately STAYS facett_ui::TabBar (the migration brief permits keeping it as the menubar host): the 28-tab top strip + the workspace/live/🎨-palette pickers and the ℹ About / 🐞 action-log toggles — the stateful chrome that has no clean menu mapping and that the whole existing robot suite drives by label. The scene ADDS an in-window View / Go / Help menubar (facett-menu) with shortcut hints + routes.

f1 — the shell builder (shell_scene.rs)

nornir_shell_scene() (src/viz/shell_scene.rs:80) builds the shell with the Rust builder; the identical value round-trips byte-stable through RON.

root  ─ Split(H, 0.74, DRAGGABLE)              [phone → Tabs under 760pt]
├─ workspace ─ Split(V, 0.82, DRAGGABLE)
│  ├─ panes      (Fixed)    slot:active_pane    — the ACTIVE tab's pane (28 Tab slots)
│  └─ action_log (Foldable 🐞, drawer@760) slot:action_log  — the action trail
└─ detail        (Foldable 🔍)  slot:detail     — the "Time machine" inspector

menubar: View { Toggle Time machine (Ctrl+I), Toggle Action trail (Ctrl+L), Reload (Ctrl+R) }
         Go   { Home (Ctrl+1), Release (Ctrl+2), Test (Ctrl+3), Warehouse (Ctrl+4) }
         Help { About (F1) }
routes:  Ctrl+I → Toggle(detail); button focus-detail → Focus(detail); go.release → Show(panes)

• Pane::split is DRAGGABLE by default: a real drag handle re-apportions the live ratio, kept in NavState.split_ratio (observable). The workspace|detail divider seeds 0.74 (≈ the old 360pt inspector); the panes|log divider seeds 0.82 (≈ the old 160pt bottom panel).
• The 28 [Tab] panes are the host-filled slots (tab_slot_ids(), src/viz/shell_scene.rs:65) the central active_pane slot delegates to — so every tab is a Content::Slot(Tab::id()) filled by impl SceneHost (per the brief).

f2 — NavState + render wiring (app.rs)

UrdrThreadsApp holds one nav: NavState (the live fold / split-ratio / route state) seeded in the constructor from nornir_shell_scene(). Each frame, inside the central egui::CentralPanel (src/viz/app.rs:3232), draw_ui:

1. rebuilds the (cheap, 28-pane) scene;
2. syncs the action-log drawer fold to the top-bar 🐞 toggle (set_fold(ACTION_LOG_SLOT, !show_action_log));
3. takes nav OUT (std::mem::replace) so self is free to be the SceneHost, then calls scene::render(&scene, &mut nav, ui, self);
4. flows a scene-side drawer toggle back to show_action_log, restores nav, and caches the returned render Value in last_scene_render.

f3 — the SceneHost that DRIVES the panes

impl facett_app::scene::SceneHost for UrdrThreadsApp (src/viz/app.rs:3295) maps each slot id to a REAL widget and returns its state:

• active_pane → draw_active_pane (src/viz/app.rs:3354): the former central dispatch verbatim (per-frame active-jobs poll + onboarding/timeline guards + the push_id(Tab::id()) render root + the if self.tab == … dispatch). It delegates through every Tab::id() slot: slot("Release") renders the Release pane, etc.
• detail → draw_detail_body (src/viz/app.rs:3742): the "Time machine" inspector (workspace freshness + the selected release's git-checkout commands + gate status + published versions).
• action_log → draw_action_log_body (src/viz/app.rs:3799): the palette-coloured tail of the shared $NORNIR_VIZ_ACTIONLOG file.
• command(id) drives menu actions: refresh → reload + refresh tables; about → toggle the About window; go:<TabId> → switch the active tab.

f4 — responsive + drawer

scene::render picks a Device from the available width. The root master/detail split carries .phone(Layout::Tabs, 760) → under 760pt it collapses to Tabs; the action_log pane carries .drawer(760) → it auto-folds crossing INTO phone-class and restores above it (the desktop-rail → phone-drawer pattern). Both share the PHONE_BREAKPOINT (760pt).

f5 — observability (LAW #6) + tests

state_json()["scene"] (folded in at src/viz/app.rs:1334 via scene_state(), src/viz/app.rs:3840) carries the pane tree, the foldable / drawer / draggable-split sets, the 28 host tab slots, the live folded + split_ratio maps, the menu/route counts, and the last scene::render facts (device, per-pane rects, per-slot state, live ratios + drag-handle separators). So a robot asserts the whole shell without pixels.

Tests

• src/viz/shell_scene.rs unit tests (all green; cargo test -p nornir --features viz shell_scene):

  • shell_scene_is_valid_with_unique_names — Scene::validate (addressability).
  • shell_scene_ron_round_trips_byte_stable — RED-when-broken: RON parse ∘ serialize is a byte-stable fixed point.
  • the_detail_and_log_panes_are_foldable.
  • folding_the_detail_pane_is_observable — RED-when-broken: a fold round-trips through NavState.
  • the_master_detail_splits_are_draggable_with_live_ratios — RED-when-broken: both splits resizable, seeded ratios observable.
  • dragging_the_master_detail_divider_reapportions_the_live_ratio — RED-when-broken: the live ratio mutates (the same state a handle-drag writes).
  • the_action_log_is_a_drawer_at_the_phone_breakpoint.
  • the_root_split_collapses_to_tabs_on_a_phone_width.
  • every_tab_is_a_host_slot_id, the_menubar_carries_actions_shortcuts_and_routes.

• tests/robot_scene.rs (nornir-robotui / egui_kittest, real AccessKit):

  • the_declarative_shell_renders_and_is_observable — one paint through scene::render; asserts the draggable splits, the drawer, the 28 tab slots, the live root ratio, and that render.scene == "urdr-threads".
  • a_tab_click_switches_and_the_active_pane_slot_renders_it — RED-when-broken: a real click on the 🚀 Release header switches self.tab AND the scene's active_pane slot renders it (render.slots.active_pane.tab == "Release").