# Migrate the UI to GPUI-Kit, then native-theme

> **Status: Phase A is implemented** (on the working tree, uncommitted). The
> app builds against `gpui-kit` (resolved 0.7.3 / gpui-pre 0.3.9), every UI
> element comes from the kit, and `crates/theme` is deleted.
>
> **Follow-up (this revision, also uncommitted):** the last custom modules in
> `crates/ui` are gone — `motion`, `typography`, `layout` and `styled` were
> deleted and every call site now reads gpui-kit tokens directly (`text_xs` /
> `text_sm`, `cx.theme().radius` / `radius_lg`, `gap_2`, `Separator`). The
> dock wears the previous skin again, ported from the `signed` reference
> implementation onto the kit dock engine (`workspace::dock`: pill tabs, the
> 44px bar that doubles as the title bar, window controls, collapse buttons,
> chromeless sidebar group). The avatar with the pixel fallback is back
> (`ui::Avatar`): user image when set, deterministic pixel art from the
> profile/group seed otherwise, also as the image-load fallback. Desktop
> traffic lights recenter for the 44px bar (`workspace::TAB_BAR_HEIGHT`).
> Validation: `cargo check`, `cargo clippy` and `cargo fmt` are clean
> workspace-wide and the desktop binary builds; the wasm32 check fails
> identically before and after (pre-existing `state` → `gpui_tokio` and
> `rustls` blockers, verified at HEAD).

Plan to move coop's custom UI elements onto [GPUI-Kit](https://gpui-kit.com)
(`gpui-kit` 0.7.1), delete the custom theme implementation (`crates/theme`),
and then integrate [`native-theme`](https://github.com/tiborgats/native-theme)
through its official `native-theme-gpui` connector.

> **Revision.** This supersedes the earlier approach in this file (depend on
> the `native-theme` core crate and hand-write a `ResolvedTheme` → coop token
> mapping). Going through GPUI-Kit first makes that mapping unnecessary: the
> connector already projects native themes onto gpui-component's `Theme`, and
> every call site reads `cx.theme()` from gpui-component directly.
>
> **Revision 2.** Full replacement, no hybrids: no custom UI element is kept
> or maintained after Phase A. Earlier hybrid positions in this file (keep
> `ui::message` where it fits, possibly keep nav composites, keep an icon
> mapping shim) are dropped — kit elements are adopted outright, chat-specific
> composition moves into `chat_ui`, and the only coop-owned visuals left are
> brand SVG assets rendered through the kit `Icon`.

## 1. What the git history shows

- `516eb0e` — *move gpui-components to ui crate*: the UI crate **was** the
  upstream component library, vendored into `crates/ui`. Call sites used
  library components and its theme vocabulary
  (`cx.theme().elevated_surface_background`, `surface_background`,
  `border_variant`, …).
- `0c1c23f` — *migrate to gpui-base (#51)*: the vendored library was deleted
  and replaced by the `gpui-base` crate plus hand-written wrappers (Button,
  Switch, Dialog, Input, Dock, Menu, Notification, …) and the custom
  `crates/theme`.

"Migrate like before" therefore means: go back to the upstream component
library — this time as a dependency (`gpui-kit`), not vendored — and let it
own the theme.

## 2. Strategy

```mermaid
graph LR
    A[Phase A: GPUI-Kit] --> B[Phase B: native-theme-gpui]
    A1[A1 Bootstrap<br/>init + open_window + Root] --> A2[A2 Component swap<br/>~20 custom modules]
    A2 --> A3[A3 Theme removal<br/>cx.theme = gpui-component]
    A3 --> B1[B1 Connector<br/>apply_system_theme]
    B1 --> B2[B2 Appearance + presets<br/>settings wiring]
```

**Phase A** replaces the custom elements with `gpui_kit::component`
components and moves all color reads onto gpui-component's `Theme`
(`ThemeColor`, 139 semantic fields). The app runs on gpui-component's
built-in light/dark palettes at the end of Phase A; `crates/theme` is gone.
At the end of Phase A `crates/ui` contains no UI elements: every element
comes from the kit, and only app utilities survive there (§4.4).

**Phase B** adds `native-theme-gpui`, which installs native OS themes (or any
of 16 bundled presets) into that same `Theme`. No call site changes — the
connector is verified against exactly the versions Phase A pins.

### Target dependency set (exact versions)

| Crate | Version | Note |
|---|---|---|
| `gpui-kit` | 0.7.1 | facade: `gpui_kit::*` = GPUI (`gpui-pre`), `gpui_kit::component` (gpui-component 0.7.1), `gpui_kit::base` (gpui-base 0.7.1), `gpui_kit::assets` |
| `gpui-pre` | =0.3.8 | already pinned; gpui-kit 0.7.1 requires it |
| `native-theme-gpui` | 0.6 | Phase B; verified against gpui-kit 0.7.1 / gpui-pre 0.3.8; needs Rust ≥ 1.95 (toolchain is 1.98) |

Do not jump to `gpui-kit` 0.8: `native-theme-gpui` 0.6.1 pins 0.7.1, and a
gpui-component patch release has broken the connector before.

## 3. Current custom UI inventory

`crates/ui` is ~8,700 lines across 34 files. Consumers import it at ~138
sites (`workspace` 14 files, `chat_ui`, `nip29_ui`, `nip4e`, `settings`,
`desktop`, `web`); theme tokens are read at ~340 sites across the same
crates.

| Custom module | Lines | GPUI-Kit replacement |
|---|---|---|
| `menu/` (popup, dropdown, item) | 983 | `menu::{PopupMenu, PopupMenuItem, DropdownMenu, ContextMenu}` |
| `dock/` (mod, panel) | 1,032 | `dock` (entity-backed DockArea / panels) |
| `motion.rs` | 668 | keep — animation utility, not an element; no theme dependency |
| `notification.rs` | 594 | `notification::Notification` + `WindowExt::push_notification`; placement via `Theme.notification` |
| `button.rs` | 581 | `button::{Button, ButtonGroup, Toggle, DropdownButton}` |
| `message.rs` | 553 | `message::{Message, Bubble, MessageGroup, MessageScroller}` (avatar/header/content/footer slots); author grouping, date separators and receipts move into `chat_ui` as app code |
| `avatar.rs` | 445 | `avatar::Avatar` |
| `root.rs` | 430 | framework `Root` via `gpui_kit::open_window` (owns dialogs, notifications, tooltip/menu layers, focus traps) |
| `dialog.rs` | 394 | `WindowExt::open_dialog` / `AlertDialog`; custom footer buttons → Dialog's footer API |
| `input/` | ~290 | `input::{Input, InputState, Textarea, NumberInput}`; delete the custom styling (its `input_bg`/`selection`/`caret` reads die with it) |
| `icon.rs` | 274 | kit `Icon` + `IconName` (Lucide) at every call site; the module and the coop enum are deleted (see §4.3) |
| `kbd.rs` | 270 | `Kbd` |
| `tab/` | 385 | `tab::{Tab, TabBar, Tabs}` |
| `title_bar.rs` | 218 | `TitleBar` (keep the client-side-decoration constants) |
| `popover.rs` | 170 | `popover::Popover` |
| `styled.rs` | 161 | `h_flex`/`v_flex`/`StyledExt` from the kit; drop coop-specific helpers as their users migrate |
| `switch.rs` | 157 | `switch::Switch` |
| `markdown.rs` | 146 | `text::TextView::markdown` (code styling via `Theme.highlight_theme`) |
| `nav.rs` + `nav_item.rs` | 268 | `sidebar::{Sidebar, SidebarHeader, SidebarGroup, SidebarMenu, SidebarMenuItem, SidebarFooter}`; the nav layout is adapted to the kit structure, not preserved |
| `group_box.rs` | 126 | `group_box::GroupBox` |
| `scroll/` | ~124 | `scroll::{Scrollbar, Scrollable}` |
| `resizable/` | 31 | `resizable::{h_resizable, v_resizable, resizable_panel}` |
| `tooltip.rs` | 34 | `.tooltip()` |
| `indicator.rs` | 59 | `marker::Marker` / `badge::Badge`; the custom module is deleted either way |
| `window_ext.rs` | 90 | `gpui_kit::component::WindowExt` |

## 4. Phase A — GPUI-Kit migration

### 4.1 Bootstrap

- `desktop/main.rs` and `web/lib.rs`: `gpui_kit::init(cx)` first, then open
  the window with `gpui_kit::open_window(opts, cx, |window, cx| …)`, which
  installs the framework `Root` (dialog, sheet, notification and tooltip
  layers). Delete `ui::Root` and its layers; `workspace::init` stays as the
  window's content view.
- Register a combined `AssetSource` at app construction: coop's existing
  per-platform source for `assets/brand` and images, with
  `gpui_kit::assets::Assets` as the fallback for the component icon bundle
  (embedded on desktop; CDN-on-demand on wasm).
- `TitlebarOptions` / client-side decoration setup stays coop's
  (`CLIENT_SIDE_DECORATION_*`, `TABBAR_HEIGHT` move to `ui`).
- Keep `bind_keys` **before** `set_menus` (guide rule); coop already does.

### 4.2 Component slices (each PR compiles)

Replace one family at a time; consumers update in the same PR:

1. **Deps + bootstrap** (above). Custom components still work alongside the
   framework Root.
2. **Icons** — rewrite every icon call site onto kit `Icon`/`IconName` and
   delete `ui::icon` in the same PR (see §4.3). Mechanical churn: one Lucide
   target per coop variant, `Icon::path` for brand marks; doing it early
   settles the imports for all later slices.
3. **Small controls** — Button, Switch, Kbd, GroupBox, Avatar, Tooltip,
   Popover; Indicator → `Marker`/`Badge`.
4. **Menu** — PopupMenu/DropdownMenu/ContextMenu (+ the popup-menu actions
   already imported from `gpui_base::actions`).
5. **Input** — Input/InputState/Textarea; port the chat composer, dialog
   fields, relay editor; drop the clear-button and input-styling modules.
6. **Dialog + Notification** — `open_dialog`/`AlertDialog`/
   `push_notification`; port the settings, relays, profile, new-chat,
   import… dialogs; the custom footers move to the Dialog footer API.
7. **Scroll + Resizable + Tab** — panels and the workspace tab strip.
8. **Sidebar/Nav** — port the nav onto `sidebar::{Sidebar, SidebarGroup,
   SidebarMenu, …}` and delete `nav.rs`/`nav_item.rs` in the same PR.
9. **Title bar** — kit `TitleBar` + traffic-light handling.
10. **Dock** — the biggest single item (805 + 205 lines, `dock::add`
    registry, `DockPlacement`). Port panels onto `DockArea`; do it last so
    the panels it hosts are already kit-based.
11. **Message + Markdown** — TextView::markdown; port chat rows onto
    `Message`/`Bubble`/`MessageGroup` + `MessageScroller`. Chat-specific
    composition (author grouping, date separators, receipts) is app code in
    `chat_ui`, built from kit elements — `crates/ui` keeps no message
    component.
12. **Cleanup** — delete the replaced modules; `crates/ui` ends as a
    utilities-only crate (see §4.4).

### 4.3 Icons

No mapping shim and no coop `IconName` enum: every call site uses the kit's
`Icon` + `IconName` (Lucide) directly. During slice 2, give each of coop's
128 variants a Lucide target — exact equivalent where one exists, nearest
match otherwise, accepting the visual difference. The only coop-owned SVGs
that survive are true brand/product marks under `assets/brand`, rendered
through the kit element with `Icon::path("brand/….svg")` (the kit `Icon`
accepts any asset path). Delete `assets/icons` entirely once the last call
site is mapped.

### 4.4 Theme removal

- **Call sites**: `theme::ActiveTheme` → `gpui_kit::component`'s `ActiveTheme`
  (`cx.theme() -> &Theme`). Rewrite the ~340 token reads with the mapping
  below (done per consumer crate, one slice each: `ui`, `workspace`,
  `chat_ui`, `nip29_ui`, `settings` + `nip4e`).

| coop token (`cx.theme().x`) | gpui-component `ThemeColor` |
|---|---|
| `bg` | `background` |
| `surface` | `sidebar` |
| `surface_raised` | `secondary` |
| `surface_card` | `muted` |
| `surface_dialog`, `surface_overlay` | `popover` |
| `element_hover` | `accent` (gpui-component's accent **is** the item highlight) |
| `element_active` | `list_active` |
| `border` | `border` |
| `border_faint`, `border_strong` | `border` (one border token; faintness loss accepted) |
| `ring` | `ring` |
| `text` | `foreground` |
| `text_muted`, `text_faint`, `text_dim` | `muted_foreground` |
| `cursor`, `caret` | `caret` |
| `selection` | `selection` |
| `solid` / `on_solid` | `primary` / `primary_foreground` |
| `accent`, `accent_strong` | `primary` (emphasis ink) |
| `danger` / `danger_muted` | `danger` |
| `danger_strong` | `button_danger` |
| `warning` / `warning_muted` | `warning` / `warning.alpha(≈0.15)` at the call site |
| `success` | `success` |
| `input_bg`, `selection`, `caret` inside the custom input | die with the custom Input (§3) |
| `code_text`, `code_wash` | die with `ui::markdown` → `TextView` |
| `drop_line` / `drop_target` | `drag_border` / `drop_target` |

- **Non-color fields** move to `Theme` directly: `font_sans`/`font_mono` →
  `theme.font_family`/`mono_font_family`; `shadow` → `theme.shadow`;
  `scrollbar_mode` → `theme.scrollbar_mode`; notification placement →
  `theme.notification` (gpui-component ships the same `NotificationSettings`
  coop's was modeled on); `is_dark()` → `theme.mode`.
- **`crates/theme` disposition**:
  - delete: `lib.rs` (Theme global, `AppExt`, `sync_base`, `PaletteBuilder`),
    `colors.rs`, `palette.rs`, `brand.rs`, `appearance.rs`, `paint.rs`,
    `color.rs`, `syntax.rs`, `notification.rs`, `scrollbar_mode.rs`,
    `platform_kind.rs`;
  - the `typography`, `layout`, `styled` and `motion` modules were NOT kept:
    a follow-up revision removed them and adapted every call site to gpui-kit
    tokens — the `TextStyle` ladder collapsed to `text_xs`/`text_sm` (plus
    `font_semibold`/`font_medium`), the radius ladder to `cx.theme().radius`
    / `cx.theme().radius_lg`, `SPACE` to `gap_2`, `divider` to the kit
    `Separator`, and motion was deleted unused. `geometry.rs` and the CSD
    constants never carried over (the framework Root draws the window
    border); `TAB_BAR_HEIGHT` (44px, the dock tab bar that doubles as the
    title bar) now lives in `workspace::dock` and `SIDEBAR_WIDTH` in
    `workspace`;
  - end state: `crates/ui` is `avatar.rs` + `window_drag.rs` only — see the
    status note at the top of this file for the restored dock skin and
    avatar (the two deliberate exceptions to "no custom elements");
  - `AppearanceMode` (System/Light/Dark, serde-persisted) moves into
    `crates/settings`.
- The gpui-base projection coop did in `sync_base` is now the framework's job
  (`Theme::update` / `Theme::change` keep colors, tokens and the base layer
  in step per the coding guides).

### 4.5 Appearance handling (end of Phase A)

- `settings::apply_theme` → `Theme::change(mode, None, cx)` for a pinned
  Light/Dark, `Theme::sync_system_appearance(None, cx)` for System.
- `workspace`'s `Theme::sync_system_appearance(Some(window), cx)` call stays,
  now against the kit's `Theme`; window-appearance observation comes with the
  framework Root/theme (verify; if not, keep the existing
  `observe_window_appearance` wiring).

## 5. Phase B — native-theme-gpui

1. Add `native-theme-gpui = "0.6"` (pulls `native-theme`; keep default
   features or trim icon features coop doesn't use).
2. Boot, after `gpui_kit::init` and before opening the window:

   ```rust,ignore
   match native_theme::SystemTheme::from_system() {
       Ok(sys) => native_theme_gpui::apply_system_theme(&sys, cx),
       Err(error) => {
           log::warn!("system theme unavailable: {error}");
           // per-platform fallback preset: macos-sonoma / kde-breeze / windows-11
           let prefs = native_theme_gpui::AccessibilityPreferences::default();
           if let Ok((theme, resolved)) = native_theme_gpui::from_preset("macos-sonoma", true, &prefs) {
               native_theme_gpui::apply(theme, &resolved, &prefs, cx);
           }
       }
   }
   ```

   `apply_system_theme` stores **both** variants and a `ThemeConfig` per
   mode; afterwards the Phase A controls keep working unchanged:
   `Theme::sync_system_appearance` / `Theme::change` switch between the
   native palettes.
3. Optional preset picker (the same one proposed in the superseded plan):
   `settings.theme_preset: Option<String>`, a dropdown in Preferences →
   Appearance; selecting one calls `from_preset(name, is_dark, &prefs)` +
   `apply` for both variants.
4. Fonts, radius, scrollbar geometry and the base layer are written by the
   connector (it also re-asserts them after each upstream rebuild via its
   observer). Coop writes nothing theme-related itself.

wasm: `SystemTheme::from_system` is unavailable on wasm32 — cfg-gate step 2
to native targets; on web, apply the fallback preset (or extend
`native-theme` with a web story later; presets need no OS reader).

## 6. Testing and QA

- Per slice: `cargo check` workspace, `cargo clippy`, `cargo fmt --check`,
  plus the affected crate's tests; UI behavior verified by hand in the
  desktop app.
- **Early spike (before slice 2)**: `cargo check -p web --target
  wasm32-unknown-unknown` with the `gpui-kit` dependency added. The vendored
  library was wasm-capable; confirm the published crates are too before
  committing to the migration. If they are not, stop and reassess — the web
  target is a launch blocker.
- End of Phase A:
  - all dialogs open/close, focus trap and restore works; nested
    popover-in-dialog works (framework Root owns the layers);
  - notifications stack and auto-hide; settings' appearance dropdown switches
    Light/Dark/System with a full repaint;
  - dock panels move, split and zoom; sidebar resizes; scrollbars behave in
    Hover/Always/Scrolling modes;
  - markdown code blocks render through `TextView` with syntax colors from
    `Theme.highlight_theme`;
  - every icon renders from the kit Lucide bundle, and brand marks render
    via `Icon::path` on desktop and web (on wasm the kit bundle is fetched
    from CDN on demand; coop brand assets still come from coop's own
    source).
- End of Phase B:
  - macOS: OS light/dark follows; pinned modes; accent changes picked up at
    next launch (documented limitation — no `watch` feature);
  - Linux (KDE + GNOME/portal) and Windows: theme reads work or fall back to
    the platform preset with a logged warning;
  - preset switch renders in both modes; inputs/menus/dialogs/tooltips/
    scrollbars all paint from the native palette;
  - startup shows no wrong-palette flash (apply before the first window).

## 7. Risks

| Risk | Mitigation |
|---|---|
| Scale: ~8.7k lines of custom UI, ~140 `ui::` imports, ~340 token reads | Slices in §4.2 each compile; `crates/ui` acts as the facade during the migration so consumer churn is incremental, then shrinks to utilities (§4.4) |
| Dock port (largest, most stateful) | Scheduled last; panels are kit-based by then; DockArea owns layout state coop currently hand-rolls |
| gpui-component on wasm | Spike in §6 before committing; fallback would be staying on 0.7.1 desktop-only and parking the web target |
| Visual identity changes (shadcn-style stock palette in Phase A; kit Message/Sidebar look replacing coop's chat/nav styling) | Accepted — requirement says the current palette need not survive; Phase B replaces it with native themes anyway |
| Icon gaps (coop 128 vs Lucide 106) | Nearest-Lucide target per variant in slice 2; only true brand marks stay as coop assets via `Icon::path` |
| API drift between coop's wrappers and the kit (e.g. `Sizable`, `Disableable`, callback shapes) | Per the coding guides: never invent APIs; verify each component page / source signature during its slice |
| `TextStyle` ladder is a deliberate holdout from rem-based text | Documented exception; sizes are absolute points and don't claim to zoom. Revisit only if the kit's text scale is adopted later |
| native-theme-gpui version coupling | Pin `gpui-kit = "=0.7.1"`-era set (0.7.1, gpui-pre =0.3.8) matching the connector's verified table; bump all together |

## 8. Out of scope

- Migrating `motion.rs` or the panel-background image feature.
- Accessibility text scaling / reduce-motion plumbing (connector supports
  it; adopt after Phase B if wanted).
- Replacing coop's composited panels (chat, screening, backup…) with kit
  `Sheet`/`Settings` — revisit after the migration settles.