An internal Rust widget library for Tessera's own management windows and developer tools. It is independent of Endor's ui global, UiNode, AST and VM. Guest scripts cannot construct or control these management widgets. Only geometry, font shaping and display-list rendering are shared with the page renderer.

Modules

interaction.rs: stable semantic widget IDs, hit testing, pointer capture, release-inside activation, drag-out cancellation, keyboard focus traversal, Enter/Space activation, disabled controls and cursor roles.
theme.rs: neutral/error/success colors, accent presets, readable custom accents and shared idle/hover/pressed/selected colors.
widgets.rs: button, tab, toggle, text field chrome, borderless inline prompt target, selectable row, color swatch, splitter and scrollbar thumb. Text is clipped to its widget bounds. Hover, pressed, selection, keyboard focus and disabled states compose consistently.
mod.rs: public interface used by management surfaces.

Frame contract

All widget coordinates are logical pixels. Build a Ui<Action> from the current Theme and a clone of retained Interaction. Actions are host-defined, Hashable values; IDs come from semantic action keys, never screen coordinates or changing labels. Explicit decoration IDs are scoped by widget kind and region.

let mut ui = Ui::new(Theme::new(accent), interaction.clone());
ui.button(bounds, Action::Refresh,
    Button::new("Refresh").enabled(can_refresh));
ui.button(tab_bounds, Action::SelectTab(Tab::Sources),
    Button::new("Sources").role(Role::Tab).selected(is_sources));
ui.text_field(input_bounds, Action::FocusEditor, editor_focused);

Store ui.targets with the newly produced layout and render ui.list through the native display-list backend. Reconcile retained interaction against the new targets; request one more redraw when a target moves, disappears or changes enabled state. This settles hover under a stationary pointer after a layout change without a timer or continuous rendering loop. Paint and register splitters after pane content and toolbars so neither their appearance nor their hit regions are obscured. Preserve clipping and scale every primitive, including focus outlines, when converting logical coordinates to physical pixels.

Dispatch pointer movement, press and release to Interaction. Press establishes capture; a button action is returned only when released inside the same enabled widget. Text fields focus on press, while drag handles perform host-side resizing or scrolling during capture. Pointer exit clears hover, focus loss cancels all capture, and disabled targets block click-through to controls behind them.

Tab / Shift-Tab traverse enabled controls; Enter / Space activate a focused button on key release. The host's editor keeps plain Tab for indentation and Shift-Tab for leaving the editor. Rows and drag handles are excluded from Tab traversal. Text editing, clipboard and IME remain host adapters; the widget layer owns their chrome and focus presentation. inline_input registers a text-input target without a background or focus border; a terminal-style host draws its own caret in the same scrollable stream as output. src/shell/clipboard.rs guarantees UTF-8 for macOS clipboard subprocesses, independent of Finder's locale.

Tessera's developer tools are the first consumer. Domain actions, HTTP calls, source navigation and Console execution remain in developer_tools.rs and its page modules; none of those concepts enter this library. The library currently renders synchronously with immediate state feedback; it is not an Endor component implementation, an OS accessibility bridge or a separately published Cargo crate.

The built-in start page lives in ui_bridge/start_page.endor and uses the ordinary guest Page/Block renderer. System UI no longer paints a welcome overlay. Native window chrome uses the same neutral palette, while each tool Page has its own interaction state.