slint

Backend-agnostic core for Slint on Flutter: engine, component, render targets, input events, and the SlintView widget. Pure Dart on the surface; shared Rust lives in rust/ (slint-dart-core). Implementations: slint_interpreter (software) and slint_skia (Skia).

dependencies:
          slint: ^0.0.1

When to use it

Every app depends on slint. App code talks to UI through generated wrappers that implement these types — never by inventing a second API layer.

Library layout

Path	Role
`lib/slint.dart`	Public barrel: core abstractions + `SlintView`
`lib/slint_core.dart`	Engine / component / render-target / events / models (no widget)
`lib/src/`	Implementations of those types
`rust/`	`slint-dart-core`: shared event mapping and thread checks for FFI crates (no C ABI here)

Core types (reference)

These names match the public Dart surface today. Prefer generated wrappers (app.message, app.onAddTodo(...)) in app code; the stringly property / callback methods exist for backends and tooling.

`SlintComponent`

Live instance (mirrors slint_interpreter::ComponentInstance).

Member	What it does
`SlintComponent.load<T>(path, {component})`	Returns the typed wrapper registered for that `.slint` path. Synchronous. Requires a prior `register()`.
`SlintComponent.register<T>(path, component, create)`	Makes `load` answer that path; generated wrappers expose this as `register()`.
`SlintComponent.unregister(path)`	Forgets registrations for that path.
`getProperty` / `setProperty`	Low-level property access by Slint name.
`setCallbackHandler` / `invokeCallback`	Low-level callbacks by Slint name.
`dispose()`	Releases the instance.

SlintCallbackHandler is Object? Function(List<Object?> arguments).

`SlintComponentDefinition`

Compiled, instantiable definition (instantiate() / dispose()). Backends produce these; app code usually never holds one directly.

`SlintView`

Flutter StatefulWidget that paints a SlintRenderTarget and forwards pointer / key input. Sizes the target from layout each frame (physical pixels). In an unbounded layout (a bare Row, an unconstrained scrollable) there is no size to report — give it an explicit size or it renders nothing.

Render targets and engine

Type	Role
`SlintEngine`	Backend entry that can compile / instantiate components
`SlintRenderTarget`	Pixel / texture surface a view paints
`SlintSoftwareRenderTarget`	Software-renderer path used by the interpreter (and AOT software path)
`SlintTextureRenderTarget`	Texture-backed target (GPU backends such as Skia)

Exact constructors and factory types live in the backend packages.

Component variants

Type	Role
`SlintSoftwareComponent`	Component paired with a software render target
`SlintInspectableComponent`	Component exposing accessibility-tree queries (testing / Patrol)

Color, brush, lifecycle

Type	Role
`SlintColor` / `SlintBrush`	Value types used by properties that cross the FFI boundary
`SlintNativeDisposeGuard`	Guards native dispose ordering for FFI-backed objects

Exact constructors and factory types beyond these interfaces live in the backend packages.

Input events

Type	Role
`SlintPointerEventKind`	`move`, `down`, `up`, `scroll`, `exit`
`SlintPointerButton`	`none`, `left`, `right`, `middle`
Related event structs in `src/events.dart`	Mapped onto `slint::platform::WindowEvent` in Rust

Models and trees

Type	Role
`SlintListModel<T>`	List model bridge used by generated wrappers
`SlintSourceTree`	Source + imported files for runtime compile (`writeSlintTree`)

writeSlintTree(source, files) writes a wrapper's slintSource and slintFiles into a temporary directory and returns the entry path — for backends that compile at runtime so imports and @image-url resolve on disk.

Loading pattern

HelloApp.register(); // once at startup
        final app = SlintComponent.load<HelloApp>('ui/hello.slint')
          ..message = 'Hello from Flutter';
        // …
        SlintView(target: app.renderTarget);

defaultFactory inside the generated code follows the Flutter build mode (interpreter in debug, AOT in release/profile). Passing a factory to create() overrides it. See Backends and Getting started.