1# llimphi-widget-rive-button
2
3A **reactive** button driven by a Rive-style state machine
4(`llimphi_anim::StateMachine`).
5
6It is the first *real* consumer of the state machine outside `llimphi-anim-studio`
7(which authors it) and the `llimphi-lottie` examples. It encapsulates the
8canonical composition of the `pointer_listeners_demo` as a reusable widget: three
9states — `idle` / `hover` / `press` — each with its own Lottie clip, threaded by
10inputs the engine derives from the raw pointer:
11
12- **hover** (`bool`): the `Enter`/`Exit` listeners over the whole surface turn the
13  `hovered` input on and off; `idle ⇄ hover` with a crossfade.
14- **press** (`trigger`): the host calls `RiveButton::press` from its `on_click`;
15  that fires the `pressed` trigger, the machine enters the `press` state (a
16  **non-looping** clip) and, when the clip finishes (`ClipDone`), returns to
17  `hover` or `idle` depending on whether the pointer is still over it.
18
19The widget is **stateful** (like `text-editor`/`nodegraph`): the host keeps it in
20its `Model`, advances it with `advance` from a periodic tick, forwards the
21pointer with `pointer` and the click with `press`, and paints it with `view`.
22Hit-testing lives in the engine, not in the app.
23
24```ignore
25// In the host's Model:
26button: RiveButton::builtin(),
27// update:
28Msg::Tick       => m.button.advance(DT),
29Msg::Pointer(p) => m.button.pointer(p),
30Msg::Click      => { m.button.press(); /* the host's action */ }
31// view:
32m.button.view(Msg::Pointer, Msg::Click)
33```
34
35---
36
37Part of **llimphi** — see [llimphi](../../README.md).