Trait LightOutput 

pub trait LightOutput: Send {
    // Required methods
    fn set_on(&mut self, on: bool);
    fn set_brightness(&mut self, level: u8);
    fn set_rgb(&mut self, r: u8, g: u8, b: u8);

    // Provided methods
    fn set_color_xy(&mut self, _x: u16, _y: u16) { ... }
    fn set_color_temp(&mut self, _mireds: u16) { ... }
    fn state_update(&mut self, _state: &LightSnapshot) { ... }
}

Trait for any LED output backend. Implementations handle the actual hardware (GPIO PWM, WS2812B, etc.).

Call contract

state::LightState drives implementations under these rules:

• set_on(false) must drive the output dark immediately.
• set_on(true) must restore the most recently set color/brightness on its own. The identify/effect blink calls only set_on in alternation, so an implementation that treats set_on(true) as a bare flag renders identify invisible.
• Hardware errors are not propagated: the state machine has no recovery action for a failed LED write, so implementations log and continue.

Required Methods

fn set_on(&mut self, on: bool)

Turn the light on or off. On true, re-apply the last output state.

fn set_brightness(&mut self, level: u8)

Set brightness level (0-254, where 254 is full brightness).

fn set_rgb(&mut self, r: u8, g: u8, b: u8)

Set color using direct RGB values.

Required — the state machine renders the XY and hue/saturation color modes (and dimmed color temperature) through this method, so a silently inherited no-op would mean a light that pairs, powers, and dims but never changes color. Backends with no color channel implement it as a brightness mapping (see SimpleLed’s BT.709 luminance) or an explicit empty body — the choice must be visible in the impl, not an invisible default.

Provided Methods

fn set_color_xy(&mut self, _x: u16, _y: u16)

Set color using CIE 1931 XY coordinates (0-65535 range for each axis).

Defaults to a no-op. state::LightState never calls this — it converts XY to RGB and calls set_rgb instead — so override it only for a backend you drive with raw XY yourself.

fn set_color_temp(&mut self, _mireds: u16)

Set color temperature in mireds (153 = 6500K, 500 = 2000K).

Defaults to a no-op, so an on/off or plain-dimmable backend with no tunable white needs to implement only set_on and set_brightness.

fn state_update(&mut self, _state: &LightSnapshot)

Observe the full raw light state after every render pass.

Defaults to a no-op; the built-in backends ignore it. Pick one lane: simple hardware implements the set_* methods and ignores this hook; an effects/full-control backend treats this hook as its single source of truth and leaves the set_* bodies empty — handling both would double-apply every change.

The state::LightSnapshot carries every raw ZCL value with no Options: on, brightness (logical target, 0-254), rendered_brightness (what is being driven right now — ramps during fades; key visual effects off this one), color_mode, hue/saturation (0-254), enhanced_hue (0-65535), color_x/color_y (0-65535 CIE), color_temp_mireds (153-500). During a smooth transition it fires on every animation frame (~20-33 ms).

Note: the identify blink signals through set_on alone and does not re-render.

Dyn Compatibility

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors