system

Documentation

Overview

Package system bridges OS-level appearance signals (dark mode, accent colour) into the reactive theme runtime. Per-OS shims read the live state behind a Source interface; FromSource turns a Source plus a poll interval into an rx.Observable that emits only on change. Live wires the OS-default source for the current platform; LiveTheme then converts the appearance stream into theme.Theme emissions whose Color observable matches the OS dark-mode setting.

The package never imports Gio. It speaks to the OS directly so it can be reused from any spectrum consumer, with or without a window.

Index

• func FromSource(src Source, interval time.Duration) rx.Observable[Appearance]
• func FromSourceTheme(src Source, interval time.Duration) rx.Observable[theme.Theme]
• func Live(interval time.Duration) rx.Observable[Appearance]
• func LiveTheme(interval time.Duration) rx.Observable[theme.Theme]
• type Appearance
• type Source

Functions

func FromSource

func FromSource(src Source, interval time.Duration) rx.Observable[Appearance]

FromSource returns an Observable that polls src every interval, emitting Appearance only when the value changes. The first emission happens immediately (no initial delay).

Read errors are folded into the zero-value Appearance — the stream is never an error stream. This keeps the contract simple for consumers that only care about the last good value, and matches a11y.FromSource.

func FromSourceTheme

func FromSourceTheme(src Source, interval time.Duration) rx.Observable[theme.Theme]

FromSourceTheme is the test-friendly variant of LiveTheme: it lets a caller plug in a fake Source while exercising the same Appearance → theme.Theme bridge.

func Live

func Live(interval time.Duration) rx.Observable[Appearance]

Live returns an Observable backed by the current OS's appearance APIs, polling every interval and emitting whenever a value changes.

Recommended interval: 100–250 ms. The G2.2 acceptance budget allows up to one second between an external `defaults write` and the corresponding emission, but most desktop UIs prefer to feel snappier than that.

func LiveTheme

func LiveTheme(interval time.Duration) rx.Observable[theme.Theme]

LiveTheme bridges system-appearance changes to a theme.Theme stream. Each emission is a fresh theme.Theme whose Color field matches the OS dark-mode setting (tokens.DefaultLight or tokens.DefaultDark); the remaining token categories use their package defaults.

Accent-driven palette swaps are intentionally out of scope here — the AccentIndex is observed and propagated, but mapping it to concrete ColorTokens belongs to a later spectrum milestone.

Types

type Appearance

type Appearance struct {
	// Dark is true iff the OS reports a dark interface style.
	Dark bool

	// AccentIndex carries a platform-defined accent identifier. On macOS
	// it is the AppleAccentColor key (-1..7, where -1 means "multicolor"
	// and 4 is the default Blue); on platforms that expose no equivalent
	// it is zero. The mapping from index to a tokens.* colour belongs to
	// later milestones.
	AccentIndex int
}

Appearance is the OS-level appearance state we observe. All fields are comparable so the value can be used with rx.DistinctUntilChanged.

type Source

type Source interface {
	Read() (Appearance, error)
}

Source reads the current OS appearance state. Implement this interface to provide a custom or test-double backend.