Theme

The theme module reads the OS light/dark preference, can force a preference, and emits theme.changed. The SDK exposes it as theme / nativeTheme.

import { nativeTheme } from '@owear/core'

const info = await nativeTheme.get()
// { dark: boolean, source: 'system'|'light'|'dark', highContrast: boolean, reducedTransparency: boolean }

await nativeTheme.isDark()

// force a preference (also applied to web content where the OS supports it)
await nativeTheme.setSource('dark')   // 'system' | 'light' | 'dark'

await nativeTheme.watch()             // start emitting changes
await nativeTheme.unwatch()

Reacting to changes

// main process
nativeTheme.watch()
ow /* not available in main */ // use the SDK channel:

In the renderer, subscribe directly:

ow.on('theme.changed', (info) => {
  document.documentElement.dataset.theme = info.dark ? 'dark' : 'light'
})

In the main process, setSource already forces the color scheme on the content (Windows: WebView2 PreferredColorScheme; Linux: best effort). To react in the main process, listen on the raw channel:

import { app } from '@owear/core'
app.whenReady().then(() => {
  ;(app as any).__channel.on('theme.changed', (info: { dark: boolean }) => {
    console.log('theme changed', info)
  })
  void nativeTheme.watch()
})

How detection works per platform

Linux: GTK gtk-application-prefer-dark-theme, then GNOME 42+ org.gnome.desktop.interface color-scheme, then the GTK theme name.
Windows: the registry.

highContrast and reducedTransparency are reported honestly where the OS exposes them and default to false otherwise.

Theme

Reacting to changes

How detection works per platform

Next steps