Files
OpenSquawk/app/composables/usePmTheme.ts
itsrubberduck 9f0a51e678 atc header
2026-07-10 08:33:36 +02:00

78 lines
2.6 KiB
TypeScript

import { computed, onBeforeUnmount, ref, watch } from 'vue'
import { useTheme } from 'vuetify'
import { useCookie } from '#imports'
export type PmThemePreference = 'system' | 'light' | 'dark'
export type PmEffectiveTheme = 'light' | 'dark'
const PM_THEME_COOKIE = 'os_pm_theme'
/**
* /live-atc-scoped light/dark toggle (formerly /pm — cookie name kept for
* backwards compatibility). Defaults to dark (matching the rest of the app)
* until the user explicitly picks Light or System, at which point that choice is
* remembered and wins over the default. Only /live-atc has a light theme today —
* the Vuetify theme is reset back to the app-wide dark default on unmount so
* other pages are unaffected.
*/
export function usePmTheme() {
const vuetifyTheme = useTheme()
const storedPreference = useCookie<PmThemePreference | null>(PM_THEME_COOKIE, {
sameSite: 'lax',
path: '/',
maxAge: 60 * 60 * 24 * 365,
})
const preference = ref<PmThemePreference>(storedPreference.value ?? 'dark')
const systemPrefersLight = ref(false)
const effectiveTheme = computed<PmEffectiveTheme>(() => {
if (preference.value === 'system') {
return systemPrefersLight.value ? 'light' : 'dark'
}
return preference.value
})
function applyVuetifyTheme() {
vuetifyTheme.global.name.value = effectiveTheme.value === 'light' ? 'opensquawkLight' : 'opensquawkDark'
}
function setPreference(next: PmThemePreference) {
preference.value = next
storedPreference.value = next
}
// Mirrors effectiveTheme onto <html data-theme="..."> so the --bg/--text/--border
// CSS variables (defined in global.css) reach content that escapes .pm-page in the
// DOM — Vuetify teleports menus, dialogs, and tooltips to <body>, where they'd
// otherwise only see the app-wide dark defaults from :root.
function applyDocumentTheme() {
if (typeof document !== 'undefined') {
document.documentElement.setAttribute('data-theme', effectiveTheme.value)
}
}
if (typeof window !== 'undefined') {
const media = window.matchMedia('(prefers-color-scheme: light)')
systemPrefersLight.value = media.matches
const handleChange = (event: MediaQueryListEvent) => {
systemPrefersLight.value = event.matches
}
media.addEventListener('change', handleChange)
onBeforeUnmount(() => {
media.removeEventListener('change', handleChange)
vuetifyTheme.global.name.value = 'opensquawkDark'
document.documentElement.removeAttribute('data-theme')
})
}
watch(effectiveTheme, () => {
applyVuetifyTheme()
applyDocumentTheme()
}, { immediate: true })
return { preference, effectiveTheme, setPreference }
}