decePubClient/wwwroot/main.js

window.cascadingStateInstanceReference = (dotNetReference) => {
	try {
		window.cascadingStateInstance = dotNetReference
	} catch (e) {
		console.error(e)
	}
}
window.logFromJs = (message, where) => {
	try {
		if (!window.cascadingStateInstance ||
				typeof window.cascadingStateInstance.invokeMethodAsync != "function")
			return
		window.cascadingStateInstance.invokeMethodAsync('LogFromJs', message, where)
	} catch (e) {
		console.error(e)
	}
}
// The client once kept its error log in IndexedDB (DnetIndexedDb's database "data"). Nothing uses IndexedDB now, so a
// browser that still holds that database drops it.
try {
	window.indexedDB?.deleteDatabase("data")
} catch (e) {
	console.error(e)
}
window.getLanguage = () => {
	try {
		return navigator.language.substr(0, 2)
	} catch (e) {
		console.error(e)
		window.logFromJs(e.message, "getLanguage")
	}
}
window.isOnline = async () => {
	try {
		const isOnline = navigator.onLine
		if (navigator.connection !== undefined &&
				navigator.connection.effectiveType !== undefined &&
				navigator.connection.type !== undefined) {
			if (!isOnline)
				return isOnline
			
			return navigator.connection.type === "cellular" ?
					navigator.connection.effectiveType.indexOf("2g") === -1 :
					true
		} else
			return isOnline
	} catch (e) {
		console.error(e)
		window.logFromJs(e.message, "isOnline")
	}
}
window.setAppBadge = (counter) => {
	try {
		navigator.setAppBadge(counter)
	} catch (e) {
		console.error(e)
		window.logFromJs(e.message, "setAppBadge")
	}
}
window.clearAppBadge = () => {
	try {
		navigator.clearAppBadge()
	} catch (e) {
		console.error(e)
		window.logFromJs(e.message, "clearAppBadge")
	}
}
// On a touch screen a tap on a post (not on its links, controls or menus, and not ending a text selection) opens its
// thread, through the card's own thread link (Content.razor, data-thread-link), which Blazor's router takes.
document.addEventListener("click", event => {
	try {
		if (window.matchMedia("(hover: hover)").matches || !(event.target instanceof Element))
			return
		const card = event.target.closest("[data-thread]")
		if (!card || event.target.closest("a, button, input, textarea, select, label, summary, video, audio, [role=button], .dropdown, .modal, [data-sheet]"))
			return
		if (!window.getSelection()?.isCollapsed)
			return
		card.querySelector("a[data-thread-link]")?.click()
	} catch (e) {
		console.error(e)
		window.logFromJs(e.message, "openThread")
	}
})
// The Back button (a popstate) as opposed to the app's own navigation: Blazor's location-changing handlers can't tell
// them apart, and MainLayout lets Back close an open overlay but lets the app's navigation through. Registered for the
// capture phase, so it runs before Blazor's own listener.
let backAt = 0
window.addEventListener("popstate", () => backAt = Date.now(), { capture: true })
window.tookBack = () => {
	const back = Date.now() - backAt < 1000
	backAt = 0
	return back
}
window.canHover = () => {
	try {
		return window.matchMedia("(hover: hover)").matches
	} catch (e) {
		console.error(e)
		window.logFromJs(e.message, "canHover")
		return true
	}
}
// the selected tab of a sideways-scrolling strip, brought into its middle
window.revealActive = strip => {
	try {
		strip?.querySelector("[aria-selected=true]")?.scrollIntoView({ inline: "center", block: "nearest" })
	} catch (e) {
		console.error(e)
		window.logFromJs(e.message, "revealActive")
	}
}
// the reader asked for less motion: what would move by itself (a gifv) waits for a tap
window.prefersReducedMotion = () => {
	try {
		return window.matchMedia("(prefers-reduced-motion: reduce)").matches
	} catch (e) {
		console.error(e)
		window.logFromJs(e.message, "prefersReducedMotion")
		return false
	}
}
// a phone: narrower than Tailwind's md, or held sideways (as short as the short: variant)
window.isMobileMedia = () => {
	try {
		return window.matchMedia("(max-width: 767.98px), (max-height: 30rem)").matches
	} catch (e) {
		console.error(e)
		window.logFromJs(e.message, "isMobileMedia")
	}
}
// This device's position for located posts and the Nearby feed, asked only when the reader chooses one of them. It
// goes to PrivaPub only, which keeps located posts on the server and rounds what it stores.
window.feedPosition = () => new Promise(resolve => {
	try {
		if (!navigator.geolocation)
			return resolve({ error: "unsupported" })
		navigator.geolocation.getCurrentPosition(
			position => resolve({ latitude: position.coords.latitude, longitude: position.coords.longitude, accuracy: position.coords.accuracy }),
			error => resolve({ error: error.message || String(error.code) }),
			{ enableHighAccuracy: false, timeout: 15000, maximumAge: 600000 })
	} catch (e) {
		console.error(e)
		window.logFromJs(e.message, "feedPosition")
		resolve({ error: e.message })
	}
})