v12 (#5712)

Co-authored-by: MeiMei <30769358+mei23@users.noreply.github.com>
Co-authored-by: Satsuki Yanagi <17376330+u1-liquid@users.noreply.github.com>

src/client/theme.ts

@@ -0,0 +1,100 @@
+import * as tinycolor from 'tinycolor2';
+
+export type Theme = {
+	id: string;
+	name: string;
+	author: string;
+	desc?: string;
+	base?: 'dark' | 'light';
+	props: { [key: string]: string };
+};
+
+export const lightTheme: Theme = require('./themes/light.json5');
+export const darkTheme: Theme = require('./themes/dark.json5');
+
+export const builtinThemes = [
+	lightTheme,
+	darkTheme,
+	require('./themes/lavender.json5'),
+	require('./themes/halloween.json5'),
+	require('./themes/garden.json5'),
+	require('./themes/mauve.json5'),
+	require('./themes/elegant.json5'),
+	require('./themes/rainy.json5'),
+	require('./themes/urban.json5'),
+	require('./themes/cafe.json5'),
+];
+
+let timeout = null;
+
+export function applyTheme(theme: Theme, persist = true) {
+	if (timeout) clearTimeout(timeout);
+
+	document.documentElement.classList.add('changing-theme');
+
+	timeout = setTimeout(() => {
+		document.documentElement.classList.remove('changing-theme');
+	}, 1000);
+
+	// Deep copy
+	const _theme = JSON.parse(JSON.stringify(theme));
+
+	if (_theme.base) {
+		const base = [lightTheme, darkTheme].find(x => x.id == _theme.base);
+		_theme.props = Object.assign({}, base.props, _theme.props);
+	}
+
+	const props = compile(_theme);
+
+	for (const tag of document.head.children) {
+		if (tag.tagName === 'META' && tag.getAttribute('name') === 'theme-color') {
+			tag.setAttribute('content', props['accent']);
+			break;
+		}
+	}
+
+	for (const [k, v] of Object.entries(props)) {
+		document.documentElement.style.setProperty(`--${k}`, v.toString());
+	}
+
+	if (persist) {
+		localStorage.setItem('theme', JSON.stringify(props));
+	}
+}
+
+function compile(theme: Theme): { [key: string]: string } {
+	function getColor(code: string): tinycolor.Instance {
+		// ref
+		if (code[0] == '@') {
+			return getColor(theme.props[code.substr(1)]);
+		}
+
+		// func
+		if (code[0] == ':') {
+			const parts = code.split('<');
+			const func = parts.shift().substr(1);
+			const arg = parseFloat(parts.shift());
+			const color = getColor(parts.join('<'));
+
+			switch (func) {
+				case 'darken': return color.darken(arg);
+				case 'lighten': return color.lighten(arg);
+				case 'alpha': return color.setAlpha(arg);
+			}
+		}
+
+		return tinycolor(code);
+	}
+
+	const props = {};
+
+	for (const [k, v] of Object.entries(theme.props)) {
+		props[k] = genValue(getColor(v));
+	}
+
+	return props;
+}
+
+function genValue(c: tinycolor.Instance): string {
+	return c.toRgbString();
+}