refactor

src/client/scripts/theme.ts

@@ -0,0 +1,118 @@
+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 = [
+	require('../themes/white.json5'),
+	require('../themes/black.json5'),
+	require('../themes/lilac.json5'),
+	require('../themes/halloween.json5'),
+	require('../themes/city.json5'),
+	require('../themes/rainy.json5'),
+	require('../themes/urban.json5'),
+	require('../themes/cafe.json5'),
+	require('../themes/chocolate.json5'),
+	require('../themes/danboard.json5'),
+	require('../themes/olive.json5'),
+	require('../themes/ocean.json5'),
+] as Theme[];
+
+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['html']);
+			break;
+		}
+	}
+
+	for (const [k, v] of Object.entries(props)) {
+		document.documentElement.style.setProperty(`--${k}`, v.toString());
+	}
+
+	if (persist) {
+		localStorage.setItem('theme', JSON.stringify(props));
+	}
+}
+
+function compile(theme: Theme): Record<string, string> {
+	function getColor(val: string): tinycolor.Instance {
+		// ref (prop)
+		if (val[0] === '@') {
+			return getColor(theme.props[val.substr(1)]);
+		}
+
+		// ref (const)
+		else if (val[0] === '$') {
+			return getColor(theme.props[val]);
+		}
+
+		// func
+		else if (val[0] === ':') {
+			const parts = val.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);
+			}
+		}
+
+		// other case
+		return tinycolor(val);
+	}
+
+	const props = {};
+
+	for (const [k, v] of Object.entries(theme.props)) {
+		if (k.startsWith('$')) continue; // ignore const
+
+		props[k] = genValue(getColor(v));
+	}
+
+	return props;
+}
+
+function genValue(c: tinycolor.Instance): string {
+	return c.toRgbString();
+}
+
+export function validateTheme(theme: Record<string, any>): boolean {
+	if (theme.id == null || typeof theme.id !== 'string') return false;
+	if (theme.name == null || typeof theme.name !== 'string') return false;
+	if (theme.base == null || !['light', 'dark'].includes(theme.base)) return false;
+	if (theme.props == null || typeof theme.props !== 'object') return false;
+	return true;
+}