downthemall/windows/theme.ts
2019-10-02 14:54:51 +02:00

113 lines
2.7 KiB
TypeScript

/* eslint-disable no-magic-numbers */
"use strict";
// License: MIT
import { PrefWatcher } from "../lib/prefs";
import { theme } from "../lib/browser";
import { memoize } from "../lib/memoize";
const resolveColor = memoize(function(color) {
try {
const el = document.createElement("div");
el.style.backgroundColor = color;
el.style.display = "none";
document.body.appendChild(el);
try {
const resolved = window.getComputedStyle(el, null).backgroundColor;
return resolved;
}
finally {
document.body.removeChild(el);
}
}
catch {
return undefined;
}
}, 10, 1);
export const THEME = new class Theme extends PrefWatcher {
public systemDark: boolean;
public themeDark?: boolean;
constructor() {
super("theme", "default");
if (theme && theme.onUpdated) {
theme.onUpdated.addListener(this.onThemeUpdated.bind(this));
theme.getCurrent().then((theme: any) => this.onThemeUpdated({theme}));
}
this.themeDark = undefined;
const query = window.matchMedia("(prefers-color-scheme: dark)");
this.systemDark = query.matches;
query.addListener(e => {
this.systemDark = e.matches;
this.recalculate();
});
this.recalculate();
}
get dark() {
if (this.value === "dark") {
return true;
}
if (this.value === "light") {
return false;
}
if (typeof this.themeDark === "undefined") {
return this.systemDark;
}
return this.themeDark;
}
changed(prefs: any, key: string, value: any) {
const rv = super.changed(prefs, key, value);
this.recalculate();
return rv;
}
onThemeUpdated({theme}: {theme: any}) {
try {
if (!theme) {
this.themeDark = undefined;
return;
}
const {colors} = theme;
if (!colors) {
this.themeDark = undefined;
return;
}
const color = resolveColor(
colors.toolbar || colors.popup || colors.ntp_background);
if (!color) {
this.themeDark = undefined;
return;
}
const pieces = color.match(/^rgba?\((\d+),\s*(\d+),\s*(\d+)(?:,\s*(\d+(?:\.\d+)?))?\)$/);
if (!pieces) {
this.themeDark = undefined;
return;
}
const r = parseInt(pieces[1], 10);
const g = parseInt(pieces[2], 10);
const b = parseInt(pieces[3], 10);
// HSP (Highly Sensitive Poo) equation from
// http://alienryderflex.com/hsp.html
const hsp = Math.sqrt(
0.299 * (r * r) +
0.587 * (g * g) +
0.114 * (b * b)
);
this.themeDark = hsp < 128;
}
finally {
this.recalculate();
}
}
recalculate() {
document.documentElement.classList[this.dark ? "add" : "remove"]("dark");
}
}();