gecko-dev/browser/base/content/contentTheme.js

106 строки
2.8 KiB
JavaScript

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
{
function _isTextColorDark(r, g, b) {
return (0.2125 * r + 0.7154 * g + 0.0721 * b) <= 110;
}
const inContentVariableMap = [
["--newtab-background-color", {
lwtProperty: "ntp_background"
}],
["--newtab-text-primary-color", {
lwtProperty: "ntp_text",
processColor(rgbaChannels, element) {
if (!rgbaChannels) {
element.removeAttribute("lwt-newtab");
element.removeAttribute("lwt-newtab-brighttext");
return null;
}
element.setAttribute("lwt-newtab", "true");
const {r, g, b, a} = rgbaChannels;
if (!_isTextColorDark(r, g, b)) {
element.setAttribute("lwt-newtab-brighttext", "true");
}
return `rgba(${r}, ${g}, ${b}, ${a})`;
},
}],
];
/**
* ContentThemeController handles theme updates sent by the frame script.
* To be able to use ContentThemeController, you must add your page to the whitelist
* in LightweightThemeChildListener.jsm
*/
const ContentThemeController = {
/**
* Tell the frame script that the page supports theming, and watch for updates
* from the frame script.
*/
init() {
addEventListener("LightweightTheme:Set", this);
},
/**
* Handle theme updates from the frame script.
* @param {Object} event object containing the theme update.
*/
handleEvent({ type, detail }) {
if (type == "LightweightTheme:Set") {
let {data} = detail;
if (!data) {
data = {};
}
this._setProperties(document.body, data);
}
},
/**
* Set a CSS variable to a given value
* @param {Element} elem The element where the CSS variable should be added.
* @param {string} variableName The CSS variable to set.
* @param {string} value The new value of the CSS variable.
*/
_setProperty(elem, variableName, value) {
if (value) {
elem.style.setProperty(variableName, value);
} else {
elem.style.removeProperty(variableName);
}
},
/**
* Apply theme data to an element
* @param {Element} root The element where the properties should be applied.
* @param {Object} themeData The theme data.
*/
_setProperties(elem, themeData) {
for (let [cssVarName, definition] of inContentVariableMap) {
const {
lwtProperty,
processColor,
} = definition;
let value = themeData[lwtProperty];
if (processColor) {
value = processColor(value, document.body);
} else if (value) {
const {r, g, b, a} = value;
value = `rgba(${r}, ${g}, ${b}, ${a})`;
}
this._setProperty(elem, cssVarName, value);
}
},
};
ContentThemeController.init();
}