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/* 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
/* eslint-env browser */
"use strict";
function stylesheetLoadPromise(styleSheet) {
return new Promise((resolve, reject) => {
styleSheet.addEventListener("load", resolve, { once: true });
styleSheet.addEventListener("error", reject, { once: true });
});
}
/*
* Put the DevTools theme stylesheet into the provided chrome document.
*
* @param {Document} doc
* The chrome document where the stylesheet should be appended.
* @param {String} url
* The url of the stylesheet to load.
* @return {Object}
* - styleSheet {XMLStylesheetProcessingInstruction} the instruction node created.
* - loadPromise {Promise} that will resolve/reject when the stylesheet finishes
* or fails to load.
*/
function appendStyleSheet(doc, url) {
const styleSheet = doc.createElementNS(
"link"
);
styleSheet.setAttribute("rel", "stylesheet");
styleSheet.setAttribute("href", url);
const loadPromise = stylesheetLoadPromise(styleSheet);
// In order to make overriding styles sane, we want the order of loaded
// sheets to be something like this:
// global.css
// *-theme.css (the file loaded here)
// document-specific-sheet.css
// If there is a global sheet then insert after it.
const globalSheet = doc.querySelector(
);
if (globalSheet) {
globalSheet.after(styleSheet);
return { styleSheet, loadPromise };
}
// Otherwise insert before any existing link.
const links = doc.querySelectorAll("link");
if (links.length) {
links[0].before(styleSheet);
return { styleSheet, loadPromise };
}
// Fall back to putting at the start of the head or in a non-HTML doc the
// start of the document.
if (doc.head) {
doc.head.prepend(styleSheet);
} else {
doc.documentElement.prepend(styleSheet);
}
return { styleSheet, loadPromise };
}
exports.appendStyleSheet = appendStyleSheet;