michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: "use strict";
michael@0: 
michael@0: module.metadata =  {
michael@0:   "stability": "experimental"
michael@0: };
michael@0: 
michael@0: const { Cc, Ci } = require("chrome");
michael@0: 
michael@0: const io = Cc['@mozilla.org/network/io-service;1'].
michael@0:             getService(Ci.nsIIOService);
michael@0: 
michael@0: const SHEET_TYPE = {
michael@0:   "agent": "AGENT_SHEET",
michael@0:   "user": "USER_SHEET",
michael@0:   "author": "AUTHOR_SHEET"
michael@0: };
michael@0: 
michael@0: function getDOMWindowUtils(window) {
michael@0:   return window.QueryInterface(Ci.nsIInterfaceRequestor).
michael@0:                 getInterface(Ci.nsIDOMWindowUtils);
michael@0: };
michael@0: 
michael@0: /**
michael@0:  * Synchronously loads a style sheet from `uri` and adds it to the list of
michael@0:  * additional style sheets of the document.
michael@0:  * The sheets added takes effect immediately, and only on the document of the
michael@0:  * `window` given.
michael@0:  */
michael@0: function loadSheet(window, url, type) {
michael@0:   if (!(type && type in SHEET_TYPE))
michael@0:     type = "author";
michael@0: 
michael@0:   type = SHEET_TYPE[type];
michael@0: 
michael@0:   if (!(url instanceof Ci.nsIURI))
michael@0:     url = io.newURI(url, null, null);
michael@0: 
michael@0:   let winUtils = getDOMWindowUtils(window);
michael@0:   try {
michael@0:     winUtils.loadSheet(url, winUtils[type]);
michael@0:   }
michael@0:   catch (e) {};
michael@0: };
michael@0: exports.loadSheet = loadSheet;
michael@0: 
michael@0: /**
michael@0:  * Remove the document style sheet at `sheetURI` from the list of additional
michael@0:  * style sheets of the document.  The removal takes effect immediately.
michael@0:  */
michael@0: function removeSheet(window, url, type) {
michael@0:   if (!(type && type in SHEET_TYPE))
michael@0:     type = "author";
michael@0: 
michael@0:   type = SHEET_TYPE[type];
michael@0: 
michael@0:   if (!(url instanceof Ci.nsIURI))
michael@0:     url = io.newURI(url, null, null);
michael@0: 
michael@0:   let winUtils = getDOMWindowUtils(window);
michael@0: 
michael@0:   try {
michael@0:     winUtils.removeSheet(url, winUtils[type]);
michael@0:   }
michael@0:   catch (e) {};
michael@0: };
michael@0: exports.removeSheet = removeSheet;
michael@0: 
michael@0: /**
michael@0:  * Returns `true` if the `type` given is valid, otherwise `false`.
michael@0:  * The values currently accepted are: "agent", "user" and "author".
michael@0:  */
michael@0: function isTypeValid(type) {
michael@0:   return type in SHEET_TYPE;
michael@0: }
michael@0: exports.isTypeValid = isTypeValid;