fx-compat: Add HiddenBrowser.jsm

Remove Zotero.Browser and add HiddenBrowser.jsm. Post-Fission, web/file
content loads in a separate process, so it's not possible (as best as I
can tell) to directly access the contents of a hidden browser -- it just
appears as about:blank in the parent process. We now use Mozilla's
JSWindowActor mechanism [1] to get page data, including character set
and body text for full-text indexing. We'll have to evaluate other uses
of hidden browsers to see how to handle them.

This also adds include.jsm for loading the Zotero object into a JSM.

[1] https://firefox-source-docs.mozilla.org/dom/ipc/jsactors.html

chrome/content/zotero/HiddenBrowser.jsm

@@ -0,0 +1,166 @@
+/*
+    ***** BEGIN LICENSE BLOCK *****
+    
+    Copyright © 2022 Corporation for Digital Scholarship
+                     Vienna, Virginia, USA
+                     https://www.zotero.org
+    
+    This file is part of Zotero.
+    
+    Zotero is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+    
+    Zotero is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+    
+    You should have received a copy of the GNU Affero General Public License
+    along with Zotero.  If not, see <http://www.gnu.org/licenses/>.
+    
+    ***** END LICENSE BLOCK *****
+*/
+
+
+var EXPORTED_SYMBOLS = ["HiddenBrowser"];
+
+const { XPCOMUtils } = ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
+
+/* global HiddenFrame, E10SUtils, this */
+XPCOMUtils.defineLazyModuleGetters(this, {
+	E10SUtils: "resource://gre/modules/E10SUtils.jsm",
+	HiddenFrame: "resource://gre/modules/HiddenFrame.jsm",
+	Services: "resource://gre/modules/Services.jsm",
+	setTimeout: "resource://gre/modules/Timer.jsm",
+	Zotero: "chrome://zotero/content/include.jsm"
+});
+
+ChromeUtils.registerWindowActor("PageData", {
+	child: {
+		moduleURI: "chrome://zotero/content/actors/PageDataChild.jsm"
+	}
+});
+
+const progressListeners = new Set();
+const browserFrameMap = new WeakMap();
+
+/**
+ * Functions for creating and destroying hidden browser objects
+ **/
+const HiddenBrowser = {
+	/**
+	 * @param {String) source - HTTP URL, file: URL, or file path
+	 */
+	async create(source, options = {}) {
+		let url;
+		if (/^(file|https?):/.test(source)) {
+			url = source;
+		}
+		// Convert string path to file: URL
+		else {
+			url = Zotero.File.pathToFileURI(source);
+		}
+		
+		Zotero.debug(`Loading ${url} in hidden browser`);
+		
+		var frame = new HiddenFrame();
+		var windowlessBrowser = await frame.get();
+		windowlessBrowser.browsingContext.allowJavascript = options.allowJavaScript !== false;
+		windowlessBrowser.docShell.allowImages = false;
+		var doc = windowlessBrowser.document;
+		var browser = doc.createXULElement("browser");
+		browser.setAttribute("type", "content");
+		browser.setAttribute("remote", "true");
+		browser.setAttribute('maychangeremoteness', 'true');
+		browser.setAttribute("disableglobalhistory", "true");
+		doc.documentElement.appendChild(browser);
+		
+		browserFrameMap.set(browser, frame);
+		
+		// Next bit adapted from Mozilla's HeadlessShell.jsm
+		const principal = Services.scriptSecurityManager.getSystemPrincipal();
+		try {
+			await new Promise((resolve, reject) => {
+				// Avoid a hang if page is never loaded for some reason
+				setTimeout(function () {
+					reject(new Error("Page never loaded in hidden browser"));
+				}, 5000);
+				
+				let oa = E10SUtils.predictOriginAttributes({ browser });
+				let loadURIOptions = {
+					triggeringPrincipal: principal,
+					remoteType: E10SUtils.getRemoteTypeForURI(
+						url,
+						true,
+						false,
+						E10SUtils.DEFAULT_REMOTE_TYPE,
+						null,
+						oa
+					)
+				};
+				browser.loadURI(url, loadURIOptions);
+				let { webProgress } = browser;
+				
+				let progressListener = {
+					onLocationChange(progress, request, location, flags) {
+						// Ignore inner-frame events
+						if (!progress.isTopLevel) {
+							return;
+						}
+						// Ignore events that don't change the document
+						if (flags & Ci.nsIWebProgressListener.LOCATION_CHANGE_SAME_DOCUMENT) {
+							return;
+						}
+						// Ignore the initial about:blank, unless about:blank is requested
+						if (location.spec == "about:blank" && url != "about:blank") {
+							return;
+						}
+						progressListeners.delete(progressListener);
+						webProgress.removeProgressListener(progressListener);
+						resolve();
+					},
+					QueryInterface: ChromeUtils.generateQI([
+						"nsIWebProgressListener",
+						"nsISupportsWeakReference"
+					])
+				};
+				
+				progressListeners.add(progressListener);
+				webProgress.addProgressListener(
+					progressListener,
+					Ci.nsIWebProgress.NOTIFY_LOCATION
+				);
+			});
+		}
+		catch (e) {
+			Zotero.logError(e);
+			return false;
+		}
+		
+		return browser;
+	},
+	
+	/**
+	 * @param {Browser} browser
+	 * @param {String[]} props - 'characterSet', 'title', 'bodyText'
+	 */
+	async getPageData(browser, props) {
+		var actor = browser.browsingContext.currentWindowGlobal.getActor("PageData");
+		var data = {};
+		for (let prop of props) {
+			data[prop] = await actor.sendQuery(prop);
+		}
+		return data;
+	},
+	
+	destroy(browser) {
+		var frame = browserFrameMap.get(browser);
+		if (frame) {
+			frame.destroy();
+			Zotero.debug("Deleted hidden browser");
+			browserFrameMap.delete(frame);
+		}
+	}
+};

chrome/content/zotero/actors/PageDataChild.jsm

@@ -0,0 +1,52 @@
+var EXPORTED_SYMBOLS = ["PageDataChild"];
+
+class PageDataChild extends JSWindowActorChild {
+	async receiveMessage(message) {
+		let window = this.contentWindow;
+		let document = window.document;
+		
+		await this.documentIsReady();
+		
+		switch (message.name) {
+			case "characterSet":
+				return document.characterSet;
+			
+			case "title":
+				return document.title;
+			
+			case "bodyText":
+				return document.documentElement.innerText;
+		}
+	}
+	
+	// From Mozilla's ScreenshotsComponentChild.jsm
+	documentIsReady() {
+		const contentWindow = this.contentWindow;
+		const document = this.document;
+		
+		// Make sure the document element has been created
+		function readyEnough() {
+			return document.readyState !== "uninitialized" && document.documentElement;
+		}
+		
+		if (readyEnough()) {
+			return Promise.resolve();
+		}
+		return new Promise((resolve, reject) => {
+			function onChange(event) {
+				if (event.type === "pagehide") {
+					document.removeEventListener("readystatechange", onChange);
+					contentWindow.removeEventListener("pagehide", onChange);
+					reject(new Error("document unloaded before it was ready"));
+				}
+				else if (readyEnough()) {
+					document.removeEventListener("readystatechange", onChange);
+					contentWindow.removeEventListener("pagehide", onChange);
+					resolve();
+				}
+			}
+			document.addEventListener("readystatechange", onChange);
+			contentWindow.addEventListener("pagehide", onChange, { once: true });
+		});
+	}
+}

chrome/content/zotero/include.jsm

@@ -0,0 +1,5 @@
+var EXPORTED_SYMBOLS = ["Zotero"];
+
+var Zotero = Components.classes['@zotero.org/Zotero;1']
+	.getService(Components.interfaces.nsISupports)
+	.wrappedJSObject;

chrome/content/zotero/xpcom/zotero.js

@@ -2081,59 +2081,6 @@ Zotero.DragDrop = {
 }
 
 
-/**
- * Functions for creating and destroying hidden browser objects
- **/
-Zotero.Browser = new function() {
-	var nBrowsers = 0;
-	
-	this.createHiddenBrowser = function (win, options = {}) {
-		if (!win) {
-			win = Services.wm.getMostRecentWindow("navigator:browser");
-			if (!win) {
-				win = Services.ww.activeWindow;
-			}
-			// Use the hidden DOM window on macOS with the main window closed
-			if (!win) {
-				let appShellService = Components.classes["@mozilla.org/appshell/appShellService;1"]
-					.getService(Components.interfaces.nsIAppShellService);
-				win = appShellService.hiddenDOMWindow;
-			}
-			if (!win) {
-				throw new Error("Parent window not available for hidden browser");
-			}
-		}
-		
-		// Create a hidden browser
-		var hiddenBrowser = win.document.createElement("browser");
-		hiddenBrowser.setAttribute('type', 'content');
-		hiddenBrowser.setAttribute('disableglobalhistory', 'true');
-		win.document.documentElement.appendChild(hiddenBrowser);
-		// Disable some features
-		hiddenBrowser.docShell.allowAuth = false;
-		hiddenBrowser.docShell.allowDNSPrefetch = false;
-		hiddenBrowser.docShell.allowImages = false;
-		hiddenBrowser.docShell.allowJavascript = options.allowJavaScript !== false
-		hiddenBrowser.docShell.allowMetaRedirects = false;
-		hiddenBrowser.docShell.allowPlugins = false;
-		Zotero.debug("Created hidden browser (" + (nBrowsers++) + ")");
-		return hiddenBrowser;
-	}
-	
-	this.deleteHiddenBrowser = function (myBrowsers) {
-		if(!(myBrowsers instanceof Array)) myBrowsers = [myBrowsers];
-		for(var i=0; i<myBrowsers.length; i++) {
-			var myBrowser = myBrowsers[i];
-			myBrowser.stop();
-			myBrowser.destroy();
-			myBrowser.parentNode.removeChild(myBrowser);
-			myBrowser = null;
-			Zotero.debug("Deleted hidden browser (" + (--nBrowsers) + ")");
-		}
-	}
-}
-
-
 /*
  * Implements nsIWebProgressListener
  */

test/tests/HiddenBrowserTest.js

@@ -0,0 +1,39 @@
+describe("HiddenBrowser", function() {
+	const { HiddenBrowser } = ChromeUtils.import(
+		"chrome://zotero/content/HiddenBrowser.jsm"
+	);
+	
+	describe("#getPageData()", function () {
+		it("should handle local UTF-8 HTML file", async function () {
+			var path = OS.Path.join(getTestDataDirectory().path, 'test-hidden.html');
+			var browser = await HiddenBrowser.create(path);
+			var { characterSet, bodyText } = await HiddenBrowser.getPageData(
+				browser, ['characterSet', 'bodyText']
+			);
+			assert.equal(characterSet, 'UTF-8');
+			// Should ignore hidden text
+			assert.equal(bodyText, 'This is a test.');
+		});
+		
+		it("should handle local GBK HTML file", async function () {
+			var path = OS.Path.join(getTestDataDirectory().path, 'charsets', 'gbk.html');
+			var browser = await HiddenBrowser.create(path);
+			var { characterSet, bodyText } = await HiddenBrowser.getPageData(
+				browser, ['characterSet', 'bodyText']
+			);
+			assert.equal(characterSet, 'GBK');
+			assert.equal(bodyText, '主体');
+		});
+		
+		it("should handle local GBK text file", async function () {
+			var path = OS.Path.join(getTestDataDirectory().path, 'charsets', 'gbk.txt');
+			var browser = await HiddenBrowser.create(path);
+			var { characterSet, bodyText } = await HiddenBrowser.getPageData(
+				browser, ['characterSet', 'bodyText']
+			);
+			HiddenBrowser.destroy(browser);
+			assert.equal(characterSet, 'GBK');
+			assert.equal(bodyText, '这是一个测试文件。');
+		});
+	});
+});

test/tests/data/charsets/gbk.html

@@ -0,0 +1,12 @@
+<!DOCTYPE html>
+<html lang="zh-CN">
+<head>
+	<title>标题</title>
+	<meta name="keywords" content="简讯,新闻摘要">
+	<meta name="description" content="加拿大本地新闻简讯,突发新闻,即时新闻">
+
+    <meta http-equiv="Content-Type" content="text/html; charset=gbk">
+</head>
+
+<body>主体</body>
+</html>

test/tests/data/charsets/gbk.txt

@@ -1 +1 @@
-　
+这是一个测试文件。