1 files changed, 147 insertions, 0 deletions
diff --git a/toolkit/components/webextensions/ext-backgroundPage.js b/toolkit/components/webextensions/ext-backgroundPage.js
new file mode 100644
index 000000000..fce6100ca
--- /dev/null
+++ b/toolkit/components/webextensions/ext-backgroundPage.js
@@ -0,0 +1,147 @@
+"use strict";
+
+var {interfaces: Ci, utils: Cu} = Components;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/Task.jsm");
+
+XPCOMUtils.defineLazyModuleGetter(this, "AddonManager",
+                                  "resource://gre/modules/AddonManager.jsm");
+XPCOMUtils.defineLazyModuleGetter(this, "PrivateBrowsingUtils",
+                                  "resource://gre/modules/PrivateBrowsingUtils.jsm");
+
+Cu.import("resource://gre/modules/ExtensionUtils.jsm");
+const {
+  promiseDocumentLoaded,
+  promiseObserved,
+} = ExtensionUtils;
+
+const XUL_URL = "data:application/vnd.mozilla.xul+xml;charset=utf-8," + encodeURI(
+  `<?xml version="1.0"?>
+  <window id="documentElement"/>`);
+
+// WeakMap[Extension -> BackgroundPage]
+var backgroundPagesMap = new WeakMap();
+
+// Responsible for the background_page section of the manifest.
+function BackgroundPage(options, extension) {
+  this.extension = extension;
+  this.page = options.page || null;
+  this.isGenerated = !!options.scripts;
+  this.windowlessBrowser = null;
+  this.webNav = null;
+}
+
+BackgroundPage.prototype = {
+  build: Task.async(function* () {
+    let windowlessBrowser = Services.appShell.createWindowlessBrowser(true);
+    this.windowlessBrowser = windowlessBrowser;
+
+    let url;
+    if (this.page) {
+      url = this.extension.baseURI.resolve(this.page);
+    } else if (this.isGenerated) {
+      url = this.extension.baseURI.resolve("_generated_background_page.html");
+    }
+
+    if (!this.extension.isExtensionURL(url)) {
+      this.extension.manifestError("Background page must be a file within the extension");
+      url = this.extension.baseURI.resolve("_blank.html");
+    }
+
+    let system = Services.scriptSecurityManager.getSystemPrincipal();
+
+    // The windowless browser is a thin wrapper around a docShell that keeps
+    // its related resources alive. It implements nsIWebNavigation and
+    // forwards its methods to the underlying docShell, but cannot act as a
+    // docShell itself. Calling `getInterface(nsIDocShell)` gives us the
+    // underlying docShell, and `QueryInterface(nsIWebNavigation)` gives us
+    // access to the webNav methods that are already available on the
+    // windowless browser, but contrary to appearances, they are not the same
+    // object.
+    let chromeShell = windowlessBrowser.QueryInterface(Ci.nsIInterfaceRequestor)
+                                       .getInterface(Ci.nsIDocShell)
+                                       .QueryInterface(Ci.nsIWebNavigation);
+
+    if (PrivateBrowsingUtils.permanentPrivateBrowsing) {
+      let attrs = chromeShell.getOriginAttributes();
+      attrs.privateBrowsingId = 1;
+      chromeShell.setOriginAttributes(attrs);
+    }
+
+    chromeShell.useGlobalHistory = false;
+    chromeShell.createAboutBlankContentViewer(system);
+    chromeShell.loadURI(XUL_URL, 0, null, null, null);
+
+
+    yield promiseObserved("chrome-document-global-created",
+                          win => win.document == chromeShell.document);
+
+    let chromeDoc = yield promiseDocumentLoaded(chromeShell.document);
+
+    let browser = chromeDoc.createElement("browser");
+    browser.setAttribute("type", "content");
+    browser.setAttribute("disableglobalhistory", "true");
+    chromeDoc.documentElement.appendChild(browser);
+
+    extensions.emit("extension-browser-inserted", browser);
+    browser.messageManager.sendAsyncMessage("Extension:InitExtensionView", {
+      viewType: "background",
+      url,
+    });
+
+    yield new Promise(resolve => {
+      browser.messageManager.addMessageListener("Extension:ExtensionViewLoaded", function onLoad() {
+        browser.messageManager.removeMessageListener("Extension:ExtensionViewLoaded", onLoad);
+        resolve();
+      });
+    });
+
+    // TODO(robwu): This is not webext-oop compatible.
+    this.webNav = browser.docShell.QueryInterface(Ci.nsIWebNavigation);
+    let window = this.webNav.document.defaultView;
+
+
+    // Set the add-on's main debugger global, for use in the debugger
+    // console.
+    if (this.extension.addonData.instanceID) {
+      AddonManager.getAddonByInstanceID(this.extension.addonData.instanceID)
+                  .then(addon => addon.setDebugGlobal(window));
+    }
+
+    this.extension.emit("startup");
+  }),
+
+  shutdown() {
+    if (this.extension.addonData.instanceID) {
+      AddonManager.getAddonByInstanceID(this.extension.addonData.instanceID)
+                  .then(addon => addon.setDebugGlobal(null));
+    }
+
+    // Navigate away from the background page to invalidate any
+    // setTimeouts or other callbacks.
+    if (this.webNav) {
+      this.webNav.loadURI("about:blank", 0, null, null, null);
+      this.webNav = null;
+    }
+
+    this.windowlessBrowser.loadURI("about:blank", 0, null, null, null);
+    this.windowlessBrowser.close();
+    this.windowlessBrowser = null;
+  },
+};
+
+/* eslint-disable mozilla/balanced-listeners */
+extensions.on("manifest_background", (type, directive, extension, manifest) => {
+  let bgPage = new BackgroundPage(manifest.background, extension);
+  backgroundPagesMap.set(extension, bgPage);
+  return bgPage.build();
+});
+
+extensions.on("shutdown", (type, extension) => {
+  if (backgroundPagesMap.has(extension)) {
+    backgroundPagesMap.get(extension).shutdown();
+    backgroundPagesMap.delete(extension);
+  }
+});
+/* eslint-enable mozilla/balanced-listeners */