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-rw-r--r--devtools/shared/content-observer.js71
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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
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+"use strict";
+
+const {Cc, Ci, Cu, Cr} = require("chrome");
+const Services = require("Services");
+
+const events = require("sdk/event/core");
+
+/**
+ * Handles adding an observer for the creation of content document globals,
+ * event sent immediately after a web content document window has been set up,
+ * but before any script code has been executed.
+ */
+function ContentObserver(tabActor) {
+ this._contentWindow = tabActor.window;
+ this._onContentGlobalCreated = this._onContentGlobalCreated.bind(this);
+ this._onInnerWindowDestroyed = this._onInnerWindowDestroyed.bind(this);
+ this.startListening();
+}
+
+module.exports.ContentObserver = ContentObserver;
+
+ContentObserver.prototype = {
+ /**
+ * Starts listening for the required observer messages.
+ */
+ startListening: function () {
+ Services.obs.addObserver(
+ this._onContentGlobalCreated, "content-document-global-created", false);
+ Services.obs.addObserver(
+ this._onInnerWindowDestroyed, "inner-window-destroyed", false);
+ },
+
+ /**
+ * Stops listening for the required observer messages.
+ */
+ stopListening: function () {
+ Services.obs.removeObserver(
+ this._onContentGlobalCreated, "content-document-global-created", false);
+ Services.obs.removeObserver(
+ this._onInnerWindowDestroyed, "inner-window-destroyed", false);
+ },
+
+ /**
+ * Fired immediately after a web content document window has been set up.
+ */
+ _onContentGlobalCreated: function (subject, topic, data) {
+ if (subject == this._contentWindow) {
+ events.emit(this, "global-created", subject);
+ }
+ },
+
+ /**
+ * Fired when an inner window is removed from the backward/forward cache.
+ */
+ _onInnerWindowDestroyed: function (subject, topic, data) {
+ let id = subject.QueryInterface(Ci.nsISupportsPRUint64).data;
+ events.emit(this, "global-destroyed", id);
+ }
+};
+
+// Utility functions.
+
+ContentObserver.GetInnerWindowID = function (window) {
+ return window
+ .QueryInterface(Ci.nsIInterfaceRequestor)
+ .getInterface(Ci.nsIDOMWindowUtils)
+ .currentInnerWindowID;
+};