extensionSystem: Turn into a class

The extension system started out as a set of simple functions, but
gained more state later, and even some hacks to emit signals without
having an object to emit them on.

There is no good reason for that weirdness, so rather than imitating an
object, wrap the existing system into a real ExtensionManager object.

https://bugzilla.gnome.org/show_bug.cgi?id=789852

js/ui/extensionDownloader.js

@@ -7,6 +7,7 @@ const Dialog = imports.ui.dialog;
 const ExtensionUtils = imports.misc.extensionUtils;
 const ExtensionSystem = imports.ui.extensionSystem;
 const FileUtils = imports.misc.fileUtils;
+const Main = imports.ui.main;
 const ModalDialog = imports.ui.modalDialog;
 
 var REPOSITORY_URL_BASE = 'https://extensions.gnome.org';
@@ -24,7 +25,7 @@ function installExtension(uuid, invocation) {
 
     _httpSession.queue_message(message, (session, message) => {
         if (message.status_code != Soup.KnownStatusCode.OK) {
-            ExtensionSystem.logExtensionError(uuid, `downloading info: ${message.status_code}`);
+            Main.extensionManager.logExtensionError(uuid, `downloading info: ${message.status_code}`);
             invocation.return_dbus_error('org.gnome.Shell.DownloadInfoError', message.status_code.toString());
             return;
         }
@@ -33,7 +34,7 @@ function installExtension(uuid, invocation) {
         try {
             info = JSON.parse(message.response_body.data);
         } catch (e) {
-            ExtensionSystem.logExtensionError(uuid, `parsing info: ${e}`);
+            Main.extensionManager.logExtensionError(uuid, `parsing info: ${e}`);
             invocation.return_dbus_error('org.gnome.Shell.ParseInfoError', e.toString());
             return;
         }
@@ -52,7 +53,7 @@ function uninstallExtension(uuid) {
     if (extension.type != ExtensionUtils.ExtensionType.PER_USER)
         return false;
 
-    if (!ExtensionSystem.unloadExtension(extension))
+    if (!Main.extensionManager.unloadExtension(extension))
         return false;
 
     FileUtils.recursivelyDeleteDir(extension.dir, true);
@@ -116,7 +117,7 @@ function updateExtension(uuid) {
             let oldExtension = ExtensionUtils.extensions[uuid];
             let extensionDir = oldExtension.dir;
 
-            if (!ExtensionSystem.unloadExtension(oldExtension))
+            if (!Main.extensionManager.unloadExtension(oldExtension))
                 return;
 
             FileUtils.recursivelyMoveDir(extensionDir, oldExtensionTmpDir);
@@ -126,10 +127,10 @@ function updateExtension(uuid) {
 
             try {
                 extension = ExtensionUtils.createExtensionObject(uuid, extensionDir, ExtensionUtils.ExtensionType.PER_USER);
-                ExtensionSystem.loadExtension(extension);
+                Main.extensionManager.loadExtension(extension);
             } catch (e) {
                 if (extension)
-                    ExtensionSystem.unloadExtension(extension);
+                    Main.extensionManager.unloadExtension(extension);
 
                 logError(e, 'Error loading extension %s'.format(uuid));
 
@@ -138,7 +139,7 @@ function updateExtension(uuid) {
 
                 // Restore what was there before. We can't do much if we
                 // fail here.
-                ExtensionSystem.loadExtension(oldExtension);
+                Main.extensionManager.loadExtension(oldExtension);
                 return;
             }
 
@@ -233,7 +234,7 @@ class InstallExtensionDialog extends ModalDialog.ModalDialog {
 
             try {
                 let extension = ExtensionUtils.createExtensionObject(uuid, dir, ExtensionUtils.ExtensionType.PER_USER);
-                ExtensionSystem.loadExtension(extension);
+                Main.extensionManager.loadExtension(extension);
             } catch (e) {
                 uninstallExtension(uuid);
                 errback('LoadExtensionError', e);

js/ui/extensionSystem.js

@@ -8,356 +8,351 @@ const Main = imports.ui.main;
 
 const { ExtensionState } = ExtensionUtils;
 
-// Arrays of uuids
-var enabledExtensions;
-// Contains the order that extensions were enabled in.
-var extensionOrder = [];
-
-// We don't really have a class to add signals on. So, create
-// a simple dummy object, add the signal methods, and export those
-// publically.
-var _signals = {};
-Signals.addSignalMethods(_signals);
-
-var connect = _signals.connect.bind(_signals);
-var disconnect = _signals.disconnect.bind(_signals);
-
 const ENABLED_EXTENSIONS_KEY = 'enabled-extensions';
 const DISABLE_USER_EXTENSIONS_KEY = 'disable-user-extensions';
 const EXTENSION_DISABLE_VERSION_CHECK_KEY = 'disable-extension-version-validation';
 
-var initted = false;
+var ExtensionManager = class {
-var enabled;
+    constructor() {
+        this._initted = false;
+        this._enabled = false;
 
-function disableExtension(uuid) {
+        this._enabledExtensions = [];
-    let extension = ExtensionUtils.extensions[uuid];
+        this._extensionOrder = [];
-    if (!extension)
-        return;
 
-    if (extension.state != ExtensionState.ENABLED)
+        Main.sessionMode.connect('updated', this._sessionUpdated.bind(this));
-        return;
+        this._sessionUpdated();
+    }
 
-    // "Rebase" the extension order by disabling and then enabling extensions
+    disableExtension(uuid) {
-    // in order to help prevent conflicts.
+        let extension = ExtensionUtils.extensions[uuid];
+        if (!extension)
+            return;
 
-    // Example:
+        if (extension.state != ExtensionState.ENABLED)
-    //   order = [A, B, C, D, E]
+            return;
-    //   user disables C
-    //   this should: disable E, disable D, disable C, enable D, enable E
 
-    let orderIdx = extensionOrder.indexOf(uuid);
+        // "Rebase" the extension order by disabling and then enabling extensions
-    let order = extensionOrder.slice(orderIdx + 1);
+        // in order to help prevent conflicts.
-    let orderReversed = order.slice().reverse();
+
+        // Example:
+        //   order = [A, B, C, D, E]
+        //   user disables C
+        //   this should: disable E, disable D, disable C, enable D, enable E
+
+        let orderIdx = this._extensionOrder.indexOf(uuid);
+        let order = this._extensionOrder.slice(orderIdx + 1);
+        let orderReversed = order.slice().reverse();
+
+        for (let i = 0; i < orderReversed.length; i++) {
+            let uuid = orderReversed[i];
+            try {
+                ExtensionUtils.extensions[uuid].stateObj.disable();
+            } catch (e) {
+                this.logExtensionError(uuid, e);
+            }
+        }
+
+        if (extension.stylesheet) {
+            let theme = St.ThemeContext.get_for_stage(global.stage).get_theme();
+            theme.unload_stylesheet(extension.stylesheet);
+            delete extension.stylesheet;
+        }
 
-    for (let i = 0; i < orderReversed.length; i++) {
-        let uuid = orderReversed[i];
         try {
-            ExtensionUtils.extensions[uuid].stateObj.disable();
+            extension.stateObj.disable();
         } catch (e) {
-            logExtensionError(uuid, e);
+            this.logExtensionError(uuid, e);
+        }
+
+        for (let i = 0; i < order.length; i++) {
+            let uuid = order[i];
+            try {
+                ExtensionUtils.extensions[uuid].stateObj.enable();
+            } catch (e) {
+                this.logExtensionError(uuid, e);
+            }
+        }
+
+        this._extensionOrder.splice(orderIdx, 1);
+
+        if (extension.state != ExtensionState.ERROR) {
+            extension.state = ExtensionState.DISABLED;
+            this.emit('extension-state-changed', extension);
         }
     }
 
-    if (extension.stylesheet) {
+    enableExtension(uuid) {
+        let extension = ExtensionUtils.extensions[uuid];
+        if (!extension)
+            return;
+
+        if (extension.state == ExtensionState.INITIALIZED)
+            this.initExtension(uuid);
+
+        if (extension.state != ExtensionState.DISABLED)
+            return;
+
+        this._extensionOrder.push(uuid);
+
+        let stylesheetNames = [`${global.session_mode}.css`, 'stylesheet.css'];
         let theme = St.ThemeContext.get_for_stage(global.stage).get_theme();
-        theme.unload_stylesheet(extension.stylesheet);
+        for (let i = 0; i < stylesheetNames.length; i++) {
-        delete extension.stylesheet;
+            try {
-    }
+                let stylesheetFile = extension.dir.get_child(stylesheetNames[i]);
-
+                theme.load_stylesheet(stylesheetFile);
-    try {
+                extension.stylesheet = stylesheetFile;
-        extension.stateObj.disable();
+                break;
-    } catch (e) {
+            } catch (e) {
-        logExtensionError(uuid, e);
+                if (e.matches(Gio.IOErrorEnum, Gio.IOErrorEnum.NOT_FOUND))
-    }
+                    continue; // not an error
-
+                log(`Failed to load stylesheet for extension ${uuid}: ${e.message}`);
-    for (let i = 0; i < order.length; i++) {
+                return;
-        let uuid = order[i];
+            }
-        try {
-            ExtensionUtils.extensions[uuid].stateObj.enable();
-        } catch (e) {
-            logExtensionError(uuid, e);
         }
-    }
 
-    extensionOrder.splice(orderIdx, 1);
-
-    if ( extension.state != ExtensionState.ERROR ) {
-        extension.state = ExtensionState.DISABLED;
-        _signals.emit('extension-state-changed', extension);
-    }
-}
-
-function enableExtension(uuid) {
-    let extension = ExtensionUtils.extensions[uuid];
-    if (!extension)
-        return;
-
-    if (extension.state == ExtensionState.INITIALIZED)
-        initExtension(uuid);
-
-    if (extension.state != ExtensionState.DISABLED)
-        return;
-
-    extensionOrder.push(uuid);
-
-    let stylesheetNames = [`${global.session_mode}.css`, 'stylesheet.css'];
-    let theme = St.ThemeContext.get_for_stage(global.stage).get_theme();
-    for (let i = 0; i < stylesheetNames.length; i++) {
         try {
-            let stylesheetFile = extension.dir.get_child(stylesheetNames[i]);
+            extension.stateObj.enable();
-            theme.load_stylesheet(stylesheetFile);
+            extension.state = ExtensionState.ENABLED;
-            extension.stylesheet = stylesheetFile;
+            this.emit('extension-state-changed', extension);
-            break;
+            return;
         } catch (e) {
-            if (e.matches(Gio.IOErrorEnum, Gio.IOErrorEnum.NOT_FOUND))
+            if (extension.stylesheet) {
-                continue; // not an error
+                theme.unload_stylesheet(extension.stylesheet);
-            log(`Failed to load stylesheet for extension ${uuid}: ${e.message}`);
+                delete extension.stylesheet;
+            }
+            this.logExtensionError(uuid, e);
             return;
         }
     }
 
-    try {
+    logExtensionError(uuid, error) {
-        extension.stateObj.enable();
+        let extension = ExtensionUtils.extensions[uuid];
-        extension.state = ExtensionState.ENABLED;
+        if (!extension)
-        _signals.emit('extension-state-changed', extension);
+            return;
-        return;
-    } catch (e) {
-        if (extension.stylesheet) {
-            theme.unload_stylesheet(extension.stylesheet);
-            delete extension.stylesheet;
-        }
-        logExtensionError(uuid, e);
-        return;
-    }
-}
 
-function logExtensionError(uuid, error) {
+        let message = `${error}`;
-    let extension = ExtensionUtils.extensions[uuid];
-    if (!extension)
-        return;
 
-    let message = `${error}`;
+        extension.state = ExtensionState.ERROR;
+        if (!extension.errors)
+            extension.errors = [];
+        extension.errors.push(message);
 
-    extension.state = ExtensionState.ERROR;
+        log('Extension "%s" had error: %s'.format(uuid, message));
-    if (!extension.errors)
+        this.emit('extension-state-changed', { uuid: uuid,
-        extension.errors = [];
-    extension.errors.push(message);
-
-    log('Extension "%s" had error: %s'.format(uuid, message));
-    _signals.emit('extension-state-changed', { uuid: uuid,
                                                error: message,
                                                state: extension.state });
-}
+    }
 
-function loadExtension(extension) {
+    loadExtension(extension) {
-    // Default to error, we set success as the last step
+        // Default to error, we set success as the last step
-    extension.state = ExtensionState.ERROR;
+        extension.state = ExtensionState.ERROR;
 
-    let checkVersion = !global.settings.get_boolean(EXTENSION_DISABLE_VERSION_CHECK_KEY);
+        let checkVersion = !global.settings.get_boolean(EXTENSION_DISABLE_VERSION_CHECK_KEY);
 
-    if (checkVersion && ExtensionUtils.isOutOfDate(extension)) {
+        if (checkVersion && ExtensionUtils.isOutOfDate(extension)) {
-        extension.state = ExtensionState.OUT_OF_DATE;
+            extension.state = ExtensionState.OUT_OF_DATE;
-    } else {
-        let enabled = enabledExtensions.includes(extension.uuid);
-        if (enabled) {
-            if (!initExtension(extension.uuid))
-                return;
-            if (extension.state == ExtensionState.DISABLED)
-                enableExtension(extension.uuid);
         } else {
-            extension.state = ExtensionState.INITIALIZED;
+            let enabled = this._enabledExtensions.includes(extension.uuid);
+            if (enabled) {
+                if (!this.initExtension(extension.uuid))
+                    return;
+                if (extension.state == ExtensionState.DISABLED)
+                    this.enableExtension(extension.uuid);
+            } else {
+                extension.state = ExtensionState.INITIALIZED;
+            }
         }
+
+        this.emit('extension-state-changed', extension);
     }
 
-    _signals.emit('extension-state-changed', extension);
+    unloadExtension(extension) {
-}
+        // Try to disable it -- if it's ERROR'd, we can't guarantee that,
+        // but it will be removed on next reboot, and hopefully nothing
+        // broke too much.
+        this.disableExtension(extension.uuid);
 
-function unloadExtension(extension) {
+        extension.state = ExtensionState.UNINSTALLED;
-    // Try to disable it -- if it's ERROR'd, we can't guarantee that,
+        this.emit('extension-state-changed', extension);
-    // but it will be removed on next reboot, and hopefully nothing
-    // broke too much.
-    disableExtension(extension.uuid);
 
-    extension.state = ExtensionState.UNINSTALLED;
+        delete ExtensionUtils.extensions[extension.uuid];
-    _signals.emit('extension-state-changed', extension);
+        return true;
-
-    delete ExtensionUtils.extensions[extension.uuid];
-    return true;
-}
-
-function reloadExtension(oldExtension) {
-    // Grab the things we'll need to pass to createExtensionObject
-    // to reload it.
-    let { uuid: uuid, dir: dir, type: type } = oldExtension;
-
-    // Then unload the old extension.
-    unloadExtension(oldExtension);
-
-    // Now, recreate the extension and load it.
-    let newExtension;
-    try {
-        newExtension = ExtensionUtils.createExtensionObject(uuid, dir, type);
-    } catch (e) {
-        logExtensionError(uuid, e);
-        return;
     }
 
-    loadExtension(newExtension);
+    reloadExtension(oldExtension) {
-}
+        // Grab the things we'll need to pass to createExtensionObject
+        // to reload it.
+        let { uuid: uuid, dir: dir, type: type } = oldExtension;
 
-function initExtension(uuid) {
+        // Then unload the old extension.
-    let extension = ExtensionUtils.extensions[uuid];
+        this.unloadExtension(oldExtension);
-    let dir = extension.dir;
 
-    if (!extension)
+        // Now, recreate the extension and load it.
-        throw new Error("Extension was not properly created. Call loadExtension first");
+        let newExtension;
-
-    let extensionJs = dir.get_child('extension.js');
-    if (!extensionJs.query_exists(null)) {
-        logExtensionError(uuid, new Error('Missing extension.js'));
-        return false;
-    }
-
-    let extensionModule;
-    let extensionState = null;
-
-    ExtensionUtils.installImporter(extension);
-    try {
-        extensionModule = extension.imports.extension;
-    } catch (e) {
-        logExtensionError(uuid, e);
-        return false;
-    }
-
-    if (extensionModule.init) {
         try {
-            extensionState = extensionModule.init(extension);
+            newExtension = ExtensionUtils.createExtensionObject(uuid, dir, type);
         } catch (e) {
-            logExtensionError(uuid, e);
+            this.logExtensionError(uuid, e);
+            return;
+        }
+
+        this.loadExtension(newExtension);
+    }
+
+    initExtension(uuid) {
+        let extension = ExtensionUtils.extensions[uuid];
+        let dir = extension.dir;
+
+        if (!extension)
+            throw new Error("Extension was not properly created. Call loadExtension first");
+
+        let extensionJs = dir.get_child('extension.js');
+        if (!extensionJs.query_exists(null)) {
+            this.logExtensionError(uuid, new Error('Missing extension.js'));
             return false;
         }
+
+        let extensionModule;
+        let extensionState = null;
+
+        ExtensionUtils.installImporter(extension);
+        try {
+            extensionModule = extension.imports.extension;
+        } catch (e) {
+            this.logExtensionError(uuid, e);
+            return false;
+        }
+
+        if (extensionModule.init) {
+            try {
+                extensionState = extensionModule.init(extension);
+            } catch (e) {
+                this.logExtensionError(uuid, e);
+                return false;
+            }
+        }
+
+        if (!extensionState)
+            extensionState = extensionModule;
+        extension.stateObj = extensionState;
+
+        extension.state = ExtensionState.DISABLED;
+        this.emit('extension-loaded', uuid);
+        return true;
     }
 
-    if (!extensionState)
+    _getEnabledExtensions() {
-        extensionState = extensionModule;
+        let extensions;
-    extension.stateObj = extensionState;
+        if (Array.isArray(Main.sessionMode.enabledExtensions))
+            extensions = Main.sessionMode.enabledExtensions;
+        else
+            extensions = [];
 
-    extension.state = ExtensionState.DISABLED;
+        if (global.settings.get_boolean(DISABLE_USER_EXTENSIONS_KEY))
-    _signals.emit('extension-loaded', uuid);
+            return extensions;
-    return true;
-}
 
-function getEnabledExtensions() {
+        return extensions.concat(global.settings.get_strv(ENABLED_EXTENSIONS_KEY));
-    let extensions;
+    }
-    if (Array.isArray(Main.sessionMode.enabledExtensions))
-        extensions = Main.sessionMode.enabledExtensions;
-    else
-        extensions = [];
 
-    if (global.settings.get_boolean(DISABLE_USER_EXTENSIONS_KEY))
+    _onEnabledExtensionsChanged() {
-        return extensions;
+        let newEnabledExtensions = this._getEnabledExtensions();
 
-    return extensions.concat(global.settings.get_strv(ENABLED_EXTENSIONS_KEY));
+        if (!this._enabled)
-}
+            return;
 
-function onEnabledExtensionsChanged() {
+        // Find and enable all the newly enabled extensions: UUIDs found in the
-    let newEnabledExtensions = getEnabledExtensions();
+        // new setting, but not in the old one.
-
+        newEnabledExtensions.filter(
-    if (!enabled)
+            uuid => !this._enabledExtensions.includes(uuid)
-        return;
+        ).forEach(uuid => {
-
+            this.enableExtension(uuid);
-    // Find and enable all the newly enabled extensions: UUIDs found in the
-    // new setting, but not in the old one.
-    newEnabledExtensions.filter(
-        uuid => !enabledExtensions.includes(uuid)
-    ).forEach(uuid => {
-        enableExtension(uuid);
-    });
-
-    // Find and disable all the newly disabled extensions: UUIDs found in the
-    // old setting, but not in the new one.
-    enabledExtensions.filter(
-        item => !newEnabledExtensions.includes(item)
-    ).forEach(uuid => {
-        disableExtension(uuid);
-    });
-
-    enabledExtensions = newEnabledExtensions;
-}
-
-function _onVersionValidationChanged() {
-    // we want to reload all extensions, but only enable
-    // extensions when allowed by the sessionMode, so
-    // temporarily disable them all
-    enabledExtensions = [];
-    for (let uuid in ExtensionUtils.extensions)
-        reloadExtension(ExtensionUtils.extensions[uuid]);
-    enabledExtensions = getEnabledExtensions();
-
-    if (Main.sessionMode.allowExtensions) {
-        enabledExtensions.forEach(uuid => {
-            enableExtension(uuid);
         });
-    }
-}
 
-function _loadExtensions() {
+        // Find and disable all the newly disabled extensions: UUIDs found in the
-    global.settings.connect(`changed::${ENABLED_EXTENSIONS_KEY}`, onEnabledExtensionsChanged);
+        // old setting, but not in the new one.
-    global.settings.connect(`changed::${DISABLE_USER_EXTENSIONS_KEY}`, onEnabledExtensionsChanged);
+        this._enabledExtensions.filter(
-    global.settings.connect(`changed::${EXTENSION_DISABLE_VERSION_CHECK_KEY}`, _onVersionValidationChanged);
+            item => !newEnabledExtensions.includes(item)
-
+        ).forEach(uuid => {
-    enabledExtensions = getEnabledExtensions();
+            this.disableExtension(uuid);
-
-    let finder = new ExtensionUtils.ExtensionFinder();
-    finder.connect('extension-found', (finder, extension) => {
-        loadExtension(extension);
-    });
-    finder.scanExtensions();
-}
-
-function enableAllExtensions() {
-    if (enabled)
-        return;
-
-    if (!initted) {
-        _loadExtensions();
-        initted = true;
-    } else {
-        enabledExtensions.forEach(uuid => {
-            enableExtension(uuid);
         });
+
+        this._enabledExtensions = newEnabledExtensions;
     }
-    enabled = true;
-}
 
-function disableAllExtensions() {
+    _onVersionValidationChanged() {
-    if (!enabled)
+        // we want to reload all extensions, but only enable
-        return;
+        // extensions when allowed by the sessionMode, so
+        // temporarily disable them all
+        this._enabledExtensions = [];
+        for (let uuid in ExtensionUtils.extensions)
+            this.reloadExtension(ExtensionUtils.extensions[uuid]);
+        this._enabledExtensions = this._getEnabledExtensions();
 
-    if (initted) {
+        if (Main.sessionMode.allowExtensions) {
-        extensionOrder.slice().reverse().forEach(uuid => {
+            this._enabledExtensions.forEach(uuid => {
-            disableExtension(uuid);
+                this.enableExtension(uuid);
+            });
+        }
+    }
+
+    _loadExtensions() {
+        global.settings.connect(`changed::${ENABLED_EXTENSIONS_KEY}`,
+            this._onEnabledExtensionsChanged.bind(this));
+        global.settings.connect(`changed::${DISABLE_USER_EXTENSIONS_KEY}`,
+            this._onEnabledExtensionsChanged.bind(this));
+        global.settings.connect(`changed::${EXTENSION_DISABLE_VERSION_CHECK_KEY}`,
+            this._onVersionValidationChanged.bind(this));
+
+        this._enabledExtensions = this._getEnabledExtensions();
+
+        let finder = new ExtensionUtils.ExtensionFinder();
+        finder.connect('extension-found', (finder, extension) => {
+            this.loadExtension(extension);
         });
+        finder.scanExtensions();
     }
 
-    enabled = false;
+    enableAllExtensions() {
-}
+        if (this._enabled)
+            return;
 
-function _sessionUpdated() {
+        if (!this._initted) {
-    // For now sessionMode.allowExtensions controls extensions from both the
+            this._loadExtensions();
-    // 'enabled-extensions' preference and the sessionMode.enabledExtensions
+            this._initted = true;
-    // property; it might make sense to make enabledExtensions independent
+        } else {
-    // from allowExtensions in the future
+            this._enabledExtensions.forEach(uuid => {
-    if (Main.sessionMode.allowExtensions) {
+                this.enableExtension(uuid);
-        if (initted)
+            });
-            enabledExtensions = getEnabledExtensions();
+        }
-        enableAllExtensions();
+        this._enabled = true;
-    } else {
-        disableAllExtensions();
     }
-}
 
-function init() {
+    disableAllExtensions() {
-    Main.sessionMode.connect('updated', _sessionUpdated);
+        if (!this._enabled)
-    _sessionUpdated();
+            return;
-}
+
+        if (this._initted) {
+            this._extensionOrder.slice().reverse().forEach(uuid => {
+                this.disableExtension(uuid);
+            });
+        }
+
+        this._enabled = false;
+    }
+
+    _sessionUpdated() {
+        // For now sessionMode.allowExtensions controls extensions from both the
+        // 'enabled-extensions' preference and the sessionMode.enabledExtensions
+        // property; it might make sense to make enabledExtensions independent
+        // from allowExtensions in the future
+        if (Main.sessionMode.allowExtensions) {
+            if (this._initted)
+                this._enabledExtensions = this._getEnabledExtensions();
+            this.enableAllExtensions();
+        } else {
+            this.disableAllExtensions();
+        }
+    }
+};
+Signals.addSignalMethods(ExtensionManager.prototype);

js/ui/lookingGlass.js

@@ -7,7 +7,6 @@ const Signals = imports.signals;
 const System = imports.system;
 
 const History = imports.misc.history;
-const ExtensionSystem = imports.ui.extensionSystem;
 const ExtensionUtils = imports.misc.extensionUtils;
 const ShellEntry = imports.ui.shellEntry;
 const Tweener = imports.ui.tweener;
@@ -628,8 +627,8 @@ var Extensions = class Extensions {
         for (let uuid in ExtensionUtils.extensions)
             this._loadExtension(null, uuid);
 
-        ExtensionSystem.connect('extension-loaded',
+        Main.extensionManager.connect('extension-loaded',
-                                this._loadExtension.bind(this));
+                                      this._loadExtension.bind(this));
     }
 
     _loadExtension(o, uuid) {

js/ui/main.js

@@ -46,6 +46,7 @@ const LOG_DOMAIN = 'GNOME Shell';
 const GNOMESHELL_STARTED_MESSAGE_ID = 'f3ea493c22934e26811cd62abe8e203a';
 
 var componentManager = null;
+var extensionManager = null;
 var panel = null;
 var overview = null;
 var runDialog = null;
@@ -226,7 +227,7 @@ function _initializeUI() {
     _startDate = new Date();
 
     ExtensionDownloader.init();
-    ExtensionSystem.init();
+    extensionManager = new ExtensionSystem.ExtensionManager();
 
     if (sessionMode.isGreeter && screenShield) {
         layoutManager.connect('startup-prepared', () => {

js/ui/shellDBus.js

@@ -4,7 +4,6 @@ const { Gio, GLib, Meta, Shell } = imports.gi;
 const Lang = imports.lang;
 
 const Config = imports.misc.config;
-const ExtensionSystem = imports.ui.extensionSystem;
 const ExtensionDownloader = imports.ui.extensionDownloader;
 const ExtensionUtils = imports.misc.extensionUtils;
 const Main = imports.ui.main;
@@ -251,8 +250,8 @@ var GnomeShellExtensions = class {
     constructor() {
         this._dbusImpl = Gio.DBusExportedObject.wrapJSObject(GnomeShellExtensionsIface, this);
         this._dbusImpl.export(Gio.DBus.session, '/org/gnome/Shell');
-        ExtensionSystem.connect('extension-state-changed',
+        Main.extensionManager.connect('extension-state-changed',
-                                this._extensionStateChanged.bind(this));
+                                      this._extensionStateChanged.bind(this));
     }
 
     ListExtensions() {
@@ -335,7 +334,7 @@ var GnomeShellExtensions = class {
         if (!extension)
             return;
 
-        ExtensionSystem.reloadExtension(extension);
+        Main.extensionManager.reloadExtension(extension);
     }
 
     CheckForUpdates() {