1 files changed, 58 insertions, 0 deletions
diff --git a/js/ui/components/__init__.js b/js/ui/components/__init__.js
new file mode 100644
index 0000000..7430013
--- /dev/null
+++ b/js/ui/components/__init__.js
@@ -0,0 +1,58 @@
+/* exported ComponentManager */
+const Main = imports.ui.main;
+
+var ComponentManager = class {
+    constructor() {
+        this._allComponents = {};
+        this._enabledComponents = [];
+
+        Main.sessionMode.connect('updated', this._sessionUpdated.bind(this));
+        this._sessionUpdated();
+    }
+
+    _sessionUpdated() {
+        let newEnabledComponents = Main.sessionMode.components;
+
+        newEnabledComponents
+            .filter(name => !this._enabledComponents.includes(name))
+            .forEach(name => this._enableComponent(name));
+
+        this._enabledComponents
+            .filter(name => !newEnabledComponents.includes(name))
+            .forEach(name => this._disableComponent(name));
+
+        this._enabledComponents = newEnabledComponents;
+    }
+
+    _importComponent(name) {
+        let module = imports.ui.components[name];
+        return module.Component;
+    }
+
+    _ensureComponent(name) {
+        let component = this._allComponents[name];
+        if (component)
+            return component;
+
+        if (Main.sessionMode.isLocked)
+            return null;
+
+        let constructor = this._importComponent(name);
+        component = new constructor();
+        this._allComponents[name] = component;
+        return component;
+    }
+
+    _enableComponent(name) {
+        let component = this._ensureComponent(name);
+        if (component)
+            component.enable();
+    }
+
+    _disableComponent(name) {
+        let component = this._allComponents[name];
+        if (component == null)
+            return;
+        component.disable();
+    }
+};