refactor(client): add support for optional children in layout

src/public/app/layouts/desktop_layout.js

@@ -92,15 +92,17 @@ export default class DesktopLayout {
     getRootWidget(appContext) {
         appContext.noteTreeWidget = new NoteTreeWidget();
 
+        const launcherPaneIsHorizontal = true;
+        const launcherPane = new FlexContainer("column")
+            .id("launcher-pane")
+            .css("width", "53px")
+            .child(new GlobalMenuWidget())
+            .child(new LauncherContainer())
+            .child(new LeftPaneToggleWidget());
+
         return new RootContainer()
             .setParent(appContext)
-            .child(new FlexContainer("column")
+            .optChild(!launcherPaneIsHorizontal, launcherPane)
-                .id("launcher-pane")
-                .css("width", "53px")
-                .child(new GlobalMenuWidget())
-                .child(new LauncherContainer())
-                .child(new LeftPaneToggleWidget())
-            )
             .child(new LeftPaneContainer()
                 .child(new QuickSearchWidget())
                 .child(appContext.noteTreeWidget)

src/public/app/widgets/basic_widget.js

@@ -40,6 +40,21 @@ class BasicWidget extends Component {
         return this;
     }
 
+    /**
+     * Conditionally adds the given components as children to this component.
+     * 
+     * @param {boolean} condition whether to add the components.
+     * @param  {...any} components the components to be added as children to this component provided the condition is truthy. 
+     * @returns self for chaining.
+     */
+    optChild(condition, ...components) {
+        if (condition) {
+            return this.child(...components);
+        } else {
+            return this;
+        }
+    }
+
     id(id) {
         this.attrs.id = id;
         return this;