ATL-938: Added menu group categories.

Signed-off-by: Akos Kitta <kittaakos@typefox.io>

arduino-ide-extension/src/browser/menu/arduino-menus.ts

@@ -1,6 +1,6 @@
 import { isOSX } from '@theia/core/lib/common/os';
 import { CommonMenus } from '@theia/core/lib/browser/common-frontend-contribution';
-import { MAIN_MENU_BAR, MenuModelRegistry, MenuNode } from '@theia/core/lib/common/menu';
+import { MAIN_MENU_BAR, MenuModelRegistry, MenuNode, MenuPath, SubMenuOptions } from '@theia/core/lib/common/menu';
 
 export namespace ArduinoMenus {
 
@@ -99,3 +99,24 @@ export function unregisterSubmenu(menuPath: string[], menuRegistry: MenuModelReg
     }
     (parent.children as Array<MenuNode>).splice(index, 1);
 }
+
+/**
+ * Special menu node that is not backed by any commands and is always disabled.
+ */
+export class PlaceholderMenuNode implements MenuNode {
+
+    constructor(protected readonly menuPath: MenuPath, readonly label: string, protected options: SubMenuOptions = { order: '0' }) { }
+
+    get icon(): string | undefined {
+        return this.options?.iconClass;
+    }
+
+    get sortString(): string {
+        return this.options?.order || this.label;
+    }
+
+    get id(): string {
+        return [...this.menuPath, 'placeholder'].join('-');
+    }
+
+}