Handle isFileSystemResource context key

packages/navigator/src/browser/navigator-context-key-service.ts

@@ -45,12 +45,22 @@ export class NavigatorContextKeyService {
         return this._explorerResourceIsFolder;
     }
 
+    protected _isFileSystemResource: ContextKey<boolean>;
+
+    /**
+     * True when the Explorer or editor file is a file system resource that can be handled from a file system provider.
+     */
+    get isFileSystemResource(): ContextKey<boolean> {
+        return this._isFileSystemResource;
+    }
+
     @postConstruct()
     protected init(): void {
         this._explorerViewletVisible = this.contextKeyService.createKey<boolean>('explorerViewletVisible', false);
         this._explorerViewletFocus = this.contextKeyService.createKey<boolean>('explorerViewletFocus', false);
         this._filesExplorerFocus = this.contextKeyService.createKey<boolean>('filesExplorerFocus', false);
         this._explorerResourceIsFolder = this.contextKeyService.createKey<boolean>('explorerResourceIsFolder', false);
+        this._isFileSystemResource = this.contextKeyService.createKey<boolean>('isFileSystemResource', false);
     }
 
 }

packages/navigator/src/browser/navigator-widget.tsx

@@ -19,7 +19,7 @@ import { Message } from '@theia/core/shared/@phosphor/messaging';
 import URI from '@theia/core/lib/common/uri';
 import { CommandService } from '@theia/core/lib/common';
 import { Key, TreeModel, ContextMenuRenderer, ExpandableTreeNode, TreeProps, TreeNode } from '@theia/core/lib/browser';
-import { DirNode } from '@theia/filesystem/lib/browser';
+import { DirNode, FileStatNodeData } from '@theia/filesystem/lib/browser';
 import { WorkspaceService, WorkspaceCommands } from '@theia/workspace/lib/browser';
 import { WorkspaceNode, WorkspaceRootNode } from './navigator-tree';
 import { FileNavigatorModel } from './navigator-model';
@@ -210,6 +210,10 @@ export class FileNavigatorWidget extends AbstractNavigatorTreeWidget {
 
     protected updateSelectionContextKeys(): void {
         this.contextKeyService.explorerResourceIsFolder.set(DirNode.is(this.model.selectedNodes[0]));
+        // As `FileStatNode` only created if `FileService.resolve` was successful, we can safely assume that
+        // a valid `FileSystemProvider` is available for the selected node. So we skip an additional check
+        // for provider availability here and check the node type.
+        this.contextKeyService.isFileSystemResource.set(FileStatNodeData.is(this.model.selectedNodes[0]));
     }
 
 }