Guard against no workspaces root.

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

arduino-ide-extension/src/browser/workspace-service-ext-impl.ts

@@ -1,4 +1,6 @@
 import { inject, injectable } from 'inversify';
+import URI from '@theia/core/lib/common/uri';
+import { FileSystem } from '@theia/filesystem/lib/common';
 import { WorkspaceService } from '@theia/workspace/lib/browser/workspace-service';
 import { WorkspaceServiceExt } from './workspace-service-ext';
 
@@ -8,6 +10,9 @@ import { WorkspaceServiceExt } from './workspace-service-ext';
 @injectable()
 export class WorkspaceServiceExtImpl implements WorkspaceServiceExt {
 
+    @inject(FileSystem)
+    protected readonly fileSystem: FileSystem;
+
     @inject(WorkspaceService)
     protected readonly delegate: WorkspaceService;
 
@@ -16,4 +21,27 @@ export class WorkspaceServiceExtImpl implements WorkspaceServiceExt {
         return stats.map(stat => stat.uri);
     }
 
-}
+    async defaultWorkspaceUri(): Promise<string> {
+        const home = await this.fileSystem.getCurrentUserHome();
+        if (home) {
+            return new URI(home.uri).resolve('Arduino-PoC').resolve('workspace').toString();
+        }
+        throw new Error(`Could not locate current user's home folder.`);
+    }
+
+    async defaultDownloadsDirUri(): Promise<string> {
+        const home = await this.fileSystem.getCurrentUserHome();
+        if (home) {
+            return new URI(home.uri).resolve('Arduino-PoC').resolve('downloads').toString();
+        }
+        throw new Error(`Could not locate current user's home folder.`);
+    }
+
+    async defaultDataDirUri(): Promise<string> {
+        const home = await this.fileSystem.getCurrentUserHome();
+        if (home) {
+            return new URI(home.uri).resolve('Arduino-PoC').resolve('data').toString();
+        }
+        throw new Error(`Could not locate current user's home folder.`);
+    }
+}

arduino-ide-extension/src/browser/workspace-service-ext.ts

@@ -2,4 +2,11 @@ export const WorkspaceServiceExtPath = '/services/workspace-service-ext';
 export const WorkspaceServiceExt = Symbol('WorkspaceServiceExt');
 export interface WorkspaceServiceExt {
     roots(): Promise<string[]>;
+    /**
+     * By default it is under `~/Arduino-PoC/workspace`.
+     * It might not exist yet.
+     */
+    defaultWorkspaceUri(): Promise<string>;
+    defaultDownloadsDirUri(): Promise<string>;
+    defaultDataDirUri(): Promise<string>;
 }