[workspace] Store the most recently used workspace root in the user’s…

… home directory and use it when the backend is started without an explicit root argument.

Signed-off-by: Sven Efftinge <sven.efftinge@typefox.io>

packages/markers/src/browser/problem/problem-widget.ts

@@ -22,7 +22,7 @@ import { WorkspaceService } from '@theia/workspace/lib/browser';
 @injectable()
 export class ProblemWidget extends TreeWidget {
 
-    protected workspacePath: string;
+    protected workspacePath: string | undefined;
 
     constructor(
         @inject(ProblemManager) protected readonly problemManager: ProblemManager,
@@ -40,8 +40,8 @@ export class ProblemWidget extends TreeWidget {
         this.title.closable = true;
         this.addClass('theia-marker-container');
 
-        this.workspaceService.tryRoot.then(workspaceFileStat => {
-            this.workspacePath = workspaceFileStat ? workspaceFileStat.uri : '';
+        this.workspaceService.root.then(workspaceFileStat => {
+            this.workspacePath = workspaceFileStat ? workspaceFileStat.uri : undefined;
             this.update();
         });
 

packages/workspace/src/node/default-workspace-server.ts

@@ -7,6 +7,9 @@
 
 import * as path from 'path';
 import * as yargs from 'yargs';
+import * as fs from 'fs-extra';
+import * as os from 'os';
+
 import { injectable, inject } from "inversify";
 import { FileUri } from '@theia/core/lib/node';
 import { CliContribution } from '@theia/core/lib/node/cli';
@@ -51,6 +54,14 @@ export class DefaultWorkspaceServer implements WorkspaceServer {
         @inject(WorkspaceCliContribution) protected readonly cliParams: WorkspaceCliContribution
     ) {
         this.root = this.getRootURIFromCli();
+        this.root.then(async root => {
+            if (!root) {
+                const data = await this.readFromUserHome();
+                if (data && data.recentRoots) {
+                    this.root = Promise.resolve(data.recentRoots[0]);
+                }
+            }
+        });
     }
 
     getRoot(): Promise<string | undefined> {
@@ -59,6 +70,9 @@ export class DefaultWorkspaceServer implements WorkspaceServer {
 
     setRoot(uri: string): Promise<void> {
         this.root = Promise.resolve(uri);
+        this.writeToUserHome({
+            recentRoots: [uri]
+        });
         return Promise.resolve();
     }
 
@@ -67,4 +81,45 @@ export class DefaultWorkspaceServer implements WorkspaceServer {
         return arg !== undefined ? FileUri.create(arg).toString() : undefined;
     }
 
+    /**
+     * Writes the given uri as the most recently used workspace root to the user's home directory.
+     * @param uri most recently used uri
+     */
+    private async writeToUserHome(data: WorkspaceData): Promise<void> {
+        const file = this.getUserStoragePath();
+        if (!await fs.pathExists(file)) {
+            await fs.mkdirs(path.resolve(file, '..'));
+        }
+        await fs.writeJson(file, data);
+    }
+
+    /**
+     * Reads the most recently used workspace root from the user's home directory.
+     */
+    private async readFromUserHome(): Promise<WorkspaceData | undefined> {
+        const file = this.getUserStoragePath();
+        if (await fs.pathExists(file)) {
+            const config = await fs.readJson(file);
+            if (WorkspaceData.is(config)) {
+                return config;
+            }
+        }
+        return undefined;
+    }
+
+    protected getUserStoragePath(): string {
+        return path.resolve(os.homedir(), '.theia', 'recentworkspace.json');
+    }
+
 }
+
+interface WorkspaceData {
+    recentRoots: string[];
+}
+
+namespace WorkspaceData {
+    // tslint:disable-next-line:no-any
+    export function is(data: any): data is WorkspaceData {
+        return data.recentRoots !== undefined;
+    }
+}