From 2527596e59f822660f6f4c81fa5d1b1fead215a9 Mon Sep 17 00:00:00 2001
From: Mark Sujew <mark.sujew@typefox.io>
Date: Tue, 19 Dec 2023 16:53:57 +0100
Subject: [PATCH] Save untitled files to the last active folder (#13184)

---
 .../browser/frontend-application-module.ts    |  1 +
 .../user-working-directory-provider.ts        | 35 +++++++++++++++++--
 .../file-dialog/file-dialog-service.ts        |  6 ++--
 ...rkspace-user-working-directory-provider.ts |  1 +
 4 files changed, 38 insertions(+), 5 deletions(-)

diff --git a/packages/core/src/browser/frontend-application-module.ts b/packages/core/src/browser/frontend-application-module.ts
index 45e83b311720e..ca1bb7f3ab971 100644
--- a/packages/core/src/browser/frontend-application-module.ts
+++ b/packages/core/src/browser/frontend-application-module.ts
@@ -445,6 +445,7 @@ export const frontendApplicationModule = new ContainerModule((bind, _unbind, _is
 
     bind(SaveResourceService).toSelf().inSingletonScope();
     bind(UserWorkingDirectoryProvider).toSelf().inSingletonScope();
+    bind(FrontendApplicationContribution).toService(UserWorkingDirectoryProvider);
 
     bind(HoverService).toSelf().inSingletonScope();
 
diff --git a/packages/core/src/browser/user-working-directory-provider.ts b/packages/core/src/browser/user-working-directory-provider.ts
index 002ed8e4bf475..ccc9c63a14bc5 100644
--- a/packages/core/src/browser/user-working-directory-provider.ts
+++ b/packages/core/src/browser/user-working-directory-provider.ts
@@ -16,14 +16,34 @@
 
 import { inject, injectable } from 'inversify';
 import URI from '../common/uri';
-import { MaybePromise, SelectionService, UriSelection } from '../common';
+import { MaybePromise, SelectionService, UNTITLED_SCHEME, UriSelection } from '../common';
 import { EnvVariablesServer } from '../common/env-variables';
+import { FrontendApplication } from './frontend-application';
+import { FrontendApplicationContribution } from './frontend-application-contribution';
+import { Widget } from './widgets';
+import { Navigatable } from './navigatable-types';
 
 @injectable()
-export class UserWorkingDirectoryProvider {
+export class UserWorkingDirectoryProvider implements FrontendApplicationContribution {
     @inject(SelectionService) protected readonly selectionService: SelectionService;
     @inject(EnvVariablesServer) protected readonly envVariables: EnvVariablesServer;
 
+    protected lastOpenResource: URI | undefined;
+
+    configure(app: FrontendApplication): void {
+        app.shell.onDidChangeCurrentWidget(e => this.setLastOpenResource(e.newValue ?? undefined));
+        this.setLastOpenResource(app.shell.currentWidget);
+    }
+
+    protected setLastOpenResource(widget?: Widget): void {
+        if (Navigatable.is(widget)) {
+            const uri = widget.getResourceUri();
+            if (uri && uri.scheme !== UNTITLED_SCHEME) {
+                this.lastOpenResource = uri;
+            }
+        }
+    }
+
     /**
      * @returns A {@link URI} that represents a good guess about the directory in which the user is currently operating.
      *
@@ -35,7 +55,16 @@ export class UserWorkingDirectoryProvider {
     }
 
     protected getFromSelection(): MaybePromise<URI | undefined> {
-        return this.ensureIsDirectory(UriSelection.getUri(this.selectionService.selection));
+        const uri = UriSelection.getUri(this.selectionService.selection);
+        if (uri?.scheme === UNTITLED_SCHEME) {
+            // An untitled file is not a valid working directory context.
+            return undefined;
+        }
+        return this.ensureIsDirectory(uri);
+    }
+
+    protected getFromLastOpenResource(): MaybePromise<URI | undefined> {
+        return this.ensureIsDirectory(this.lastOpenResource);
     }
 
     protected getFromUserHome(): MaybePromise<URI> {
diff --git a/packages/filesystem/src/browser/file-dialog/file-dialog-service.ts b/packages/filesystem/src/browser/file-dialog/file-dialog-service.ts
index a6c9f8ce28565..afc42899c64db 100644
--- a/packages/filesystem/src/browser/file-dialog/file-dialog-service.ts
+++ b/packages/filesystem/src/browser/file-dialog/file-dialog-service.ts
@@ -16,7 +16,7 @@
 
 import { injectable, inject } from '@theia/core/shared/inversify';
 import URI from '@theia/core/lib/common/uri';
-import { MaybeArray, nls } from '@theia/core/lib/common';
+import { MaybeArray, UNTITLED_SCHEME, nls } from '@theia/core/lib/common';
 import { LabelProvider } from '@theia/core/lib/browser';
 import { FileStat } from '../../common/files';
 import { DirNode } from '../file-tree';
@@ -81,7 +81,9 @@ export class DefaultFileDialogService implements FileDialogService {
     }
 
     protected async getRootNode(folderToOpen?: FileStat): Promise<DirNode | undefined> {
-        const folderExists = folderToOpen && await this.fileService.exists(folderToOpen.resource);
+        const folderExists = folderToOpen
+            && folderToOpen.resource.scheme !== UNTITLED_SCHEME
+            && await this.fileService.exists(folderToOpen.resource);
         const folder = folderToOpen && folderExists ? folderToOpen : {
             resource: await this.rootProvider.getUserWorkingDir(),
             isDirectory: true
diff --git a/packages/workspace/src/browser/workspace-user-working-directory-provider.ts b/packages/workspace/src/browser/workspace-user-working-directory-provider.ts
index 26d4121f7add8..af8f69d2a2cb5 100644
--- a/packages/workspace/src/browser/workspace-user-working-directory-provider.ts
+++ b/packages/workspace/src/browser/workspace-user-working-directory-provider.ts
@@ -28,6 +28,7 @@ export class WorkspaceUserWorkingDirectoryProvider extends UserWorkingDirectoryP
 
     override async getUserWorkingDir(): Promise<URI> {
         return await this.getFromSelection()
+            ?? await this.getFromLastOpenResource()
             ?? await this.getFromWorkspace()
             ?? this.getFromUserHome();
     }