Implement outlineViewType setting that changes the Project Outline View (#3799) (#4538)

* Implement outlineViewType setting that changes the Project Outline View (#3799)

* fixing lint errors

* Fix outlineViewType setting to properly toggle between tree and list views

- Move onChange subscription from workspace-level to per-project
  ConfigurationReader, fixing resource-scoped setting detection and
  multi-project refresh (Bugs #1 and #2 from audit)
- Branch in WorkspaceFolderNode.updateCodeModel() to restore the
  pre-1.15 multi-project outline in tree mode, bypassing the
  populateViewCodeModel() flattening (Bug #3)
- Revert ProjectNode to original 3-param constructor (remove
  ConfigurationReader dependency)
- Revert ProjectNode.update() to standard folder-based target
  grouping (tree structure comes from separate ProjectNodes)
- Add CHANGELOG entry

Co-authored-by: Copilot <[email protected]>

---------

Co-authored-by: Dimitar Ushatov <[email protected]>
Co-authored-by: Hannia Valera <[email protected]>
Co-authored-by: Copilot <[email protected]>

Author: 4 people

CHANGELOG.md

@@ -20,6 +20,7 @@ Features:
 - Complete Bookmarks context menu with "Set Build Target", "Set Launch/Debug Target", "Open CMakeLists.txt", and "Run Utility Target" actions to match the Project Outline. [#4788](https://github.com/microsoft/vscode-cmake-tools/issues/4788)
 - Relax `intelliSenseMode` validation in CMake Presets. [#4815](https://github.com/microsoft/vscode-cmake-tools/issues/4815) [@halflifefan](https://github.com/halflifefan)
 - Support string arrays in kit `cmakeSettings` to pass CMake lists without escaping semicolons (e.g., `"LLVM_ENABLE_PROJECTS": ["clang", "lld"]`). [#4503](https://github.com/microsoft/vscode-cmake-tools/issues/4503)
+- Add `cmake.outlineViewType` setting to toggle the Project Outline between a flat list view and the prior hierarchical tree view that shows each CMake project separately. [#3799](https://github.com/microsoft/vscode-cmake-tools/issues/3799) [#4538](https://github.com/microsoft/vscode-cmake-tools/pull/4538) [@ar1m4n](https://github.com/ar1m4n)
 
 Improvements:
 - Run tests sequentially in alphabetical order (matching the Test Explorer display order) when `cmake.ctest.allowParallelJobs` is disabled. [#4829](https://github.com/microsoft/vscode-cmake-tools/issues/4829)

docs/cmake-settings.md

@@ -77,6 +77,7 @@ Options that support substitution, in the table below, allow variable references
 | `cmake.options.advanced` | Advanced options for CMake Tools. | See package.json | no |
 | `cmake.options.statusBarVisibility` | Controls visibility of the status bar. | `hidden` | no |
 | `cmake.outputLogEncoding` | Encoding to use for tool output. | `auto` | no |
+| `cmake.outlineViewType` | Project Outline View`s type. | `["list", "tree"]` | no |
 | `cmake.parallelJobs` | Specify the number of jobs run in parallel during the build. Using the value `0` will detect and use the number of CPUs. Using the value `1` will disable build parallelism. | `0` | no |
 | `cmake.parseBuildDiagnostics` | If `true`, parse compiler output for diagnostics. | `true` | no |
 | `cmake.pinnedCommands` | List of commands pinned to the command palette. | `["workbench.action.tasks.configureTaskRunner", "workbench.action.tasks.runTask"]` | no |

package.json

@@ -3292,6 +3292,16 @@
           ],
           "scope": "window"
         },
+        "cmake.outlineViewType": {
+          "type": "string",
+          "enum": [
+            "list",
+            "tree"
+          ],
+          "default": "list",
+          "description": "%cmake-tools.configuration.cmake.outlineViewType.description%",
+          "scope": "resource"
+        },
         "cmake.options.advanced": {
           "type": "object",
           "default": {

package.nls.json

@@ -428,6 +428,7 @@
     },
     "cmake-tools.configuration.cmake.launchBehavior.newTerminal.markdownDescriptions": "A new terminal instance is created and the target is launched in it. Existing terminals are not automatically cleaned up.",
     "cmake-tools.configuration.cmake.loadCompileCommands.description": "Controls whether the extension reads compile_commands.json to enable single file compilation.",
+    "cmake-tools.configuration.cmake.outlineViewType.description": "Project Outline View`s type. Available options are: \"list\" and \"tree\".",
     "cmake-tools.command.cmake.projectStatus.update.title": "Refresh the project status",
     "cmake-tools.command.cmake.pinnedCommands.add.title": "Add a CMake command to pin",
     "cmake-tools.command.cmake.pinnedCommands.remove.title": "Unpin Command",

src/config.ts

@@ -258,6 +258,7 @@ export interface ExtensionConfigurationSettings {
     additionalBuildProblemMatchers: BuildProblemMatcherConfig[];
     shell: string | null;
     modifyLists: ModifyListsSettings;
+    outlineViewType: string;
 }
 
 type EmittersOf<T> = {
@@ -679,6 +680,10 @@ export class ConfigurationReader implements vscode.Disposable {
         return this.configData.modifyLists;
     }
 
+    get outlineViewType(): string {
+        return this.configData.outlineViewType;
+    }
+
     private readonly emitters: EmittersOf<ExtensionConfigurationSettings> = {
         autoSelectActiveFolder: new vscode.EventEmitter<boolean>(),
         defaultActiveFolder: new vscode.EventEmitter<string | null>(),
@@ -754,7 +759,8 @@ export class ConfigurationReader implements vscode.Disposable {
         additionalBuildProblemMatchers: new vscode.EventEmitter<BuildProblemMatcherConfig[]>(),
         shell: new vscode.EventEmitter<string | null>(),
         setBuildTargetSameAsLaunchTarget: new vscode.EventEmitter<boolean>(),
-        modifyLists: new vscode.EventEmitter<ModifyListsSettings>()
+        modifyLists: new vscode.EventEmitter<ModifyListsSettings>(),
+        outlineViewType: new vscode.EventEmitter<string>()
     };
 
     /**

src/extension.ts

@@ -190,6 +190,7 @@ export class ExtensionManager implements vscode.Disposable {
                 subs.push(project.onTargetNameChanged(FireLate, () => this.updateCodeModel(project)));
                 subs.push(project.onLaunchTargetNameChanged(FireLate, () => this.updateCodeModel(project)));
                 subs.push(project.onActiveBuildPresetChanged(FireLate, () => this.updateCodeModel(project)));
+                subs.push(project.workspaceContext.config.onChange('outlineViewType', () => this.updateCodeModel(project)));
                 subs.push(project.cTestController.onTestsChanged(() => this.updateTestsInOutline(project)));
                 this.codeModelUpdateSubs.set(project.folderPath, subs);
                 rollbar.takePromise('Post-folder-open', { folder: folder, project: project }, this.postWorkspaceOpen(project));

src/ui/projectOutline/projectOutline.ts

@@ -713,10 +713,6 @@ export class WorkspaceFolderNode extends BaseNode {
 
     private readonly _projects = new Map<string, Map<string, ProjectNode>>();
 
-    private getNode(cmakeProject: CMakeProject, modelProjectName: string) {
-        return this._projects.get(cmakeProject.folderPath)?.get(modelProjectName);
-    }
-
     private setNode(cmakeProject: CMakeProject, modelProjectName: string, node: ProjectNode) {
         let sub_map = this._projects.get(cmakeProject.folderPath);
         if (!sub_map) {
@@ -737,23 +733,37 @@ export class WorkspaceFolderNode extends BaseNode {
             return;
         }
 
-        if (model.configurations[0].projects.length === 0) {
+        const configuration = model.configurations[0];
+        if (configuration.projects.length === 0) {
             this.removeNodes(cmakeProject);
             ctx.nodesToUpdate.push(this);
             return;
         }
 
-        const projectOutlineModel = populateViewCodeModel(model);
-        const rootProject = projectOutlineModel.project;
-        let item = this.getNode(cmakeProject, rootProject.name);
-        if (!item) {
-            // Remove stale entries for this cmakeProject so that a renamed
-            // project replaces the old node instead of appearing alongside it.
-            this.removeNodes(cmakeProject);
-            item = new ProjectNode(rootProject.name, this.wsFolder, cmakeProject.folderPath);
+        const outlineViewType = cmakeProject.workspaceContext.config.outlineViewType;
+
+        // Always remove existing nodes first to ensure clean state when
+        // switching between view types or when projects change.
+        this.removeNodes(cmakeProject);
+
+        if (outlineViewType === "tree") {
+            // Tree mode: create a separate ProjectNode for each CMake project,
+            // restoring the pre-1.15 hierarchical outline.
+            for (const project of configuration.projects) {
+                const item = new ProjectNode(project.name, this.wsFolder, project.sourceDirectory);
+                this.setNode(cmakeProject, project.name, item);
+                item.update(project, ctx);
+            }
+        } else {
+            // List mode (default): flatten all projects into a single node.
+            const projectOutlineModel = populateViewCodeModel(model);
+            const rootProject = projectOutlineModel.project;
+            const item = new ProjectNode(rootProject.name, this.wsFolder, cmakeProject.folderPath);
             this.setNode(cmakeProject, rootProject.name, item);
+            item.update(rootProject, ctx);
         }
-        item.update(rootProject, ctx);
+
+        ctx.nodesToUpdate.push(this);
     }
 
     getChildren() {

test/unit-tests/config.test.ts

@@ -91,6 +91,7 @@ function createConfig(conf: Partial<ExtensionConfigurationSettings>): Configurat
         additionalBuildProblemMatchers: [],
         shell: null,
         setBuildTargetSameAsLaunchTarget: false,
+        outlineViewType: "list",
         modifyLists: {
             addNewSourceFiles: 'ask',
             removeDeletedSourceFiles: 'ask',