fix(tree): 🐛 allow navigating between breadcrumbs using arrow keys

.vscode/settings.json

@@ -42,9 +42,7 @@
 		}
 	],
 	"eslint.options": {
-		"rulePaths": [
-			"./build/lib/eslint"
-		]
+		"rulePaths": ["./build/lib/eslint"]
 	},
 	"typescript.tsdk": "node_modules/typescript/lib",
 	"npm.exclude": "**/extensions/**",
@@ -54,15 +52,11 @@
 	"typescript.preferences.quoteStyle": "single",
 	"json.schemas": [
 		{
-			"fileMatch": [
-				"cgmanifest.json"
-			],
+			"fileMatch": ["cgmanifest.json"],
 			"url": "./.vscode/cgmanifest.schema.json"
 		},
 		{
-			"fileMatch": [
-				"cglicenses.json"
-			],
+			"fileMatch": ["cglicenses.json"],
 			"url": "./.vscode/cglicenses.schema.json"
 		}
 	],
@@ -73,16 +67,17 @@
 	"gulp.autoDetect": "off",
 	"files.insertFinalNewline": true,
 	"[plaintext]": {
-		"files.insertFinalNewline": false,
+		"files.insertFinalNewline": false
 	},
 	"[typescript]": {
 		"editor.defaultFormatter": "vscode.typescript-language-features",
-		"editor.formatOnSave": true,
+		"editor.formatOnSave": true
 	},
 	"[javascript]": {
 		"editor.defaultFormatter": "vscode.typescript-language-features",
-		"editor.formatOnSave": true,
+		"editor.formatOnSave": true
 	},
 	"typescript.tsc.autoDetect": "off",
 	"testing.autoRun.mode": "rerun",
+	"conventionalCommits.scopes": ["tree"]
 }

src/vs/base/browser/ui/tree/abstractTree.ts

@@ -1293,6 +1293,7 @@ export abstract class AbstractTree<T, TFilterData, TRef> implements IDisposable
 	get onDidFocus(): Event<void> { return this.view.onDidFocus; }
 	get onDidBlur(): Event<void> { return this.view.onDidBlur; }
 
+	get onDidChangeModel(): Event<void> { return Event.signal(this.model.onDidSplice); }
 	get onDidChangeCollapseState(): Event<ICollapseStateChangeEvent<T, TFilterData>> { return this.model.onDidChangeCollapseState; }
 	get onDidChangeRenderNodeCount(): Event<ITreeNode<T, TFilterData>> { return this.model.onDidChangeRenderNodeCount; }
 

src/vs/base/browser/ui/tree/asyncDataTree.ts

@@ -341,6 +341,7 @@ export class AsyncDataTree<TInput, T, TFilterData = void> implements IDisposable
 	get onDidFocus(): Event<void> { return this.tree.onDidFocus; }
 	get onDidBlur(): Event<void> { return this.tree.onDidBlur; }
 
+	get onDidChangeModel(): Event<void> { return this.tree.onDidChangeModel; }
 	get onDidChangeCollapseState(): Event<ICollapseStateChangeEvent<IAsyncDataTreeNode<TInput, T> | null, TFilterData>> { return this.tree.onDidChangeCollapseState; }
 
 	get onDidUpdateOptions(): Event<IAsyncDataTreeOptionsUpdate> { return this.tree.onDidUpdateOptions; }

src/vs/platform/list/browser/listService.ts

@@ -110,6 +110,10 @@ export const WorkbenchListHasSelectionOrFocus = new RawContextKey<boolean>('list
 export const WorkbenchListDoubleSelection = new RawContextKey<boolean>('listDoubleSelection', false);
 export const WorkbenchListMultiSelection = new RawContextKey<boolean>('listMultiSelection', false);
 export const WorkbenchListSelectionNavigation = new RawContextKey<boolean>('listSelectionNavigation', false);
+export const WorkbenchTreeElementCanCollapse = new RawContextKey<boolean>('treeElementCanCollapse', false);
+export const WorkbenchTreeElementHasParent = new RawContextKey<boolean>('treeElementHasParent', false);
+export const WorkbenchTreeElementCanExpand = new RawContextKey<boolean>('treeElementCanExpand', false);
+export const WorkbenchTreeElementHasChild = new RawContextKey<boolean>('treeElementHasChild', false);
 export const WorkbenchListAutomaticKeyboardNavigationKey = 'listAutomaticKeyboardNavigation';
 
 function createScopedContextKeyService(contextKeyService: IContextKeyService, widget: ListWidget): IContextKeyService {
@@ -1087,6 +1091,10 @@ class WorkbenchTreeInternals<TInput, T, TFilterData> {
 	private hasSelectionOrFocus: IContextKey<boolean>;
 	private hasDoubleSelection: IContextKey<boolean>;
 	private hasMultiSelection: IContextKey<boolean>;
+	private treeElementCanCollapse: IContextKey<boolean>;
+	private treeElementHasParent: IContextKey<boolean>;
+	private treeElementCanExpand: IContextKey<boolean>;
+	private treeElementHasChild: IContextKey<boolean>;
 	private _useAltAsMultipleSelectionModifier: boolean;
 	private disposables: IDisposable[] = [];
 	private styler: IDisposable | undefined;
@@ -1117,6 +1125,11 @@ class WorkbenchTreeInternals<TInput, T, TFilterData> {
 		this.hasDoubleSelection = WorkbenchListDoubleSelection.bindTo(this.contextKeyService);
 		this.hasMultiSelection = WorkbenchListMultiSelection.bindTo(this.contextKeyService);
 
+		this.treeElementCanCollapse = WorkbenchTreeElementCanCollapse.bindTo(this.contextKeyService);
+		this.treeElementHasParent = WorkbenchTreeElementHasParent.bindTo(this.contextKeyService);
+		this.treeElementCanExpand = WorkbenchTreeElementCanExpand.bindTo(this.contextKeyService);
+		this.treeElementHasChild = WorkbenchTreeElementHasChild.bindTo(this.contextKeyService);
+
 		this._useAltAsMultipleSelectionModifier = useAltAsMultipleSelectionModifier(configurationService);
 
 		const interestingContextKeys = new Set();
@@ -1132,6 +1145,20 @@ class WorkbenchTreeInternals<TInput, T, TFilterData> {
 
 		this.updateStyleOverrides(overrideStyles);
 
+		const updateCollapseContextKeys = () => {
+			const focus = tree.getFocus()[0];
+
+			if (!focus) {
+				return;
+			}
+
+			const node = tree.getNode(focus);
+			this.treeElementCanCollapse.set(node.collapsible && !node.collapsed);
+			this.treeElementHasParent.set(!!tree.getParentElement(focus));
+			this.treeElementCanExpand.set(node.collapsible && node.collapsed);
+			this.treeElementHasChild.set(!!tree.getFirstElementChild(focus));
+		};
+
 		this.disposables.push(
 			this.contextKeyService,
 			(listService as ListService).register(tree),
@@ -1150,7 +1177,10 @@ class WorkbenchTreeInternals<TInput, T, TFilterData> {
 				const focus = tree.getFocus();
 
 				this.hasSelectionOrFocus.set(selection.length > 0 || focus.length > 0);
+				updateCollapseContextKeys();
 			}),
+			tree.onDidChangeCollapseState(updateCollapseContextKeys),
+			tree.onDidChangeModel(updateCollapseContextKeys),
 			configurationService.onDidChangeConfiguration(e => {
 				let newOptions: IAbstractTreeOptionsUpdate = {};
 				if (e.affectsConfiguration(multiSelectModifierSettingKey)) {

src/vs/workbench/browser/actions/listCommands.ts

@@ -7,7 +7,7 @@ import { KeyMod, KeyCode } from 'vs/base/common/keyCodes';
 import { ServicesAccessor } from 'vs/platform/instantiation/common/instantiation';
 import { KeybindingsRegistry, KeybindingWeight } from 'vs/platform/keybinding/common/keybindingsRegistry';
 import { List } from 'vs/base/browser/ui/list/listWidget';
-import { WorkbenchListFocusContextKey, IListService, WorkbenchListSupportsMultiSelectContextKey, ListWidget, WorkbenchListHasSelectionOrFocus, getSelectionKeyboardEvent, WorkbenchListWidget, WorkbenchListSelectionNavigation } from 'vs/platform/list/browser/listService';
+import { WorkbenchListFocusContextKey, IListService, WorkbenchListSupportsMultiSelectContextKey, ListWidget, WorkbenchListHasSelectionOrFocus, getSelectionKeyboardEvent, WorkbenchListWidget, WorkbenchListSelectionNavigation, WorkbenchTreeElementCanCollapse, WorkbenchTreeElementHasParent, WorkbenchTreeElementHasChild, WorkbenchTreeElementCanExpand } from 'vs/platform/list/browser/listService';
 import { PagedList } from 'vs/base/browser/ui/list/listPaging';
 import { equals, range } from 'vs/base/common/arrays';
 import { ContextKeyExpr } from 'vs/platform/contextkey/common/contextkey';
@@ -252,7 +252,7 @@ KeybindingsRegistry.registerCommandAndKeybindingRule({
 KeybindingsRegistry.registerCommandAndKeybindingRule({
 	id: 'list.collapse',
 	weight: KeybindingWeight.WorkbenchContrib,
-	when: WorkbenchListFocusContextKey,
+	when: ContextKeyExpr.and(WorkbenchListFocusContextKey, ContextKeyExpr.or(WorkbenchTreeElementCanCollapse, WorkbenchTreeElementHasParent)),
 	primary: KeyCode.LeftArrow,
 	mac: {
 		primary: KeyCode.LeftArrow,
@@ -336,7 +336,7 @@ KeybindingsRegistry.registerCommandAndKeybindingRule({
 KeybindingsRegistry.registerCommandAndKeybindingRule({
 	id: 'list.expand',
 	weight: KeybindingWeight.WorkbenchContrib,
-	when: WorkbenchListFocusContextKey,
+	when: ContextKeyExpr.and(WorkbenchListFocusContextKey, ContextKeyExpr.or(WorkbenchTreeElementCanExpand, WorkbenchTreeElementHasChild)),
 	primary: KeyCode.RightArrow,
 	handler: (accessor) => {
 		const widget = accessor.get(IListService).lastFocusedList;