undo general focus/selection preservation from lists and trees (#201309)

fixes #174768
fixes #127622

src/vs/base/browser/ui/list/listWidget.ts

@@ -109,9 +109,8 @@ class TraitRenderer<T> implements IListRenderer<T, ITraitTemplateData>
 
 class Trait<T> implements ISpliceable<boolean>, IDisposable {
 
-	private length = 0;
-	private indexes: number[] = [];
-	private sortedIndexes: number[] = [];
+	protected indexes: number[] = [];
+	protected sortedIndexes: number[] = [];
 
 	private readonly _onChange = new Emitter<ITraitChangeEvent>();
 	readonly onChange: Event<ITraitChangeEvent> = this._onChange.event;
@@ -126,8 +125,6 @@ class Trait<T> implements ISpliceable<boolean>, IDisposable {
 	constructor(private _trait: string) { }
 
 	splice(start: number, deleteCount: number, elements: boolean[]): void {
-		deleteCount = Math.max(0, Math.min(deleteCount, this.length - start));
-
 		const diff = elements.length - deleteCount;
 		const end = start + deleteCount;
 		const sortedIndexes: number[] = [];
@@ -147,16 +144,8 @@ class Trait<T> implements ISpliceable<boolean>, IDisposable {
 			sortedIndexes.push(this.sortedIndexes[i++] + diff);
 		}
 
-		const length = this.length + diff;
-
-		if (this.sortedIndexes.length > 0 && sortedIndexes.length === 0 && length > 0) {
-			const first = this.sortedIndexes.find(index => index >= start) ?? length - 1;
-			sortedIndexes.push(Math.min(first, length - 1));
-		}
-
 		this.renderer.splice(start, deleteCount, elements.length);
 		this._set(sortedIndexes, sortedIndexes);
-		this.length = length;
 	}
 
 	renderIndex(index: number, container: HTMLElement): void {

src/vs/workbench/contrib/files/browser/explorerService.ts

@@ -448,6 +448,7 @@ export class ExplorerService implements IExplorerService {
 					// Remove Element from Parent (Model)
 					const parent = modelElement.parent;
 					parent.removeChild(modelElement);
+					this.view?.focusNext();
 
 					const oldNestedParent = modelElement.nestedParent;
 					if (oldNestedParent) {
@@ -456,6 +457,10 @@ export class ExplorerService implements IExplorerService {
 					}
 					// Refresh Parent (View)
 					await this.view?.refresh(shouldDeepRefresh, parent);
+
+					if (this.view?.getFocus().length === 0) {
+						this.view?.focusLast();
+					}
 				}
 			}));
 		}

src/vs/workbench/contrib/files/browser/files.ts

@@ -60,6 +60,9 @@ export interface IExplorerView {
 	isItemVisible(item: ExplorerItem): boolean;
 	isItemCollapsed(item: ExplorerItem): boolean;
 	hasFocus(): boolean;
+	getFocus(): ExplorerItem[];
+	focusNext(): void;
+	focusLast(): void;
 }
 
 function getFocus(listService: IListService): unknown | undefined {

src/vs/workbench/contrib/files/browser/views/explorerView.ts

@@ -348,6 +348,18 @@ export class ExplorerView extends ViewPane implements IExplorerView {
 		return DOM.isAncestorOfActiveElement(this.container);
 	}
 
+	getFocus(): ExplorerItem[] {
+		return this.tree.getFocus();
+	}
+
+	focusNext(): void {
+		this.tree.focusNext();
+	}
+
+	focusLast(): void {
+		this.tree.focusLast();
+	}
+
 	getContext(respectMultiSelection: boolean): ExplorerItem[] {
 		return getContext(this.tree.getFocus(), this.tree.getSelection(), respectMultiSelection, this.renderer);
 	}

src/vs/workbench/contrib/workspace/browser/workspaceTrustEditor.ts

@@ -155,6 +155,11 @@ class WorkspaceTrustedUrisTable extends Disposable {
 						return localize('trustedFolderWithHostAriaLabel', "{0} on {1}, trusted", this.labelService.getUriLabel(item.uri), hostLabel);
 					},
 					getWidgetAriaLabel: () => localize('trustedFoldersAndWorkspaces', "Trusted Folders & Workspaces")
+				},
+				identityProvider: {
+					getId(element: ITrustedUriItem) {
+						return element.uri.toString();
+					},
 				}
 			}
 		) as WorkbenchTable<ITrustedUriItem>;
@@ -336,8 +341,14 @@ class WorkspaceTrustedUrisTable extends Disposable {
 	}
 
 	async delete(item: ITrustedUriItem) {
+		this.table.focusNext();
 		await this.workspaceTrustManagementService.setUrisTrust([item.uri], false);
+
+		if (this.table.getFocus().length === 0) {
+			this.table.focusLast();
+		}
 		this._onDelete.fire(item);
+		this.table.domFocus();
 	}
 
 	async edit(item: ITrustedUriItem, usePickerIfPossible?: boolean) {