clear cell output in the core

src/vs/workbench/api/common/extHostNotebook.ts

@@ -251,6 +251,10 @@ export class ExtHostNotebookDocument extends Disposable implements vscode.Notebo
 			this.$spliceNotebookCells(event.changes);
 		} else if (event.kind === NotebookCellsChangeType.Move) {
 			this.$moveCell(event.index, event.newIdx);
+		} else if (event.kind === NotebookCellsChangeType.CellClearOutput) {
+			this.$clearCellOutputs(event.index);
+		} else if (event.kind === NotebookCellsChangeType.CellsClearOutput) {
+			this.$clearAllCellOutputs();
 		}
 
 		this._versionId = event.versionId;
@@ -299,6 +303,15 @@ export class ExtHostNotebookDocument extends Disposable implements vscode.Notebo
 		this.cells.splice(newIdx, 0, ...cells);
 	}
 
+	private $clearCellOutputs(index: number) {
+		const cell = this.cells[index];
+		cell.outputs = [];
+	}
+
+	private $clearAllCellOutputs() {
+		this.cells.forEach(cell => cell.outputs = []);
+	}
+
 	eventuallyUpdateCellOutputs(cell: ExtHostCell, diffs: ISplice<vscode.CellOutput>[]) {
 		let renderers = new Set<number>();
 		let outputDtos: NotebookCellOutputsSplice[] = diffs.map(diff => {

src/vs/workbench/contrib/notebook/browser/contrib/coreActions.ts

@@ -41,6 +41,9 @@ const CANCEL_CELL_COMMAND_ID = 'workbench.notebook.cell.cancelExecution';
 const EXECUTE_NOTEBOOK_COMMAND_ID = 'workbench.notebook.executeNotebook';
 const CANCEL_NOTEBOOK_COMMAND_ID = 'workbench.notebook.cancelExecution';
 
+const CLEAR_CELL_OUTPUTS_COMMAND_ID = 'workbench.action.notebook.clearCellOutputs';
+const CLEAR_ALL_CELLS_OUTPUTS_COMMAND_ID = 'workbench.action.notebook.clearAllCellsOutputs';
+
 const NOTEBOOK_ACTIONS_CATEGORY = localize('notebookActions.category', "Notebook");
 
 const EDITOR_WIDGET_ACTION_WEIGHT = KeybindingWeight.EditorContrib; // smaller than Suggest Widget, etc
@@ -50,6 +53,7 @@ const enum CellToolbarOrder {
 	MoveCellDown,
 	EditCell,
 	SaveCell,
+	ClearCellOutput,
 	InsertCell,
 	DeleteCell
 }
@@ -1171,3 +1175,69 @@ registerAction2(class extends Action2 {
 		editor.focusNotebookCell(firstCell, false);
 	}
 });
+
+registerAction2(class extends Action2 {
+	constructor() {
+		super({
+			id: CLEAR_CELL_OUTPUTS_COMMAND_ID,
+			title: 'Notebook Clear Active Cell Outputs',
+			menu: {
+				id: MenuId.NotebookCellTitle,
+				when: ContextKeyExpr.and(NOTEBOOK_CELL_TYPE.isEqualTo('code'), NOTEBOOK_EDITOR_RUNNABLE),
+				order: CellToolbarOrder.ClearCellOutput
+			},
+			icon: { id: 'codicon/clear-all' },
+			f1: true
+		});
+	}
+
+	async run(accessor: ServicesAccessor, context?: INotebookCellActionContext): Promise<void> {
+		if (!isCellActionContext(context)) {
+			context = getActiveCellContext(accessor);
+			if (!context) {
+				return;
+			}
+		}
+
+		const editor = context.notebookEditor;
+		if (!editor.viewModel || !editor.viewModel.length) {
+			return;
+		}
+
+		editor.viewModel.notebookDocument.clearCellOutput(context.cell.handle);
+	}
+});
+
+registerAction2(class extends Action2 {
+	constructor() {
+		super({
+			id: CLEAR_ALL_CELLS_OUTPUTS_COMMAND_ID,
+			title: 'Notebook Clear All Cells Outputs',
+			menu: {
+				id: MenuId.EditorTitle,
+				when: NOTEBOOK_EDITOR_FOCUSED,
+				group: 'navigation',
+				order: 0
+			},
+			icon: { id: 'codicon/clear-all' },
+			f1: true
+		});
+	}
+
+	async run(accessor: ServicesAccessor, context?: INotebookCellActionContext): Promise<void> {
+		if (!isCellActionContext(context)) {
+			context = getActiveCellContext(accessor);
+			if (!context) {
+				return;
+			}
+		}
+
+		const editor = context.notebookEditor;
+		if (!editor.viewModel || !editor.viewModel.length) {
+			return;
+		}
+
+		editor.viewModel.notebookDocument.clearAllCellOutputs();
+	}
+});
+

src/vs/workbench/contrib/notebook/browser/notebookEditor.ts

@@ -466,9 +466,10 @@ export class NotebookEditor extends BaseEditor implements INotebookEditor {
 				const scrollTop = this.list?.scrollTop || 0;
 				const scrollHeight = this.list?.scrollHeight || 0;
 				this.webview!.element.style.height = `${scrollHeight}px`;
-				let updateItems: { cell: CodeCellViewModel, output: IOutput, cellTop: number }[] = [];
 
 				if (this.webview?.insetMapping) {
+					let updateItems: { cell: CodeCellViewModel, output: IOutput, cellTop: number }[] = [];
+					let removedItems: IOutput[] = [];
 					this.webview?.insetMapping.forEach((value, key) => {
 						const cell = value.cell;
 						const viewIndex = this.list?.getViewIndex(cell);
@@ -477,6 +478,11 @@ export class NotebookEditor extends BaseEditor implements INotebookEditor {
 							return;
 						}
 
+						if (cell.outputs.indexOf(key) < 0) {
+							// output is already gone
+							removedItems.push(key);
+						}
+
 						const cellTop = this.list?.getAbsoluteTopOfElement(cell) || 0;
 						if (this.webview!.shouldUpdateInset(cell, key, cellTop)) {
 							updateItems.push({
@@ -487,6 +493,8 @@ export class NotebookEditor extends BaseEditor implements INotebookEditor {
 						}
 					});
 
+					removedItems.forEach(output => this.webview?.removeInset(output));
+
 					if (updateItems.length) {
 						this.webview?.updateViewScrollTop(-scrollTop, updateItems);
 					}

src/vs/workbench/contrib/notebook/common/model/notebookTextModel.ts

@@ -286,6 +286,28 @@ export class NotebookTextModel extends Disposable implements INotebookTextModel
 		cell?.spliceNotebookCellOutputs(splices);
 	}
 
+	clearCellOutput(handle: number) {
+		let cell = this._mapping.get(handle);
+		if (cell) {
+			cell.spliceNotebookCellOutputs([
+				[0, cell.outputs.length, []]
+			]);
+
+			this._increaseVersionId();
+			this._onDidModelChangeProxy.fire({ kind: NotebookCellsChangeType.CellClearOutput, versionId: this._versionId, index: this.cells.indexOf(cell) });
+		}
+	}
+
+	clearAllCellOutputs() {
+		this.cells.forEach(cell => {
+			cell.spliceNotebookCellOutputs([
+				[0, cell.outputs.length, []]
+			]);
+		});
+		this._increaseVersionId();
+		this._onDidModelChangeProxy.fire({ kind: NotebookCellsChangeType.CellsClearOutput, versionId: this._versionId });
+	}
+
 	dispose() {
 		this._onWillDispose.fire();
 		this._cellListeners.forEach(val => val.dispose());

src/vs/workbench/contrib/notebook/common/notebookCommon.ts

@@ -219,7 +219,9 @@ export type NotebookCellsSplice2 = [
 
 export enum NotebookCellsChangeType {
 	ModelChange = 1,
-	Move = 2
+	Move = 2,
+	CellClearOutput = 3,
+	CellsClearOutput = 4
 }
 
 export interface NotebookCellsModelChangedEvent {
@@ -235,7 +237,18 @@ export interface NotebookCellsModelMoveEvent {
 	readonly versionId: number;
 }
 
-export type NotebookCellsChangedEvent = NotebookCellsModelChangedEvent | NotebookCellsModelMoveEvent;
+export interface NotebookCellClearOutputEvent {
+	readonly kind: NotebookCellsChangeType.CellClearOutput;
+	readonly index: number;
+	readonly versionId: number;
+}
+
+export interface NotebookCellsClearOutputEvent {
+	readonly kind: NotebookCellsChangeType.CellsClearOutput;
+	readonly versionId: number;
+}
+
+export type NotebookCellsChangedEvent = NotebookCellsModelChangedEvent | NotebookCellsModelMoveEvent | NotebookCellClearOutputEvent | NotebookCellsClearOutputEvent;
 export enum CellEditType {
 	Insert = 1,
 	Delete = 2