notebook multiselect revamp for actions

src/vs/workbench/contrib/positronNotebook/browser/IPositronNotebookInstance.ts

@@ -219,25 +219,28 @@ export interface IPositronNotebookInstance extends IPositronNotebookEditor {
 	/**
 	 * Removes a cell from the notebook.
 	 *
-	 * @param cell Optional cell to delete. If not provided, deletes the currently selected cell
+	 * @param cell Optional cell to delete. If not provided, deletes the currently active cell
 	 */
 	deleteCell(cell?: IPositronNotebookCell): void;
 
 	/**
-	 * Moves a cell up by one position.
-	 * Supports multi-cell selection - moves all selected cells as a group.
+	 * Removes multiple cells from the notebook.
 	 *
-	 * @param cell The cell to move up
+	 * @param cells Optional array of cells to delete. If not provided, uses current selection.
 	 */
-	moveCellUp(cell: IPositronNotebookCell): void;
+	deleteCells(cells?: IPositronNotebookCell[]): void;
 
 	/**
-	 * Moves a cell down by one position.
+	 * Moves the selected cell(s) up by one position.
+	 * Supports multi-cell selection - moves all selected cells as a group.
+	 */
+	moveCellsUp(): void;
+
+	/**
+	 * Moves the selected cell(s) down by one position.
 	 * Supports multi-cell selection - moves all selected cells as a group.
-	 *
-	 * @param cell The cell to move down
 	 */
-	moveCellDown(cell: IPositronNotebookCell): void;
+	moveCellsDown(): void;
 
 	/**
 	 * Moves cells to a specific index.

src/vs/workbench/contrib/positronNotebook/browser/PositronNotebookComponent.css

@@ -66,6 +66,15 @@
 	}
 }
 
+/**
+* Override the global keyoard focus outline style for notebook containers.
+* This prevents focus outline from showing when a user clicks on the notebook.
+* This prevents empty notebooks from showing an outline when they are focused.
+*/
+.monaco-workbench .positron-notebook-container[tabindex="-1"]:focus {
+	outline: none;
+}
+
 .positron-notebook-cells-container {
 	padding-block: 1.5rem;
 	padding-inline: 1rem;

src/vs/workbench/contrib/positronNotebook/browser/PositronNotebookEditor.tsx

@@ -199,6 +199,8 @@ export class PositronNotebookEditor extends AbstractEditorWithViewState<INoteboo
 
 		this._logService.debug(this._identifier, 'createEditor');
 		this._parentDiv = DOM.$('.positron-notebook-container');
+		// Make container focusable so it can maintain focus when empty
+		this._parentDiv.tabIndex = -1;
 		parent.appendChild(this._parentDiv);
 		this._parentDiv.style.display = 'relative';
 	}

src/vs/workbench/contrib/positronNotebook/browser/PositronNotebookInstance.ts

@@ -836,12 +836,13 @@ export class PositronNotebookInstance extends Disposable implements IPositronNot
 		this.deleteCells([cell]);
 	}
 
-
 	/**
 	 * Deletes multiple cells from the notebook.
-	 * @param cellsToDelete Array of cells to delete
+	 * @param cells Array of cells to delete
 	 */
-	deleteCells(cellsToDelete: IPositronNotebookCell[]): void {
+	deleteCells(cells?: IPositronNotebookCell[]): void {
+		const cellsToDelete = cells || getSelectedCells(this.selectionStateMachine.state.get());
+
 		this._assertTextModel();
 
 		if (cellsToDelete.length === 0) {
@@ -905,18 +906,17 @@ export class PositronNotebookInstance extends Disposable implements IPositronNot
 	}
 
 	/**
-	 * Moves a cell up by one position.
+	 * Moves the selected cell(s) up by one position.
 	 * Supports multi-cell selection - moves all selected cells as a group.
-	 * @param cell The cell to move up
 	 */
-	moveCellUp(cell: IPositronNotebookCell): void {
+	moveCellsUp(): void {
 		this._assertTextModel();
 
-		if (cell.index <= 0) {
+		const cellsToMove = getSelectedCells(this.selectionStateMachine.state.get());
+		if (cellsToMove.length === 0) {
 			return;
 		}
 
-		const cellsToMove = getSelectedCells(this.selectionStateMachine.state.get());
 		const firstIndex = Math.min(...cellsToMove.map(c => c.index));
 		const lastIndex = Math.max(...cellsToMove.map(c => c.index));
 		const length = lastIndex - firstIndex + 1;
@@ -956,19 +956,18 @@ export class PositronNotebookInstance extends Disposable implements IPositronNot
 	}
 
 	/**
-	 * Moves a cell down by one position.
+	 * Moves the selected cell(s) down by one position.
 	 * Supports multi-cell selection - moves all selected cells as a group.
-	 * @param cell The cell to move down
 	 */
-	moveCellDown(cell: IPositronNotebookCell): void {
+	moveCellsDown(): void {
 		this._assertTextModel();
 
-		const cells = this.cells.get();
-		if (cell.index >= cells.length - 1) {
+		const cellsToMove = getSelectedCells(this.selectionStateMachine.state.get());
+		if (cellsToMove.length === 0) {
 			return;
 		}
 
-		const cellsToMove = getSelectedCells(this.selectionStateMachine.state.get());
+		const cells = this.cells.get();
 		const firstIndex = Math.min(...cellsToMove.map(c => c.index));
 		const lastIndex = Math.max(...cellsToMove.map(c => c.index));
 		const length = lastIndex - firstIndex + 1;
@@ -1210,6 +1209,10 @@ export class PositronNotebookInstance extends Disposable implements IPositronNot
 		this._assertTextModel();
 		const modelCells = this.textModel.cells;
 
+		// Track if we're transitioning from empty to non-empty or vice versa
+		const wasEmpty = this.cells.get().length === 0;
+		const willBeEmpty = modelCells.length === 0;
+
 		const cellModelToCellMap = new Map(
 			this.cells.get().map(cell => [cell.model, cell])
 		);
@@ -1251,6 +1254,12 @@ export class PositronNotebookInstance extends Disposable implements IPositronNot
 		cellModelToCellMap.forEach(cell => cell.dispose());
 
 		this.cells.set(cells, undefined);
+
+		// Handle focus management for empty/non-empty transitions
+		if (!wasEmpty && willBeEmpty && this._container) {
+			// Transitioned to empty: focus the container
+			this._container.focus();
+		}
 	}
 
 	/**
@@ -1460,7 +1469,7 @@ export class PositronNotebookInstance extends Disposable implements IPositronNot
 
 	/**
 	 * Pastes cells from the clipboard at the specified index.
-	 * @param index The position to paste cells at. If not provided, pastes after the last selected cell
+	 * @param index The position to paste cells at. If not provided, pastes after active cell or at end of notebook.
 	 */
 	pasteCells(index?: number): void {
 		if (!this.canPaste()) {
@@ -1517,13 +1526,12 @@ export class PositronNotebookInstance extends Disposable implements IPositronNot
 	}
 
 	/**
-	 * Pastes cells from the clipboard above the first selected cell.
+	 * Pastes cells from the clipboard above the active cell.
 	 */
 	pasteCellsAbove(): void {
-		const selection = getSelectedCells(this.selectionStateMachine.state.get());
-		if (selection.length > 0) {
-			const firstSelectedIndex = selection[0].index;
-			this.pasteCells(firstSelectedIndex);
+		const activeCell = getActiveCell(this.selectionStateMachine.state.get());
+		if (activeCell) {
+			this.pasteCells(activeCell.index);
 		} else {
 			this.pasteCells(0);
 		}
@@ -1564,10 +1572,10 @@ export class PositronNotebookInstance extends Disposable implements IPositronNot
 
 	// Helper method to get insertion index
 	private getInsertionIndex(): number {
-		const selections = getSelectedCells(this.selectionStateMachine.state.get());
-		if (selections.length > 0) {
-			const lastSelectedIndex = selections[selections.length - 1].index;
-			return lastSelectedIndex + 1;
+		// Use the active cell position for determining insertion, or at the end if no active cell
+		const activeCell = getActiveCell(this.selectionStateMachine.state.get());
+		if (activeCell) {
+			return activeCell.index + 1;
 		}
 		return this.cells.get().length;
 	}

src/vs/workbench/contrib/positronNotebook/browser/contrib/undoRedo/positronNotebookUndoRedo.ts

@@ -37,25 +37,29 @@ class PositronNotebookUndoRedoContribution extends Disposable {
 			return false;
 		}
 
+		// Determine if the notebook is empty. This is important because when there are no cells,
+		// neither the container or cell editor will have focus, but we still want undo/redo to work.
+		// This enables undoing cell operations (cut and delete) that result in an empty notebook.
+		const emptyNotebook = instance.cells.get().length === 0;
+
 		// Use the notebook-specific scoped context key service instead of the global one
 		const scopedContextKeyService = instance.contextManager.getScopedContextKeyService();
 		if (!scopedContextKeyService) {
 			// Fallback to global context service if scoped service is not available
 			// This shouldn't happen in normal operation, but provides a safety net
 			const containerFocused = this.contextKeyService.getContextKeyValue<boolean>(POSITRON_NOTEBOOK_EDITOR_CONTAINER_FOCUSED.key) ?? false;
 			const cellEditorFocused = this.contextKeyService.getContextKeyValue<boolean>(POSITRON_NOTEBOOK_CELL_EDITOR_FOCUSED.key) ?? false;
-			// Handle undo/redo if either the container is focused OR a cell editor is focused
-			// This matches VS Code's behavior where notebook undo works regardless of specific focus location
-			return containerFocused || cellEditorFocused;
+			// Handle undo/redo if the container is focused OR a cell editor is focused OR the notebook is empty
+			return containerFocused || cellEditorFocused || emptyNotebook;
 		}
 
 		// Read context keys from the scoped context service that actually has these keys bound
 		const containerFocused = scopedContextKeyService.getContextKeyValue<boolean>(POSITRON_NOTEBOOK_EDITOR_CONTAINER_FOCUSED.key) ?? false;
 		const cellEditorFocused = scopedContextKeyService.getContextKeyValue<boolean>(POSITRON_NOTEBOOK_CELL_EDITOR_FOCUSED.key) ?? false;
 
-		// Handle undo/redo if either the container is focused OR a cell editor is focused
+		// Handle undo/redo if the container is focused OR a cell editor is focused OR the notebook is empty
 		// This allows undo to work even when typing in a cell (common after adding a new cell)
-		return containerFocused || cellEditorFocused;
+		return containerFocused || cellEditorFocused || emptyNotebook;
 	}
 
 	private handleUndo(): boolean | Promise<void> {