reduce event emitters on notebook baseviewmodel

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

@@ -421,6 +421,15 @@ export enum CursorAtBoundary {
 	Both
 }
 
+export interface CellViewModelStateChangeEvent {
+	metadataChanged?: boolean;
+	selectionChanged?: boolean;
+	focusModeChanged?: boolean;
+	runStateChanged?: boolean;
+	editStateChanged?: boolean;
+	languageChanged?: boolean;
+}
+
 /**
  * [start, start + length - 1]
  */

src/vs/workbench/contrib/notebook/browser/view/notebookCellList.ts

@@ -98,8 +98,10 @@ export class NotebookCellList extends WorkbenchList<CellViewModel> implements ID
 				// we only validate the first focused element
 				const focusedElement = e.elements[0];
 
-				cursorSelectionListener = focusedElement.onDidChangeCursorSelection(() => {
+				cursorSelectionListener = focusedElement.onDidChangeState((e) => {
+					if (e.selectionChanged) {
 						recomputeContext(focusedElement);
+					}
 				});
 
 				textEditorAttachListener = focusedElement.onDidChangeEditorAttachState(() => {
@@ -478,7 +480,9 @@ export class NotebookCellList extends WorkbenchList<CellViewModel> implements ID
 			}
 
 			const editorAttachedPromise = new Promise((resolve, reject) => {
-				element.onDidChangeEditorAttachState(state => state ? resolve() : reject());
+				element.onDidChangeEditorAttachState(() => {
+					element.editorAttached ? resolve() : reject();
+				});
 			});
 
 			editorAttachedPromise.then(() => {
@@ -750,7 +754,7 @@ export class NotebookCellList extends WorkbenchList<CellViewModel> implements ID
 
 function getEditorAttachedPromise(element: CellViewModel) {
 	return new Promise((resolve, reject) => {
-		Event.once(element.onDidChangeEditorAttachState)(state => state ? resolve() : reject());
+		Event.once(element.onDidChangeEditorAttachState)(() => element.editorAttached ? resolve() : reject());
 	});
 }
 

src/vs/workbench/contrib/notebook/browser/view/renderers/cellRenderer.ts

@@ -327,13 +327,17 @@ export class MarkdownCellRenderer extends AbstractCellRenderer implements IListR
 			};
 
 			updateForMetadata();
-			elementDisposable.add(element.onDidChangeMetadata(() => {
+			elementDisposable.add(element.onDidChangeState((e) => {
+				if (e.metadataChanged) {
 					updateForMetadata();
+				}
 			}));
 
 			const editModeKey = contextKeyService.createKey(NOTEBOOK_CELL_MARKDOWN_EDIT_MODE_CONTEXT_KEY, element.editState === CellEditState.Editing);
-			elementDisposable.add(element.onDidChangeCellEditState(() => {
+			elementDisposable.add(element.onDidChangeState((e) => {
+				if (e.editStateChanged) {
 					editModeKey.set(element.editState === CellEditState.Editing);
+				}
 			}));
 
 			this.setupCellToolbarActions(contextKeyService, templateData, elementDisposable);
@@ -517,13 +521,21 @@ export class CodeCellRenderer extends AbstractCellRenderer implements IListRende
 
 		const runStateKey = contextKeyService.createKey(NOTEBOOK_CELL_RUN_STATE_CONTEXT_KEY, CellRunState[element.runState]);
 		this.updateForRunState(element, templateData, runStateKey);
-		elementDisposable.add(element.onDidChangeCellRunState(() => this.updateForRunState(element, templateData, runStateKey)));
+		elementDisposable.add(element.onDidChangeState((e) => {
+			if (e.runStateChanged) {
+				this.updateForRunState(element, templateData, runStateKey);
+			}
+		}));
 
 		contextKeyService.createKey(NOTEBOOK_CELL_TYPE_CONTEXT_KEY, 'code');
 		contextKeyService.createKey(NOTEBOOK_VIEW_TYPE, element.viewType);
 		const cellEditableKey = contextKeyService.createKey(NOTEBOOK_CELL_EDITABLE_CONTEXT_KEY, !!(element.metadata?.editable));
 		this.updateForMetadata(element, templateData, cellEditableKey);
-		elementDisposable.add(element.onDidChangeMetadata(() => this.updateForMetadata(element, templateData, cellEditableKey)));
+		elementDisposable.add(element.onDidChangeState((e) => {
+			if (e.metadataChanged) {
+				this.updateForMetadata(element, templateData, cellEditableKey);
+			}
+		}));
 
 		this.setupCellToolbarActions(contextKeyService, templateData, elementDisposable);
 

src/vs/workbench/contrib/notebook/browser/view/renderers/codeCell.ts

@@ -69,19 +69,29 @@ export class CodeCell extends Disposable {
 			}
 		});
 
-		this._register(viewCell.onDidChangeFocusMode(() => {
+		this._register(viewCell.onDidChangeState((e) => {
+			if (!e.focusModeChanged) {
+				return;
+			}
+
 			if (viewCell.focusMode === CellFocusMode.Editor) {
 				templateData.editor?.focus();
 			}
 		}));
 
 		templateData.editor?.updateOptions({ readOnly: !(viewCell.getEvaluatedMetadata(notebookEditor.viewModel?.metadata).editable) });
-		this._register(viewCell.onDidChangeMetadata(() => {
+		this._register(viewCell.onDidChangeState((e) => {
+			if (e.metadataChanged) {
 				templateData.editor?.updateOptions({ readOnly: !(viewCell.getEvaluatedMetadata(notebookEditor.viewModel?.metadata).editable) });
+			}
 		}));
 
-		this._register(viewCell.onDidChangeLanguage((e) => {
-			const mode = this._modeService.create(e);
+		this._register(viewCell.onDidChangeState((e) => {
+			if (!e.languageChanged) {
+				return;
+			}
+
+			const mode = this._modeService.create(viewCell.language);
 			templateData.editor?.getModel()?.setMode(mode.languageIdentifier);
 		}));
 

src/vs/workbench/contrib/notebook/browser/view/renderers/markdownCell.ts

@@ -142,12 +142,18 @@ export class StatefullMarkdownCell extends Disposable {
 			}
 		};
 
-		this._register(viewCell.onDidChangeCellEditState(() => {
+		this._register(viewCell.onDidChangeState((e) => {
+			if (e.editStateChanged) {
 				this.localDisposables.clear();
 				viewUpdate();
+			}
 		}));
 
-		this._register(viewCell.onDidChangeFocusMode(() => {
+		this._register(viewCell.onDidChangeState((e) => {
+			if (!e.focusModeChanged) {
+				return;
+			}
+
 			if (viewCell.focusMode === CellFocusMode.Editor) {
 				this.editor?.focus();
 			}

src/vs/workbench/contrib/notebook/browser/viewModel/baseCellViewModel.ts

@@ -12,7 +12,7 @@ import * as editorCommon from 'vs/editor/common/editorCommon';
 import * as model from 'vs/editor/common/model';
 import { SearchParams } from 'vs/editor/common/model/textModelSearch';
 import { EDITOR_TOOLBAR_HEIGHT, EDITOR_TOP_MARGIN } from 'vs/workbench/contrib/notebook/browser/constants';
-import { CellEditState, CellFocusMode, CellRunState, CursorAtBoundary, ICellViewModel } from 'vs/workbench/contrib/notebook/browser/notebookBrowser';
+import { CellEditState, CellFocusMode, CellRunState, CursorAtBoundary, ICellViewModel, CellViewModelStateChangeEvent } from 'vs/workbench/contrib/notebook/browser/notebookBrowser';
 import { CellKind, NotebookCellMetadata, NotebookDocumentMetadata } from 'vs/workbench/contrib/notebook/common/notebookCommon';
 import { NotebookCellTextModel } from 'vs/workbench/contrib/notebook/common/model/notebookCellTextModel';
 
@@ -22,22 +22,12 @@ export const NotebookCellMetadataDefaults = {
 };
 
 export abstract class BaseCellViewModel extends Disposable implements ICellViewModel {
-	protected readonly _onDidDispose = new Emitter<void>();
-	readonly onDidDispose = this._onDidDispose.event;
-	protected readonly _onDidChangeCellEditState = new Emitter<void>();
-	readonly onDidChangeCellEditState = this._onDidChangeCellEditState.event;
-	protected readonly _onDidChangeCellRunState = new Emitter<void>();
-	readonly onDidChangeCellRunState = this._onDidChangeCellRunState.event;
-	protected readonly _onDidChangeFocusMode = new Emitter<void>();
-	readonly onDidChangeFocusMode = this._onDidChangeFocusMode.event;
-	protected readonly _onDidChangeEditorAttachState = new Emitter<boolean>();
+	protected readonly _onDidChangeEditorAttachState = new Emitter<void>();
+	// Do not merge this event with `onDidChangeState` as we are using `Event.once(onDidChangeEditorAttachState)` elsewhere.
 	readonly onDidChangeEditorAttachState = this._onDidChangeEditorAttachState.event;
-	protected readonly _onDidChangeCursorSelection: Emitter<void> = this._register(new Emitter<void>());
-	public readonly onDidChangeCursorSelection: Event<void> = this._onDidChangeCursorSelection.event;
-	protected readonly _onDidChangeMetadata: Emitter<void> = this._register(new Emitter<void>());
-	public readonly onDidChangeMetadata: Event<void> = this._onDidChangeMetadata.event;
-	protected readonly _onDidChangeLanguage: Emitter<string> = this._register(new Emitter<string>());
-	public readonly onDidChangeLanguage: Event<string> = this._onDidChangeLanguage.event;
+	protected readonly _onDidChangeState: Emitter<CellViewModelStateChangeEvent> = this._register(new Emitter<CellViewModelStateChangeEvent>());
+	public readonly onDidChangeState: Event<CellViewModelStateChangeEvent> = this._onDidChangeState.event;
+
 	get handle() {
 		return this.model.handle;
 	}
@@ -50,6 +40,9 @@ export abstract class BaseCellViewModel extends Disposable implements ICellViewM
 	get metadata() {
 		return this.model.metadata;
 	}
+	get language() {
+		return this.model.language;
+	}
 
 	abstract cellKind: CellKind;
 
@@ -65,14 +58,14 @@ export abstract class BaseCellViewModel extends Disposable implements ICellViewM
 		}
 
 		this._editState = newState;
-		this._onDidChangeCellEditState.fire();
+		this._onDidChangeState.fire({ editStateChanged: true });
 	}
 
 	// TODO - move any "run"/"status" concept to Code-specific places
 	private _currentTokenSource: CancellationTokenSource | undefined;
 	public set currentTokenSource(v: CancellationTokenSource | undefined) {
 		this._currentTokenSource = v;
-		this._onDidChangeCellRunState.fire();
+		this._onDidChangeState.fire({ runStateChanged: true });
 	}
 
 	public get currentTokenSource(): CancellationTokenSource | undefined {
@@ -89,7 +82,7 @@ export abstract class BaseCellViewModel extends Disposable implements ICellViewM
 	}
 	set focusMode(newMode: CellFocusMode) {
 		this._focusMode = newMode;
-		this._onDidChangeFocusMode.fire();
+		this._onDidChangeState.fire({ focusModeChanged: true });
 	}
 
 	protected _textEditor?: ICodeEditor;
@@ -108,12 +101,12 @@ export abstract class BaseCellViewModel extends Disposable implements ICellViewM
 	constructor(readonly viewType: string, readonly notebookHandle: number, readonly model: NotebookCellTextModel, public id: string) {
 		super();
 
-		this._register(model.onDidChangeLanguage((e) => {
-			this._onDidChangeLanguage.fire(e);
+		this._register(model.onDidChangeLanguage(() => {
+			this._onDidChangeState.fire({ languageChanged: true });
 		}));
 
 		this._register(model.onDidChangeMetadata(() => {
-			this._onDidChangeMetadata.fire();
+			this._onDidChangeState.fire({ metadataChanged: true });
 		}));
 	}
 
@@ -136,8 +129,8 @@ export abstract class BaseCellViewModel extends Disposable implements ICellViewM
 
 		if (this._textEditor === editor) {
 			if (this._cursorChangeListener === null) {
-				this._cursorChangeListener = this._textEditor.onDidChangeCursorSelection(() => this._onDidChangeCursorSelection.fire());
-				this._onDidChangeCursorSelection.fire();
+				this._cursorChangeListener = this._textEditor.onDidChangeCursorSelection(() => { this._onDidChangeState.fire({ selectionChanged: true }); });
+				this._onDidChangeState.fire({ selectionChanged: true });
 			}
 			return;
 		}
@@ -160,9 +153,9 @@ export abstract class BaseCellViewModel extends Disposable implements ICellViewM
 			}
 		});
 
-		this._cursorChangeListener = this._textEditor.onDidChangeCursorSelection(() => this._onDidChangeCursorSelection.fire());
-		this._onDidChangeCursorSelection.fire();
-		this._onDidChangeEditorAttachState.fire(true);
+		this._cursorChangeListener = this._textEditor.onDidChangeCursorSelection(() => { this._onDidChangeState.fire({ selectionChanged: true }); });
+		this._onDidChangeState.fire({ selectionChanged: true });
+		this._onDidChangeEditorAttachState.fire();
 	}
 
 	detachTextEditor() {
@@ -179,7 +172,7 @@ export abstract class BaseCellViewModel extends Disposable implements ICellViewM
 		this._textEditor = undefined;
 		this._cursorChangeListener?.dispose();
 		this._cursorChangeListener = null;
-		this._onDidChangeEditorAttachState.fire(false);
+		this._onDidChangeEditorAttachState.fire();
 	}
 
 	getText(): string {

src/vs/workbench/contrib/notebook/browser/viewModel/codeCellViewModel.ts

@@ -73,10 +73,6 @@ export class CodeCellViewModel extends BaseCellViewModel implements ICellViewMod
 			this._onDidChangeOutputs.fire(splices);
 		}));
 
-		this._register(this.model.onDidChangeMetadata(() => {
-			this._onDidChangeMetadata.fire();
-		}));
-
 		this._outputCollection = new Array(this.model.outputs.length);
 		this._buffer = null;
 
@@ -97,7 +93,11 @@ export class CodeCellViewModel extends BaseCellViewModel implements ICellViewMod
 			}
 		}));
 
-		this._register(this.onDidChangeLanguage((e) => {
+		this._register(this.onDidChangeState((e) => {
+			if (!e.languageChanged) {
+				return;
+			}
+
 			if (this._textModel && !this._textModel.isDisposed()) {
 
 			}