From 13c66745802d895e655f08fc7796146e36b6deaf Mon Sep 17 00:00:00 2001
From: Johannes Rieken <johannes.rieken@gmail.com>
Date: Fri, 26 Mar 2021 12:32:57 +0100
Subject: [PATCH] add `NotebookDocument#getCells(range?)`,
 https://github.com/microsoft/vscode/issues/119602

---
 src/vs/vscode.proposed.d.ts                   | 16 +++++++++-
 .../api/common/extHostNotebookDocument.ts     | 29 +++++++++++++++++--
 src/vs/workbench/api/common/extHostTypes.ts   | 16 ++++++++++
 3 files changed, 58 insertions(+), 3 deletions(-)

diff --git a/src/vs/vscode.proposed.d.ts b/src/vs/vscode.proposed.d.ts
index 407f4ad13b4..4245c92aeb0 100644
--- a/src/vs/vscode.proposed.d.ts
+++ b/src/vs/vscode.proposed.d.ts
@@ -1067,13 +1067,24 @@ declare module 'vscode' {
 
 		readonly isDirty: boolean;
 		readonly isUntitled: boolean;
-		readonly cells: ReadonlyArray<NotebookCell>;
 
 		readonly metadata: NotebookDocumentMetadata;
 
 		// todo@API should we really expose this?
 		readonly viewType: string;
 
+		/** @deprecated Use `getCells(<...>) instead */
+		readonly cells: ReadonlyArray<NotebookCell>;
+
+		/**
+		 * Get the cells of this notebook. A subset can be retrieved by providing
+		 * a range. The range will be adjuset to the notebook.
+		 *
+		 * @param range A notebook range.
+		 * @returns The cells contained by the range or all cells.
+		 */
+		getCells(range?: NotebookCellRange): ReadonlyArray<NotebookCell>;
+
 		/**
 		 * Save the document. The saving will be handled by the corresponding content provider
 		 *
@@ -1084,6 +1095,7 @@ declare module 'vscode' {
 		save(): Thenable<boolean>;
 	}
 
+	// todo@API RENAME to NotebookRange
 	// todo@API maybe have a NotebookCellPosition sibling
 	export class NotebookCellRange {
 		readonly start: number;
@@ -1095,6 +1107,8 @@ declare module 'vscode' {
 		readonly isEmpty: boolean;
 
 		constructor(start: number, end: number);
+
+		with(change: { start?: number, end?: number }): NotebookCellRange;
 	}
 
 	export enum NotebookEditorRevealType {
diff --git a/src/vs/workbench/api/common/extHostNotebookDocument.ts b/src/vs/workbench/api/common/extHostNotebookDocument.ts
index c923100305a..aaf7203dfd2 100644
--- a/src/vs/workbench/api/common/extHostNotebookDocument.ts
+++ b/src/vs/workbench/api/common/extHostNotebookDocument.ts
@@ -177,10 +177,16 @@ export class ExtHostNotebookDocument extends Disposable {
 				get viewType() { return that._viewType; },
 				get isDirty() { return that._isDirty; },
 				get isUntitled() { return that.uri.scheme === Schemas.untitled; },
-				get cells(): ReadonlyArray<vscode.NotebookCell> { return that._cells.map(cell => cell.cell); },
 				get metadata() { return that._metadata; },
 				set metadata(_value: Required<vscode.NotebookDocumentMetadata>) { throw new Error('Use WorkspaceEdit to update metadata.'); },
-				save() { return that._save(); }
+				get cells(): ReadonlyArray<vscode.NotebookCell> { return that._cells.map(cell => cell.cell); },
+				getCells(range) {
+					const cells = range ? that._getCells(range) : that._cells;
+					return cells.map(cell => cell.cell);
+				},
+				save() {
+					return that._save();
+				}
 			});
 		}
 		return this._notebook;
@@ -225,6 +231,25 @@ export class ExtHostNotebookDocument extends Disposable {
 		}
 	}
 
+	private _validateRange(range: vscode.NotebookCellRange): vscode.NotebookCellRange {
+		if (range.start < 0) {
+			range = range.with({ start: 0 });
+		}
+		if (range.end > this._cells.length) {
+			range = range.with({ end: this._cells.length });
+		}
+		return range;
+	}
+
+	private _getCells(range: vscode.NotebookCellRange): ExtHostCell[] {
+		range = this._validateRange(range);
+		const result: ExtHostCell[] = [];
+		for (let i = range.start; i < range.end; i++) {
+			result.push(this._cells[i]);
+		}
+		return result;
+	}
+
 	private async _save(): Promise<boolean> {
 		if (this._disposed) {
 			return Promise.reject(new Error('Notebook has been closed'));
diff --git a/src/vs/workbench/api/common/extHostTypes.ts b/src/vs/workbench/api/common/extHostTypes.ts
index 655b37984c4..cc7cd797140 100644
--- a/src/vs/workbench/api/common/extHostTypes.ts
+++ b/src/vs/workbench/api/common/extHostTypes.ts
@@ -2922,6 +2922,22 @@ export class NotebookCellRange {
 		this._start = start;
 		this._end = end;
 	}
+
+	with(change: { start?: number, end?: number }): NotebookCellRange {
+		let start = this._start;
+		let end = this._end;
+
+		if (change.start !== undefined) {
+			start = change.start;
+		}
+		if (change.end !== undefined) {
+			end = change.end;
+		}
+		if (start === this._start && end === this._end) {
+			return this;
+		}
+		return new NotebookCellRange(start, end);
+	}
 }
 
 export class NotebookCellMetadata {