Merge pull request #107126 from Timmmm/atomic_tabs

Add atomic tabs option

src/vs/editor/browser/controller/mouseTarget.ts

@@ -18,6 +18,7 @@ import { ViewContext } from 'vs/editor/common/view/viewContext';
 import { IViewModel } from 'vs/editor/common/viewModel/viewModel';
 import { CursorColumns } from 'vs/editor/common/controller/cursorCommon';
 import * as dom from 'vs/base/browser/dom';
+import { AtomicTabMoveOperations, Direction } from 'vs/editor/common/controller/cursorAtomicMoveOperations';
 
 export interface IViewZoneData {
 	viewZoneId: string;
@@ -239,6 +240,7 @@ export class HitTestContext {
 	public readonly layoutInfo: EditorLayoutInfo;
 	public readonly viewDomNode: HTMLElement;
 	public readonly lineHeight: number;
+	public readonly atomicSoftTabs: boolean;
 	public readonly typicalHalfwidthCharacterWidth: number;
 	public readonly lastRenderData: PointerHandlerLastRenderData;
 
@@ -251,6 +253,7 @@ export class HitTestContext {
 		this.layoutInfo = options.get(EditorOption.layoutInfo);
 		this.viewDomNode = viewHelper.viewDomNode;
 		this.lineHeight = options.get(EditorOption.lineHeight);
+		this.atomicSoftTabs = options.get(EditorOption.atomicSoftTabs);
 		this.typicalHalfwidthCharacterWidth = options.get(EditorOption.fontInfo).typicalHalfwidthCharacterWidth;
 		this.lastRenderData = lastRenderData;
 		this._context = context;
@@ -1010,6 +1013,17 @@ export class MouseTargetFactory {
 		};
 	}
 
+	private static _snapToSoftTabBoundary(position: Position, viewModel: IViewModel): Position {
+		const minColumn = viewModel.getLineMinColumn(position.lineNumber);
+		const lineContent = viewModel.getLineContent(position.lineNumber);
+		const { tabSize } = viewModel.getTextModelOptions();
+		const newPosition = AtomicTabMoveOperations.atomicPosition(lineContent, position.column - minColumn, tabSize, Direction.Nearest);
+		if (newPosition !== -1) {
+			return new Position(position.lineNumber, newPosition + minColumn);
+		}
+		return position;
+	}
+
 	private static _doHitTest(ctx: HitTestContext, request: BareHitTestRequest): IHitTestResult {
 		// State of the art (18.10.2012):
 		// The spec says browsers should support document.caretPositionFromPoint, but nobody implemented it (http://dev.w3.org/csswg/cssom-view/)
@@ -1028,24 +1042,24 @@ export class MouseTargetFactory {
 
 		// Thank you browsers for making this so 'easy' :)
 
+		let result: IHitTestResult;
 		if (typeof document.caretRangeFromPoint === 'function') {
-
-			return this._doHitTestWithCaretRangeFromPoint(ctx, request);
-
+			result = this._doHitTestWithCaretRangeFromPoint(ctx, request);
 		} else if ((<any>document).caretPositionFromPoint) {
-
-			return this._doHitTestWithCaretPositionFromPoint(ctx, request.pos.toClientCoordinates());
-
+			result = this._doHitTestWithCaretPositionFromPoint(ctx, request.pos.toClientCoordinates());
 		} else if ((<any>document.body).createTextRange) {
-
-			return this._doHitTestWithMoveToPoint(ctx, request.pos.toClientCoordinates());
-
+			result = this._doHitTestWithMoveToPoint(ctx, request.pos.toClientCoordinates());
+		} else {
+			result = {
+				position: null,
+				hitTarget: null
+			};
 		}
-
-		return {
-			position: null,
-			hitTarget: null
-		};
+		// Snap to the nearest soft tab boundary if atomic soft tabs are enabled.
+		if (result.position && ctx.atomicSoftTabs) {
+			result.position = this._snapToSoftTabBoundary(result.position, ctx.model);
+		}
+		return result;
 	}
 }
 

src/vs/editor/common/config/editorOptions.ts

@@ -420,6 +420,11 @@ export interface IEditorOptions {
 	 * Defaults to advanced.
 	 */
 	autoIndent?: 'none' | 'keep' | 'brackets' | 'advanced' | 'full';
+	/**
+	 * Emulate selection behaviour of hard tabs when using soft tabs (spaces) for indentation.
+	 * This means selection will snap to indentation boundaries.
+	 */
+	atomicSoftTabs?: boolean;
 	/**
 	 * Enable format on type.
 	 * Defaults to false.
@@ -3631,6 +3636,7 @@ export const enum EditorOption {
 	autoIndent,
 	automaticLayout,
 	autoSurround,
+	atomicSoftTabs,
 	codeLens,
 	codeLensFontFamily,
 	codeLensFontSize,
@@ -3859,6 +3865,10 @@ export const EditorOptions = {
 			description: nls.localize('autoSurround', "Controls whether the editor should automatically surround selections when typing quotes or brackets.")
 		}
 	)),
+	atomicSoftTabs: register(new EditorBooleanOption(
+		EditorOption.atomicSoftTabs, 'atomicSoftTabs', false,
+		{ description: nls.localize('atomicSoftTabs', "Emulate selection behaviour of hard tabs when using soft tabs (spaces) for indentation. This means selection will snap to indentation boundaries.") }
+	)),
 	codeLens: register(new EditorBooleanOption(
 		EditorOption.codeLens, 'codeLens', true,
 		{ description: nls.localize('codeLens', "Controls whether the editor shows CodeLens.") }

src/vs/editor/common/controller/cursorAtomicMoveOperations.ts

+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { CharCode } from 'vs/base/common/charCode';
+import { CursorColumns } from 'vs/editor/common/controller/cursorCommon';
+
+export const enum Direction {
+	Left,
+	Right,
+	Nearest,
+}
+
+export class AtomicTabMoveOperations {
+	/**
+	 * Get the visible column at the position. If we get to a non-whitespace character first
+	 * or past the end of string then return -1.
+	 *
+	 * **Note** `position` and the return value are 0-based.
+	 */
+	public static whitespaceVisibleColumn(lineContent: string, position: number, tabSize: number): [number, number, number] {
+		const lineLength = lineContent.length;
+		let visibleColumn = 0;
+		let prevTabStopPosition = -1;
+		let prevTabStopVisibleColumn = -1;
+		for (let i = 0; i < lineLength; i++) {
+			if (i === position) {
+				return [prevTabStopPosition, prevTabStopVisibleColumn, visibleColumn];
+			}
+			if (visibleColumn % tabSize === 0) {
+				prevTabStopPosition = i;
+				prevTabStopVisibleColumn = visibleColumn;
+			}
+			const chCode = lineContent.charCodeAt(i);
+			switch (chCode) {
+				case CharCode.Space:
+					visibleColumn += 1;
+					break;
+				case CharCode.Tab:
+					// Skip to the next multiple of tabSize.
+					visibleColumn = CursorColumns.nextRenderTabStop(visibleColumn, tabSize);
+					break;
+				default:
+					return [-1, -1, -1];
+			}
+		}
+		if (position === lineLength) {
+			return [prevTabStopPosition, prevTabStopVisibleColumn, visibleColumn];
+		}
+		return [-1, -1, -1];
+	}
+
+	/**
+	 * Return the position that should result from a move left, right or to the
+	 * nearest tab, if atomic tabs are enabled. Left and right are used for the
+	 * arrow key movements, nearest is used for mouse selection. It returns
+	 * -1 if atomic tabs are not relevant and you should fall back to normal
+	 * behaviour.
+	 *
+	 * **Note**: `position` and the return value are 0-based.
+	 */
+	public static atomicPosition(lineContent: string, position: number, tabSize: number, direction: Direction): number {
+		const lineLength = lineContent.length;
+
+		// Get the 0-based visible column corresponding to the position, or return
+		// -1 if it is not in the initial whitespace.
+		const [prevTabStopPosition, prevTabStopVisibleColumn, visibleColumn] = AtomicTabMoveOperations.whitespaceVisibleColumn(lineContent, position, tabSize);
+
+		if (visibleColumn === -1) {
+			return -1;
+		}
+
+		// Is the output left or right of the current position. The case for nearest
+		// where it is the same as the current position is handled in the switch.
+		let left: boolean;
+		switch (direction) {
+			case Direction.Left:
+				left = true;
+				break;
+			case Direction.Right:
+				left = false;
+				break;
+			case Direction.Nearest:
+				// The code below assumes the output position is either left or right
+				// of the input position. If it is the same, return immediately.
+				if (visibleColumn % tabSize === 0) {
+					return position;
+				}
+				// Go to the nearest indentation.
+				left = visibleColumn % tabSize <= (tabSize / 2);
+				break;
+		}
+
+		// If going left, we can just use the info about the last tab stop position and
+		// last tab stop visible column that we computed in the first walk over the whitespace.
+		if (left) {
+			if (prevTabStopPosition === -1) {
+				return -1;
+			}
+			// If the direction is left, we need to keep scanning right to ensure
+			// that targetVisibleColumn + tabSize is before non-whitespace.
+			// This is so that when we press left at the end of a partial
+			// indentation it only goes one character. For example '      foo' with
+			// tabSize 4, should jump from position 6 to position 5, not 4.
+			let currentVisibleColumn = prevTabStopVisibleColumn;
+			for (let i = prevTabStopPosition; i < lineLength; ++i) {
+				if (currentVisibleColumn === prevTabStopVisibleColumn + tabSize) {
+					// It is a full indentation.
+					return prevTabStopPosition;
+				}
+
+				const chCode = lineContent.charCodeAt(i);
+				switch (chCode) {
+					case CharCode.Space:
+						currentVisibleColumn += 1;
+						break;
+					case CharCode.Tab:
+						currentVisibleColumn = CursorColumns.nextRenderTabStop(currentVisibleColumn, tabSize);
+						break;
+					default:
+						return -1;
+				}
+			}
+			if (currentVisibleColumn === prevTabStopVisibleColumn + tabSize) {
+				return prevTabStopPosition;
+			}
+			// It must have been a partial indentation.
+			return -1;
+		}
+
+		// We are going right.
+		const targetVisibleColumn = CursorColumns.nextRenderTabStop(visibleColumn, tabSize);
+
+		// We can just continue from where whitespaceVisibleColumn got to.
+		let currentVisibleColumn = visibleColumn;
+		for (let i = position; i < lineLength; i++) {
+			if (currentVisibleColumn === targetVisibleColumn) {
+				return i;
+			}
+
+			const chCode = lineContent.charCodeAt(i);
+			switch (chCode) {
+				case CharCode.Space:
+					currentVisibleColumn += 1;
+					break;
+				case CharCode.Tab:
+					currentVisibleColumn = CursorColumns.nextRenderTabStop(currentVisibleColumn, tabSize);
+					break;
+				default:
+					return -1;
+			}
+		}
+		// This condition handles when the target column is at the end of the line.
+		if (currentVisibleColumn === targetVisibleColumn) {
+			return lineLength;
+		}
+		return -1;
+	}
+}

src/vs/editor/common/controller/cursorCommon.ts

@@ -62,6 +62,7 @@ export class CursorConfiguration {
 	public readonly tabSize: number;
 	public readonly indentSize: number;
 	public readonly insertSpaces: boolean;
+	public readonly atomicSoftTabs: boolean;
 	public readonly pageSize: number;
 	public readonly lineHeight: number;
 	public readonly useTabStops: boolean;
@@ -113,6 +114,7 @@ export class CursorConfiguration {
 		this.tabSize = modelOptions.tabSize;
 		this.indentSize = modelOptions.indentSize;
 		this.insertSpaces = modelOptions.insertSpaces;
+		this.atomicSoftTabs = options.get(EditorOption.atomicSoftTabs);
 		this.lineHeight = options.get(EditorOption.lineHeight);
 		this.pageSize = Math.max(1, Math.floor(layoutInfo.height / this.lineHeight) - 2);
 		this.useTabStops = options.get(EditorOption.useTabStops);
@@ -554,14 +556,14 @@ export class CursorColumns {
 	}
 
 	/**
-	 * ATTENTION: This works with 0-based columns (as oposed to the regular 1-based columns)
+	 * ATTENTION: This works with 0-based columns (as opposed to the regular 1-based columns)
 	 */
 	public static prevRenderTabStop(column: number, tabSize: number): number {
 		return column - 1 - (column - 1) % tabSize;
 	}
 
 	/**
-	 * ATTENTION: This works with 0-based columns (as oposed to the regular 1-based columns)
+	 * ATTENTION: This works with 0-based columns (as opposed to the regular 1-based columns)
 	 */
 	public static prevIndentTabStop(column: number, indentSize: number): number {
 		return column - 1 - (column - 1) % indentSize;

src/vs/editor/common/controller/cursorMoveOperations.ts

@@ -8,6 +8,7 @@ import { Position } from 'vs/editor/common/core/position';
 import { Range } from 'vs/editor/common/core/range';
 import * as strings from 'vs/base/common/strings';
 import { Constants } from 'vs/base/common/uint';
+import { AtomicTabMoveOperations, Direction } from 'vs/editor/common/controller/cursorAtomicMoveOperations';
 
 export class CursorPosition {
 	_cursorPositionBrand: void;
@@ -35,8 +36,20 @@ export class MoveOperations {
 		return new Position(lineNumber, column);
 	}
 
+	public static leftPositionAtomicSoftTabs(model: ICursorSimpleModel, lineNumber: number, column: number, tabSize: number): Position {
+		const minColumn = model.getLineMinColumn(lineNumber);
+		const lineContent = model.getLineContent(lineNumber);
+		const newPosition = AtomicTabMoveOperations.atomicPosition(lineContent, column - minColumn, tabSize, Direction.Left);
+		if (newPosition === -1) {
+			return this.leftPosition(model, lineNumber, column);
+		}
+		return new Position(lineNumber, minColumn + newPosition);
+	}
+
 	public static left(config: CursorConfiguration, model: ICursorSimpleModel, lineNumber: number, column: number): CursorPosition {
-		const pos = MoveOperations.leftPosition(model, lineNumber, column);
+		const pos = config.atomicSoftTabs
+			? MoveOperations.leftPositionAtomicSoftTabs(model, lineNumber, column, config.tabSize)
+			: MoveOperations.leftPosition(model, lineNumber, column);
 		return new CursorPosition(pos.lineNumber, pos.column, 0);
 	}
 
@@ -67,8 +80,20 @@ export class MoveOperations {
 		return new Position(lineNumber, column);
 	}
 
+	public static rightPositionAtomicSoftTabs(model: ICursorSimpleModel, lineNumber: number, column: number, tabSize: number, indentSize: number): Position {
+		const minColumn = model.getLineMinColumn(lineNumber);
+		const lineContent = model.getLineContent(lineNumber);
+		const newPosition = AtomicTabMoveOperations.atomicPosition(lineContent, column - minColumn, tabSize, Direction.Right);
+		if (newPosition === -1) {
+			return this.rightPosition(model, lineNumber, column);
+		}
+		return new Position(lineNumber, minColumn + newPosition);
+	}
+
 	public static right(config: CursorConfiguration, model: ICursorSimpleModel, lineNumber: number, column: number): CursorPosition {
-		const pos = MoveOperations.rightPosition(model, lineNumber, column);
+		const pos = config.atomicSoftTabs
+			? MoveOperations.rightPositionAtomicSoftTabs(model, lineNumber, column, config.tabSize, config.indentSize)
+			: MoveOperations.rightPosition(model, lineNumber, column);
 		return new CursorPosition(pos.lineNumber, pos.column, 0);
 	}
 

src/vs/editor/common/standalone/standaloneEnums.ts

@@ -178,117 +178,118 @@ export enum EditorOption {
 	autoIndent = 8,
 	automaticLayout = 9,
 	autoSurround = 10,
-	codeLens = 11,
-	codeLensFontFamily = 12,
-	codeLensFontSize = 13,
-	colorDecorators = 14,
-	columnSelection = 15,
-	comments = 16,
-	contextmenu = 17,
-	copyWithSyntaxHighlighting = 18,
-	cursorBlinking = 19,
-	cursorSmoothCaretAnimation = 20,
-	cursorStyle = 21,
-	cursorSurroundingLines = 22,
-	cursorSurroundingLinesStyle = 23,
-	cursorWidth = 24,
-	disableLayerHinting = 25,
-	disableMonospaceOptimizations = 26,
-	dragAndDrop = 27,
-	emptySelectionClipboard = 28,
-	extraEditorClassName = 29,
-	fastScrollSensitivity = 30,
-	find = 31,
-	fixedOverflowWidgets = 32,
-	folding = 33,
-	foldingStrategy = 34,
-	foldingHighlight = 35,
-	unfoldOnClickAfterEndOfLine = 36,
-	fontFamily = 37,
-	fontInfo = 38,
-	fontLigatures = 39,
-	fontSize = 40,
-	fontWeight = 41,
-	formatOnPaste = 42,
-	formatOnType = 43,
-	glyphMargin = 44,
-	gotoLocation = 45,
-	hideCursorInOverviewRuler = 46,
-	highlightActiveIndentGuide = 47,
-	hover = 48,
-	inDiffEditor = 49,
-	letterSpacing = 50,
-	lightbulb = 51,
-	lineDecorationsWidth = 52,
-	lineHeight = 53,
-	lineNumbers = 54,
-	lineNumbersMinChars = 55,
-	links = 56,
-	matchBrackets = 57,
-	minimap = 58,
-	mouseStyle = 59,
-	mouseWheelScrollSensitivity = 60,
-	mouseWheelZoom = 61,
-	multiCursorMergeOverlapping = 62,
-	multiCursorModifier = 63,
-	multiCursorPaste = 64,
-	occurrencesHighlight = 65,
-	overviewRulerBorder = 66,
-	overviewRulerLanes = 67,
-	padding = 68,
-	parameterHints = 69,
-	peekWidgetDefaultFocus = 70,
-	definitionLinkOpensInPeek = 71,
-	quickSuggestions = 72,
-	quickSuggestionsDelay = 73,
-	readOnly = 74,
-	renameOnType = 75,
-	renderControlCharacters = 76,
-	renderIndentGuides = 77,
-	renderFinalNewline = 78,
-	renderLineHighlight = 79,
-	renderLineHighlightOnlyWhenFocus = 80,
-	renderValidationDecorations = 81,
-	renderWhitespace = 82,
-	revealHorizontalRightPadding = 83,
-	roundedSelection = 84,
-	rulers = 85,
-	scrollbar = 86,
-	scrollBeyondLastColumn = 87,
-	scrollBeyondLastLine = 88,
-	scrollPredominantAxis = 89,
-	selectionClipboard = 90,
-	selectionHighlight = 91,
-	selectOnLineNumbers = 92,
-	showFoldingControls = 93,
-	showUnused = 94,
-	snippetSuggestions = 95,
-	smartSelect = 96,
-	smoothScrolling = 97,
-	stopRenderingLineAfter = 98,
-	suggest = 99,
-	suggestFontSize = 100,
-	suggestLineHeight = 101,
-	suggestOnTriggerCharacters = 102,
-	suggestSelection = 103,
-	tabCompletion = 104,
-	tabIndex = 105,
-	unusualLineTerminators = 106,
-	useTabStops = 107,
-	wordSeparators = 108,
-	wordWrap = 109,
-	wordWrapBreakAfterCharacters = 110,
-	wordWrapBreakBeforeCharacters = 111,
-	wordWrapColumn = 112,
-	wordWrapMinified = 113,
-	wrappingIndent = 114,
-	wrappingStrategy = 115,
-	showDeprecated = 116,
-	editorClassName = 117,
-	pixelRatio = 118,
-	tabFocusMode = 119,
-	layoutInfo = 120,
-	wrappingInfo = 121
+	atomicSoftTabs = 11,
+	codeLens = 12,
+	codeLensFontFamily = 13,
+	codeLensFontSize = 14,
+	colorDecorators = 15,
+	columnSelection = 16,
+	comments = 17,
+	contextmenu = 18,
+	copyWithSyntaxHighlighting = 19,
+	cursorBlinking = 20,
+	cursorSmoothCaretAnimation = 21,
+	cursorStyle = 22,
+	cursorSurroundingLines = 23,
+	cursorSurroundingLinesStyle = 24,
+	cursorWidth = 25,
+	disableLayerHinting = 26,
+	disableMonospaceOptimizations = 27,
+	dragAndDrop = 28,
+	emptySelectionClipboard = 29,
+	extraEditorClassName = 30,
+	fastScrollSensitivity = 31,
+	find = 32,
+	fixedOverflowWidgets = 33,
+	folding = 34,
+	foldingStrategy = 35,
+	foldingHighlight = 36,
+	unfoldOnClickAfterEndOfLine = 37,
+	fontFamily = 38,
+	fontInfo = 39,
+	fontLigatures = 40,
+	fontSize = 41,
+	fontWeight = 42,
+	formatOnPaste = 43,
+	formatOnType = 44,
+	glyphMargin = 45,
+	gotoLocation = 46,
+	hideCursorInOverviewRuler = 47,
+	highlightActiveIndentGuide = 48,
+	hover = 49,
+	inDiffEditor = 50,
+	letterSpacing = 51,
+	lightbulb = 52,
+	lineDecorationsWidth = 53,
+	lineHeight = 54,
+	lineNumbers = 55,
+	lineNumbersMinChars = 56,
+	links = 57,
+	matchBrackets = 58,
+	minimap = 59,
+	mouseStyle = 60,
+	mouseWheelScrollSensitivity = 61,
+	mouseWheelZoom = 62,
+	multiCursorMergeOverlapping = 63,
+	multiCursorModifier = 64,
+	multiCursorPaste = 65,
+	occurrencesHighlight = 66,
+	overviewRulerBorder = 67,
+	overviewRulerLanes = 68,
+	padding = 69,
+	parameterHints = 70,
+	peekWidgetDefaultFocus = 71,
+	definitionLinkOpensInPeek = 72,
+	quickSuggestions = 73,
+	quickSuggestionsDelay = 74,
+	readOnly = 75,
+	renameOnType = 76,
+	renderControlCharacters = 77,
+	renderIndentGuides = 78,
+	renderFinalNewline = 79,
+	renderLineHighlight = 80,
+	renderLineHighlightOnlyWhenFocus = 81,
+	renderValidationDecorations = 82,
+	renderWhitespace = 83,
+	revealHorizontalRightPadding = 84,
+	roundedSelection = 85,
+	rulers = 86,
+	scrollbar = 87,
+	scrollBeyondLastColumn = 88,
+	scrollBeyondLastLine = 89,
+	scrollPredominantAxis = 90,
+	selectionClipboard = 91,
+	selectionHighlight = 92,
+	selectOnLineNumbers = 93,
+	showFoldingControls = 94,
+	showUnused = 95,
+	snippetSuggestions = 96,
+	smartSelect = 97,
+	smoothScrolling = 98,
+	stopRenderingLineAfter = 99,
+	suggest = 100,
+	suggestFontSize = 101,
+	suggestLineHeight = 102,
+	suggestOnTriggerCharacters = 103,
+	suggestSelection = 104,
+	tabCompletion = 105,
+	tabIndex = 106,
+	unusualLineTerminators = 107,
+	useTabStops = 108,
+	wordSeparators = 109,
+	wordWrap = 110,
+	wordWrapBreakAfterCharacters = 111,
+	wordWrapBreakBeforeCharacters = 112,
+	wordWrapColumn = 113,
+	wordWrapMinified = 114,
+	wrappingIndent = 115,
+	wrappingStrategy = 116,
+	showDeprecated = 117,
+	editorClassName = 118,
+	pixelRatio = 119,
+	tabFocusMode = 120,
+	layoutInfo = 121,
+	wrappingInfo = 122
 }
 
 /**

src/vs/editor/test/common/controller/cursorAtomicMoveOperations.test.ts

+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as assert from 'assert';
+import { AtomicTabMoveOperations, Direction } from 'vs/editor/common/controller/cursorAtomicMoveOperations';
+
+suite('Cursor move command test', () => {
+
+	test('Test whitespaceVisibleColumn', () => {
+		const testCases = [
+			{
+				lineContent: '        ',
+				tabSize: 4,
+				expectedPrevTabStopPosition: [-1, 0, 0, 0, 0, 4, 4, 4, 4, -1],
+				expectedPrevTabStopVisibleColumn: [-1, 0, 0, 0, 0, 4, 4, 4, 4, -1],
+				expectedVisibleColumn: [0, 1, 2, 3, 4, 5, 6, 7, 8, -1],
+			},
+			{
+				lineContent: '  ',
+				tabSize: 4,
+				expectedPrevTabStopPosition: [-1, 0, 0, -1],
+				expectedPrevTabStopVisibleColumn: [-1, 0, 0, -1],
+				expectedVisibleColumn: [0, 1, 2, -1],
+			},
+			{
+				lineContent: '\t',
+				tabSize: 4,
+				expectedPrevTabStopPosition: [-1, 0, -1],
+				expectedPrevTabStopVisibleColumn: [-1, 0, -1],
+				expectedVisibleColumn: [0, 4, -1],
+			},
+			{
+				lineContent: '\t ',
+				tabSize: 4,
+				expectedPrevTabStopPosition: [-1, 0, 1, -1],
+				expectedPrevTabStopVisibleColumn: [-1, 0, 4, -1],
+				expectedVisibleColumn: [0, 4, 5, -1],
+			},
+			{
+				lineContent: ' \t\t ',
+				tabSize: 4,
+				expectedPrevTabStopPosition: [-1, 0, 0, 2, 3, -1],
+				expectedPrevTabStopVisibleColumn: [-1, 0, 0, 4, 8, -1],
+				expectedVisibleColumn: [0, 1, 4, 8, 9, -1],
+			},
+			{
+				lineContent: ' \tA',
+				tabSize: 4,
+				expectedPrevTabStopPosition: [-1, 0, 0, -1, -1],
+				expectedPrevTabStopVisibleColumn: [-1, 0, 0, -1, -1],
+				expectedVisibleColumn: [0, 1, 4, -1, -1],
+			},
+			{
+				lineContent: 'A',
+				tabSize: 4,
+				expectedPrevTabStopPosition: [-1, -1, -1],
+				expectedPrevTabStopVisibleColumn: [-1, -1, -1],
+				expectedVisibleColumn: [0, -1, -1],
+			},
+			{
+				lineContent: '',
+				tabSize: 4,
+				expectedPrevTabStopPosition: [-1, -1],
+				expectedPrevTabStopVisibleColumn: [-1, -1],
+				expectedVisibleColumn: [0, -1],
+			},
+		];
+
+		for (const testCase of testCases) {
+			const maxPosition = testCase.expectedVisibleColumn.length;
+			for (let position = 0; position < maxPosition; position++) {
+				const actual = AtomicTabMoveOperations.whitespaceVisibleColumn(testCase.lineContent, position, testCase.tabSize);
+				const expected = [
+					testCase.expectedPrevTabStopPosition[position],
+					testCase.expectedPrevTabStopVisibleColumn[position],
+					testCase.expectedVisibleColumn[position]
+				];
+				assert.deepStrictEqual(actual, expected);
+			}
+		}
+	});
+
+	test('Test atomicPosition', () => {
+		const testCases = [
+			{
+				lineContent: '        ',
+				tabSize: 4,
+				expectedLeft: [-1, 0, 0, 0, 0, 4, 4, 4, 4, -1],
+				expectedRight: [4, 4, 4, 4, 8, 8, 8, 8, -1, -1],
+				expectedNearest: [0, 0, 0, 4, 4, 4, 4, 8, 8, -1],
+			},
+			{
+				lineContent: ' \t',
+				tabSize: 4,
+				expectedLeft: [-1, 0, 0, -1],
+				expectedRight: [2, 2, -1, -1],
+				expectedNearest: [0, 0, 2, -1],
+			},
+			{
+				lineContent: '\t ',
+				tabSize: 4,
+				expectedLeft: [-1, 0, -1, -1],
+				expectedRight: [1, -1, -1, -1],
+				expectedNearest: [0, 1, -1, -1],
+			},
+			{
+				lineContent: ' \t ',
+				tabSize: 4,
+				expectedLeft: [-1, 0, 0, -1, -1],
+				expectedRight: [2, 2, -1, -1, -1],
+				expectedNearest: [0, 0, 2, -1, -1],
+			},
+			{
+				lineContent: '        A',
+				tabSize: 4,
+				expectedLeft: [-1, 0, 0, 0, 0, 4, 4, 4, 4, -1, -1],
+				expectedRight: [4, 4, 4, 4, 8, 8, 8, 8, -1, -1, -1],
+				expectedNearest: [0, 0, 0, 4, 4, 4, 4, 8, 8, -1, -1],
+			},
+			{
+				lineContent: '      foo',
+				tabSize: 4,
+				expectedLeft: [-1, 0, 0, 0, 0, -1, -1, -1, -1, -1, -1],
+				expectedRight: [4, 4, 4, 4, -1, -1, -1, -1, -1, -1, -1],
+				expectedNearest: [0, 0, 0, 4, 4, -1, -1, -1, -1, -1, -1],
+			},
+		];
+
+		for (const testCase of testCases) {
+			for (const { direction, expected } of [
+				{
+					direction: Direction.Left,
+					expected: testCase.expectedLeft,
+				},
+				{
+					direction: Direction.Right,
+					expected: testCase.expectedRight,
+				},
+				{
+					direction: Direction.Nearest,
+					expected: testCase.expectedNearest,
+				},
+			]) {
+
+				const actual = expected.map((_, i) => AtomicTabMoveOperations.atomicPosition(testCase.lineContent, i, testCase.tabSize, direction));
+				assert.deepStrictEqual(actual, expected);
+			}
+		}
+	});
+});

src/vs/monaco.d.ts

@@ -2967,6 +2967,11 @@ declare namespace monaco.editor {
 		 * Defaults to advanced.
 		 */
 		autoIndent?: 'none' | 'keep' | 'brackets' | 'advanced' | 'full';
+		/**
+		 * Emulate selection behaviour of hard tabs when using soft tabs (spaces) for indentation.
+		 * This means selection will snap to indentation boundaries.
+		 */
+		atomicSoftTabs?: boolean;
 		/**
 		 * Enable format on type.
 		 * Defaults to false.
@@ -3898,117 +3903,118 @@ declare namespace monaco.editor {
 		autoIndent = 8,
 		automaticLayout = 9,
 		autoSurround = 10,
-		codeLens = 11,
-		codeLensFontFamily = 12,
-		codeLensFontSize = 13,
-		colorDecorators = 14,
-		columnSelection = 15,
-		comments = 16,
-		contextmenu = 17,
-		copyWithSyntaxHighlighting = 18,
-		cursorBlinking = 19,
-		cursorSmoothCaretAnimation = 20,
-		cursorStyle = 21,
-		cursorSurroundingLines = 22,
-		cursorSurroundingLinesStyle = 23,
-		cursorWidth = 24,
-		disableLayerHinting = 25,
-		disableMonospaceOptimizations = 26,
-		dragAndDrop = 27,
-		emptySelectionClipboard = 28,
-		extraEditorClassName = 29,
-		fastScrollSensitivity = 30,
-		find = 31,
-		fixedOverflowWidgets = 32,
-		folding = 33,
-		foldingStrategy = 34,
-		foldingHighlight = 35,
-		unfoldOnClickAfterEndOfLine = 36,
-		fontFamily = 37,
-		fontInfo = 38,
-		fontLigatures = 39,
-		fontSize = 40,
-		fontWeight = 41,
-		formatOnPaste = 42,
-		formatOnType = 43,
-		glyphMargin = 44,
-		gotoLocation = 45,
-		hideCursorInOverviewRuler = 46,
-		highlightActiveIndentGuide = 47,
-		hover = 48,
-		inDiffEditor = 49,
-		letterSpacing = 50,
-		lightbulb = 51,
-		lineDecorationsWidth = 52,
-		lineHeight = 53,
-		lineNumbers = 54,
-		lineNumbersMinChars = 55,
-		links = 56,
-		matchBrackets = 57,
-		minimap = 58,
-		mouseStyle = 59,
-		mouseWheelScrollSensitivity = 60,
-		mouseWheelZoom = 61,
-		multiCursorMergeOverlapping = 62,
-		multiCursorModifier = 63,
-		multiCursorPaste = 64,
-		occurrencesHighlight = 65,
-		overviewRulerBorder = 66,
-		overviewRulerLanes = 67,
-		padding = 68,
-		parameterHints = 69,
-		peekWidgetDefaultFocus = 70,
-		definitionLinkOpensInPeek = 71,
-		quickSuggestions = 72,
-		quickSuggestionsDelay = 73,
-		readOnly = 74,
-		renameOnType = 75,
-		renderControlCharacters = 76,
-		renderIndentGuides = 77,
-		renderFinalNewline = 78,
-		renderLineHighlight = 79,
-		renderLineHighlightOnlyWhenFocus = 80,
-		renderValidationDecorations = 81,
-		renderWhitespace = 82,
-		revealHorizontalRightPadding = 83,
-		roundedSelection = 84,
-		rulers = 85,
-		scrollbar = 86,
-		scrollBeyondLastColumn = 87,
-		scrollBeyondLastLine = 88,
-		scrollPredominantAxis = 89,
-		selectionClipboard = 90,
-		selectionHighlight = 91,
-		selectOnLineNumbers = 92,
-		showFoldingControls = 93,
-		showUnused = 94,
-		snippetSuggestions = 95,
-		smartSelect = 96,
-		smoothScrolling = 97,
-		stopRenderingLineAfter = 98,
-		suggest = 99,
-		suggestFontSize = 100,
-		suggestLineHeight = 101,
-		suggestOnTriggerCharacters = 102,
-		suggestSelection = 103,
-		tabCompletion = 104,
-		tabIndex = 105,
-		unusualLineTerminators = 106,
-		useTabStops = 107,
-		wordSeparators = 108,
-		wordWrap = 109,
-		wordWrapBreakAfterCharacters = 110,
-		wordWrapBreakBeforeCharacters = 111,
-		wordWrapColumn = 112,
-		wordWrapMinified = 113,
-		wrappingIndent = 114,
-		wrappingStrategy = 115,
-		showDeprecated = 116,
-		editorClassName = 117,
-		pixelRatio = 118,
-		tabFocusMode = 119,
-		layoutInfo = 120,
-		wrappingInfo = 121
+		atomicSoftTabs = 11,
+		codeLens = 12,
+		codeLensFontFamily = 13,
+		codeLensFontSize = 14,
+		colorDecorators = 15,
+		columnSelection = 16,
+		comments = 17,
+		contextmenu = 18,
+		copyWithSyntaxHighlighting = 19,
+		cursorBlinking = 20,
+		cursorSmoothCaretAnimation = 21,
+		cursorStyle = 22,
+		cursorSurroundingLines = 23,
+		cursorSurroundingLinesStyle = 24,
+		cursorWidth = 25,
+		disableLayerHinting = 26,
+		disableMonospaceOptimizations = 27,
+		dragAndDrop = 28,
+		emptySelectionClipboard = 29,
+		extraEditorClassName = 30,
+		fastScrollSensitivity = 31,
+		find = 32,
+		fixedOverflowWidgets = 33,
+		folding = 34,
+		foldingStrategy = 35,
+		foldingHighlight = 36,
+		unfoldOnClickAfterEndOfLine = 37,
+		fontFamily = 38,
+		fontInfo = 39,
+		fontLigatures = 40,
+		fontSize = 41,
+		fontWeight = 42,
+		formatOnPaste = 43,
+		formatOnType = 44,
+		glyphMargin = 45,
+		gotoLocation = 46,
+		hideCursorInOverviewRuler = 47,
+		highlightActiveIndentGuide = 48,
+		hover = 49,
+		inDiffEditor = 50,
+		letterSpacing = 51,
+		lightbulb = 52,
+		lineDecorationsWidth = 53,
+		lineHeight = 54,
+		lineNumbers = 55,
+		lineNumbersMinChars = 56,
+		links = 57,
+		matchBrackets = 58,
+		minimap = 59,
+		mouseStyle = 60,
+		mouseWheelScrollSensitivity = 61,
+		mouseWheelZoom = 62,
+		multiCursorMergeOverlapping = 63,
+		multiCursorModifier = 64,
+		multiCursorPaste = 65,
+		occurrencesHighlight = 66,
+		overviewRulerBorder = 67,
+		overviewRulerLanes = 68,
+		padding = 69,
+		parameterHints = 70,
+		peekWidgetDefaultFocus = 71,
+		definitionLinkOpensInPeek = 72,
+		quickSuggestions = 73,
+		quickSuggestionsDelay = 74,
+		readOnly = 75,
+		renameOnType = 76,
+		renderControlCharacters = 77,
+		renderIndentGuides = 78,
+		renderFinalNewline = 79,
+		renderLineHighlight = 80,
+		renderLineHighlightOnlyWhenFocus = 81,
+		renderValidationDecorations = 82,
+		renderWhitespace = 83,
+		revealHorizontalRightPadding = 84,
+		roundedSelection = 85,
+		rulers = 86,
+		scrollbar = 87,
+		scrollBeyondLastColumn = 88,
+		scrollBeyondLastLine = 89,
+		scrollPredominantAxis = 90,
+		selectionClipboard = 91,
+		selectionHighlight = 92,
+		selectOnLineNumbers = 93,
+		showFoldingControls = 94,
+		showUnused = 95,
+		snippetSuggestions = 96,
+		smartSelect = 97,
+		smoothScrolling = 98,
+		stopRenderingLineAfter = 99,
+		suggest = 100,
+		suggestFontSize = 101,
+		suggestLineHeight = 102,
+		suggestOnTriggerCharacters = 103,
+		suggestSelection = 104,
+		tabCompletion = 105,
+		tabIndex = 106,
+		unusualLineTerminators = 107,
+		useTabStops = 108,
+		wordSeparators = 109,
+		wordWrap = 110,
+		wordWrapBreakAfterCharacters = 111,
+		wordWrapBreakBeforeCharacters = 112,
+		wordWrapColumn = 113,
+		wordWrapMinified = 114,
+		wrappingIndent = 115,
+		wrappingStrategy = 116,
+		showDeprecated = 117,
+		editorClassName = 118,
+		pixelRatio = 119,
+		tabFocusMode = 120,
+		layoutInfo = 121,
+		wrappingInfo = 122
 	}
 	export const EditorOptions: {
 		acceptSuggestionOnCommitCharacter: IEditorOption<EditorOption.acceptSuggestionOnCommitCharacter, boolean>;
@@ -4022,6 +4028,7 @@ declare namespace monaco.editor {
 		autoIndent: IEditorOption<EditorOption.autoIndent, EditorAutoIndentStrategy>;
 		automaticLayout: IEditorOption<EditorOption.automaticLayout, boolean>;
 		autoSurround: IEditorOption<EditorOption.autoSurround, EditorAutoSurroundStrategy>;
+		atomicSoftTabs: IEditorOption<EditorOption.atomicSoftTabs, boolean>;
 		codeLens: IEditorOption<EditorOption.codeLens, boolean>;
 		codeLensFontFamily: IEditorOption<EditorOption.codeLensFontFamily, string>;
 		codeLensFontSize: IEditorOption<EditorOption.codeLensFontSize, number>;