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/*---------------------------------------------------------------------------------------------
cursorAtomicMoveOperations.ts
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* Copyright (c) Microsoft Corporation. All rights reserved.
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* Licensed under the MIT License. See License.txt in the project root for license information.
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*--------------------------------------------------------------------------------------------*/
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import { CharCode } from '../../../base/common/charCode.js';
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import { CursorColumns } from '../core/cursorColumns.js';
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export const enum Direction {
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Left,
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Right,
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Nearest,
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}
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export class AtomicTabMoveOperations {
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/**
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* Get the visible column at the position. If we get to a non-whitespace character first
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* or past the end of string then return -1.
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*
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* **Note** `position` and the return value are 0-based.
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*/
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public static whitespaceVisibleColumn(lineContent: string, position: number, tabSize: number): [number, number, number] {
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const lineLength = lineContent.length;
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let visibleColumn = 0;
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let prevTabStopPosition = -1;
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let prevTabStopVisibleColumn = -1;
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for (let i = 0; i < lineLength; i++) {
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if (i === position) {
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return [prevTabStopPosition, prevTabStopVisibleColumn, visibleColumn];
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}
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if (visibleColumn % tabSize === 0) {
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prevTabStopPosition = i;
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prevTabStopVisibleColumn = visibleColumn;
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}
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const chCode = lineContent.charCodeAt(i);
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switch (chCode) {
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case CharCode.Space:
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visibleColumn += 1;
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break;
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case CharCode.Tab:
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// Skip to the next multiple of tabSize.
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visibleColumn = CursorColumns.nextRenderTabStop(visibleColumn, tabSize);
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break;
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default:
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return [-1, -1, -1];
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}
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}
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if (position === lineLength) {
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return [prevTabStopPosition, prevTabStopVisibleColumn, visibleColumn];
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}
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return [-1, -1, -1];
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}
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/**
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* Return the position that should result from a move left, right or to the
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* nearest tab, if atomic tabs are enabled. Left and right are used for the
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* arrow key movements, nearest is used for mouse selection. It returns
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* -1 if atomic tabs are not relevant and you should fall back to normal
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* behaviour.
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*
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* **Note**: `position` and the return value are 0-based.
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*/
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public static atomicPosition(lineContent: string, position: number, tabSize: number, direction: Direction): number {
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const lineLength = lineContent.length;
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