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gemini-cli/packages/cli/src/ui/components/shared/text-buffer.ts
2026-01-16 17:33:13 +00:00

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/**
* @license
* Copyright 2025 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
import { spawnSync } from 'node:child_process';
import fs from 'node:fs';
import os from 'node:os';
import pathMod from 'node:path';
import * as path from 'node:path';
import { useState, useCallback, useEffect, useMemo, useReducer } from 'react';
import {
coreEvents,
CoreEvent,
debugLogger,
unescapePath,
type EditorType,
getEditorCommand,
isGuiEditor,
LruCache,
} from '@google/gemini-cli-core';
import {
toCodePoints,
cpLen,
cpSlice,
stripUnsafeCharacters,
getCachedStringWidth,
} from '../../utils/textUtils.js';
import { parsePastedPaths } from '../../utils/clipboardUtils.js';
import type { Key } from '../../contexts/KeypressContext.js';
import { keyMatchers, Command } from '../../keyMatchers.js';
import type { VimAction } from './vim-buffer-actions.js';
import { handleVimAction } from './vim-buffer-actions.js';
import { LRU_BUFFER_PERF_CACHE_LIMIT } from '../../constants.js';
export type Direction =
| 'left'
| 'right'
| 'up'
| 'down'
| 'wordLeft'
| 'wordRight'
| 'home'
| 'end';
// Helper functions for line-based word navigation
export const isWordCharStrict = (char: string): boolean =>
/[\w\p{L}\p{N}]/u.test(char); // Matches a single character that is any Unicode letter, any Unicode number, or an underscore
export const isWhitespace = (char: string): boolean => /\s/.test(char);
// Check if a character is a combining mark (only diacritics for now)
export const isCombiningMark = (char: string): boolean => /\p{M}/u.test(char);
// Check if a character should be considered part of a word (including combining marks)
export const isWordCharWithCombining = (char: string): boolean =>
isWordCharStrict(char) || isCombiningMark(char);
// Get the script of a character (simplified for common scripts)
export const getCharScript = (char: string): string => {
if (/[\p{Script=Latin}]/u.test(char)) return 'latin'; // All Latin script chars including diacritics
if (/[\p{Script=Han}]/u.test(char)) return 'han'; // Chinese
if (/[\p{Script=Arabic}]/u.test(char)) return 'arabic';
if (/[\p{Script=Hiragana}]/u.test(char)) return 'hiragana';
if (/[\p{Script=Katakana}]/u.test(char)) return 'katakana';
if (/[\p{Script=Cyrillic}]/u.test(char)) return 'cyrillic';
return 'other';
};
// Check if two characters are from different scripts (indicating word boundary)
export const isDifferentScript = (char1: string, char2: string): boolean => {
if (!isWordCharStrict(char1) || !isWordCharStrict(char2)) return false;
return getCharScript(char1) !== getCharScript(char2);
};
// Find next word start within a line, starting from col
export const findNextWordStartInLine = (
line: string,
col: number,
): number | null => {
const chars = toCodePoints(line);
let i = col;
if (i >= chars.length) return null;
const currentChar = chars[i];
// Skip current word/sequence based on character type
if (isWordCharStrict(currentChar)) {
while (i < chars.length && isWordCharWithCombining(chars[i])) {
// Check for script boundary - if next character is from different script, stop here
if (
i + 1 < chars.length &&
isWordCharStrict(chars[i + 1]) &&
isDifferentScript(chars[i], chars[i + 1])
) {
i++; // Include current character
break; // Stop at script boundary
}
i++;
}
} else if (!isWhitespace(currentChar)) {
while (
i < chars.length &&
!isWordCharStrict(chars[i]) &&
!isWhitespace(chars[i])
) {
i++;
}
}
// Skip whitespace
while (i < chars.length && isWhitespace(chars[i])) {
i++;
}
return i < chars.length ? i : null;
};
// Find previous word start within a line
export const findPrevWordStartInLine = (
line: string,
col: number,
): number | null => {
const chars = toCodePoints(line);
let i = col;
if (i <= 0) return null;
i--;
// Skip whitespace moving backwards
while (i >= 0 && isWhitespace(chars[i])) {
i--;
}
if (i < 0) return null;
if (isWordCharStrict(chars[i])) {
// We're in a word, move to its beginning
while (i >= 0 && isWordCharStrict(chars[i])) {
// Check for script boundary - if previous character is from different script, stop here
if (
i - 1 >= 0 &&
isWordCharStrict(chars[i - 1]) &&
isDifferentScript(chars[i], chars[i - 1])
) {
return i; // Return current position at script boundary
}
i--;
}
return i + 1;
} else {
// We're in punctuation, move to its beginning
while (i >= 0 && !isWordCharStrict(chars[i]) && !isWhitespace(chars[i])) {
i--;
}
return i + 1;
}
};
// Find word end within a line
export const findWordEndInLine = (line: string, col: number): number | null => {
const chars = toCodePoints(line);
let i = col;
// If we're already at the end of a word (including punctuation sequences), advance to next word
// This includes both regular word endings and script boundaries
const atEndOfWordChar =
i < chars.length &&
isWordCharWithCombining(chars[i]) &&
(i + 1 >= chars.length ||
!isWordCharWithCombining(chars[i + 1]) ||
(isWordCharStrict(chars[i]) &&
i + 1 < chars.length &&
isWordCharStrict(chars[i + 1]) &&
isDifferentScript(chars[i], chars[i + 1])));
const atEndOfPunctuation =
i < chars.length &&
!isWordCharWithCombining(chars[i]) &&
!isWhitespace(chars[i]) &&
(i + 1 >= chars.length ||
isWhitespace(chars[i + 1]) ||
isWordCharWithCombining(chars[i + 1]));
if (atEndOfWordChar || atEndOfPunctuation) {
// We're at the end of a word or punctuation sequence, move forward to find next word
i++;
// Skip whitespace to find next word or punctuation
while (i < chars.length && isWhitespace(chars[i])) {
i++;
}
}
// If we're not on a word character, find the next word or punctuation sequence
if (i < chars.length && !isWordCharWithCombining(chars[i])) {
// Skip whitespace to find next word or punctuation
while (i < chars.length && isWhitespace(chars[i])) {
i++;
}
}
// Move to end of current word (including combining marks, but stop at script boundaries)
let foundWord = false;
let lastBaseCharPos = -1;
if (i < chars.length && isWordCharWithCombining(chars[i])) {
// Handle word characters
while (i < chars.length && isWordCharWithCombining(chars[i])) {
foundWord = true;
// Track the position of the last base character (not combining mark)
if (isWordCharStrict(chars[i])) {
lastBaseCharPos = i;
}
// Check if next character is from a different script (word boundary)
if (
i + 1 < chars.length &&
isWordCharStrict(chars[i + 1]) &&
isDifferentScript(chars[i], chars[i + 1])
) {
i++; // Include current character
if (isWordCharStrict(chars[i - 1])) {
lastBaseCharPos = i - 1;
}
break; // Stop at script boundary
}
i++;
}
} else if (i < chars.length && !isWhitespace(chars[i])) {
// Handle punctuation sequences (like ████)
while (
i < chars.length &&
!isWordCharStrict(chars[i]) &&
!isWhitespace(chars[i])
) {
foundWord = true;
lastBaseCharPos = i;
i++;
}
}
// Only return a position if we actually found a word
// Return the position of the last base character, not combining marks
if (foundWord && lastBaseCharPos >= col) {
return lastBaseCharPos;
}
return null;
};
// Initialize segmenter for word boundary detection
const segmenter = new Intl.Segmenter(undefined, { granularity: 'word' });
function findPrevWordBoundary(line: string, cursorCol: number): number {
const codePoints = toCodePoints(line);
// Convert cursorCol (CP index) to string index
const prefix = codePoints.slice(0, cursorCol).join('');
const cursorIdx = prefix.length;
let targetIdx = 0;
for (const seg of segmenter.segment(line)) {
// We want the last word start strictly before the cursor.
// If we've reached or passed the cursor, we stop.
if (seg.index >= cursorIdx) break;
if (seg.isWordLike) {
targetIdx = seg.index;
}
}
return toCodePoints(line.slice(0, targetIdx)).length;
}
function findNextWordBoundary(line: string, cursorCol: number): number {
const codePoints = toCodePoints(line);
const prefix = codePoints.slice(0, cursorCol).join('');
const cursorIdx = prefix.length;
let targetIdx = line.length;
for (const seg of segmenter.segment(line)) {
const segEnd = seg.index + seg.segment.length;
if (segEnd > cursorIdx) {
if (seg.isWordLike) {
targetIdx = segEnd;
break;
}
}
}
return toCodePoints(line.slice(0, targetIdx)).length;
}
// Find next word across lines
export const findNextWordAcrossLines = (
lines: string[],
cursorRow: number,
cursorCol: number,
searchForWordStart: boolean,
): { row: number; col: number } | null => {
// First try current line
const currentLine = lines[cursorRow] || '';
const colInCurrentLine = searchForWordStart
? findNextWordStartInLine(currentLine, cursorCol)
: findWordEndInLine(currentLine, cursorCol);
if (colInCurrentLine !== null) {
return { row: cursorRow, col: colInCurrentLine };
}
// Search subsequent lines
for (let row = cursorRow + 1; row < lines.length; row++) {
const line = lines[row] || '';
const chars = toCodePoints(line);
// For empty lines, if we haven't found any words yet, return the empty line
if (chars.length === 0) {
// Check if there are any words in remaining lines
let hasWordsInLaterLines = false;
for (let laterRow = row + 1; laterRow < lines.length; laterRow++) {
const laterLine = lines[laterRow] || '';
const laterChars = toCodePoints(laterLine);
let firstNonWhitespace = 0;
while (
firstNonWhitespace < laterChars.length &&
isWhitespace(laterChars[firstNonWhitespace])
) {
firstNonWhitespace++;
}
if (firstNonWhitespace < laterChars.length) {
hasWordsInLaterLines = true;
break;
}
}
// If no words in later lines, return the empty line
if (!hasWordsInLaterLines) {
return { row, col: 0 };
}
continue;
}
// Find first non-whitespace
let firstNonWhitespace = 0;
while (
firstNonWhitespace < chars.length &&
isWhitespace(chars[firstNonWhitespace])
) {
firstNonWhitespace++;
}
if (firstNonWhitespace < chars.length) {
if (searchForWordStart) {
return { row, col: firstNonWhitespace };
} else {
// For word end, find the end of the first word
const endCol = findWordEndInLine(line, firstNonWhitespace);
if (endCol !== null) {
return { row, col: endCol };
}
}
}
}
return null;
};
// Find previous word across lines
export const findPrevWordAcrossLines = (
lines: string[],
cursorRow: number,
cursorCol: number,
): { row: number; col: number } | null => {
// First try current line
const currentLine = lines[cursorRow] || '';
const colInCurrentLine = findPrevWordStartInLine(currentLine, cursorCol);
if (colInCurrentLine !== null) {
return { row: cursorRow, col: colInCurrentLine };
}
// Search previous lines
for (let row = cursorRow - 1; row >= 0; row--) {
const line = lines[row] || '';
const chars = toCodePoints(line);
if (chars.length === 0) continue;
// Find last word start
let lastWordStart = chars.length;
while (lastWordStart > 0 && isWhitespace(chars[lastWordStart - 1])) {
lastWordStart--;
}
if (lastWordStart > 0) {
// Find start of this word
const wordStart = findPrevWordStartInLine(line, lastWordStart);
if (wordStart !== null) {
return { row, col: wordStart };
}
}
}
return null;
};
// Helper functions for vim line operations
export const getPositionFromOffsets = (
startOffset: number,
endOffset: number,
lines: string[],
) => {
let offset = 0;
let startRow = 0;
let startCol = 0;
let endRow = 0;
let endCol = 0;
// Find start position
for (let i = 0; i < lines.length; i++) {
const lineLength = lines[i].length + 1; // +1 for newline
if (offset + lineLength > startOffset) {
startRow = i;
startCol = startOffset - offset;
break;
}
offset += lineLength;
}
// Find end position
offset = 0;
for (let i = 0; i < lines.length; i++) {
const lineLength = lines[i].length + (i < lines.length - 1 ? 1 : 0); // +1 for newline except last line
if (offset + lineLength >= endOffset) {
endRow = i;
endCol = endOffset - offset;
break;
}
offset += lineLength;
}
return { startRow, startCol, endRow, endCol };
};
export const getLineRangeOffsets = (
startRow: number,
lineCount: number,
lines: string[],
) => {
let startOffset = 0;
// Calculate start offset
for (let i = 0; i < startRow; i++) {
startOffset += lines[i].length + 1; // +1 for newline
}
// Calculate end offset
let endOffset = startOffset;
for (let i = 0; i < lineCount; i++) {
const lineIndex = startRow + i;
if (lineIndex < lines.length) {
endOffset += lines[lineIndex].length;
if (lineIndex < lines.length - 1) {
endOffset += 1; // +1 for newline
}
}
}
return { startOffset, endOffset };
};
export const replaceRangeInternal = (
state: TextBufferState,
startRow: number,
startCol: number,
endRow: number,
endCol: number,
text: string,
): TextBufferState => {
const currentLine = (row: number) => state.lines[row] || '';
const currentLineLen = (row: number) => cpLen(currentLine(row));
const clamp = (value: number, min: number, max: number) =>
Math.min(Math.max(value, min), max);
if (
startRow > endRow ||
(startRow === endRow && startCol > endCol) ||
startRow < 0 ||
startCol < 0 ||
endRow >= state.lines.length ||
(endRow < state.lines.length && endCol > currentLineLen(endRow))
) {
return state; // Invalid range
}
const newLines = [...state.lines];
const sCol = clamp(startCol, 0, currentLineLen(startRow));
const eCol = clamp(endCol, 0, currentLineLen(endRow));
const prefix = cpSlice(currentLine(startRow), 0, sCol);
const suffix = cpSlice(currentLine(endRow), eCol);
const normalisedReplacement = text
.replace(/\r\n/g, '\n')
.replace(/\r/g, '\n');
const replacementParts = normalisedReplacement.split('\n');
// The combined first line of the new text
const firstLine = prefix + replacementParts[0];
if (replacementParts.length === 1) {
// No newlines in replacement: combine prefix, replacement, and suffix on one line.
newLines.splice(startRow, endRow - startRow + 1, firstLine + suffix);
} else {
// Newlines in replacement: create new lines.
const lastLine = replacementParts[replacementParts.length - 1] + suffix;
const middleLines = replacementParts.slice(1, -1);
newLines.splice(
startRow,
endRow - startRow + 1,
firstLine,
...middleLines,
lastLine,
);
}
const finalCursorRow = startRow + replacementParts.length - 1;
const finalCursorCol =
(replacementParts.length > 1 ? 0 : sCol) +
cpLen(replacementParts[replacementParts.length - 1]);
return {
...state,
lines: newLines,
cursorRow: Math.min(Math.max(finalCursorRow, 0), newLines.length - 1),
cursorCol: Math.max(
0,
Math.min(finalCursorCol, cpLen(newLines[finalCursorRow] || '')),
),
preferredCol: null,
};
};
export interface Viewport {
height: number;
width: number;
}
function clamp(v: number, min: number, max: number): number {
return v < min ? min : v > max ? max : v;
}
/* ────────────────────────────────────────────────────────────────────────── */
interface UseTextBufferProps {
initialText?: string;
initialCursorOffset?: number;
viewport: Viewport; // Viewport dimensions needed for scrolling
stdin?: NodeJS.ReadStream | null; // For external editor
setRawMode?: (mode: boolean) => void; // For external editor
onChange?: (text: string) => void; // Callback for when text changes
isValidPath: (path: string) => boolean;
shellModeActive?: boolean; // Whether the text buffer is in shell mode
inputFilter?: (text: string) => string; // Optional filter for input text
singleLine?: boolean;
getPreferredEditor?: () => EditorType | undefined;
}
interface UndoHistoryEntry {
lines: string[];
cursorRow: number;
cursorCol: number;
}
function calculateInitialCursorPosition(
initialLines: string[],
offset: number,
): [number, number] {
let remainingChars = offset;
let row = 0;
while (row < initialLines.length) {
const lineLength = cpLen(initialLines[row]);
// Add 1 for the newline character (except for the last line)
const totalCharsInLineAndNewline =
lineLength + (row < initialLines.length - 1 ? 1 : 0);
if (remainingChars <= lineLength) {
// Cursor is on this line
return [row, remainingChars];
}
remainingChars -= totalCharsInLineAndNewline;
row++;
}
// Offset is beyond the text, place cursor at the end of the last line
if (initialLines.length > 0) {
const lastRow = initialLines.length - 1;
return [lastRow, cpLen(initialLines[lastRow])];
}
return [0, 0]; // Default for empty text
}
export function offsetToLogicalPos(
text: string,
offset: number,
): [number, number] {
let row = 0;
let col = 0;
let currentOffset = 0;
if (offset === 0) return [0, 0];
const lines = text.split('\n');
for (let i = 0; i < lines.length; i++) {
const line = lines[i];
const lineLength = cpLen(line);
const lineLengthWithNewline = lineLength + (i < lines.length - 1 ? 1 : 0);
if (offset <= currentOffset + lineLength) {
// Check against lineLength first
row = i;
col = offset - currentOffset;
return [row, col];
} else if (offset <= currentOffset + lineLengthWithNewline) {
// Check if offset is the newline itself
row = i;
col = lineLength; // Position cursor at the end of the current line content
// If the offset IS the newline, and it's not the last line, advance to next line, col 0
if (
offset === currentOffset + lineLengthWithNewline &&
i < lines.length - 1
) {
return [i + 1, 0];
}
return [row, col]; // Otherwise, it's at the end of the current line content
}
currentOffset += lineLengthWithNewline;
}
// If offset is beyond the text length, place cursor at the end of the last line
// or [0,0] if text is empty
if (lines.length > 0) {
row = lines.length - 1;
col = cpLen(lines[row]);
} else {
row = 0;
col = 0;
}
return [row, col];
}
/**
* Converts logical row/col position to absolute text offset
* Inverse operation of offsetToLogicalPos
*/
export function logicalPosToOffset(
lines: string[],
row: number,
col: number,
): number {
let offset = 0;
// Clamp row to valid range
const actualRow = Math.min(row, lines.length - 1);
// Add lengths of all lines before the target row
for (let i = 0; i < actualRow; i++) {
offset += cpLen(lines[i]) + 1; // +1 for newline
}
// Add column offset within the target row
if (actualRow >= 0 && actualRow < lines.length) {
offset += Math.min(col, cpLen(lines[actualRow]));
}
return offset;
}
/**
* Transformations allow for the CLI to render terse representations of things like file paths
* (e.g., "@some/path/to/an/image.png" to "[Image image.png]")
* When the cursor enters a transformed representation, it expands to reveal the logical representation.
* (e.g., "[Image image.png]" to "@some/path/to/an/image.png")
*/
export interface Transformation {
logStart: number;
logEnd: number;
logicalText: string;
collapsedText: string;
}
export const imagePathRegex =
/@((?:\\.|[^\s\r\n\\])+?\.(?:png|jpg|jpeg|gif|webp|svg|bmp))\b/gi;
export function getTransformedImagePath(filePath: string): string {
const raw = filePath;
// Ignore leading @ when stripping directories, but keep it for simple '@file.png'
const withoutAt = raw.startsWith('@') ? raw.slice(1) : raw;
// Unescape the path to handle escaped spaces and other characters
const unescaped = unescapePath(withoutAt);
// Find last directory separator, supporting both POSIX and Windows styles
const lastSepIndex = Math.max(
unescaped.lastIndexOf('/'),
unescaped.lastIndexOf('\\'),
);
// If we saw a separator, take the segment after it; otherwise fall back to the unescaped string
const fileName =
lastSepIndex >= 0 ? unescaped.slice(lastSepIndex + 1) : unescaped;
const extension = path.extname(fileName);
const baseName = path.basename(fileName, extension);
const maxBaseLength = 10;
const truncatedBase =
baseName.length > maxBaseLength
? `...${baseName.slice(-maxBaseLength)}`
: baseName;
return `[Image ${truncatedBase}${extension}]`;
}
const transformationsCache = new LruCache<string, Transformation[]>(
LRU_BUFFER_PERF_CACHE_LIMIT,
);
export function calculateTransformationsForLine(
line: string,
): Transformation[] {
const cached = transformationsCache.get(line);
if (cached) {
return cached;
}
const transformations: Transformation[] = [];
let match: RegExpExecArray | null;
// Reset regex state to ensure clean matching from start of line
imagePathRegex.lastIndex = 0;
while ((match = imagePathRegex.exec(line)) !== null) {
const logicalText = match[0];
const logStart = cpLen(line.substring(0, match.index));
const logEnd = logStart + cpLen(logicalText);
transformations.push({
logStart,
logEnd,
logicalText,
collapsedText: getTransformedImagePath(logicalText),
});
}
transformationsCache.set(line, transformations);
return transformations;
}
export function calculateTransformations(lines: string[]): Transformation[][] {
return lines.map((ln) => calculateTransformationsForLine(ln));
}
export function getTransformUnderCursor(
row: number,
col: number,
spansByLine: Transformation[][],
): Transformation | null {
const spans = spansByLine[row];
if (!spans || spans.length === 0) return null;
for (const span of spans) {
if (col >= span.logStart && col <= span.logEnd) {
return span;
}
if (col < span.logStart) break;
}
return null;
}
export function calculateTransformedLine(
logLine: string,
logIndex: number,
logicalCursor: [number, number],
transformations: Transformation[],
): { transformedLine: string; transformedToLogMap: number[] } {
let transformedLine = '';
const transformedToLogMap: number[] = [];
let lastLogPos = 0;
const cursorIsOnThisLine = logIndex === logicalCursor[0];
const cursorCol = logicalCursor[1];
for (const transform of transformations) {
const textBeforeTransformation = cpSlice(
logLine,
lastLogPos,
transform.logStart,
);
transformedLine += textBeforeTransformation;
for (let i = 0; i < cpLen(textBeforeTransformation); i++) {
transformedToLogMap.push(lastLogPos + i);
}
const isExpanded =
cursorIsOnThisLine &&
cursorCol >= transform.logStart &&
cursorCol <= transform.logEnd;
const transformedText = isExpanded
? transform.logicalText
: transform.collapsedText;
transformedLine += transformedText;
// Map transformed characters back to logical characters
const transformedLen = cpLen(transformedText);
if (isExpanded) {
for (let i = 0; i < transformedLen; i++) {
transformedToLogMap.push(transform.logStart + i);
}
} else {
// Collapsed: distribute transformed positions monotonically across the raw span.
// This preserves ordering across wrapped slices so logicalToVisualMap has
// increasing startColInLogical and visual cursor mapping remains consistent.
const logicalLength = Math.max(0, transform.logEnd - transform.logStart);
for (let i = 0; i < transformedLen; i++) {
// Map the i-th transformed code point into [logStart, logEnd)
const transformationToLogicalOffset =
logicalLength === 0
? 0
: Math.floor((i * logicalLength) / transformedLen);
const transformationToLogicalIndex =
transform.logStart +
Math.min(
transformationToLogicalOffset,
Math.max(logicalLength - 1, 0),
);
transformedToLogMap.push(transformationToLogicalIndex);
}
}
lastLogPos = transform.logEnd;
}
// Append text after last transform
const remainingUntransformedText = cpSlice(logLine, lastLogPos);
transformedLine += remainingUntransformedText;
for (let i = 0; i < cpLen(remainingUntransformedText); i++) {
transformedToLogMap.push(lastLogPos + i);
}
// For a cursor at the very end of the transformed line
transformedToLogMap.push(cpLen(logLine));
return { transformedLine, transformedToLogMap };
}
export interface VisualLayout {
visualLines: string[];
// For each logical line, an array of [visualLineIndex, startColInLogical]
logicalToVisualMap: Array<Array<[number, number]>>;
// For each visual line, its [logicalLineIndex, startColInLogical]
visualToLogicalMap: Array<[number, number]>;
// Image paths are transformed (e.g., "@some/path/to/an/image.png" to "[Image image.png]")
// For each logical line, an array that maps each transformedCol to a logicalCol
transformedToLogicalMaps: number[][];
// For each visual line, its [startColInTransformed]
visualToTransformedMap: number[];
}
// Caches for layout calculation
interface LineLayoutResult {
visualLines: string[];
logicalToVisualMap: Array<[number, number]>;
visualToLogicalMap: Array<[number, number]>;
transformedToLogMap: number[];
visualToTransformedMap: number[];
}
const lineLayoutCache = new LruCache<string, LineLayoutResult>(
LRU_BUFFER_PERF_CACHE_LIMIT,
);
function getLineLayoutCacheKey(
line: string,
viewportWidth: number,
isCursorOnLine: boolean,
cursorCol: number,
): string {
// Most lines (99.9% in a large buffer) are not cursor lines.
// We use a simpler key for them to reduce string allocation overhead.
if (!isCursorOnLine) {
return `${viewportWidth}:N:${line}`;
}
return `${viewportWidth}:C:${cursorCol}:${line}`;
}
// Calculates the visual wrapping of lines and the mapping between logical and visual coordinates.
// This is an expensive operation and should be memoized.
function calculateLayout(
logicalLines: string[],
viewportWidth: number,
logicalCursor: [number, number],
): VisualLayout {
const visualLines: string[] = [];
const logicalToVisualMap: Array<Array<[number, number]>> = [];
const visualToLogicalMap: Array<[number, number]> = [];
const transformedToLogicalMaps: number[][] = [];
const visualToTransformedMap: number[] = [];
logicalLines.forEach((logLine, logIndex) => {
logicalToVisualMap[logIndex] = [];
const isCursorOnLine = logIndex === logicalCursor[0];
const cacheKey = getLineLayoutCacheKey(
logLine,
viewportWidth,
isCursorOnLine,
logicalCursor[1],
);
const cached = lineLayoutCache.get(cacheKey);
if (cached) {
const visualLineOffset = visualLines.length;
visualLines.push(...cached.visualLines);
cached.logicalToVisualMap.forEach(([relVisualIdx, logCol]) => {
logicalToVisualMap[logIndex].push([
visualLineOffset + relVisualIdx,
logCol,
]);
});
cached.visualToLogicalMap.forEach(([, logCol]) => {
visualToLogicalMap.push([logIndex, logCol]);
});
transformedToLogicalMaps[logIndex] = cached.transformedToLogMap;
visualToTransformedMap.push(...cached.visualToTransformedMap);
return;
}
// Not in cache, calculate
const transformations = calculateTransformationsForLine(logLine);
const { transformedLine, transformedToLogMap } = calculateTransformedLine(
logLine,
logIndex,
logicalCursor,
transformations,
);
const lineVisualLines: string[] = [];
const lineLogicalToVisualMap: Array<[number, number]> = [];
const lineVisualToLogicalMap: Array<[number, number]> = [];
const lineVisualToTransformedMap: number[] = [];
if (transformedLine.length === 0) {
// Handle empty logical line
lineLogicalToVisualMap.push([0, 0]);
lineVisualToLogicalMap.push([logIndex, 0]);
lineVisualToTransformedMap.push(0);
lineVisualLines.push('');
} else {
// Non-empty logical line
let currentPosInLogLine = 0; // Tracks position within the current logical line (code point index)
const codePointsInLogLine = toCodePoints(transformedLine);
while (currentPosInLogLine < codePointsInLogLine.length) {
let currentChunk = '';
let currentChunkVisualWidth = 0;
let numCodePointsInChunk = 0;
let lastWordBreakPoint = -1; // Index in codePointsInLogLine for word break
let numCodePointsAtLastWordBreak = 0;
// Iterate through code points to build the current visual line (chunk)
for (let i = currentPosInLogLine; i < codePointsInLogLine.length; i++) {
const char = codePointsInLogLine[i];
const charVisualWidth = getCachedStringWidth(char);
if (currentChunkVisualWidth + charVisualWidth > viewportWidth) {
// Character would exceed viewport width
if (
lastWordBreakPoint !== -1 &&
numCodePointsAtLastWordBreak > 0 &&
currentPosInLogLine + numCodePointsAtLastWordBreak < i
) {
// We have a valid word break point to use, and it's not the start of the current segment
currentChunk = codePointsInLogLine
.slice(
currentPosInLogLine,
currentPosInLogLine + numCodePointsAtLastWordBreak,
)
.join('');
numCodePointsInChunk = numCodePointsAtLastWordBreak;
} else {
// No word break, or word break is at the start of this potential chunk, or word break leads to empty chunk.
// Hard break: take characters up to viewportWidth, or just the current char if it alone is too wide.
if (
numCodePointsInChunk === 0 &&
charVisualWidth > viewportWidth
) {
// Single character is wider than viewport, take it anyway
currentChunk = char;
numCodePointsInChunk = 1;
}
}
break; // Break from inner loop to finalize this chunk
}
currentChunk += char;
currentChunkVisualWidth += charVisualWidth;
numCodePointsInChunk++;
// Check for word break opportunity (space)
if (char === ' ') {
lastWordBreakPoint = i; // Store code point index of the space
// Store the state *before* adding the space, if we decide to break here.
numCodePointsAtLastWordBreak = numCodePointsInChunk - 1; // Chars *before* the space
}
}
if (
numCodePointsInChunk === 0 &&
currentPosInLogLine < codePointsInLogLine.length
) {
const firstChar = codePointsInLogLine[currentPosInLogLine];
currentChunk = firstChar;
numCodePointsInChunk = 1;
}
const logicalStartCol = transformedToLogMap[currentPosInLogLine] ?? 0;
lineLogicalToVisualMap.push([lineVisualLines.length, logicalStartCol]);
lineVisualToLogicalMap.push([logIndex, logicalStartCol]);
lineVisualToTransformedMap.push(currentPosInLogLine);
lineVisualLines.push(currentChunk);
const logicalStartOfThisChunk = currentPosInLogLine;
currentPosInLogLine += numCodePointsInChunk;
if (
logicalStartOfThisChunk + numCodePointsInChunk <
codePointsInLogLine.length &&
currentPosInLogLine < codePointsInLogLine.length &&
codePointsInLogLine[currentPosInLogLine] === ' '
) {
currentPosInLogLine++;
}
}
}
// Cache the result for this line
lineLayoutCache.set(cacheKey, {
visualLines: lineVisualLines,
logicalToVisualMap: lineLogicalToVisualMap,
visualToLogicalMap: lineVisualToLogicalMap,
transformedToLogMap,
visualToTransformedMap: lineVisualToTransformedMap,
});
const visualLineOffset = visualLines.length;
visualLines.push(...lineVisualLines);
lineLogicalToVisualMap.forEach(([relVisualIdx, logCol]) => {
logicalToVisualMap[logIndex].push([
visualLineOffset + relVisualIdx,
logCol,
]);
});
lineVisualToLogicalMap.forEach(([, logCol]) => {
visualToLogicalMap.push([logIndex, logCol]);
});
transformedToLogicalMaps[logIndex] = transformedToLogMap;
visualToTransformedMap.push(...lineVisualToTransformedMap);
});
// If the entire logical text was empty, ensure there's one empty visual line.
if (
logicalLines.length === 0 ||
(logicalLines.length === 1 && logicalLines[0] === '')
) {
if (visualLines.length === 0) {
visualLines.push('');
if (!logicalToVisualMap[0]) logicalToVisualMap[0] = [];
logicalToVisualMap[0].push([0, 0]);
visualToLogicalMap.push([0, 0]);
visualToTransformedMap.push(0);
}
}
return {
visualLines,
logicalToVisualMap,
visualToLogicalMap,
transformedToLogicalMaps,
visualToTransformedMap,
};
}
// Calculates the visual cursor position based on a pre-calculated layout.
// This is a lightweight operation.
function calculateVisualCursorFromLayout(
layout: VisualLayout,
logicalCursor: [number, number],
): [number, number] {
const { logicalToVisualMap, visualLines, transformedToLogicalMaps } = layout;
const [logicalRow, logicalCol] = logicalCursor;
const segmentsForLogicalLine = logicalToVisualMap[logicalRow];
if (!segmentsForLogicalLine || segmentsForLogicalLine.length === 0) {
// This can happen for an empty document.
return [0, 0];
}
// Find the segment where the logical column fits.
// The segments are sorted by startColInLogical.
let targetSegmentIndex = segmentsForLogicalLine.findIndex(
([, startColInLogical], index) => {
const nextStartColInLogical =
index + 1 < segmentsForLogicalLine.length
? segmentsForLogicalLine[index + 1][1]
: Infinity;
return (
logicalCol >= startColInLogical && logicalCol < nextStartColInLogical
);
},
);
// If not found, it means the cursor is at the end of the logical line.
if (targetSegmentIndex === -1) {
if (logicalCol === 0) {
targetSegmentIndex = 0;
} else {
targetSegmentIndex = segmentsForLogicalLine.length - 1;
}
}
const [visualRow, startColInLogical] =
segmentsForLogicalLine[targetSegmentIndex];
// Find the coordinates in transformed space in order to conver to visual
const transformedToLogicalMap = transformedToLogicalMaps[logicalRow] ?? [];
let transformedCol = 0;
for (let i = 0; i < transformedToLogicalMap.length; i++) {
if (transformedToLogicalMap[i] > logicalCol) {
transformedCol = Math.max(0, i - 1);
break;
}
if (i === transformedToLogicalMap.length - 1) {
transformedCol = transformedToLogicalMap.length - 1;
}
}
let startColInTransformed = 0;
while (
startColInTransformed < transformedToLogicalMap.length &&
transformedToLogicalMap[startColInTransformed] < startColInLogical
) {
startColInTransformed++;
}
const clampedTransformedCol = Math.min(
transformedCol,
Math.max(0, transformedToLogicalMap.length - 1),
);
const visualCol = clampedTransformedCol - startColInTransformed;
const clampedVisualCol = Math.min(
Math.max(visualCol, 0),
cpLen(visualLines[visualRow] ?? ''),
);
return [visualRow, clampedVisualCol];
}
// --- Start of reducer logic ---
export interface TextBufferState {
lines: string[];
cursorRow: number;
cursorCol: number;
transformationsByLine: Transformation[][];
preferredCol: number | null; // This is the logical character offset in the visual line
undoStack: UndoHistoryEntry[];
redoStack: UndoHistoryEntry[];
clipboard: string | null;
selectionAnchor: [number, number] | null;
viewportWidth: number;
viewportHeight: number;
visualLayout: VisualLayout;
}
const historyLimit = 100;
export const pushUndo = (currentState: TextBufferState): TextBufferState => {
const snapshot = {
lines: [...currentState.lines],
cursorRow: currentState.cursorRow,
cursorCol: currentState.cursorCol,
};
const newStack = [...currentState.undoStack, snapshot];
if (newStack.length > historyLimit) {
newStack.shift();
}
return { ...currentState, undoStack: newStack, redoStack: [] };
};
export type TextBufferAction =
| { type: 'set_text'; payload: string; pushToUndo?: boolean }
| { type: 'insert'; payload: string }
| { type: 'backspace' }
| {
type: 'move';
payload: {
dir: Direction;
};
}
| {
type: 'set_cursor';
payload: {
cursorRow: number;
cursorCol: number;
preferredCol: number | null;
};
}
| { type: 'delete' }
| { type: 'delete_word_left' }
| { type: 'delete_word_right' }
| { type: 'kill_line_right' }
| { type: 'kill_line_left' }
| { type: 'undo' }
| { type: 'redo' }
| {
type: 'replace_range';
payload: {
startRow: number;
startCol: number;
endRow: number;
endCol: number;
text: string;
};
}
| { type: 'move_to_offset'; payload: { offset: number } }
| { type: 'create_undo_snapshot' }
| { type: 'set_viewport'; payload: { width: number; height: number } }
| { type: 'vim_delete_word_forward'; payload: { count: number } }
| { type: 'vim_delete_word_backward'; payload: { count: number } }
| { type: 'vim_delete_word_end'; payload: { count: number } }
| { type: 'vim_change_word_forward'; payload: { count: number } }
| { type: 'vim_change_word_backward'; payload: { count: number } }
| { type: 'vim_change_word_end'; payload: { count: number } }
| { type: 'vim_delete_line'; payload: { count: number } }
| { type: 'vim_change_line'; payload: { count: number } }
| { type: 'vim_delete_to_end_of_line' }
| { type: 'vim_change_to_end_of_line' }
| {
type: 'vim_change_movement';
payload: { movement: 'h' | 'j' | 'k' | 'l'; count: number };
}
// New vim actions for stateless command handling
| { type: 'vim_move_left'; payload: { count: number } }
| { type: 'vim_move_right'; payload: { count: number } }
| { type: 'vim_move_up'; payload: { count: number } }
| { type: 'vim_move_down'; payload: { count: number } }
| { type: 'vim_move_word_forward'; payload: { count: number } }
| { type: 'vim_move_word_backward'; payload: { count: number } }
| { type: 'vim_move_word_end'; payload: { count: number } }
| { type: 'vim_delete_char'; payload: { count: number } }
| { type: 'vim_insert_at_cursor' }
| { type: 'vim_append_at_cursor' }
| { type: 'vim_open_line_below' }
| { type: 'vim_open_line_above' }
| { type: 'vim_append_at_line_end' }
| { type: 'vim_insert_at_line_start' }
| { type: 'vim_move_to_line_start' }
| { type: 'vim_move_to_line_end' }
| { type: 'vim_move_to_first_nonwhitespace' }
| { type: 'vim_move_to_first_line' }
| { type: 'vim_move_to_last_line' }
| { type: 'vim_move_to_line'; payload: { lineNumber: number } }
| { type: 'vim_escape_insert_mode' };
export interface TextBufferOptions {
inputFilter?: (text: string) => string;
singleLine?: boolean;
}
function textBufferReducerLogic(
state: TextBufferState,
action: TextBufferAction,
options: TextBufferOptions = {},
): TextBufferState {
const pushUndoLocal = pushUndo;
const currentLine = (r: number): string => state.lines[r] ?? '';
const currentLineLen = (r: number): number => cpLen(currentLine(r));
switch (action.type) {
case 'set_text': {
let nextState = state;
if (action.pushToUndo !== false) {
nextState = pushUndoLocal(state);
}
const newContentLines = action.payload
.replace(/\r\n?/g, '\n')
.split('\n');
const lines = newContentLines.length === 0 ? [''] : newContentLines;
const lastNewLineIndex = lines.length - 1;
return {
...nextState,
lines,
cursorRow: lastNewLineIndex,
cursorCol: cpLen(lines[lastNewLineIndex] ?? ''),
preferredCol: null,
};
}
case 'insert': {
const nextState = pushUndoLocal(state);
const newLines = [...nextState.lines];
let newCursorRow = nextState.cursorRow;
let newCursorCol = nextState.cursorCol;
const currentLine = (r: number) => newLines[r] ?? '';
let payload = action.payload;
if (options.singleLine) {
payload = payload.replace(/[\r\n]/g, '');
}
if (options.inputFilter) {
payload = options.inputFilter(payload);
}
if (payload.length === 0) {
return state;
}
const str = stripUnsafeCharacters(
payload.replace(/\r\n/g, '\n').replace(/\r/g, '\n'),
);
const parts = str.split('\n');
const lineContent = currentLine(newCursorRow);
const before = cpSlice(lineContent, 0, newCursorCol);
const after = cpSlice(lineContent, newCursorCol);
if (parts.length > 1) {
newLines[newCursorRow] = before + parts[0];
const remainingParts = parts.slice(1);
const lastPartOriginal = remainingParts.pop() ?? '';
newLines.splice(newCursorRow + 1, 0, ...remainingParts);
newLines.splice(
newCursorRow + parts.length - 1,
0,
lastPartOriginal + after,
);
newCursorRow = newCursorRow + parts.length - 1;
newCursorCol = cpLen(lastPartOriginal);
} else {
newLines[newCursorRow] = before + parts[0] + after;
newCursorCol = cpLen(before) + cpLen(parts[0]);
}
return {
...nextState,
lines: newLines,
cursorRow: newCursorRow,
cursorCol: newCursorCol,
preferredCol: null,
};
}
case 'backspace': {
const nextState = pushUndoLocal(state);
const newLines = [...nextState.lines];
let newCursorRow = nextState.cursorRow;
let newCursorCol = nextState.cursorCol;
const currentLine = (r: number) => newLines[r] ?? '';
if (newCursorCol === 0 && newCursorRow === 0) return state;
if (newCursorCol > 0) {
const lineContent = currentLine(newCursorRow);
newLines[newCursorRow] =
cpSlice(lineContent, 0, newCursorCol - 1) +
cpSlice(lineContent, newCursorCol);
newCursorCol--;
} else if (newCursorRow > 0) {
const prevLineContent = currentLine(newCursorRow - 1);
const currentLineContentVal = currentLine(newCursorRow);
const newCol = cpLen(prevLineContent);
newLines[newCursorRow - 1] = prevLineContent + currentLineContentVal;
newLines.splice(newCursorRow, 1);
newCursorRow--;
newCursorCol = newCol;
}
return {
...nextState,
lines: newLines,
cursorRow: newCursorRow,
cursorCol: newCursorCol,
preferredCol: null,
};
}
case 'set_viewport': {
const { width, height } = action.payload;
if (width === state.viewportWidth && height === state.viewportHeight) {
return state;
}
return {
...state,
viewportWidth: width,
viewportHeight: height,
};
}
case 'move': {
const { dir } = action.payload;
const { cursorRow, cursorCol, lines, visualLayout, preferredCol } = state;
// Visual movements
if (
dir === 'left' ||
dir === 'right' ||
dir === 'up' ||
dir === 'down' ||
dir === 'home' ||
dir === 'end'
) {
const visualCursor = calculateVisualCursorFromLayout(visualLayout, [
cursorRow,
cursorCol,
]);
const { visualLines, visualToLogicalMap } = visualLayout;
let newVisualRow = visualCursor[0];
let newVisualCol = visualCursor[1];
let newPreferredCol = preferredCol;
const currentVisLineLen = cpLen(visualLines[newVisualRow] ?? '');
switch (dir) {
case 'left':
newPreferredCol = null;
if (newVisualCol > 0) {
newVisualCol--;
} else if (newVisualRow > 0) {
newVisualRow--;
newVisualCol = cpLen(visualLines[newVisualRow] ?? '');
}
break;
case 'right':
newPreferredCol = null;
if (newVisualCol < currentVisLineLen) {
newVisualCol++;
} else if (newVisualRow < visualLines.length - 1) {
newVisualRow++;
newVisualCol = 0;
}
break;
case 'up':
if (newVisualRow > 0) {
if (newPreferredCol === null) newPreferredCol = newVisualCol;
newVisualRow--;
newVisualCol = clamp(
newPreferredCol,
0,
cpLen(visualLines[newVisualRow] ?? ''),
);
}
break;
case 'down':
if (newVisualRow < visualLines.length - 1) {
if (newPreferredCol === null) newPreferredCol = newVisualCol;
newVisualRow++;
newVisualCol = clamp(
newPreferredCol,
0,
cpLen(visualLines[newVisualRow] ?? ''),
);
}
break;
case 'home':
newPreferredCol = null;
newVisualCol = 0;
break;
case 'end':
newPreferredCol = null;
newVisualCol = currentVisLineLen;
break;
default: {
const exhaustiveCheck: never = dir;
debugLogger.error(
`Unknown visual movement direction: ${exhaustiveCheck}`,
);
return state;
}
}
if (visualToLogicalMap[newVisualRow]) {
const [logRow, logicalStartCol] = visualToLogicalMap[newVisualRow];
const transformedToLogicalMap =
visualLayout.transformedToLogicalMaps?.[logRow] ?? [];
let transformedStartCol = 0;
while (
transformedStartCol < transformedToLogicalMap.length &&
transformedToLogicalMap[transformedStartCol] < logicalStartCol
) {
transformedStartCol++;
}
const clampedTransformedCol = Math.min(
transformedStartCol + newVisualCol,
Math.max(0, transformedToLogicalMap.length - 1),
);
const newLogicalCol =
transformedToLogicalMap[clampedTransformedCol] ??
cpLen(lines[logRow] ?? '');
return {
...state,
cursorRow: logRow,
cursorCol: newLogicalCol,
preferredCol: newPreferredCol,
};
}
return state;
}
// Logical movements
switch (dir) {
case 'wordLeft': {
if (cursorCol === 0 && cursorRow === 0) return state;
let newCursorRow = cursorRow;
let newCursorCol = cursorCol;
if (cursorCol === 0) {
newCursorRow--;
newCursorCol = cpLen(lines[newCursorRow] ?? '');
} else {
const lineContent = lines[cursorRow];
newCursorCol = findPrevWordBoundary(lineContent, cursorCol);
}
return {
...state,
cursorRow: newCursorRow,
cursorCol: newCursorCol,
preferredCol: null,
};
}
case 'wordRight': {
const lineContent = lines[cursorRow] ?? '';
if (
cursorRow === lines.length - 1 &&
cursorCol === cpLen(lineContent)
) {
return state;
}
let newCursorRow = cursorRow;
let newCursorCol = cursorCol;
const lineLen = cpLen(lineContent);
if (cursorCol >= lineLen) {
newCursorRow++;
newCursorCol = 0;
} else {
newCursorCol = findNextWordBoundary(lineContent, cursorCol);
}
return {
...state,
cursorRow: newCursorRow,
cursorCol: newCursorCol,
preferredCol: null,
};
}
default:
return state;
}
}
case 'set_cursor': {
return {
...state,
...action.payload,
};
}
case 'delete': {
const { cursorRow, cursorCol, lines } = state;
const lineContent = currentLine(cursorRow);
if (cursorCol < currentLineLen(cursorRow)) {
const nextState = pushUndoLocal(state);
const newLines = [...nextState.lines];
newLines[cursorRow] =
cpSlice(lineContent, 0, cursorCol) +
cpSlice(lineContent, cursorCol + 1);
return {
...nextState,
lines: newLines,
preferredCol: null,
};
} else if (cursorRow < lines.length - 1) {
const nextState = pushUndoLocal(state);
const nextLineContent = currentLine(cursorRow + 1);
const newLines = [...nextState.lines];
newLines[cursorRow] = lineContent + nextLineContent;
newLines.splice(cursorRow + 1, 1);
return {
...nextState,
lines: newLines,
preferredCol: null,
};
}
return state;
}
case 'delete_word_left': {
const { cursorRow, cursorCol } = state;
if (cursorCol === 0 && cursorRow === 0) return state;
const nextState = pushUndoLocal(state);
const newLines = [...nextState.lines];
let newCursorRow = cursorRow;
let newCursorCol = cursorCol;
if (newCursorCol > 0) {
const lineContent = currentLine(newCursorRow);
const prevWordStart = findPrevWordStartInLine(
lineContent,
newCursorCol,
);
const start = prevWordStart === null ? 0 : prevWordStart;
newLines[newCursorRow] =
cpSlice(lineContent, 0, start) + cpSlice(lineContent, newCursorCol);
newCursorCol = start;
} else {
// Act as a backspace
const prevLineContent = currentLine(cursorRow - 1);
const currentLineContentVal = currentLine(cursorRow);
const newCol = cpLen(prevLineContent);
newLines[cursorRow - 1] = prevLineContent + currentLineContentVal;
newLines.splice(cursorRow, 1);
newCursorRow--;
newCursorCol = newCol;
}
return {
...nextState,
lines: newLines,
cursorRow: newCursorRow,
cursorCol: newCursorCol,
preferredCol: null,
};
}
case 'delete_word_right': {
const { cursorRow, cursorCol, lines } = state;
const lineContent = currentLine(cursorRow);
const lineLen = cpLen(lineContent);
if (cursorCol >= lineLen && cursorRow === lines.length - 1) {
return state;
}
const nextState = pushUndoLocal(state);
const newLines = [...nextState.lines];
if (cursorCol >= lineLen) {
// Act as a delete, joining with the next line
const nextLineContent = currentLine(cursorRow + 1);
newLines[cursorRow] = lineContent + nextLineContent;
newLines.splice(cursorRow + 1, 1);
} else {
const nextWordStart = findNextWordStartInLine(lineContent, cursorCol);
const end = nextWordStart === null ? lineLen : nextWordStart;
newLines[cursorRow] =
cpSlice(lineContent, 0, cursorCol) + cpSlice(lineContent, end);
}
return {
...nextState,
lines: newLines,
preferredCol: null,
};
}
case 'kill_line_right': {
const { cursorRow, cursorCol, lines } = state;
const lineContent = currentLine(cursorRow);
if (cursorCol < currentLineLen(cursorRow)) {
const nextState = pushUndoLocal(state);
const newLines = [...nextState.lines];
newLines[cursorRow] = cpSlice(lineContent, 0, cursorCol);
return {
...nextState,
lines: newLines,
};
} else if (cursorRow < lines.length - 1) {
// Act as a delete
const nextState = pushUndoLocal(state);
const nextLineContent = currentLine(cursorRow + 1);
const newLines = [...nextState.lines];
newLines[cursorRow] = lineContent + nextLineContent;
newLines.splice(cursorRow + 1, 1);
return {
...nextState,
lines: newLines,
preferredCol: null,
};
}
return state;
}
case 'kill_line_left': {
const { cursorRow, cursorCol } = state;
if (cursorCol > 0) {
const nextState = pushUndoLocal(state);
const lineContent = currentLine(cursorRow);
const newLines = [...nextState.lines];
newLines[cursorRow] = cpSlice(lineContent, cursorCol);
return {
...nextState,
lines: newLines,
cursorCol: 0,
preferredCol: null,
};
}
return state;
}
case 'undo': {
const stateToRestore = state.undoStack[state.undoStack.length - 1];
if (!stateToRestore) return state;
const currentSnapshot = {
lines: [...state.lines],
cursorRow: state.cursorRow,
cursorCol: state.cursorCol,
};
return {
...state,
...stateToRestore,
undoStack: state.undoStack.slice(0, -1),
redoStack: [...state.redoStack, currentSnapshot],
};
}
case 'redo': {
const stateToRestore = state.redoStack[state.redoStack.length - 1];
if (!stateToRestore) return state;
const currentSnapshot = {
lines: [...state.lines],
cursorRow: state.cursorRow,
cursorCol: state.cursorCol,
};
return {
...state,
...stateToRestore,
redoStack: state.redoStack.slice(0, -1),
undoStack: [...state.undoStack, currentSnapshot],
};
}
case 'replace_range': {
const { startRow, startCol, endRow, endCol, text } = action.payload;
const nextState = pushUndoLocal(state);
return replaceRangeInternal(
nextState,
startRow,
startCol,
endRow,
endCol,
text,
);
}
case 'move_to_offset': {
const { offset } = action.payload;
const [newRow, newCol] = offsetToLogicalPos(
state.lines.join('\n'),
offset,
);
return {
...state,
cursorRow: newRow,
cursorCol: newCol,
preferredCol: null,
};
}
case 'create_undo_snapshot': {
return pushUndoLocal(state);
}
// Vim-specific operations
case 'vim_delete_word_forward':
case 'vim_delete_word_backward':
case 'vim_delete_word_end':
case 'vim_change_word_forward':
case 'vim_change_word_backward':
case 'vim_change_word_end':
case 'vim_delete_line':
case 'vim_change_line':
case 'vim_delete_to_end_of_line':
case 'vim_change_to_end_of_line':
case 'vim_change_movement':
case 'vim_move_left':
case 'vim_move_right':
case 'vim_move_up':
case 'vim_move_down':
case 'vim_move_word_forward':
case 'vim_move_word_backward':
case 'vim_move_word_end':
case 'vim_delete_char':
case 'vim_insert_at_cursor':
case 'vim_append_at_cursor':
case 'vim_open_line_below':
case 'vim_open_line_above':
case 'vim_append_at_line_end':
case 'vim_insert_at_line_start':
case 'vim_move_to_line_start':
case 'vim_move_to_line_end':
case 'vim_move_to_first_nonwhitespace':
case 'vim_move_to_first_line':
case 'vim_move_to_last_line':
case 'vim_move_to_line':
case 'vim_escape_insert_mode':
return handleVimAction(state, action as VimAction);
default: {
const exhaustiveCheck: never = action;
debugLogger.error(`Unknown action encountered: ${exhaustiveCheck}`);
return state;
}
}
}
export function textBufferReducer(
state: TextBufferState,
action: TextBufferAction,
options: TextBufferOptions = {},
): TextBufferState {
const newState = textBufferReducerLogic(state, action, options);
const newTransformedLines =
newState.lines !== state.lines
? calculateTransformations(newState.lines)
: state.transformationsByLine;
const oldTransform = getTransformUnderCursor(
state.cursorRow,
state.cursorCol,
state.transformationsByLine,
);
const newTransform = getTransformUnderCursor(
newState.cursorRow,
newState.cursorCol,
newTransformedLines,
);
const oldInside = oldTransform !== null;
const newInside = newTransform !== null;
const movedBetweenTransforms =
oldTransform !== newTransform &&
(oldTransform !== null || newTransform !== null);
if (
newState.lines !== state.lines ||
newState.viewportWidth !== state.viewportWidth ||
oldInside !== newInside ||
movedBetweenTransforms
) {
const shouldResetPreferred =
oldInside !== newInside || movedBetweenTransforms;
return {
...newState,
preferredCol: shouldResetPreferred ? null : newState.preferredCol,
visualLayout: calculateLayout(newState.lines, newState.viewportWidth, [
newState.cursorRow,
newState.cursorCol,
]),
transformationsByLine: newTransformedLines,
};
}
return newState;
}
// --- End of reducer logic ---
export function useTextBuffer({
initialText = '',
initialCursorOffset = 0,
viewport,
stdin,
setRawMode,
onChange,
isValidPath,
shellModeActive = false,
inputFilter,
singleLine = false,
getPreferredEditor,
}: UseTextBufferProps): TextBuffer {
const initialState = useMemo((): TextBufferState => {
const lines = initialText.split('\n');
const [initialCursorRow, initialCursorCol] = calculateInitialCursorPosition(
lines.length === 0 ? [''] : lines,
initialCursorOffset,
);
const transformationsByLine = calculateTransformations(
lines.length === 0 ? [''] : lines,
);
const visualLayout = calculateLayout(
lines.length === 0 ? [''] : lines,
viewport.width,
[initialCursorRow, initialCursorCol],
);
return {
lines: lines.length === 0 ? [''] : lines,
cursorRow: initialCursorRow,
cursorCol: initialCursorCol,
transformationsByLine,
preferredCol: null,
undoStack: [],
redoStack: [],
clipboard: null,
selectionAnchor: null,
viewportWidth: viewport.width,
viewportHeight: viewport.height,
visualLayout,
};
}, [initialText, initialCursorOffset, viewport.width, viewport.height]);
const [state, dispatch] = useReducer(
(s: TextBufferState, a: TextBufferAction) =>
textBufferReducer(s, a, { inputFilter, singleLine }),
initialState,
);
const {
lines,
cursorRow,
cursorCol,
preferredCol,
selectionAnchor,
visualLayout,
transformationsByLine,
} = state;
const text = useMemo(() => lines.join('\n'), [lines]);
const visualCursor = useMemo(
() => calculateVisualCursorFromLayout(visualLayout, [cursorRow, cursorCol]),
[visualLayout, cursorRow, cursorCol],
);
const {
visualLines,
visualToLogicalMap,
transformedToLogicalMaps,
visualToTransformedMap,
} = visualLayout;
const [visualScrollRow, setVisualScrollRow] = useState<number>(0);
useEffect(() => {
if (onChange) {
onChange(text);
}
}, [text, onChange]);
useEffect(() => {
dispatch({
type: 'set_viewport',
payload: { width: viewport.width, height: viewport.height },
});
}, [viewport.width, viewport.height]);
// Update visual scroll (vertical)
useEffect(() => {
const { height } = viewport;
const totalVisualLines = visualLines.length;
const maxScrollStart = Math.max(0, totalVisualLines - height);
let newVisualScrollRow = visualScrollRow;
if (visualCursor[0] < visualScrollRow) {
newVisualScrollRow = visualCursor[0];
} else if (visualCursor[0] >= visualScrollRow + height) {
newVisualScrollRow = visualCursor[0] - height + 1;
}
// When the number of visual lines shrinks (e.g., after widening the viewport),
// ensure scroll never starts beyond the last valid start so we can render a full window.
newVisualScrollRow = clamp(newVisualScrollRow, 0, maxScrollStart);
if (newVisualScrollRow !== visualScrollRow) {
setVisualScrollRow(newVisualScrollRow);
}
}, [visualCursor, visualScrollRow, viewport, visualLines.length]);
const insert = useCallback(
(ch: string, { paste = false }: { paste?: boolean } = {}): void => {
if (!singleLine && /[\n\r]/.test(ch)) {
dispatch({ type: 'insert', payload: ch });
return;
}
const minLengthToInferAsDragDrop = 3;
if (
ch.length >= minLengthToInferAsDragDrop &&
!shellModeActive &&
paste
) {
let potentialPath = ch.trim();
const quoteMatch = potentialPath.match(/^'(.*)'$/);
if (quoteMatch) {
potentialPath = quoteMatch[1];
}
potentialPath = potentialPath.trim();
const processed = parsePastedPaths(potentialPath, isValidPath);
if (processed) {
ch = processed;
}
}
let currentText = '';
for (const char of toCodePoints(ch)) {
if (char.codePointAt(0) === 127) {
if (currentText.length > 0) {
dispatch({ type: 'insert', payload: currentText });
currentText = '';
}
dispatch({ type: 'backspace' });
} else {
currentText += char;
}
}
if (currentText.length > 0) {
dispatch({ type: 'insert', payload: currentText });
}
},
[isValidPath, shellModeActive, singleLine],
);
const newline = useCallback((): void => {
if (singleLine) {
return;
}
dispatch({ type: 'insert', payload: '\n' });
}, [singleLine]);
const backspace = useCallback((): void => {
dispatch({ type: 'backspace' });
}, []);
const del = useCallback((): void => {
dispatch({ type: 'delete' });
}, []);
const move = useCallback(
(dir: Direction): void => {
dispatch({ type: 'move', payload: { dir } });
},
[dispatch],
);
const undo = useCallback((): void => {
dispatch({ type: 'undo' });
}, []);
const redo = useCallback((): void => {
dispatch({ type: 'redo' });
}, []);
const setText = useCallback((newText: string): void => {
dispatch({ type: 'set_text', payload: newText });
}, []);
const deleteWordLeft = useCallback((): void => {
dispatch({ type: 'delete_word_left' });
}, []);
const deleteWordRight = useCallback((): void => {
dispatch({ type: 'delete_word_right' });
}, []);
const killLineRight = useCallback((): void => {
dispatch({ type: 'kill_line_right' });
}, []);
const killLineLeft = useCallback((): void => {
dispatch({ type: 'kill_line_left' });
}, []);
// Vim-specific operations
const vimDeleteWordForward = useCallback((count: number): void => {
dispatch({ type: 'vim_delete_word_forward', payload: { count } });
}, []);
const vimDeleteWordBackward = useCallback((count: number): void => {
dispatch({ type: 'vim_delete_word_backward', payload: { count } });
}, []);
const vimDeleteWordEnd = useCallback((count: number): void => {
dispatch({ type: 'vim_delete_word_end', payload: { count } });
}, []);
const vimChangeWordForward = useCallback((count: number): void => {
dispatch({ type: 'vim_change_word_forward', payload: { count } });
}, []);
const vimChangeWordBackward = useCallback((count: number): void => {
dispatch({ type: 'vim_change_word_backward', payload: { count } });
}, []);
const vimChangeWordEnd = useCallback((count: number): void => {
dispatch({ type: 'vim_change_word_end', payload: { count } });
}, []);
const vimDeleteLine = useCallback((count: number): void => {
dispatch({ type: 'vim_delete_line', payload: { count } });
}, []);
const vimChangeLine = useCallback((count: number): void => {
dispatch({ type: 'vim_change_line', payload: { count } });
}, []);
const vimDeleteToEndOfLine = useCallback((): void => {
dispatch({ type: 'vim_delete_to_end_of_line' });
}, []);
const vimChangeToEndOfLine = useCallback((): void => {
dispatch({ type: 'vim_change_to_end_of_line' });
}, []);
const vimChangeMovement = useCallback(
(movement: 'h' | 'j' | 'k' | 'l', count: number): void => {
dispatch({ type: 'vim_change_movement', payload: { movement, count } });
},
[],
);
// New vim navigation and operation methods
const vimMoveLeft = useCallback((count: number): void => {
dispatch({ type: 'vim_move_left', payload: { count } });
}, []);
const vimMoveRight = useCallback((count: number): void => {
dispatch({ type: 'vim_move_right', payload: { count } });
}, []);
const vimMoveUp = useCallback((count: number): void => {
dispatch({ type: 'vim_move_up', payload: { count } });
}, []);
const vimMoveDown = useCallback((count: number): void => {
dispatch({ type: 'vim_move_down', payload: { count } });
}, []);
const vimMoveWordForward = useCallback((count: number): void => {
dispatch({ type: 'vim_move_word_forward', payload: { count } });
}, []);
const vimMoveWordBackward = useCallback((count: number): void => {
dispatch({ type: 'vim_move_word_backward', payload: { count } });
}, []);
const vimMoveWordEnd = useCallback((count: number): void => {
dispatch({ type: 'vim_move_word_end', payload: { count } });
}, []);
const vimDeleteChar = useCallback((count: number): void => {
dispatch({ type: 'vim_delete_char', payload: { count } });
}, []);
const vimInsertAtCursor = useCallback((): void => {
dispatch({ type: 'vim_insert_at_cursor' });
}, []);
const vimAppendAtCursor = useCallback((): void => {
dispatch({ type: 'vim_append_at_cursor' });
}, []);
const vimOpenLineBelow = useCallback((): void => {
dispatch({ type: 'vim_open_line_below' });
}, []);
const vimOpenLineAbove = useCallback((): void => {
dispatch({ type: 'vim_open_line_above' });
}, []);
const vimAppendAtLineEnd = useCallback((): void => {
dispatch({ type: 'vim_append_at_line_end' });
}, []);
const vimInsertAtLineStart = useCallback((): void => {
dispatch({ type: 'vim_insert_at_line_start' });
}, []);
const vimMoveToLineStart = useCallback((): void => {
dispatch({ type: 'vim_move_to_line_start' });
}, []);
const vimMoveToLineEnd = useCallback((): void => {
dispatch({ type: 'vim_move_to_line_end' });
}, []);
const vimMoveToFirstNonWhitespace = useCallback((): void => {
dispatch({ type: 'vim_move_to_first_nonwhitespace' });
}, []);
const vimMoveToFirstLine = useCallback((): void => {
dispatch({ type: 'vim_move_to_first_line' });
}, []);
const vimMoveToLastLine = useCallback((): void => {
dispatch({ type: 'vim_move_to_last_line' });
}, []);
const vimMoveToLine = useCallback((lineNumber: number): void => {
dispatch({ type: 'vim_move_to_line', payload: { lineNumber } });
}, []);
const vimEscapeInsertMode = useCallback((): void => {
dispatch({ type: 'vim_escape_insert_mode' });
}, []);
const openInExternalEditor = useCallback(async (): Promise<void> => {
const tmpDir = fs.mkdtempSync(pathMod.join(os.tmpdir(), 'gemini-edit-'));
const filePath = pathMod.join(tmpDir, 'buffer.txt');
fs.writeFileSync(filePath, text, 'utf8');
let command: string | undefined = undefined;
const args = [filePath];
const preferredEditorType = getPreferredEditor?.();
if (!command && preferredEditorType) {
command = getEditorCommand(preferredEditorType);
if (isGuiEditor(preferredEditorType)) {
args.unshift('--wait');
}
}
if (!command) {
command =
(process.env['VISUAL'] ??
process.env['EDITOR'] ??
process.platform === 'win32')
? 'notepad'
: 'vi';
}
dispatch({ type: 'create_undo_snapshot' });
const wasRaw = stdin?.isRaw ?? false;
try {
setRawMode?.(false);
const { status, error } = spawnSync(command, args, {
stdio: 'inherit',
});
if (error) throw error;
if (typeof status === 'number' && status !== 0)
throw new Error(`External editor exited with status ${status}`);
let newText = fs.readFileSync(filePath, 'utf8');
newText = newText.replace(/\r\n?/g, '\n');
dispatch({ type: 'set_text', payload: newText, pushToUndo: false });
} catch (err) {
coreEvents.emitFeedback(
'error',
'[useTextBuffer] external editor error',
err,
);
} finally {
coreEvents.emit(CoreEvent.ExternalEditorClosed);
if (wasRaw) setRawMode?.(true);
try {
fs.unlinkSync(filePath);
} catch {
/* ignore */
}
try {
fs.rmdirSync(tmpDir);
} catch {
/* ignore */
}
}
}, [text, stdin, setRawMode, getPreferredEditor]);
const handleInput = useCallback(
(key: Key): void => {
const { sequence: input } = key;
if (key.name === 'paste') insert(input, { paste: true });
else if (keyMatchers[Command.RETURN](key)) newline();
else if (keyMatchers[Command.MOVE_LEFT](key)) move('left');
else if (keyMatchers[Command.MOVE_RIGHT](key)) move('right');
else if (keyMatchers[Command.MOVE_UP](key)) move('up');
else if (keyMatchers[Command.MOVE_DOWN](key)) move('down');
else if (keyMatchers[Command.MOVE_WORD_LEFT](key)) move('wordLeft');
else if (keyMatchers[Command.MOVE_WORD_RIGHT](key)) move('wordRight');
else if (keyMatchers[Command.HOME](key)) move('home');
else if (keyMatchers[Command.END](key)) move('end');
else if (keyMatchers[Command.DELETE_WORD_BACKWARD](key)) deleteWordLeft();
else if (keyMatchers[Command.DELETE_WORD_FORWARD](key)) deleteWordRight();
else if (keyMatchers[Command.DELETE_CHAR_LEFT](key)) backspace();
else if (keyMatchers[Command.DELETE_CHAR_RIGHT](key)) del();
else if (keyMatchers[Command.UNDO](key)) undo();
else if (keyMatchers[Command.REDO](key)) redo();
else if (key.insertable) insert(input, { paste: false });
},
[
newline,
move,
deleteWordLeft,
deleteWordRight,
backspace,
del,
insert,
undo,
redo,
],
);
const renderedVisualLines = useMemo(
() => visualLines.slice(visualScrollRow, visualScrollRow + viewport.height),
[visualLines, visualScrollRow, viewport.height],
);
const replaceRange = useCallback(
(
startRow: number,
startCol: number,
endRow: number,
endCol: number,
text: string,
): void => {
dispatch({
type: 'replace_range',
payload: { startRow, startCol, endRow, endCol, text },
});
},
[],
);
const replaceRangeByOffset = useCallback(
(startOffset: number, endOffset: number, replacementText: string): void => {
const [startRow, startCol] = offsetToLogicalPos(text, startOffset);
const [endRow, endCol] = offsetToLogicalPos(text, endOffset);
replaceRange(startRow, startCol, endRow, endCol, replacementText);
},
[text, replaceRange],
);
const moveToOffset = useCallback((offset: number): void => {
dispatch({ type: 'move_to_offset', payload: { offset } });
}, []);
const moveToVisualPosition = useCallback(
(visRow: number, visCol: number): void => {
const {
visualLines,
visualToLogicalMap,
transformedToLogicalMaps,
visualToTransformedMap,
} = visualLayout;
// Clamp visRow to valid range
const clampedVisRow = Math.max(
0,
Math.min(visRow, visualLines.length - 1),
);
const visualLine = visualLines[clampedVisRow] || '';
if (visualToLogicalMap[clampedVisRow]) {
const [logRow] = visualToLogicalMap[clampedVisRow];
const transformedToLogicalMap =
transformedToLogicalMaps?.[logRow] ?? [];
// Where does this visual line begin within the transformed line?
const startColInTransformed =
visualToTransformedMap?.[clampedVisRow] ?? 0;
// Handle wide characters: convert visual X position to character offset
const codePoints = toCodePoints(visualLine);
let currentVisX = 0;
let charOffset = 0;
for (const char of codePoints) {
const charWidth = getCachedStringWidth(char);
// If the click is within this character
if (visCol < currentVisX + charWidth) {
// Check if we clicked the second half of a wide character
if (charWidth > 1 && visCol >= currentVisX + charWidth / 2) {
charOffset++;
}
break;
}
currentVisX += charWidth;
charOffset++;
}
// Clamp charOffset to length
charOffset = Math.min(charOffset, codePoints.length);
// Map character offset through transformations to get logical position
const transformedCol = Math.min(
startColInTransformed + charOffset,
Math.max(0, transformedToLogicalMap.length - 1),
);
const newCursorRow = logRow;
const newCursorCol =
transformedToLogicalMap[transformedCol] ?? cpLen(lines[logRow] ?? '');
dispatch({
type: 'set_cursor',
payload: {
cursorRow: newCursorRow,
cursorCol: newCursorCol,
preferredCol: charOffset,
},
});
}
},
[visualLayout, lines],
);
const getOffset = useCallback(
(): number => logicalPosToOffset(lines, cursorRow, cursorCol),
[lines, cursorRow, cursorCol],
);
const returnValue: TextBuffer = useMemo(
() => ({
lines,
text,
cursor: [cursorRow, cursorCol],
preferredCol,
selectionAnchor,
allVisualLines: visualLines,
viewportVisualLines: renderedVisualLines,
visualCursor,
visualScrollRow,
visualToLogicalMap,
transformedToLogicalMaps,
visualToTransformedMap,
transformationsByLine,
visualLayout,
setText,
insert,
newline,
backspace,
del,
move,
undo,
redo,
replaceRange,
replaceRangeByOffset,
moveToOffset,
getOffset,
moveToVisualPosition,
deleteWordLeft,
deleteWordRight,
killLineRight,
killLineLeft,
handleInput,
openInExternalEditor,
// Vim-specific operations
vimDeleteWordForward,
vimDeleteWordBackward,
vimDeleteWordEnd,
vimChangeWordForward,
vimChangeWordBackward,
vimChangeWordEnd,
vimDeleteLine,
vimChangeLine,
vimDeleteToEndOfLine,
vimChangeToEndOfLine,
vimChangeMovement,
vimMoveLeft,
vimMoveRight,
vimMoveUp,
vimMoveDown,
vimMoveWordForward,
vimMoveWordBackward,
vimMoveWordEnd,
vimDeleteChar,
vimInsertAtCursor,
vimAppendAtCursor,
vimOpenLineBelow,
vimOpenLineAbove,
vimAppendAtLineEnd,
vimInsertAtLineStart,
vimMoveToLineStart,
vimMoveToLineEnd,
vimMoveToFirstNonWhitespace,
vimMoveToFirstLine,
vimMoveToLastLine,
vimMoveToLine,
vimEscapeInsertMode,
}),
[
lines,
text,
cursorRow,
cursorCol,
preferredCol,
selectionAnchor,
visualLines,
renderedVisualLines,
visualCursor,
visualScrollRow,
visualToLogicalMap,
transformedToLogicalMaps,
visualToTransformedMap,
transformationsByLine,
visualLayout,
setText,
insert,
newline,
backspace,
del,
move,
undo,
redo,
replaceRange,
replaceRangeByOffset,
moveToOffset,
getOffset,
moveToVisualPosition,
deleteWordLeft,
deleteWordRight,
killLineRight,
killLineLeft,
handleInput,
openInExternalEditor,
vimDeleteWordForward,
vimDeleteWordBackward,
vimDeleteWordEnd,
vimChangeWordForward,
vimChangeWordBackward,
vimChangeWordEnd,
vimDeleteLine,
vimChangeLine,
vimDeleteToEndOfLine,
vimChangeToEndOfLine,
vimChangeMovement,
vimMoveLeft,
vimMoveRight,
vimMoveUp,
vimMoveDown,
vimMoveWordForward,
vimMoveWordBackward,
vimMoveWordEnd,
vimDeleteChar,
vimInsertAtCursor,
vimAppendAtCursor,
vimOpenLineBelow,
vimOpenLineAbove,
vimAppendAtLineEnd,
vimInsertAtLineStart,
vimMoveToLineStart,
vimMoveToLineEnd,
vimMoveToFirstNonWhitespace,
vimMoveToFirstLine,
vimMoveToLastLine,
vimMoveToLine,
vimEscapeInsertMode,
],
);
return returnValue;
}
export interface TextBuffer {
// State
lines: string[]; // Logical lines
text: string;
cursor: [number, number]; // Logical cursor [row, col]
/**
* When the user moves the caret vertically we try to keep their original
* horizontal column even when passing through shorter lines. We remember
* that *preferred* column in this field while the user is still travelling
* vertically. Any explicit horizontal movement resets the preference.
*/
preferredCol: number | null; // Preferred visual column
selectionAnchor: [number, number] | null; // Logical selection anchor
// Visual state (handles wrapping)
allVisualLines: string[]; // All visual lines for the current text and viewport width.
viewportVisualLines: string[]; // The subset of visual lines to be rendered based on visualScrollRow and viewport.height
visualCursor: [number, number]; // Visual cursor [row, col] relative to the start of all visualLines
visualScrollRow: number; // Scroll position for visual lines (index of the first visible visual line)
/**
* For each visual line (by absolute index in allVisualLines) provides a tuple
* [logicalLineIndex, startColInLogical] that maps where that visual line
* begins within the logical buffer. Indices are code-point based.
*/
visualToLogicalMap: Array<[number, number]>;
/**
* For each logical line, an array mapping transformed positions (in the transformed
* line) back to logical column indices.
*/
transformedToLogicalMaps: number[][];
/**
* For each visual line (absolute index across all visual lines), the start index
* within that logical line's transformed content.
*/
visualToTransformedMap: number[];
/** Cached transformations per logical line */
transformationsByLine: Transformation[][];
visualLayout: VisualLayout;
// Actions
/**
* Replaces the entire buffer content with the provided text.
* The operation is undoable.
*/
setText: (text: string) => void;
/**
* Insert a single character or string without newlines.
*/
insert: (ch: string, opts?: { paste?: boolean }) => void;
newline: () => void;
backspace: () => void;
del: () => void;
move: (dir: Direction) => void;
undo: () => void;
redo: () => void;
/**
* Replaces the text within the specified range with new text.
* Handles both single-line and multi-line ranges.
*
* @param startRow The starting row index (inclusive).
* @param startCol The starting column index (inclusive, code-point based).
* @param endRow The ending row index (inclusive).
* @param endCol The ending column index (exclusive, code-point based).
* @param text The new text to insert.
* @returns True if the buffer was modified, false otherwise.
*/
replaceRange: (
startRow: number,
startCol: number,
endRow: number,
endCol: number,
text: string,
) => void;
/**
* Delete the word to the *left* of the caret, mirroring common
* Ctrl/Alt+Backspace behaviour in editors & terminals. Both the adjacent
* whitespace *and* the word characters immediately preceding the caret are
* removed. If the caret is already at column0 this becomes a no-op.
*/
deleteWordLeft: () => void;
/**
* Delete the word to the *right* of the caret, akin to many editors'
* Ctrl/Alt+Delete shortcut. Removes any whitespace/punctuation that
* follows the caret and the next contiguous run of word characters.
*/
deleteWordRight: () => void;
/**
* Deletes text from the cursor to the end of the current line.
*/
killLineRight: () => void;
/**
* Deletes text from the start of the current line to the cursor.
*/
killLineLeft: () => void;
/**
* High level "handleInput" receives what Ink gives us.
*/
handleInput: (key: Key) => void;
/**
* Opens the current buffer contents in the user's preferred terminal text
* editor ($VISUAL or $EDITOR, falling back to "vi"). The method blocks
* until the editor exits, then reloads the file and replaces the inmemory
* buffer with whatever the user saved.
*
* The operation is treated as a single undoable edit we snapshot the
* previous state *once* before launching the editor so one `undo()` will
* revert the entire change set.
*
* Note: We purposefully rely on the *synchronous* spawn API so that the
* calling process genuinely waits for the editor to close before
* continuing. This mirrors Git's behaviour and simplifies downstream
* controlflow (callers can simply `await` the Promise).
*/
openInExternalEditor: () => Promise<void>;
replaceRangeByOffset: (
startOffset: number,
endOffset: number,
replacementText: string,
) => void;
getOffset: () => number;
moveToOffset(offset: number): void;
moveToVisualPosition(visualRow: number, visualCol: number): void;
// Vim-specific operations
/**
* Delete N words forward from cursor position (vim 'dw' command)
*/
vimDeleteWordForward: (count: number) => void;
/**
* Delete N words backward from cursor position (vim 'db' command)
*/
vimDeleteWordBackward: (count: number) => void;
/**
* Delete to end of N words from cursor position (vim 'de' command)
*/
vimDeleteWordEnd: (count: number) => void;
/**
* Change N words forward from cursor position (vim 'cw' command)
*/
vimChangeWordForward: (count: number) => void;
/**
* Change N words backward from cursor position (vim 'cb' command)
*/
vimChangeWordBackward: (count: number) => void;
/**
* Change to end of N words from cursor position (vim 'ce' command)
*/
vimChangeWordEnd: (count: number) => void;
/**
* Delete N lines from cursor position (vim 'dd' command)
*/
vimDeleteLine: (count: number) => void;
/**
* Change N lines from cursor position (vim 'cc' command)
*/
vimChangeLine: (count: number) => void;
/**
* Delete from cursor to end of line (vim 'D' command)
*/
vimDeleteToEndOfLine: () => void;
/**
* Change from cursor to end of line (vim 'C' command)
*/
vimChangeToEndOfLine: () => void;
/**
* Change movement operations (vim 'ch', 'cj', 'ck', 'cl' commands)
*/
vimChangeMovement: (movement: 'h' | 'j' | 'k' | 'l', count: number) => void;
/**
* Move cursor left N times (vim 'h' command)
*/
vimMoveLeft: (count: number) => void;
/**
* Move cursor right N times (vim 'l' command)
*/
vimMoveRight: (count: number) => void;
/**
* Move cursor up N times (vim 'k' command)
*/
vimMoveUp: (count: number) => void;
/**
* Move cursor down N times (vim 'j' command)
*/
vimMoveDown: (count: number) => void;
/**
* Move cursor forward N words (vim 'w' command)
*/
vimMoveWordForward: (count: number) => void;
/**
* Move cursor backward N words (vim 'b' command)
*/
vimMoveWordBackward: (count: number) => void;
/**
* Move cursor to end of Nth word (vim 'e' command)
*/
vimMoveWordEnd: (count: number) => void;
/**
* Delete N characters at cursor (vim 'x' command)
*/
vimDeleteChar: (count: number) => void;
/**
* Enter insert mode at cursor (vim 'i' command)
*/
vimInsertAtCursor: () => void;
/**
* Enter insert mode after cursor (vim 'a' command)
*/
vimAppendAtCursor: () => void;
/**
* Open new line below and enter insert mode (vim 'o' command)
*/
vimOpenLineBelow: () => void;
/**
* Open new line above and enter insert mode (vim 'O' command)
*/
vimOpenLineAbove: () => void;
/**
* Move to end of line and enter insert mode (vim 'A' command)
*/
vimAppendAtLineEnd: () => void;
/**
* Move to first non-whitespace and enter insert mode (vim 'I' command)
*/
vimInsertAtLineStart: () => void;
/**
* Move cursor to beginning of line (vim '0' command)
*/
vimMoveToLineStart: () => void;
/**
* Move cursor to end of line (vim '$' command)
*/
vimMoveToLineEnd: () => void;
/**
* Move cursor to first non-whitespace character (vim '^' command)
*/
vimMoveToFirstNonWhitespace: () => void;
/**
* Move cursor to first line (vim 'gg' command)
*/
vimMoveToFirstLine: () => void;
/**
* Move cursor to last line (vim 'G' command)
*/
vimMoveToLastLine: () => void;
/**
* Move cursor to specific line number (vim '[N]G' command)
*/
vimMoveToLine: (lineNumber: number) => void;
/**
* Handle escape from insert mode (moves cursor left if not at line start)
*/
vimEscapeInsertMode: () => void;
}