monaco-editor-core
Version:
A browser based code editor
269 lines (268 loc) • 8.72 kB
JavaScript
/*---------------------------------------------------------------------------------------------
* Copyright (c) Microsoft Corporation. All rights reserved.
* Licensed under the MIT License. See License.txt in the project root for license information.
*--------------------------------------------------------------------------------------------*/
import { strictEquals } from '../equals.js';
import { DebugNameData, getFunctionName } from './debugName.js';
import { getLogger } from './logging.js';
let _recomputeInitiallyAndOnChange;
export function _setRecomputeInitiallyAndOnChange(recomputeInitiallyAndOnChange) {
_recomputeInitiallyAndOnChange = recomputeInitiallyAndOnChange;
}
let _keepObserved;
export function _setKeepObserved(keepObserved) {
_keepObserved = keepObserved;
}
let _derived;
/**
* @internal
* This is to allow splitting files.
*/
export function _setDerivedOpts(derived) {
_derived = derived;
}
export class ConvenientObservable {
get TChange() { return null; }
reportChanges() {
this.get();
}
/** @sealed */
read(reader) {
if (reader) {
return reader.readObservable(this);
}
else {
return this.get();
}
}
map(fnOrOwner, fnOrUndefined) {
const owner = fnOrUndefined === undefined ? undefined : fnOrOwner;
const fn = fnOrUndefined === undefined ? fnOrOwner : fnOrUndefined;
return _derived({
owner,
debugName: () => {
const name = getFunctionName(fn);
if (name !== undefined) {
return name;
}
// regexp to match `x => x.y` or `x => x?.y` where x and y can be arbitrary identifiers (uses backref):
const regexp = /^\s*\(?\s*([a-zA-Z_$][a-zA-Z_$0-9]*)\s*\)?\s*=>\s*\1(?:\??)\.([a-zA-Z_$][a-zA-Z_$0-9]*)\s*$/;
const match = regexp.exec(fn.toString());
if (match) {
return `${this.debugName}.${match[2]}`;
}
if (!owner) {
return `${this.debugName} (mapped)`;
}
return undefined;
},
debugReferenceFn: fn,
}, (reader) => fn(this.read(reader), reader));
}
/**
* @sealed
* Converts an observable of an observable value into a direct observable of the value.
*/
flatten() {
return _derived({
owner: undefined,
debugName: () => `${this.debugName} (flattened)`,
}, (reader) => this.read(reader).read(reader));
}
recomputeInitiallyAndOnChange(store, handleValue) {
store.add(_recomputeInitiallyAndOnChange(this, handleValue));
return this;
}
/**
* Ensures that this observable is observed. This keeps the cache alive.
* However, in case of deriveds, it does not force eager evaluation (only when the value is read/get).
* Use `recomputeInitiallyAndOnChange` for eager evaluation.
*/
keepObserved(store) {
store.add(_keepObserved(this));
return this;
}
}
export class BaseObservable extends ConvenientObservable {
constructor() {
super(...arguments);
this.observers = new Set();
}
addObserver(observer) {
const len = this.observers.size;
this.observers.add(observer);
if (len === 0) {
this.onFirstObserverAdded();
}
}
removeObserver(observer) {
const deleted = this.observers.delete(observer);
if (deleted && this.observers.size === 0) {
this.onLastObserverRemoved();
}
}
onFirstObserverAdded() { }
onLastObserverRemoved() { }
}
/**
* Starts a transaction in which many observables can be changed at once.
* {@link fn} should start with a JS Doc using `@description` to give the transaction a debug name.
* Reaction run on demand or when the transaction ends.
*/
export function transaction(fn, getDebugName) {
const tx = new TransactionImpl(fn, getDebugName);
try {
fn(tx);
}
finally {
tx.finish();
}
}
let _globalTransaction = undefined;
export function globalTransaction(fn) {
if (_globalTransaction) {
fn(_globalTransaction);
}
else {
const tx = new TransactionImpl(fn, undefined);
_globalTransaction = tx;
try {
fn(tx);
}
finally {
tx.finish(); // During finish, more actions might be added to the transaction.
// Which is why we only clear the global transaction after finish.
_globalTransaction = undefined;
}
}
}
export async function asyncTransaction(fn, getDebugName) {
const tx = new TransactionImpl(fn, getDebugName);
try {
await fn(tx);
}
finally {
tx.finish();
}
}
/**
* Allows to chain transactions.
*/
export function subtransaction(tx, fn, getDebugName) {
if (!tx) {
transaction(fn, getDebugName);
}
else {
fn(tx);
}
}
export class TransactionImpl {
constructor(_fn, _getDebugName) {
this._fn = _fn;
this._getDebugName = _getDebugName;
this.updatingObservers = [];
getLogger()?.handleBeginTransaction(this);
}
getDebugName() {
if (this._getDebugName) {
return this._getDebugName();
}
return getFunctionName(this._fn);
}
updateObserver(observer, observable) {
// When this gets called while finish is active, they will still get considered
this.updatingObservers.push({ observer, observable });
observer.beginUpdate(observable);
}
finish() {
const updatingObservers = this.updatingObservers;
for (let i = 0; i < updatingObservers.length; i++) {
const { observer, observable } = updatingObservers[i];
observer.endUpdate(observable);
}
// Prevent anyone from updating observers from now on.
this.updatingObservers = null;
getLogger()?.handleEndTransaction();
}
}
export function observableValue(nameOrOwner, initialValue) {
let debugNameData;
if (typeof nameOrOwner === 'string') {
debugNameData = new DebugNameData(undefined, nameOrOwner, undefined);
}
else {
debugNameData = new DebugNameData(nameOrOwner, undefined, undefined);
}
return new ObservableValue(debugNameData, initialValue, strictEquals);
}
export class ObservableValue extends BaseObservable {
get debugName() {
return this._debugNameData.getDebugName(this) ?? 'ObservableValue';
}
constructor(_debugNameData, initialValue, _equalityComparator) {
super();
this._debugNameData = _debugNameData;
this._equalityComparator = _equalityComparator;
this._value = initialValue;
}
get() {
return this._value;
}
set(value, tx, change) {
if (change === undefined && this._equalityComparator(this._value, value)) {
return;
}
let _tx;
if (!tx) {
tx = _tx = new TransactionImpl(() => { }, () => `Setting ${this.debugName}`);
}
try {
const oldValue = this._value;
this._setValue(value);
getLogger()?.handleObservableChanged(this, { oldValue, newValue: value, change, didChange: true, hadValue: true });
for (const observer of this.observers) {
tx.updateObserver(observer, this);
observer.handleChange(this, change);
}
}
finally {
if (_tx) {
_tx.finish();
}
}
}
toString() {
return `${this.debugName}: ${this._value}`;
}
_setValue(newValue) {
this._value = newValue;
}
}
/**
* A disposable observable. When disposed, its value is also disposed.
* When a new value is set, the previous value is disposed.
*/
export function disposableObservableValue(nameOrOwner, initialValue) {
let debugNameData;
if (typeof nameOrOwner === 'string') {
debugNameData = new DebugNameData(undefined, nameOrOwner, undefined);
}
else {
debugNameData = new DebugNameData(nameOrOwner, undefined, undefined);
}
return new DisposableObservableValue(debugNameData, initialValue, strictEquals);
}
export class DisposableObservableValue extends ObservableValue {
_setValue(newValue) {
if (this._value === newValue) {
return;
}
if (this._value) {
this._value.dispose();
}
this._value = newValue;
}
dispose() {
this._value?.dispose();
}
}