monaco-editor
Version:
A browser based code editor
124 lines (121 loc) • 5.03 kB
JavaScript
import { subtransaction } from '../transaction.js';
import { strictEquals } from '../../equals.js';
import '../../event.js';
import '../../lifecycle.js';
import { DebugNameData } from '../debugName.js';
import { getLogger } from '../logging/logging.js';
import { BaseObservable } from './baseObservable.js';
import { DebugLocation } from '../debugLocation.js';
/*---------------------------------------------------------------------------------------------
* Copyright (c) Microsoft Corporation. All rights reserved.
* Licensed under the MIT License. See License.txt in the project root for license information.
*--------------------------------------------------------------------------------------------*/
function observableFromEvent(...args) {
let owner;
let event;
let getValue;
let debugLocation;
if (args.length === 2) {
[event, getValue] = args;
}
else {
[owner, event, getValue, debugLocation] = args;
}
return new FromEventObservable(new DebugNameData(owner, undefined, getValue), event, getValue, () => FromEventObservable.globalTransaction, strictEquals, debugLocation ?? DebugLocation.ofCaller());
}
function observableFromEventOpts(options, event, getValue, debugLocation = DebugLocation.ofCaller()) {
return new FromEventObservable(new DebugNameData(options.owner, options.debugName, options.debugReferenceFn ?? getValue), event, getValue, () => FromEventObservable.globalTransaction, options.equalsFn ?? strictEquals, debugLocation);
}
class FromEventObservable extends BaseObservable {
constructor(_debugNameData, event, _getValue, _getTransaction, _equalityComparator, debugLocation) {
super(debugLocation);
this._debugNameData = _debugNameData;
this.event = event;
this._getValue = _getValue;
this._getTransaction = _getTransaction;
this._equalityComparator = _equalityComparator;
this._hasValue = false;
this.handleEvent = (args) => {
const newValue = this._getValue(args);
const oldValue = this._value;
const didChange = !this._hasValue || !(this._equalityComparator(oldValue, newValue));
let didRunTransaction = false;
if (didChange) {
this._value = newValue;
if (this._hasValue) {
didRunTransaction = true;
subtransaction(this._getTransaction(), (tx) => {
getLogger()?.handleObservableUpdated(this, { oldValue, newValue, change: undefined, didChange, hadValue: this._hasValue });
for (const o of this._observers) {
tx.updateObserver(o, this);
o.handleChange(this, undefined);
}
}, () => {
const name = this.getDebugName();
return 'Event fired' + (name ? `: ${name}` : '');
});
}
this._hasValue = true;
}
if (!didRunTransaction) {
getLogger()?.handleObservableUpdated(this, { oldValue, newValue, change: undefined, didChange, hadValue: this._hasValue });
}
};
}
getDebugName() {
return this._debugNameData.getDebugName(this);
}
get debugName() {
const name = this.getDebugName();
return 'From Event' + (name ? `: ${name}` : '');
}
onFirstObserverAdded() {
this._subscription = this.event(this.handleEvent);
}
onLastObserverRemoved() {
this._subscription.dispose();
this._subscription = undefined;
this._hasValue = false;
this._value = undefined;
}
get() {
if (this._subscription) {
if (!this._hasValue) {
this.handleEvent(undefined);
}
return this._value;
}
else {
// no cache, as there are no subscribers to keep it updated
const value = this._getValue(undefined);
return value;
}
}
debugSetValue(value) {
// eslint-disable-next-line local/code-no-any-casts
this._value = value;
}
debugGetState() {
return { value: this._value, hasValue: this._hasValue };
}
}
(function (observableFromEvent) {
observableFromEvent.Observer = FromEventObservable;
function batchEventsGlobally(tx, fn) {
let didSet = false;
if (FromEventObservable.globalTransaction === undefined) {
FromEventObservable.globalTransaction = tx;
didSet = true;
}
try {
fn();
}
finally {
if (didSet) {
FromEventObservable.globalTransaction = undefined;
}
}
}
observableFromEvent.batchEventsGlobally = batchEventsGlobally;
})(observableFromEvent || (observableFromEvent = {}));
export { FromEventObservable, observableFromEvent, observableFromEventOpts };