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// Copyright (c) 2022, Compiler Explorer Authors
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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import GoldenLayout from 'golden-layout';
import Sentry from '@sentry/browser';
import {Hub} from './hub';
export type EventHubCallback<T extends unknown[]> = (...args: T) => void;
export interface DependencyProxies<T1 extends unknown[], T2 extends unknown[] = T1> {
dependencyProxy: EventHubCallback<T1>;
dependentProxy: EventHubCallback<T2>;
}
export interface Event<T extends unknown[], C = any> {
evt: string;
fn: EventHubCallback<T>;
ctx?: C;
}
/**
* Event Hub which is enclosed inside a Hub, allowing for dependent calls and
* deferred execution based on the parent Hub.
*/
export class EventHub {
private readonly hub: Hub;
private readonly layoutEventHub: GoldenLayout.EventEmitter;
private subscriptions: Event<any>[] = [];
public constructor(hub: any, layoutEventHub: GoldenLayout.EventEmitter) {
this.hub = hub;
this.layoutEventHub = layoutEventHub;
}
/**
* Emit an event to the layout event hub.
*
* Events are deferred by the parent hub during initialization to allow all
* components to install their listeners before the emission is performed.
* This fixes some ordering issues.
*/
public emit(event: string, ...args: unknown[]): void {
if (this.hub.deferred) {
this.hub.deferredEmissions.push([event, ...args]);
} else {
this.layoutEventHub.emit(event, ...args);
}
}
/** Attach a listener to the layout event hub. */
public on<T extends unknown[], C = any>(event: string, callback: EventHubCallback<T>, context?: C): void {
this.layoutEventHub.on(event, callback, context);
this.subscriptions.push({evt: event, fn: callback, ctx: context});
}
/** Remove all listeners from the layout event hub. */
public unsubscribe(): void {
for (const subscription of this.subscriptions) {
try {
this.layoutEventHub.off(subscription.evt, subscription.fn, subscription.ctx);
} catch (e) {
Sentry.captureMessage(`Can not unsubscribe from ${subscription.evt.toString()}`);
Sentry.captureException(e);
}
}
this.subscriptions = [];
}
public mediateDependentCalls<T1 extends unknown[], T2 extends unknown[] = T1>(
dependent: EventHubCallback<any>,
dependency: EventHubCallback<any>
): DependencyProxies<T1, T2> {
let hasDependencyExecuted = false;
let lastDependentArguments: unknown[] | null = null;
const dependencyProxy = function (this: unknown, ...args: unknown[]) {
dependency.apply(this, args);
hasDependencyExecuted = true;
if (lastDependentArguments) {
dependent.apply(this, lastDependentArguments);
lastDependentArguments = null;
}
};
const dependentProxy = function (this: unknown, ...args: unknown[]) {
if (hasDependencyExecuted) {
dependent.apply(this, args);
} else {
lastDependentArguments = args;
}
};
return {dependencyProxy, dependentProxy};
}
}