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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
"use strict";
/**
* The CustomElementWatcher can be used to be notified if a custom element definition
* is created for a node.
*
* When a custom element is defined for a monitored name, an "element-defined" event is
* fired with the following Object argument:
* - {String} name: name of the custom element defined
* - {Set} Set of impacted node actors
*/
class CustomElementWatcher extends EventEmitter {
constructor(chromeEventHandler) {
super();
this.chromeEventHandler = chromeEventHandler;
this._onCustomElementDefined = this._onCustomElementDefined.bind(this);
this.chromeEventHandler.addEventListener(
"customelementdefined",
this._onCustomElementDefined
);
/**
* Each window keeps its own custom element registry, all of them are watched
* separately. The struture of the watchedRegistries is as follows
*
* WeakMap(
* registry -> Map (
* name -> Set(NodeActors)
* )
* )
*/
this.watchedRegistries = new WeakMap();
}
destroy() {
this.watchedRegistries = null;
this.chromeEventHandler.removeEventListener(
"customelementdefined",
this._onCustomElementDefined
);
}
/**
* Watch for custom element definitions matching the name of the provided NodeActor.
*/
manageNode(nodeActor) {
if (!this._isValidNode(nodeActor)) {
return;
}
if (!this._shouldWatchDefinition(nodeActor)) {
return;
}
const registry = nodeActor.rawNode.ownerGlobal.customElements;
const registryMap = this._getMapForRegistry(registry);
const name = nodeActor.rawNode.localName;
const actorsSet = this._getActorsForName(name, registryMap);
actorsSet.add(nodeActor);
}
/**
* Stop watching the provided NodeActor.
*/
unmanageNode(nodeActor) {
if (!this._isValidNode(nodeActor)) {
return;
}
const win = nodeActor.rawNode.ownerGlobal;
const registry = win.customElements;
const registryMap = this._getMapForRegistry(registry);
const name = nodeActor.rawNode.localName;
if (registryMap.has(name)) {
registryMap.get(name).delete(nodeActor);
}
}
/**
* Retrieve the map of name->nodeActors for a given CustomElementsRegistry.
* Will create the map if not created yet.
*/
_getMapForRegistry(registry) {
if (!this.watchedRegistries.has(registry)) {
this.watchedRegistries.set(registry, new Map());
}
return this.watchedRegistries.get(registry);
}
/**
* Retrieve the set of nodeActors for a given name and registry.
* Will create the set if not created yet.
*/
_getActorsForName(name, registryMap) {
if (!registryMap.has(name)) {
registryMap.set(name, new Set());
}
return registryMap.get(name);
}
_shouldWatchDefinition(nodeActor) {
const doc = nodeActor.rawNode.ownerDocument;
const namespaceURI = doc.documentElement.namespaceURI;
const name = nodeActor.rawNode.localName;
const isValidName = InspectorUtils.isCustomElementName(name, namespaceURI);
const customElements = doc.defaultView.customElements;
return isValidName && !customElements.get(name);
}
_onCustomElementDefined(event) {
const doc = event.target;
const registry = doc.defaultView.customElements;
const registryMap = this._getMapForRegistry(registry);
const name = event.detail;
const actors = this._getActorsForName(name, registryMap);
this.emit("element-defined", { name, actors });
registryMap.delete(name);
}
/**
* Some nodes (e.g. inside of <template> tags) don't have a documentElement or an
* ownerGlobal and can't be watched by this helper.
*/
_isValidNode(nodeActor) {
const node = nodeActor.rawNode;
return (
!Cu.isDeadWrapper(node) &&
node.ownerGlobal &&
node.ownerDocument?.documentElement
);
}
}
exports.CustomElementWatcher = CustomElementWatcher;