Source code
Revision control
Copy as Markdown
Other Tools
/* 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";
/**
* WalkerEventListener provides a mechanism to listen the walker event of the inspector
* while reflecting the updating of TargetCommand.
*/
class WalkerEventListener {
/**
* @param {Inspector} - inspector
* @param {Object} - listenerMap
* The structure of listenerMap should be as follows.
* {
* walkerEventName1: eventHandler1,
* walkerEventName2: eventHandler2,
* ...
* }
*/
constructor(inspector, listenerMap) {
this._inspector = inspector;
this._listenerMap = listenerMap;
this._onTargetAvailable = this._onTargetAvailable.bind(this);
this._onTargetDestroyed = this._onTargetDestroyed.bind(this);
this._init();
}
/**
* Clean up function.
*/
destroy() {
this._inspector.commands.targetCommand.unwatchTargets({
types: [this._inspector.commands.targetCommand.TYPES.FRAME],
onAvailable: this._onTargetAvailable,
onDestroyed: this._onTargetDestroyed,
});
const targets = this._inspector.commands.targetCommand.getAllTargets([
this._inspector.commands.targetCommand.TYPES.FRAME,
]);
for (const targetFront of targets) {
this._onTargetDestroyed({
targetFront,
});
}
this._inspector = null;
this._listenerMap = null;
}
_init() {
this._inspector.commands.targetCommand.watchTargets({
types: [this._inspector.commands.targetCommand.TYPES.FRAME],
onAvailable: this._onTargetAvailable,
onDestroyed: this._onTargetDestroyed,
});
}
async _onTargetAvailable({ targetFront }) {
const inspectorFront = await targetFront.getFront("inspector");
// In case of multiple fast navigations, the front may already be destroyed,
// in such scenario bail out and ignore this short lived target.
if (inspectorFront.isDestroyed() || !this._listenerMap) {
return;
}
const { walker } = inspectorFront;
for (const [name, listener] of Object.entries(this._listenerMap)) {
walker.on(name, listener);
}
}
_onTargetDestroyed({ targetFront }) {
const inspectorFront = targetFront.getCachedFront("inspector");
if (inspectorFront) {
const { walker } = inspectorFront;
for (const [name, listener] of Object.entries(this._listenerMap)) {
walker.off(name, listener);
}
}
}
}
module.exports = WalkerEventListener;