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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";
const TrackChangeEmitter = require("resource://devtools/server/actors/utils/track-change-emitter.js");
/**
* The ChangesActor stores a stack of changes made by devtools on
* the document in the associated tab.
*/
class ChangesActor extends Actor {
/**
* Create a ChangesActor.
*
* @param {DevToolsServerConnection} conn
* The server connection.
* @param {TargetActor} targetActor
* The top-level Actor for this tab.
*/
constructor(conn, targetActor) {
super(conn, changesSpec);
this.targetActor = targetActor;
this.onTrackChange = this.pushChange.bind(this);
this.onWillNavigate = this.onWillNavigate.bind(this);
TrackChangeEmitter.on("track-change", this.onTrackChange);
this.targetActor.on("will-navigate", this.onWillNavigate);
this.changes = [];
}
destroy() {
// Stop trying to emit RDP event on destruction.
this._changesHaveBeenRequested = false;
this.clearChanges();
this.targetActor.off("will-navigate", this.onWillNavigate);
TrackChangeEmitter.off("track-change", this.onTrackChange);
super.destroy();
}
start() {
/**
* This function currently does nothing and returns nothing. It exists only
* so that the client can trigger the creation of the ChangesActor through
* the front, without triggering side effects, and with a sensible semantic
* meaning.
*/
}
changeCount() {
return this.changes.length;
}
change(index) {
if (index >= 0 && index < this.changes.length) {
// Return a copy of the change at index.
return Object.assign({}, this.changes[index]);
}
// No change at that index -- return undefined.
return undefined;
}
allChanges() {
/**
* This function is called by all change event consumers on the client
* to get their initial state synchronized with the ChangesActor. We
* set a flag when this function is called so we know that it's worthwhile
* to send events.
*/
this._changesHaveBeenRequested = true;
return this.changes.slice();
}
/**
* Handler for "will-navigate" event from the browsing context. The event is fired for
* the host page and any nested resources, like iframes. The list of changes should be
* cleared only when the host page navigates, ignoring any of its iframes.
*
*
* @param {Object} eventData
* Event data with these properties:
* {
* window: Object // Window DOM object of the event source page
* isTopLevel: Boolean // true if the host page will navigate
* newURI: String // URI towards which the page will navigate
* request: Object // Request data.
* }
*/
onWillNavigate(eventData) {
if (eventData.isTopLevel) {
this.clearChanges();
}
}
pushChange(change) {
this.changes.push(change);
if (this._changesHaveBeenRequested) {
this.emit("add-change", change);
}
}
popChange() {
const change = this.changes.pop();
if (this._changesHaveBeenRequested) {
this.emit("remove-change", change);
}
return change;
}
clearChanges() {
this.changes.length = 0;
if (this._changesHaveBeenRequested) {
this.emit("clear-changes");
}
}
}
exports.ChangesActor = ChangesActor;