gecko-dev/dom/apps/MessageBroadcaster.jsm

133 lines
3.5 KiB
JavaScript

/* 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 file,
* You can obtain one at http://mozilla.org/MPL/2.0/. */
"use strict";
// Manages registration of message managers from child processes and
// broadcasting messages to them.
this.EXPORTED_SYMBOLS = ["MessageBroadcaster"];
this.MessageBroadcaster = {
appGetter: null,
children: [],
init: function(aAppGetter) {
if (!aAppGetter || typeof aAppGetter !== "function") {
throw "MessageBroadcaster.init needs a function parameter";
}
this.appGetter = aAppGetter;
},
// We manage refcounting of listeners per message manager.
addMessageListener: function(aMsgNames, aApp, aMm) {
aMsgNames.forEach(aMsgName => {
let manifestURL = aApp && aApp.manifestURL;
if (!(aMsgName in this.children)) {
this.children[aMsgName] = [];
}
let mmFound = this.children[aMsgName].some(mmRef => {
if (mmRef.mm === aMm) {
mmRef.refCount++;
return true;
}
return false;
});
if (!mmFound) {
this.children[aMsgName].push({
mm: aMm,
refCount: 1
});
}
// If the state reported by the registration is outdated, update it now.
if (manifestURL && ((aMsgName === 'Webapps:FireEvent') ||
(aMsgName === 'Webapps:UpdateState'))) {
let app = this.appGetter(aApp.manifestURL);
if (app && ((aApp.installState !== app.installState) ||
(aApp.downloading !== app.downloading))) {
debug("Got a registration from an outdated app: " +
manifestURL);
let aEvent ={
type: app.installState,
app: app,
manifestURL: app.manifestURL,
manifest: app.manifest
};
aMm.sendAsyncMessage(aMsgName, aEvent);
}
}
});
},
removeMessageListener: function(aMsgNames, aMm) {
if (aMsgNames.length === 1 &&
aMsgNames[0] === "Webapps:Internal:AllMessages") {
for (let msgName in this.children) {
let msg = this.children[msgName];
for (let mmI = msg.length - 1; mmI >= 0; mmI -= 1) {
let mmRef = msg[mmI];
if (mmRef.mm === aMm) {
msg.splice(mmI, 1);
}
}
if (msg.length === 0) {
delete this.children[msgName];
}
}
return;
}
aMsgNames.forEach(aMsgName => {
if (!(aMsgName in this.children)) {
return;
}
let removeIndex;
this.children[aMsgName].some((mmRef, index) => {
if (mmRef.mm === aMm) {
mmRef.refCount--;
if (mmRef.refCount === 0) {
removeIndex = index;
}
return true;
}
return false;
});
if (removeIndex) {
this.children[aMsgName].splice(removeIndex, 1);
}
});
},
// Some messages can be listened by several content processes:
// Webapps:AddApp
// Webapps:RemoveApp
// Webapps:Install:Return:OK
// Webapps:Uninstall:Return:OK
// Webapps:Uninstall:Broadcast:Return:OK
// Webapps:FireEvent
// Webapps:checkForUpdate:Return:OK
// Webapps:UpdateState
broadcastMessage: function(aMsgName, aContent) {
if (!(aMsgName in this.children)) {
return;
}
this.children[aMsgName].forEach((mmRef) => {
mmRef.mm.sendAsyncMessage(aMsgName, this.formatMessage(aContent));
});
},
formatMessage: function(aData) {
let msg = aData;
delete msg["mm"];
return msg;
},
}