The Tor Browser / file comparison
comparison: addon-sdk/source/lib/sdk/output/system.js
addon-sdk/source/lib/sdk/output/system.js
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| -1:000000000000 | 0:0925d5552996 |
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| 1 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 2 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 4 "use strict"; | |
| 5 | |
| 6 const { Cc, Ci, Cr } = require("chrome"); | |
| 7 const { Input, start, stop, receive, outputs } = require("../event/utils"); | |
| 8 const { id: addonID } = require("../self"); | |
| 9 const { setImmediate } = require("../timers"); | |
| 10 const { notifyObservers } = Cc['@mozilla.org/observer-service;1']. | |
| 11 getService(Ci.nsIObserverService); | |
| 12 | |
| 13 const NOT_AN_INPUT = "OutputPort can be used only for sending messages"; | |
| 14 | |
| 15 // `OutputPort` creates a port to which messages can be send. Those | |
| 16 // messages are actually disptached as `subject`'s of the observer | |
| 17 // notifications. This is handy for communicating between different | |
| 18 // components of the SDK. By default messages are dispatched | |
| 19 // asynchronously, although `options.sync` can be used to make them | |
| 20 // synchronous. If `options.id` is given `topic` for observer | |
| 21 // notifications is generated by namespacing it, to avoid spamming | |
| 22 // other SDK add-ons. It's also possible to provide `options.topic` | |
| 23 // to use excat `topic` without namespacing it. | |
| 24 // | |
| 25 // Note: Symmetric `new InputPort({ id: "x" })` instances can be used to | |
| 26 // receive messages send to the instances of `new OutputPort({ id: "x" })`. | |
| 27 const OutputPort = function({id, topic, sync}) { | |
| 28 this.id = id || topic; | |
| 29 this.sync = !!sync; | |
| 30 this.topic = topic || "sdk:" + addonID + ":" + id; | |
| 31 }; | |
| 32 // OutputPort extends base signal type to implement same message | |
| 33 // receiving interface. | |
| 34 OutputPort.prototype = new Input(); | |
| 35 OutputPort.constructor = OutputPort; | |
| 36 | |
| 37 // OutputPort can not be consumed there for starting or stopping it | |
| 38 // is not supported. | |
| 39 OutputPort.prototype[start] = _ => { throw TypeError(NOT_AN_INPUT); }; | |
| 40 OutputPort.prototype[stop] = _ => { throw TypeError(NOT_AN_INPUT); }; | |
| 41 | |
| 42 // Port reecives message send to it, which will be dispatched via | |
| 43 // observer notification service. | |
| 44 OutputPort.receive = ({topic, sync}, message) => { | |
| 45 const type = typeof(message); | |
| 46 const supported = message === null || | |
| 47 type === "object" || | |
| 48 type === "function"; | |
| 49 | |
| 50 // There is no sensible way to wrap JS primitives that would make sense | |
| 51 // for general observer notification users. It's also probably not very | |
| 52 // useful to dispatch JS primitives as subject of observer service, there | |
| 53 // for we do not support those use cases. | |
| 54 if (!supported) | |
| 55 throw new TypeError("Unsupproted message type: `" + type + "`"); | |
| 56 | |
| 57 // Normalize `message` to create a valid observer notification `subject`. | |
| 58 // If `message` is `null`, implements `nsISupports` interface or already | |
| 59 // represents wrapped JS object use it as is. Otherwise create a wrapped | |
| 60 // object so that observers could receive it. | |
| 61 const subject = message === null ? null : | |
| 62 message instanceof Ci.nsISupports ? message : | |
| 63 message.wrappedJSObject ? message : | |
| 64 {wrappedJSObject: message}; | |
| 65 if (sync) | |
| 66 notifyObservers(subject, topic, null); | |
| 67 else | |
| 68 setImmediate(notifyObservers, subject, topic, null); | |
| 69 }; | |
| 70 OutputPort.prototype[receive] = OutputPort.receive; | |
| 71 exports.OutputPort = OutputPort; |
