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Diffstat (limited to 'addon-sdk/source/lib/sdk/input/system.js')
-rw-r--r-- | addon-sdk/source/lib/sdk/input/system.js | 113 |
1 files changed, 0 insertions, 113 deletions
diff --git a/addon-sdk/source/lib/sdk/input/system.js b/addon-sdk/source/lib/sdk/input/system.js deleted file mode 100644 index 66bc6daec..000000000 --- a/addon-sdk/source/lib/sdk/input/system.js +++ /dev/null @@ -1,113 +0,0 @@ -/* 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"; - -const { Cc, Ci, Cr, Cu } = require("chrome"); -const { Input, start, stop, end, receive, outputs } = require("../event/utils"); -const { once, off } = require("../event/core"); -const { id: addonID } = require("../self"); - -const unloadMessage = require("@loader/unload"); -const observerService = Cc['@mozilla.org/observer-service;1']. - getService(Ci.nsIObserverService); -const { ShimWaiver } = Cu.import("resource://gre/modules/ShimWaiver.jsm"); -const addObserver = ShimWaiver.getProperty(observerService, "addObserver"); -const removeObserver = ShimWaiver.getProperty(observerService, "removeObserver"); - - -const addonUnloadTopic = "sdk:loader:destroy"; - -const isXrayWrapper = Cu.isXrayWrapper; -// In the past SDK used to double-wrap notifications dispatched, which -// made them awkward to use outside of SDK. At present they no longer -// do that, although we still supported for legacy reasons. -const isLegacyWrapper = x => - x && x.wrappedJSObject && - "observersModuleSubjectWrapper" in x.wrappedJSObject; - -const unwrapLegacy = x => x.wrappedJSObject.object; - -// `InputPort` provides a way to create a signal out of the observer -// notification subject's for the given `topic`. If `options.initial` -// is provided it is used as initial value otherwise `null` is used. -// Constructor can be given `options.id` that will be used to create -// a `topic` which is namespaced to an add-on (this avoids conflicts -// when multiple add-on are used, although in a future host probably -// should just be shared across add-ons). It is also possible to -// specify a specific `topic` via `options.topic` which is used as -// without namespacing. Created signal ends whenever add-on is -// unloaded. -const InputPort = function InputPort({id, topic, initial}) { - this.id = id || topic; - this.topic = topic || "sdk:" + addonID + ":" + id; - this.value = initial === void(0) ? null : initial; - this.observing = false; - this[outputs] = []; -}; - -// InputPort type implements `Input` signal interface. -InputPort.prototype = new Input(); -InputPort.prototype.constructor = InputPort; - -// When port is started (which is when it's subgraph get's -// first subscriber) actual observer is registered. -InputPort.start = input => { - input.addListener(input); - // Also register add-on unload observer to end this signal - // when that happens. - addObserver(input, addonUnloadTopic, false); -}; -InputPort.prototype[start] = InputPort.start; - -InputPort.addListener = input => addObserver(input, input.topic, false); -InputPort.prototype.addListener = InputPort.addListener; - -// When port is stopped (which is when it's subgraph has no -// no subcribers left) an actual observer unregistered. -// Note that port stopped once it ends as well (which is when -// add-on is unloaded). -InputPort.stop = input => { - input.removeListener(input); - removeObserver(input, addonUnloadTopic); -}; -InputPort.prototype[stop] = InputPort.stop; - -InputPort.removeListener = input => removeObserver(input, input.topic); -InputPort.prototype.removeListener = InputPort.removeListener; - -// `InputPort` also implements `nsIObserver` interface and -// `nsISupportsWeakReference` interfaces as it's going to be used as such. -InputPort.prototype.QueryInterface = function(iid) { - if (!iid.equals(Ci.nsIObserver) && !iid.equals(Ci.nsISupportsWeakReference)) - throw Cr.NS_ERROR_NO_INTERFACE; - - return this; -}; - -// `InputPort` instances implement `observe` method, which is invoked when -// observer notifications are dispatched. The `subject` of that notification -// are received on this signal. -InputPort.prototype.observe = function(subject, topic, data) { - // Unwrap message from the subject. SDK used to have it's own version of - // wrappedJSObjects which take precedence, if subject has `wrappedJSObject` - // and it's not an XrayWrapper use it as message. Otherwise use subject as - // is. - const message = subject === null ? null : - isLegacyWrapper(subject) ? unwrapLegacy(subject) : - isXrayWrapper(subject) ? subject : - subject.wrappedJSObject ? subject.wrappedJSObject : - subject; - - // If observer topic matches topic of the input port receive a message. - if (topic === this.topic) { - receive(this, message); - } - - // If observe topic is add-on unload topic we create an end message. - if (topic === addonUnloadTopic && message === unloadMessage) { - end(this); - } -}; - -exports.InputPort = InputPort; |