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author | Matt A. Tobin <email@mattatobin.com> | 2018-02-10 02:51:36 -0500 |
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committer | Matt A. Tobin <email@mattatobin.com> | 2018-02-10 02:51:36 -0500 |
commit | 37d5300335d81cecbecc99812747a657588c63eb (patch) | |
tree | 765efa3b6a56bb715d9813a8697473e120436278 /toolkit/jetpack/sdk/window/events.js | |
parent | b2bdac20c02b12f2057b9ef70b0a946113a00e00 (diff) | |
parent | 4fb11cd5966461bccc3ed1599b808237be6b0de9 (diff) | |
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Merge branch 'ext-work'
Diffstat (limited to 'toolkit/jetpack/sdk/window/events.js')
-rw-r--r-- | toolkit/jetpack/sdk/window/events.js | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/toolkit/jetpack/sdk/window/events.js b/toolkit/jetpack/sdk/window/events.js new file mode 100644 index 000000000..b1d3a1f3e --- /dev/null +++ b/toolkit/jetpack/sdk/window/events.js @@ -0,0 +1,68 @@ +/* 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"; + +module.metadata = { + "stability": "unstable" +}; + +const { Ci, Cu } = require("chrome"); +const { observe } = require("../event/chrome"); +const { open } = require("../event/dom"); +const { windows } = require("../window/utils"); +const { filter, merge, map, expand } = require("../event/utils"); + +function documentMatches(weakWindow, event) { + let window = weakWindow.get(); + return window && event.target === window.document; +} + +function makeStrictDocumentFilter(window) { + // Note: Do not define a closure within this function. Otherwise + // you may leak the window argument. + let weak = Cu.getWeakReference(window); + return documentMatches.bind(null, weak); +} + +function toEventWithDefaultViewTarget({type, target}) { + return { type: type, target: target.defaultView } +} + +// Function registers single shot event listeners for relevant window events +// that forward events to exported event stream. +function eventsFor(window) { + // NOTE: Do no use pass a closure from this function into a stream + // transform function. You will capture the window in the + // closure and leak the window until the event stream is + // completely closed. + let interactive = open(window, "DOMContentLoaded", { capture: true }); + let complete = open(window, "load", { capture: true }); + let states = merge([interactive, complete]); + let changes = filter(states, makeStrictDocumentFilter(window)); + return map(changes, toEventWithDefaultViewTarget); +} + +// Create our event channels. We do this in a separate function to +// minimize the chance of leaking intermediate objects on the global. +function makeEvents() { + // In addition to observing windows that are open we also observe windows + // that are already already opened in case they're in process of loading. + var opened = windows(null, { includePrivate: true }); + var currentEvents = merge(opened.map(eventsFor)); + + // Register system event listeners for top level window open / close. + function rename({type, target, data}) { + return { type: rename[type], target: target, data: data } + } + rename.domwindowopened = "open"; + rename.domwindowclosed = "close"; + + var openEvents = map(observe("domwindowopened"), rename); + var closeEvents = map(observe("domwindowclosed"), rename); + var futureEvents = expand(openEvents, ({target}) => eventsFor(target)); + + return merge([currentEvents, futureEvents, openEvents, closeEvents]); +} + +exports.events = makeEvents(); |