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Diffstat (limited to 'comm/calendar/base/src/CalTimezoneService.jsm')
| -rw-r--r-- | comm/calendar/base/src/CalTimezoneService.jsm | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/comm/calendar/base/src/CalTimezoneService.jsm b/comm/calendar/base/src/CalTimezoneService.jsm new file mode 100644 index 0000000000..7973435d7c --- /dev/null +++ b/comm/calendar/base/src/CalTimezoneService.jsm @@ -0,0 +1,228 @@ +/* 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/. */ + +var EXPORTED_SYMBOLS = ["CalTimezoneService"]; + +var { AppConstants } = ChromeUtils.importESModule("resource://gre/modules/AppConstants.sys.mjs"); + +var { cal } = ChromeUtils.import("resource:///modules/calendar/calUtils.jsm"); +var { ICAL, unwrapSingle } = ChromeUtils.import("resource:///modules/calendar/Ical.jsm"); + +const { CalTimezone } = ChromeUtils.import("resource:///modules/CalTimezone.jsm"); + +const TIMEZONE_CHANGED_TOPIC = "default-timezone-changed"; + +// CalTimezoneService acts as an implementation of both ICAL.TimezoneService and +// the XPCOM calITimezoneService used for providing timezone objects to calendar +// code. +function CalTimezoneService() { + this.wrappedJSObject = this; + + this._timezoneDatabase = Cc["@mozilla.org/calendar/timezone-database;1"].getService( + Ci.calITimezoneDatabase + ); + + this.mZones = new Map(); + this.mZoneIds = []; + + ICAL.TimezoneService = this.wrappedJSObject; +} + +var calTimezoneServiceClassID = Components.ID("{e736f2bd-7640-4715-ab35-887dc866c587}"); +var calTimezoneServiceInterfaces = [Ci.calITimezoneService, Ci.calIStartupService]; +CalTimezoneService.prototype = { + mDefaultTimezone: null, + mVersion: null, + mZones: null, + mZoneIds: null, + + classID: calTimezoneServiceClassID, + QueryInterface: cal.generateQI(["calITimezoneService", "calIStartupService"]), + classInfo: cal.generateCI({ + classID: calTimezoneServiceClassID, + contractID: "@mozilla.org/calendar/timezone-service;1", + classDescription: "Calendar Timezone Service", + interfaces: calTimezoneServiceInterfaces, + flags: Ci.nsIClassInfo.SINGLETON, + }), + + // ical.js TimezoneService methods + has(id) { + return this.getTimezone(id) != null; + }, + get(id) { + return id ? unwrapSingle(ICAL.Timezone, this.getTimezone(id)) : null; + }, + remove() {}, + register() {}, + + // calIStartupService methods + startup(aCompleteListener) { + // Fetch list of supported canonical timezone IDs from the backing database + this.mZoneIds = this._timezoneDatabase.getCanonicalTimezoneIds(); + + // Fetch the version of the backing database + this.mVersion = this._timezoneDatabase.version; + cal.LOG("[CalTimezoneService] Timezones version " + this.version + " loaded"); + + // Set up zones for special values + const utc = new CalTimezone(ICAL.Timezone.utcTimezone); + this.mZones.set("UTC", utc); + + const floating = new CalTimezone(ICAL.Timezone.localTimezone); + this.mZones.set("floating", floating); + + // Initialize default timezone and, if unset, user timezone prefs + this._initDefaultTimezone(); + + // Watch for changes in system timezone or related user preferences + Services.prefs.addObserver("calendar.timezone.useSystemTimezone", this); + Services.prefs.addObserver("calendar.timezone.local", this); + Services.obs.addObserver(this, TIMEZONE_CHANGED_TOPIC); + + // Notify the startup service that startup is complete + if (aCompleteListener) { + aCompleteListener.onResult(null, Cr.NS_OK); + } + }, + + shutdown(aCompleteListener) { + Services.obs.removeObserver(this, TIMEZONE_CHANGED_TOPIC); + Services.prefs.removeObserver("calendar.timezone.local", this); + Services.prefs.removeObserver("calendar.timezone.useSystemTimezone", this); + aCompleteListener.onResult(null, Cr.NS_OK); + }, + + // calITimezoneService methods + get UTC() { + return this.mZones.get("UTC"); + }, + + get floating() { + return this.mZones.get("floating"); + }, + + getTimezone(tzid) { + if (!tzid) { + cal.ERROR("Unknown timezone requested\n" + cal.STACK(10)); + return null; + } + + if (tzid.startsWith("/mozilla.org/")) { + // We know that our former tzids look like "/mozilla.org/<dtstamp>/continent/..." + // The ending of the mozilla prefix is the index of that slash before the + // continent. Therefore, we start looking for the prefix-ending slash + // after position 13. + tzid = tzid.substring(tzid.indexOf("/", 13) + 1); + } + + // Per the IANA timezone database, "Z" is _not_ an alias for UTC, but our + // previous list of zones included it and Ical.js at a minimum is expecting + // it to be valid + if (tzid === "Z") { + return this.mZones.get("UTC"); + } + + // First check our cache of timezones + let timezone = this.mZones.get(tzid); + if (!timezone) { + // The requested timezone is not in the cache; ask the backing database + // for the timezone definition + const tzdef = this._timezoneDatabase.getTimezoneDefinition(tzid); + + if (!tzdef) { + cal.ERROR(`Could not find definition for ${tzid}`); + return null; + } + + timezone = new CalTimezone( + ICAL.Timezone.fromData({ + tzid, + component: tzdef, + }) + ); + + // Cache the resulting timezone + this.mZones.set(tzid, timezone); + } + + return timezone; + }, + + get timezoneIds() { + return this.mZoneIds; + }, + + get version() { + return this.mVersion; + }, + + _initDefaultTimezone() { + // If the "use system timezone" preference is unset, we default to enabling + // it if the user's system supports it + let isSetSystemTimezonePref = Services.prefs.prefHasUserValue( + "calendar.timezone.useSystemTimezone" + ); + + if (!isSetSystemTimezonePref) { + let canUseSystemTimezone = AppConstants.MOZ_CAN_FOLLOW_SYSTEM_TIME; + + Services.prefs.setBoolPref("calendar.timezone.useSystemTimezone", canUseSystemTimezone); + } + + this._updateDefaultTimezone(); + }, + + _updateDefaultTimezone() { + let prefUseSystemTimezone = Services.prefs.getBoolPref( + "calendar.timezone.useSystemTimezone", + true + ); + let prefTzid = Services.prefs.getStringPref("calendar.timezone.local", null); + + let tzid; + if (prefUseSystemTimezone || prefTzid === null || prefTzid === "floating") { + // If we do not have a timezone preference set, we default to using the + // system time; we may also do this if the user has set their preferences + // accordingly + tzid = Intl.DateTimeFormat().resolvedOptions().timeZone; + } else { + tzid = prefTzid; + } + + // Update default timezone and preference if necessary + if (!this.mDefaultTimezone || this.mDefaultTimezone.tzid != tzid) { + this.mDefaultTimezone = this.getTimezone(tzid); + cal.ASSERT(this.mDefaultTimezone, `Timezone not found: ${tzid}`); + Services.obs.notifyObservers(null, "defaultTimezoneChanged"); + + if (this.mDefaultTimezone.tzid != prefTzid) { + Services.prefs.setStringPref("calendar.timezone.local", this.mDefaultTimezone.tzid); + } + } + }, + + get defaultTimezone() { + // We expect this to be initialized when the service comes up and updated if + // the underlying default changes + return this.mDefaultTimezone; + }, + + observe(aSubject, aTopic, aData) { + // Update the default timezone if the system timezone has changed; we + // expect the update function to decide if actually making the change is + // appropriate based on user prefs + if (aTopic == TIMEZONE_CHANGED_TOPIC) { + this._updateDefaultTimezone(); + } else if ( + aTopic == "nsPref:changed" && + (aData == "calendar.timezone.useSystemTimezone" || aData == "calendar.timezone.local") + ) { + // We may get a bogus second update from the timezone pref if its change + // is a result of the system timezone changing, but it should settle, and + // trying to guard against it is full of corner cases + this._updateDefaultTimezone(); + } + }, +}; |