gecko/mobile/android/modules/SharedPreferences.jsm

255 lines
7.1 KiB
JavaScript

// -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
/* 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";
this.EXPORTED_SYMBOLS = ["SharedPreferences"];
const { classes: Cc, interfaces: Ci, utils: Cu } = Components;
// For adding observers.
Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/Messaging.jsm");
let Scope = Object.freeze({
APP: "app",
PROFILE: "profile",
GLOBAL: "global"
});
/**
* Public API to getting a SharedPreferencesImpl instance. These scopes mirror GeckoSharedPrefs.
*/
let SharedPreferences = {
forApp: function() {
return new SharedPreferencesImpl({ scope: Scope.APP });
},
forProfile: function() {
return new SharedPreferencesImpl({ scope: Scope.PROFILE });
},
/**
* Get SharedPreferences for the named profile; if the profile name is null,
* returns the preferences for the current profile (just like |forProfile|).
*/
forProfileName: function(profileName) {
return new SharedPreferencesImpl({ scope: Scope.PROFILE, profileName: profileName });
},
/**
* Get SharedPreferences for the given Android branch; if the branch is null,
* returns the default preferences branch for the application, which is the
* output of |PreferenceManager.getDefaultSharedPreferences|.
*/
forAndroid: function(branch) {
return new SharedPreferencesImpl({ scope: Scope.GLOBAL, branch: branch });
}
};
/**
* Create an interface to an Android SharedPreferences branch.
*
* options {Object} with the following valid keys:
* - scope {String} (required) specifies the scope of preferences that should be accessed.
* - branch {String} (only when using Scope.GLOBAL) should be a string describing a preferences branch,
* like "UpdateService" or "background.data", or null to access the
* default preferences branch for the application.
* - profileName {String} (optional, only valid when using Scope.PROFILE)
*/
function SharedPreferencesImpl(options = {}) {
if (!(this instanceof SharedPreferencesImpl)) {
return new SharedPreferencesImpl(level);
}
if (options.scope == null || options.scope == undefined) {
throw "Shared Preferences must specifiy a scope.";
}
this._scope = options.scope;
this._profileName = options.profileName;
this._branch = options.branch;
this._observers = {};
}
SharedPreferencesImpl.prototype = Object.freeze({
_set: function _set(prefs) {
Messaging.sendRequest({
type: "SharedPreferences:Set",
preferences: prefs,
scope: this._scope,
profileName: this._profileName,
branch: this._branch,
});
},
_setOne: function _setOne(prefName, value, type) {
let prefs = [];
prefs.push({
name: prefName,
value: value,
type: type,
});
this._set(prefs);
},
setBoolPref: function setBoolPref(prefName, value) {
this._setOne(prefName, value, "bool");
},
setCharPref: function setCharPref(prefName, value) {
this._setOne(prefName, value, "string");
},
setIntPref: function setIntPref(prefName, value) {
this._setOne(prefName, value, "int");
},
_get: function _get(prefs, callback) {
let result = null;
Messaging.sendRequestForResult({
type: "SharedPreferences:Get",
preferences: prefs,
scope: this._scope,
profileName: this._profileName,
branch: this._branch,
}).then((data) => {
result = data.values;
});
let thread = Services.tm.currentThread;
while (result == null)
thread.processNextEvent(true);
return result;
},
_getOne: function _getOne(prefName, type) {
let prefs = [];
prefs.push({
name: prefName,
type: type,
});
let values = this._get(prefs);
if (values.length != 1) {
throw new Error("Got too many values: " + values.length);
}
return values[0].value;
},
getBoolPref: function getBoolPref(prefName) {
return this._getOne(prefName, "bool");
},
getCharPref: function getCharPref(prefName) {
return this._getOne(prefName, "string");
},
getIntPref: function getIntPref(prefName) {
return this._getOne(prefName, "int");
},
/**
* Invoke `observer` after a change to the preference `domain` in
* the current branch.
*
* `observer` should implement the nsIObserver.observe interface.
*/
addObserver: function addObserver(domain, observer, holdWeak) {
if (!domain)
throw new Error("domain must not be null");
if (!observer)
throw new Error("observer must not be null");
if (holdWeak)
throw new Error("Weak references not yet implemented.");
if (!this._observers.hasOwnProperty(domain))
this._observers[domain] = [];
if (this._observers[domain].indexOf(observer) > -1)
return;
this._observers[domain].push(observer);
this._updateAndroidListener();
},
/**
* Do not invoke `observer` after a change to the preference
* `domain` in the current branch.
*/
removeObserver: function removeObserver(domain, observer) {
if (!this._observers.hasOwnProperty(domain))
return;
let index = this._observers[domain].indexOf(observer);
if (index < 0)
return;
this._observers[domain].splice(index, 1);
if (this._observers[domain].length < 1)
delete this._observers[domain];
this._updateAndroidListener();
},
_updateAndroidListener: function _updateAndroidListener() {
if (this._listening && Object.keys(this._observers).length < 1)
this._uninstallAndroidListener();
if (!this._listening && Object.keys(this._observers).length > 0)
this._installAndroidListener();
},
_installAndroidListener: function _installAndroidListener() {
if (this._listening)
return;
this._listening = true;
Services.obs.addObserver(this, "SharedPreferences:Changed", false);
Messaging.sendRequest({
type: "SharedPreferences:Observe",
enable: true,
scope: this._scope,
profileName: this._profileName,
branch: this._branch,
});
},
observe: function observe(subject, topic, data) {
if (topic != "SharedPreferences:Changed") {
return;
}
let msg = JSON.parse(data);
if (msg.scope !== this._scope ||
((this._scope === Scope.PROFILE) && (msg.profileName !== this._profileName)) ||
((this._scope === Scope.GLOBAL) && (msg.branch !== this._branch))) {
return;
}
if (!this._observers.hasOwnProperty(msg.key)) {
return;
}
let observers = this._observers[msg.key];
for (let obs of observers) {
obs.observe(obs, msg.key, msg.value);
}
},
_uninstallAndroidListener: function _uninstallAndroidListener() {
if (!this._listening)
return;
this._listening = false;
Services.obs.removeObserver(this, "SharedPreferences:Changed");
Messaging.sendRequest({
type: "SharedPreferences:Observe",
enable: false,
scope: this._scope,
profileName: this._profileName,
branch: this._branch,
});
},
});