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Diffstat (limited to 'tools/addon-sdk-1.7/packages/api-utils/lib/preferences-service.js')
-rw-r--r-- | tools/addon-sdk-1.7/packages/api-utils/lib/preferences-service.js | 124 |
1 files changed, 124 insertions, 0 deletions
diff --git a/tools/addon-sdk-1.7/packages/api-utils/lib/preferences-service.js b/tools/addon-sdk-1.7/packages/api-utils/lib/preferences-service.js new file mode 100644 index 0000000..c5ffb2a --- /dev/null +++ b/tools/addon-sdk-1.7/packages/api-utils/lib/preferences-service.js @@ -0,0 +1,124 @@ +/* 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"; + +// The minimum and maximum integers that can be set as preferences. +// The range of valid values is narrower than the range of valid JS values +// because the native preferences code treats integers as NSPR PRInt32s, +// which are 32-bit signed integers on all platforms. +const MAX_INT = 0x7FFFFFFF; +const MIN_INT = -0x80000000; + +const {Cc,Ci,Cr} = require("chrome"); + +const prefService = Cc["@mozilla.org/preferences-service;1"]. + getService(Ci.nsIPrefService); +const prefSvc = prefService.getBranch(null); +const defaultBranch = prefService.getDefaultBranch(null); + +var get = exports.get = function get(name, defaultValue) { + switch (prefSvc.getPrefType(name)) { + case Ci.nsIPrefBranch.PREF_STRING: + return prefSvc.getComplexValue(name, Ci.nsISupportsString).data; + + case Ci.nsIPrefBranch.PREF_INT: + return prefSvc.getIntPref(name); + + case Ci.nsIPrefBranch.PREF_BOOL: + return prefSvc.getBoolPref(name); + + case Ci.nsIPrefBranch.PREF_INVALID: + return defaultValue; + + default: + // This should never happen. + throw new Error("Error getting pref " + name + + "; its value's type is " + + prefSvc.getPrefType(name) + + ", which I don't know " + + "how to handle."); + } +}; + +var set = exports.set = function set(name, value) { + var prefType; + if (typeof value != "undefined" && value != null) + prefType = value.constructor.name; + + switch (prefType) { + case "String": + { + var string = Cc["@mozilla.org/supports-string;1"]. + createInstance(Ci.nsISupportsString); + string.data = value; + prefSvc.setComplexValue(name, Ci.nsISupportsString, string); + } + break; + + case "Number": + // We throw if the number is outside the range or not an integer, since + // the result will not be what the consumer wanted to store. + if (value > MAX_INT || value < MIN_INT) + throw new Error("you cannot set the " + name + + " pref to the number " + value + + ", as number pref values must be in the signed " + + "32-bit integer range -(2^31) to 2^31-1. " + + "To store numbers outside that range, store " + + "them as strings."); + if (value % 1 != 0) + throw new Error("cannot store non-integer number: " + value); + prefSvc.setIntPref(name, value); + break; + + case "Boolean": + prefSvc.setBoolPref(name, value); + break; + + default: + throw new Error("can't set pref " + name + " to value '" + value + + "'; it isn't a string, integer, or boolean"); + } +}; + +var has = exports.has = function has(name) { + return (prefSvc.getPrefType(name) != Ci.nsIPrefBranch.PREF_INVALID); +}; + +var isSet = exports.isSet = function isSet(name) { + return (has(name) && prefSvc.prefHasUserValue(name)); +}; + +var reset = exports.reset = function reset(name) { + try { + prefSvc.clearUserPref(name); + } catch (e if e.result == Cr.NS_ERROR_UNEXPECTED) { + // The pref service throws NS_ERROR_UNEXPECTED when the caller tries + // to reset a pref that doesn't exist or is already set to its default + // value. This interface fails silently in those cases, so callers + // can unconditionally reset a pref without having to check if it needs + // resetting first or trap exceptions after the fact. It passes through + // other exceptions, however, so callers know about them, since we don't + // know what other exceptions might be thrown and what they might mean. + } +}; + +exports.getLocalized = function getLocalized(name, defaultValue) { + let value = null; + try { + value = prefSvc.getComplexValue(name, Ci.nsIPrefLocalizedString).data; + } + finally { + return value || defaultValue; + } +} + +exports.setLocalized = function setLocalized(name, value) { + // We can't use `prefs.set` here as we have to use `getDefaultBranch` + // (instead of `getBranch`) in order to have `mIsDefault` set to true, here: + // http://mxr.mozilla.org/mozilla-central/source/modules/libpref/src/nsPrefBranch.cpp#233 + // Otherwise, we do not enter into this expected condition: + // http://mxr.mozilla.org/mozilla-central/source/modules/libpref/src/nsPrefBranch.cpp#244 + defaultBranch.setCharPref(name, value); +} |