xul-ext-adblock-plus-element-hiding-helper 1.2.2-1 / usr / share / xul-ext / adblock-plus-element-hiding-helper / prefs.js

/*
 * This Source Code is subject to the terms of the Mozilla Public License
 * version 2.0 (the "License"). You can obtain a copy of the License at
 * http://mozilla.org/MPL/2.0/.
 */

Cu.import("resource://gre/modules/Services.jsm");
Cu.import("resource://gre/modules/XPCOMUtils.jsm");

let {addonRoot, addonName} = require("info");
let branchName = "extensions." + addonName + ".";
let branch = Services.prefs.getBranch(branchName);
let ignorePrefChanges = false;

function init()
{
	// Load default preferences and set up properties for them
	let defaultBranch = Services.prefs.getDefaultBranch(branchName);
	let scope =
	{
		pref: function(pref, value)
		{
			if (pref.substr(0, branchName.length) != branchName)
			{
				Cu.reportError(new Error("Ignoring default preference " + pref + ", wrong branch."));
				return;
			}
			pref = pref.substr(branchName.length);

			let [getter, setter] = typeMap[typeof value];
			setter(defaultBranch, pref, value);
			defineProperty(pref, false, getter, setter);
		}
	};
	Services.scriptloader.loadSubScript(addonRoot + "defaults/preferences/prefs.js", scope);

	// Add preference change observer
	try
	{
		branch.QueryInterface(Ci.nsIPrefBranch2).addObserver("", Prefs, true);
		onShutdown.add(function() branch.removeObserver("", Prefs));
	}
	catch (e)
	{
		Cu.reportError(e);
	}
}

/**
 * Sets up getter/setter on Prefs object for preference.
 */
function defineProperty(/**String*/ name, defaultValue, /**Function*/ readFunc, /**Function*/ writeFunc)
{
	let value = defaultValue;
	Prefs["_update_" + name] = function()
	{
		try
		{
			value = readFunc(branch, name);
			triggerListeners(name);
		}
		catch(e)
		{
			Cu.reportError(e);
		}
	};
	Prefs.__defineGetter__(name, function() value);
	Prefs.__defineSetter__(name, function(newValue)
	{
		if (value == newValue)
			return value;

		try
		{
			ignorePrefChanges = true;
			writeFunc(branch, name, newValue);
			value = newValue;
			triggerListeners(name);
		}
		catch(e)
		{
			Cu.reportError(e);
		}
		finally
		{
			ignorePrefChanges = false;
		}
		return value;
	});
	Prefs["_update_" + name]();
}

let listeners = [];
function triggerListeners(/**String*/ name)
{
	for (let i = 0; i < listeners.length; i++)
	{
		try
		{
			listeners[i](name);
		}
		catch(e)
		{
			Cu.reportError(e);
		}
	}
}

/**
 * Manages the preferences for an extension, object properties corresponding
 * to extension's preferences are added automatically. Setting the property
 * will automatically change the preference, external preference changes are
 * also recognized automatically.
 */
let Prefs = exports.Prefs =
{
	/**
	 * Migrates an old preference to a new name.
	 */
	migrate: function(/**String*/ oldName, /**String*/ newName)
	{
		if (newName in this && Services.prefs.prefHasUserValue(oldName))
		{
			let [getter, setter] = typeMap[typeof this[newName]];
			try
			{
				this[newName] = getter(Services.prefs, oldName);
			} catch(e) {}
			Services.prefs.clearUserPref(oldName);
		}
	},

	/**
	 * Adds a preferences listener that will be fired whenever a preference
	 * changes.
	 */
	addListener: function(/**Function*/ listener)
	{
		if (listeners.indexOf(listener) < 0)
			listeners.push(listener);
	},

	/**
	 * Removes a preferences listener.
	 */
	removeListener: function(/**Function*/ listener)
	{
		let index = listeners.indexOf(listener);
		if (index >= 0)
			listeners.splice(index, 1);
	},

	observe: function(subject, topic, data)
	{
		if (ignorePrefChanges || topic != "nsPref:changed")
			return;

		if ("_update_" + data in this)
			this["_update_" + data]();
	},

	QueryInterface: XPCOMUtils.generateQI([Ci.nsISupportsWeakReference, Ci.nsIObserver])
};

// Getter/setter functions for difference preference types
let typeMap =
{
	boolean: [getBoolPref, setBoolPref],
	number: [getIntPref, setIntPref],
	string: [getCharPref, setCharPref],
	object: [getJSONPref, setJSONPref]
};

function getIntPref(branch, pref) branch.getIntPref(pref)
function setIntPref(branch, pref, newValue) branch.setIntPref(pref, newValue)

function getBoolPref(branch, pref) branch.getBoolPref(pref)
function setBoolPref(branch, pref, newValue) branch.setBoolPref(pref, newValue)

function getCharPref(branch, pref) branch.getComplexValue(pref, Ci.nsISupportsString).data
function setCharPref(branch, pref, newValue)
{
	let str = Cc["@mozilla.org/supports-string;1"].createInstance(Ci.nsISupportsString);
	str.data = newValue;
	branch.setComplexValue(pref, Ci.nsISupportsString, str);
}

function getJSONPref(branch, pref) JSON.parse(getCharPref(branch, pref))
function setJSONPref(branch, pref, newValue) setCharPref(branch, pref, JSON.stringify(newValue))

init();