gecko/js/xpconnect/idl/nsIAddonInterposition.idl
2014-07-14 22:10:05 -07:00

43 lines
1.9 KiB
Plaintext

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* 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/. */
#include "nsISupports.idl"
/**
* This interface allows Firefox to expose different implementations of its own
* classes to add-ons. Once an interposition is created, it must be assigned to
* an add-on using Cu.setAddonInterposition (JS) or xpc::SetAddonInterposition
* (C++). In both cases, the arguments should be the add-on ID and the
* interposition object (which must be an nsIAddonInterposition). This must
* happen before any compartments are created for the given add-on.
*
* Every time the add-on accesses a property on any object outside its own set
* of compartments, XPConnect will call the interposition's
* interpose method. If the interposition wants to replace the given
* property, it should return a replacement property descriptor for it. If not,
* it should return null.
*/
[scriptable,uuid(e5453950-d95a-11e3-9c1a-0800200c9a66)]
interface nsIAddonInterposition : nsISupports
{
/**
* Returns a replacement property descriptor for a browser object.
*
* @param addonId The ID of the add-on accessing the property.
* @param target The browser object being accessed.
* @param iface The IID of the interface the property is associated with. This
* parameter is only available for XPCWrappedNative targets. As
* such, it's only useful as an optimization to avoid
* instanceof checks on the target.
* @param prop The name of the property being accessed.
* @return A property descriptor or null.
*/
jsval interpose(in jsval addonId,
in jsval target,
in nsIIDPtr iface,
in jsval prop);
};