mirror of
https://github.com/mozilla/gecko-dev.git
synced 2024-10-11 12:25:53 +00:00
ea799cdb96
This adds an intermediate interface, nsIArrayExtensions, that inherits from nsIArray. This is necessary as nsISupportsArray implements nsIArray as well so the methods could not just be addded to nsIArray. nsIMutableArray inherits from nsIArrayExtensions and so any interface that works with an nsIMutableArray can be updated to return an nsIArrayExtensions. This will allow interfaces that currently return an nsISupportsArray to instead return an nsIArrayExtensions and internally work with an nsIMutableArray. Consumers of these functions will continue to be able to use nsISupportsArray-like iteration even though they're now working with an nsIArray. MozReview-Commit-ID: 9uRjsJbg9Jp
52 lines
1.7 KiB
Plaintext
52 lines
1.7 KiB
Plaintext
/* -*- Mode: C++; tab-width: 4; 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 "nsIArray.idl"
|
|
|
|
/**
|
|
* Helper interface for allowing scripts to treat nsIArray instances as if
|
|
* they were nsISupportsArray instances while iterating.
|
|
*
|
|
* nsISupportsArray is convenient to iterate over in JavaScript:
|
|
*
|
|
* for (let i = 0; i < array.Count(); ++i) {
|
|
* let elem = array.GetElementAt(i);
|
|
* ...
|
|
* }
|
|
*
|
|
* but doing the same with nsIArray is somewhat less convenient, since
|
|
* queryElementAt is not nearly so nice to use from JavaScript. So we provide
|
|
* this extension interface so interfaces that currently return
|
|
* nsISupportsArray can start returning nsIArrayExtensions and all JavaScript
|
|
* should Just Work. Eventually we'll roll this interface into nsIArray
|
|
* itself, possibly getting rid of the Count() method, as it duplicates
|
|
* nsIArray functionality.
|
|
*/
|
|
[scriptable, uuid(261d442e-050c-453d-8aaa-b3f23bcc528b)]
|
|
interface nsIArrayExtensions : nsIArray
|
|
{
|
|
/**
|
|
* Count()
|
|
*
|
|
* Retrieves the length of the array. This is an alias for the
|
|
* |nsIArray.length| attribute.
|
|
*/
|
|
uint32_t Count();
|
|
|
|
/**
|
|
* GetElementAt()
|
|
*
|
|
* Retrieve a specific element of the array. null is a valid result for
|
|
* this method.
|
|
*
|
|
* Note: If the index is out of bounds null will be returned.
|
|
* This differs from the behavior of nsIArray.queryElementAt() which
|
|
* will throw if an invalid index is specified.
|
|
*
|
|
* @param index position of element
|
|
*/
|
|
nsISupports GetElementAt(in uint32_t index);
|
|
};
|