xpcom/ds/nsIArray.idl

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include "nsISupports.idl"
   7
   8 interface nsISimpleEnumerator;
   9
  10 /**
  11  * nsIArray
  12  *
  13  * An indexed collection of elements. Provides basic functionality for
  14  * retrieving elements at a specific position, searching for
  15  * elements. Indexes are zero-based, such that the last element in the
  16  * array is stored at the index length-1.
  17  *
  18  * For an array which can be modified, see nsIMutableArray below.
  19  *
  20  * Neither interface makes any attempt to protect the individual
  21  * elements from modification. The convention is that the elements of
  22  * the array should not be modified. Documentation within a specific
  23  * interface should describe variations from this convention.
  24  *
  25  * It is also convention that if an interface provides access to an
  26  * nsIArray, that the array should not be QueryInterfaced to an
  27  * nsIMutableArray for modification. If the interface in question had
  28  * intended the array to be modified, it would have returned an
  29  * nsIMutableArray!
  30  *
  31  * null is a valid entry in the array, and as such any nsISupports
  32  * parameters may be null, except where noted.
  33  */
  34 [scriptable, builtinclass, uuid(114744d9-c369-456e-b55a-52fe52880d2d)]
  35 interface nsIArray : nsISupports
  36 {
  37     /**
  38      * length
  39      *
  40      * number of elements in the array.
  41      */
  42     readonly attribute unsigned long length;
  43
  44     /**
  45      * queryElementAt()
  46      *
  47      * Retrieve a specific element of the array, and QueryInterface it
  48      * to the specified interface. null is a valid result for
  49      * this method, but exceptions are thrown in other circumstances
  50      *
  51      * @param index position of element
  52      * @param uuid the IID of the requested interface
  53      * @param result the object, QI'd to the requested interface
  54      *
  55      * @throws NS_ERROR_NO_INTERFACE when an entry exists at the
  56      *         specified index, but the requested interface is not
  57      *         available.
  58      * @throws NS_ERROR_ILLEGAL_VALUE when index > length-1
  59      *
  60      */
  61     void queryElementAt(in unsigned long index,
  62                         in nsIIDRef uuid,
  63                         [iid_is(uuid), retval] out nsQIResult result);
  64
  65     /**
  66      * indexOf()
  67      *
  68      * Get the position of a specific element. Note that since null is
  69      * a valid input, exceptions are used to indicate that an element
  70      * is not found.
  71      *
  72      * @param startIndex The initial element to search in the array
  73      *                   To start at the beginning, use 0 as the
  74      *                   startIndex
  75      * @param element    The element you are looking for
  76      * @returns a number >= startIndex which is the position of the
  77      *          element in the array.
  78      * @throws NS_ERROR_FAILURE if the element was not in the array.
  79      */
  80     unsigned long indexOf(in unsigned long startIndex,
  81                           in nsISupports element);
  82
  83     /**
  84      * enumerate the array
  85      *
  86      * @returns a new enumerator positioned at the start of the array
  87      * @throws NS_ERROR_FAILURE if the array is empty (to make it easy
  88      *         to detect errors), or NS_ERROR_OUT_OF_MEMORY if out of memory.
  89      */
  90     [binaryname(ScriptedEnumerate), optional_argc]
  91     nsISimpleEnumerator enumerate([optional] in nsIIDRef aElemIID);
  92
  93     [noscript]
  94     nsISimpleEnumerator enumerateImpl(in nsIDRef aElemIID);
  95
  96     %{C++
  97     nsresult
  98     Enumerate(nsISimpleEnumerator** aRetVal, const nsID& aElemIID = NS_GET_IID(nsISupports))
  99     {
 100       return EnumerateImpl(aElemIID, aRetVal);
 101     }
 102     %}
 103 };