1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
|
/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/*
* This file is part of the LibreOffice project.
*
* 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/.
*
* This file incorporates work covered by the following license notice:
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed
* with this work for additional information regarding copyright
* ownership. The ASF licenses this file to you under the Apache
* License, Version 2.0 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.apache.org/licenses/LICENSE-2.0 .
*/
#ifndef __com_sun_star_uno_XInterface_idl__
#define __com_sun_star_uno_XInterface_idl__
module com { module sun { module star { module uno {
/** base interface of all UNO interfaces
<p> It provides lifetime control by reference counting and the
possibility of querying for other
interfaces of the same logical object.
<p>
"Logical Object" in this case means that the
interfaces actually can be supported by internal (e.g. aggregated) physical objects.</p>
<p> Deriving from this interface is mandatory for all UNO interfaces.
<p> Each language binding (Java, C++, StarBasic, Python, ... ) may
provide a different mapping of this interface, please look into the language
dependent documentation.
<p> The UNO object does not export the state of the reference count (acquire() and
release() do not have return values). In general, also the UNO object itself
should not make any assumption on the concrete value of the reference count
(except on the transition from one to zero ).
*/
published interface XInterface
{
/** queries for a new interface to an existing UNO object.
<p>
The queryInterface() method is the entry point to obtain other interfaces which
are exported by the object. The caller asks the implementation of the object,
if it supports the interface specified by the type argument. The call may either
return with an interface reference of the requested type or with a void any.
<p>
There are certain specifications, a queryInterface() implementation must not violate.
<p>
1) If queryInterface on a specific object has once returned a valid interface reference
for a given type, it must return a valid reference for any successive queryInterface
calls on this object for the same type.
<p>
2) If queryInterface on a specific object has once returned a null reference
for a given type, it must always return a null reference for the same type.
<p>
3) If queryInterface on a reference A returns reference B, queryInterface on
B for Type A must return interface reference A or calls made on the returned
reference must be equivalent to calls made on reference A.
<p>
4) If queryInterface on a reference A returns reference B, queryInterface on
A and B for XInterface must return the same interface reference (object identity).
<p> The reason for the strong specification is, that a Uno Runtime Environment (URE)
may choose to cache queryInterface() calls.
<p> As mentioned above, certain language bindings may map this function differently also
with different specifications, please visit the language dependent specification for it.
The current C++ binding sticks to the specification state
<p>
The rules mentioned above are basically identical to the rules of QueryInterface in MS COM.
@param aType a UNO interface type, for which an object reference shall be obtained.
@return an interface reference in case the requested interface is supported by the object,
a void any otherwise.
*/
any queryInterface( [in] type aType );
/** increases the reference counter by one.
<p>When you have called acquire() on the
UNO object, it is often said, that you have a reference or a hard reference
to the object.
<p>
It is only allowed to invoke a method on a UNO object, when you keep
a hard reference to it.
<p> Every call to acquire must be followed by a corresponding call to release
some time later, which may eventually lead to the destruction of the object.
*/
void acquire();
/** decreases the reference counter by one.
<p>When the reference counter reaches 0, the object gets deleted.</p>
<p>Calling release() on the object is often called releasing
or clearing the reference to an object.
*/
void release();
};
}; }; }; };
#endif
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */
|
