summaryrefslogtreecommitdiff
path: root/include/cppuhelper/weakref.hxx
blob: a5858b2e88059cf2adbc943510c1a220a22388d4 (plain)
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
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
/* -*- 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 .
 */

/*
 * This file is part of LibreOffice published API.
 */
#ifndef INCLUDED_CPPUHELPER_WEAKREF_HXX
#define INCLUDED_CPPUHELPER_WEAKREF_HXX

#include "sal/config.h"

#include <cstddef>

#include "com/sun/star/uno/Reference.hxx"
#include "com/sun/star/uno/XInterface.hpp"
#include "cppuhelper/cppuhelperdllapi.h"


namespace com
{
namespace sun
{
namespace star
{
namespace uno
{

class OWeakRefListener;
class XWeak;

/** The WeakReferenceHelper holds a weak reference to an object.

    That object must implement the css::uno::XWeak interface.

    The WeakReferenceHelper itself is *not* thread safe, just as
    Reference itself isn't, but the implementation of the listeners etc.
    behind it *is* thread-safe, so multiple threads can have their own
    WeakReferences to the same XWeak object.
*/
class CPPUHELPER_DLLPUBLIC WeakReferenceHelper
{
public:
    /** Default ctor.  Creates an empty weak reference.
    */
    WeakReferenceHelper()
        : m_pImpl( NULL )
        {}

    /** Copy ctor.  Initialize this reference with the same interface as in rWeakRef.

        @param rWeakRef another weak ref
    */
    WeakReferenceHelper( const WeakReferenceHelper & rWeakRef );

#if defined LIBO_INTERNAL_ONLY
    WeakReferenceHelper(WeakReferenceHelper && other) noexcept : m_pImpl(other.m_pImpl)
    { other.m_pImpl = nullptr; }
#endif

    /** Initialize this reference with the hard interface reference xInt. If the implementation
        behind xInt does not support XWeak or xInt is null then this reference will be null.

        @param xInt another hard interface reference
    */
    WeakReferenceHelper( const css::uno::Reference< css::uno::XInterface > & xInt );

#if defined LIBO_INTERNAL_ONLY
    /** Initialize this reference with the hard interface reference xWeak. This
         is faster than the XInterface constructor because we can skip doing an
         UNO_QUERY.

        @param xWeak another hard interface reference
    */
    WeakReferenceHelper( const css::uno::Reference< css::uno::XWeak > & xWeak );
#endif

    /** Releases this reference.
    */
    ~WeakReferenceHelper();

    /** Releases this reference and takes over rWeakRef.

        @param rWeakRef another weak ref
    */
    WeakReferenceHelper & SAL_CALL operator = ( const WeakReferenceHelper & rWeakRef );

#if defined LIBO_INTERNAL_ONLY
    WeakReferenceHelper & operator =(WeakReferenceHelper && other);
#endif

    /** Releases this reference and takes over hard reference xInt.
        If the implementation behind xInt does not support XWeak
        or XInt is null, then this reference is null.

        @param xInt another hard reference
    */
    WeakReferenceHelper & SAL_CALL operator = (
            const css::uno::Reference< css::uno::XInterface > & xInt );

#if defined LIBO_INTERNAL_ONLY
    /** Releases this reference and takes over hard reference xWeak. This
         is faster than the XInterface constructor because we can skip doing an
         UNO_QUERY.

        @param xWeak another hard reference
    */
    WeakReferenceHelper & operator = (
            const css::uno::Reference< css::uno::XWeak > & xWeak );
#endif

    /** Returns true if both weak refs reference to the same object.

        @param rObj another weak ref
        @return true, if both weak refs reference to the same object.
    */
    bool SAL_CALL operator == ( const WeakReferenceHelper & rObj ) const
        { return (get() == rObj.get()); }

    /**  Gets a hard reference to the object.

         @return hard reference or null, if the weakly referenced interface has gone
    */
    css::uno::Reference< css::uno::XInterface > SAL_CALL get() const;

    /**  Gets a hard reference to the object.

         @return hard reference or null, if the weakly referenced interface has gone
    */
    SAL_CALL operator Reference< XInterface > () const
        { return get(); }

    /** Releases this reference.

        @since UDK 3.2.12
    */
    void SAL_CALL clear();

protected:
    /// @cond INTERNAL
    OWeakRefListener * m_pImpl;
    /// @endcond
};

/** The WeakReference<> holds a weak reference to an object.

    That object must implement the css::uno::XWeak interface.

    The WeakReference itself is *not* thread safe, just as
    Reference itself isn't, but the implementation of the listeners etc.
    behind it *is* thread-safe, so multiple threads can have their own
    WeakReferences to the same XWeak object.

    @tparam interface_type type of interface
*/
template< class interface_type >
class SAL_WARN_UNUSED WeakReference : public WeakReferenceHelper
{
public:
    /** Default ctor.  Creates an empty weak reference.
    */
    WeakReference()
        : WeakReferenceHelper()
        {}

    /** Copy ctor.  Initialize this reference with a hard reference.

        @param rRef another hard ref
    */
    WeakReference( const Reference< interface_type > & rRef )
        : WeakReferenceHelper( rRef )
        {}

    /** Releases this reference and takes over hard reference xInt.
        If the implementation behind xInt does not support XWeak
        or XInt is null, then this reference is null.

        @param xInt another hard reference

        @since UDK 3.2.12
    */
    WeakReference & SAL_CALL operator = (
            const css::uno::Reference< interface_type > & xInt )
        { WeakReferenceHelper::operator=(xInt); return *this; }

#if defined LIBO_INTERNAL_ONLY
    /** Releases this reference and takes over hard reference xWeak. This
         is faster than the XInterface constructor because we can skip doing an
         UNO_QUERY.

        @param xWeak another hard reference
    */
    WeakReference & operator = (
            const css::uno::Reference< css::uno::XWeak > & xWeak )
        { WeakReferenceHelper::operator=(xWeak); return *this; }
#endif

    /**  Gets a hard reference to the object.

         @return hard reference or null, if the weakly referenced interface has gone
    */
    SAL_CALL operator Reference< interface_type > () const
        { return Reference< interface_type >::query( get() ); }
};

}
}
}
}

#endif

/* vim:set shiftwidth=4 softtabstop=4 expandtab: */