1/************************************************************** 2 * 3 * Licensed to the Apache Software Foundation (ASF) under one 4 * or more contributor license agreements. See the NOTICE file 5 * distributed with this work for additional information 6 * regarding copyright ownership. The ASF licenses this file 7 * to you under the Apache License, Version 2.0 (the 8 * "License"); you may not use this file except in compliance 9 * with the License. You may obtain a copy of the License at 10 * 11 * http://www.apache.org/licenses/LICENSE-2.0 12 * 13 * Unless required by applicable law or agreed to in writing, 14 * software distributed under the License is distributed on an 15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY 16 * KIND, either express or implied. See the License for the 17 * specific language governing permissions and limitations 18 * under the License. 19 * 20 *************************************************************/ 21 22 23#ifndef __com_sun_star_uno_XWeak_idl__ 24#define __com_sun_star_uno_XWeak_idl__ 25 26#ifndef __com_sun_star_uno_XInterface_idl__ 27#include <com/sun/star/uno/XInterface.idl> 28#endif 29 30#ifndef __com_sun_star_uno_XAdapter_idl__ 31#include <com/sun/star/uno/XAdapter.idl> 32#endif 33 34 35//============================================================================= 36 37 module com { module sun { module star { module uno { 38 39//============================================================================= 40 41// DocMerge from xml: interface com::sun::star::uno::XWeak 42/** the server-side interface to a weak object. 43 44 45 46 <p>This interface is proxy to the adapted object. 47 In order to make it possible to have weak references to objects, 48 the <type>XAdapter</type> interface must be implemented to provide 49 a weak adapter for the clients. 50 51 <h4>Concept of weak referencing:</h4> 52 53 </p> 54 <p>This module specifies the interfaces for implementing and using 55 weak references.</p> 56 <p> 57 58 </p> 59 <p>The sense of weak references is to hold a reference to an object 60 without affecting the lifetime of the object. That means that a weak 61 reference may become invalid, at any time, if the referenced object dies. 62 63 </p> 64 <p>The following interfaces describe one way to handle weak references 65 by providing a weak adapter. The weak object has to provide this 66 adapter if anyone wants to hold a weak reference. To separate their 67 lifetimes, the adapter and the original object must not share the same 68 reference counter. The weak reference is in fact only a hard reference 69 to the adapter, which knows - but does not hold - the original object. 70 That means that the implementation and synchronization of weak 71 referencing is the responsibility of the object. The following 72 interfaces are involved in the concept of weak referencing: 73 74 <dl> 75 <dt> 76 <type>XWeak</type> 77 </dt> 78 <dd>is the server-side interface of the referred object. This 79 referred object must support the <type>XAdapter</type> interface. 80 81 </dd> 82 <dt> 83 <type>XReference</type> 84 </dt> 85 <dd>is a client-side interface which must be implemented by 86 the holder of any weak reference. It is used for notification 87 when the adapted object dies. 88 89 </dd> 90 </dl> 91 </p> 92 */ 93published interface XWeak: com::sun::star::uno::XInterface 94{ 95 //------------------------------------------------------------------------- 96 97 // DocMerge from xml: method com::sun::star::uno::XWeak::queryAdapter 98 /** queries the weak adapter. 99 100 101 102 <p>It is important that the adapter must know, but not hold 103 the adapted object. If the adapted object dies, all references 104 to the adapter have to be notified to release the adapter. 105 106 </p> 107 */ 108 com::sun::star::uno::XAdapter queryAdapter(); 109 110}; 111 112//============================================================================= 113 114}; }; }; }; 115 116/*============================================================================= 117 118=============================================================================*/ 119#endif 120