1 /************************************************************************* 2 * 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * Copyright 2000, 2010 Oracle and/or its affiliates. 6 * 7 * OpenOffice.org - a multi-platform office productivity suite 8 * 9 * This file is part of OpenOffice.org. 10 * 11 * OpenOffice.org is free software: you can redistribute it and/or modify 12 * it under the terms of the GNU Lesser General Public License version 3 13 * only, as published by the Free Software Foundation. 14 * 15 * OpenOffice.org is distributed in the hope that it will be useful, 16 * but WITHOUT ANY WARRANTY; without even the implied warranty of 17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 18 * GNU Lesser General Public License version 3 for more details 19 * (a copy is included in the LICENSE file that accompanied this code). 20 * 21 * You should have received a copy of the GNU Lesser General Public License 22 * version 3 along with OpenOffice.org. If not, see 23 * <http://www.openoffice.org/license.html> 24 * for a copy of the LGPLv3 License. 25 * 26 ************************************************************************/ 27 28 #ifndef INCLUDED_CANVAS_VCLWRAPPER_HXX 29 #define INCLUDED_CANVAS_VCLWRAPPER_HXX 30 31 #include <osl/mutex.hxx> 32 #include <vos/mutex.hxx> 33 #include <vcl/svapp.hxx> 34 35 36 namespace canvas 37 { 38 namespace vcltools 39 { 40 /** This helper template wraps VCL objects, and protects 41 object deletion with the Solar mutex. All other operations 42 are unprotected, this must be handled by client code. 43 44 The reason for this template is the fact that VCL objects 45 hold by value in uno::Reference-handled classes are 46 deleted without having the chance to get inbetween and 47 lock the solar mutex. 48 49 This template handles that problem transparently, the only 50 inconvenience is the fact that object member access now 51 has to be performed via operator->, since . is not 52 overloadable. 53 54 Otherwise, the template preserves the value semantics of 55 the wrapped object, that is, copy operations are performed 56 not by copying pointers, but by copying the underlying 57 object. This includes constness, i.e. on a const 58 VCLObject, only const methods of the wrapped object can be 59 called. Simply imagine this to be a value object of type 60 "template argument", with the only peculiarity that 61 member/method access is performed by operator-> instead of 62 the non-existing "operator.". 63 */ 64 template< class _Wrappee > class VCLObject 65 { 66 public: 67 typedef _Wrappee Wrappee; 68 69 VCLObject() : 70 mpWrappee( new Wrappee() ) 71 { 72 } 73 74 // no explicit here. VCLObjects should be freely 75 // constructible with Wrappees, and AFAIK there is no other 76 // implicit conversion path that could cause harm here 77 VCLObject( Wrappee* pWrappee ) : 78 mpWrappee( pWrappee ) 79 { 80 } 81 82 // This object has value semantics, thus, forward copy 83 // to wrappee 84 VCLObject( const VCLObject& rOrig ) 85 { 86 if( rOrig.mpWrappee ) 87 mpWrappee = new Wrappee( *rOrig.mpWrappee ); 88 else 89 mpWrappee = NULL; 90 } 91 92 // This object has value semantics, thus, forward copy 93 // to wrappee 94 VCLObject( const Wrappee& rOrig ) : 95 mpWrappee( new Wrappee( rOrig ) ) 96 { 97 } 98 99 // This object has value semantics, thus, forward 100 // assignment to wrappee 101 VCLObject& operator=( const VCLObject& rhs ) 102 { 103 if( mpWrappee ) 104 { 105 if( rhs.mpWrappee ) 106 *mpWrappee = *rhs.mpWrappee; 107 } 108 else 109 { 110 if( rhs.mpWrappee ) 111 mpWrappee = new Wrappee( *rhs.mpWrappee ); 112 } 113 114 return *this; 115 } 116 117 ~VCLObject() 118 { 119 // This here is the whole purpose of the template: 120 // protecting object deletion with the solar mutex 121 ::vos::OGuard aGuard( Application::GetSolarMutex() ); 122 123 if( mpWrappee ) 124 delete mpWrappee; 125 } 126 127 Wrappee* operator->() { return mpWrappee; } 128 const Wrappee* operator->() const { return mpWrappee; } 129 130 Wrappee& operator*() { return *mpWrappee; } 131 const Wrappee& operator*() const { return *mpWrappee; } 132 133 Wrappee& get() { return *mpWrappee; } 134 const Wrappee& get() const { return *mpWrappee; } 135 136 void swap( VCLObject& rOther ) 137 { 138 ::std::swap( mpWrappee, rOther.mpWrappee ); 139 } 140 141 private: 142 143 Wrappee* mpWrappee; 144 }; 145 146 } 147 } 148 149 #endif /* INCLUDED_CANVAS_VCLWRAPPER_HXX */ 150