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Diffstat (limited to 'canvas/inc/canvas/vclwrapper.hxx')
-rw-r--r-- | canvas/inc/canvas/vclwrapper.hxx | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/canvas/inc/canvas/vclwrapper.hxx b/canvas/inc/canvas/vclwrapper.hxx new file mode 100644 index 000000000000..c8b404a02b06 --- /dev/null +++ b/canvas/inc/canvas/vclwrapper.hxx @@ -0,0 +1,149 @@ +/************************************************************************* + * + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * Copyright 2000, 2010 Oracle and/or its affiliates. + * + * OpenOffice.org - a multi-platform office productivity suite + * + * This file is part of OpenOffice.org. + * + * OpenOffice.org is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License version 3 + * only, as published by the Free Software Foundation. + * + * OpenOffice.org is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU Lesser General Public License version 3 for more details + * (a copy is included in the LICENSE file that accompanied this code). + * + * You should have received a copy of the GNU Lesser General Public License + * version 3 along with OpenOffice.org. If not, see + * <http://www.openoffice.org/license.html> + * for a copy of the LGPLv3 License. + * + ************************************************************************/ + +#ifndef INCLUDED_CANVAS_VCLWRAPPER_HXX +#define INCLUDED_CANVAS_VCLWRAPPER_HXX + +#include <osl/mutex.hxx> +#include <vos/mutex.hxx> +#include <vcl/svapp.hxx> + + +namespace canvas +{ + namespace vcltools + { + /** This helper template wraps VCL objects, and protects + object deletion with the Solar mutex. All other operations + are unprotected, this must be handled by client code. + + The reason for this template is the fact that VCL objects + hold by value in uno::Reference-handled classes are + deleted without having the chance to get inbetween and + lock the solar mutex. + + This template handles that problem transparently, the only + inconvenience is the fact that object member access now + has to be performed via operator->, since . is not + overloadable. + + Otherwise, the template preserves the value semantics of + the wrapped object, that is, copy operations are performed + not by copying pointers, but by copying the underlying + object. This includes constness, i.e. on a const + VCLObject, only const methods of the wrapped object can be + called. Simply imagine this to be a value object of type + "template argument", with the only peculiarity that + member/method access is performed by operator-> instead of + the non-existing "operator.". + */ + template< class _Wrappee > class VCLObject + { + public: + typedef _Wrappee Wrappee; + + VCLObject() : + mpWrappee( new Wrappee() ) + { + } + + // no explicit here. VCLObjects should be freely + // constructible with Wrappees, and AFAIK there is no other + // implicit conversion path that could cause harm here + VCLObject( Wrappee* pWrappee ) : + mpWrappee( pWrappee ) + { + } + + // This object has value semantics, thus, forward copy + // to wrappee + VCLObject( const VCLObject& rOrig ) + { + if( rOrig.mpWrappee ) + mpWrappee = new Wrappee( *rOrig.mpWrappee ); + else + mpWrappee = NULL; + } + + // This object has value semantics, thus, forward copy + // to wrappee + VCLObject( const Wrappee& rOrig ) : + mpWrappee( new Wrappee( rOrig ) ) + { + } + + // This object has value semantics, thus, forward + // assignment to wrappee + VCLObject& operator=( const VCLObject& rhs ) + { + if( mpWrappee ) + { + if( rhs.mpWrappee ) + *mpWrappee = *rhs.mpWrappee; + } + else + { + if( rhs.mpWrappee ) + mpWrappee = new Wrappee( *rhs.mpWrappee ); + } + + return *this; + } + + ~VCLObject() + { + // This here is the whole purpose of the template: + // protecting object deletion with the solar mutex + ::vos::OGuard aGuard( Application::GetSolarMutex() ); + + if( mpWrappee ) + delete mpWrappee; + } + + Wrappee* operator->() { return mpWrappee; } + const Wrappee* operator->() const { return mpWrappee; } + + Wrappee& operator*() { return *mpWrappee; } + const Wrappee& operator*() const { return *mpWrappee; } + + Wrappee& get() { return *mpWrappee; } + const Wrappee& get() const { return *mpWrappee; } + + void swap( VCLObject& rOther ) + { + ::std::swap( mpWrappee, rOther.mpWrappee ); + } + + private: + + Wrappee* mpWrappee; + }; + + } +} + +#endif /* INCLUDED_CANVAS_VCLWRAPPER_HXX */ |