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/*************************************************************************
*
* 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 */
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