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+/* -*- 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 .
+ */
+
+#ifndef INCLUDED_CANVAS_VCLWRAPPER_HXX
+#define INCLUDED_CANVAS_VCLWRAPPER_HXX
+
+#include <osl/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
+ SolarMutexGuard aGuard;
+
+ 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 */
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */