From 267c6f2ac71f92999e969232431ba04678e7437e Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Mon, 15 Apr 2024 07:54:39 +0200 Subject: Adding upstream version 4:24.2.0. Signed-off-by: Daniel Baumann --- canvas/inc/vclwrapper.hxx | 151 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 151 insertions(+) create mode 100644 canvas/inc/vclwrapper.hxx (limited to 'canvas/inc/vclwrapper.hxx') diff --git a/canvas/inc/vclwrapper.hxx b/canvas/inc/vclwrapper.hxx new file mode 100644 index 0000000000..3c1dfbf2d6 --- /dev/null +++ b/canvas/inc/vclwrapper.hxx @@ -0,0 +1,151 @@ +/* -*- 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 . + */ + +#pragma once + +#include +#include + +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( std::unique_ptr 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 = nullptr; + } + + VCLObject(VCLObject&& rOrig) noexcept + : mpWrappee(std::move(rOrig.mpWrappee)) + { + } + + // 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 (this != &rhs) + { + if( mpWrappee ) + { + if( rhs.mpWrappee ) + *mpWrappee = *rhs.mpWrappee; + } + else + { + if( rhs.mpWrappee ) + mpWrappee = new Wrappee( *rhs.mpWrappee ); + } + } + return *this; + } + + VCLObject& operator=(VCLObject&& rhs) noexcept + { + std::swap(mpWrappee, rhs.mpWrappee); + + return *this; + } + + ~VCLObject() + { + // This here is the whole purpose of the template: + // protecting object deletion with the solar mutex + SolarMutexGuard aGuard; + + mpWrappee.reset(); + } + + Wrappee* operator->() { return mpWrappee.get(); } + const Wrappee* operator->() const { return mpWrappee.get(); } + + 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: + + std::unique_ptr mpWrappee; + }; + + } +} + +/* vim:set shiftwidth=4 softtabstop=4 expandtab: */ -- cgit v1.2.3