libs/signals2/example/doc_view_acm_deconstruct.cpp
// Document/View sample for Boost.Signals2.
// Expands on doc_view_acm.cpp example by using boost::signals2::deconstruct
// as a post-constructing factory function.
//
// Copyright Keith MacDonald 2005.
// Copyright Frank Mori Hess 2009.
//
// Use, modification and
// distribution is subject to the Boost Software License, Version
// 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
// For more information, see http://www.boost.org
#include <iostream>
#include <string>
#include <boost/bind.hpp>
#include <boost/ref.hpp>
#include <boost/signals2/deconstruct.hpp>
#include <boost/signals2/signal.hpp>
#include <boost/shared_ptr.hpp>
class Document
{
public:
typedef boost::signals2::signal<void ()> signal_t;
public:
Document()
{}
/* Connect a slot to the signal which will be emitted whenever
text is appended to the document. */
boost::signals2::connection connect(const signal_t::slot_type &subscriber)
{
return m_sig.connect(subscriber);
}
void append(const char* s)
{
m_text += s;
m_sig();
}
const std::string& getText() const
{
return m_text;
}
private:
signal_t m_sig;
std::string m_text;
};
class TextView
{
public:
/* This adl_postconstruct function will be found
via argument-dependent lookup when using boost::signals2::deconstruct. */
template<typename T>
friend void adl_postconstruct(const boost::shared_ptr<T> &view_sp, TextView *view, Document& doc)
{
view->m_document = &doc;
{
typedef Document::signal_t::slot_type slot_type;
slot_type myslot(&TextView::refresh, view);
doc.connect(myslot.track(view_sp));
}
}
void refresh() const
{
std::cout << "TextView: " << m_document->getText() << std::endl;
}
private:
// give boost::signals2::deconstruct access to private constructor
friend class boost::signals2::deconstruct_access;
// private constructor to force use of deconstruct
TextView()
{}
Document* m_document;
};
class HexView
{
public:
/* This adl_postconstruct function will be found
via argument-dependent lookup when using boost::signals2::deconstruct. */
template<typename T>
friend void adl_postconstruct(const boost::shared_ptr<T> &view_sp, HexView *view, Document& doc)
{
view->m_document = &doc;
{
typedef Document::signal_t::slot_type slot_type;
slot_type myslot(&HexView::refresh, view);
doc.connect(myslot.track(view_sp));
}
}
void refresh() const
{
const std::string& s = m_document->getText();
std::cout << "HexView:";
for (std::string::const_iterator it = s.begin(); it != s.end(); ++it)
std::cout << ' ' << std::hex << static_cast<int>(*it);
std::cout << std::endl;
}
private:
// give boost::signals2::deconstruct access to private constructor
friend class boost::signals2::deconstruct_access;
// private constructor to force use of deconstruct
HexView()
{}
Document* m_document;
};
namespace bs2 = boost::signals2;
int main(int argc, char* argv[])
{
Document doc;
boost::shared_ptr<TextView> v1 = bs2::deconstruct<TextView>().postconstruct(boost::ref(doc));
boost::shared_ptr<HexView> v2 = bs2::deconstruct<HexView>().postconstruct(boost::ref(doc));
doc.append(argc >= 2 ? argv[1] : "Hello world!");
v2.reset(); // destroy the HexView, automatically disconnecting
doc.append(" HexView should no longer be connected.");
return 0;
}