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libs/signals2/example/doc_view.cpp

// Document/View sample for Boost.Signals
// 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/signals2/signal.hpp>
#include <boost/bind.hpp>

//[ document_def_code_snippet
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;
};
//]

//[ text_view_def_code_snippet
class TextView
{
public:
    TextView(Document& doc): m_document(doc)
    {
        m_connection = m_document.connect(boost::bind(&TextView::refresh, this));
    }

    ~TextView()
    {
        m_connection.disconnect();
    }

    void refresh() const
    {
        std::cout << "TextView: " << m_document.getText() << std::endl;
    }
private:
    Document&               m_document;
    boost::signals2::connection  m_connection;
};
//]

//[ hex_view_def_code_snippet
class HexView
{
public:
    HexView(Document& doc): m_document(doc)
    {
        m_connection = m_document.connect(boost::bind(&HexView::refresh, this));
    }

    ~HexView()
    {
        m_connection.disconnect();
    }

    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:
    Document&               m_document;
    boost::signals2::connection  m_connection;
};
//]

//[ document_view_main_code_snippet
int main(int argc, char* argv[])
{
    Document    doc;
    TextView    v1(doc);
    HexView     v2(doc);

    doc.append(argc == 2 ? argv[1] : "Hello world!");
    return 0;
}
//]