115 lines
2.6 KiB
C++
115 lines
2.6 KiB
C++
// Various simple examples involving disconnecting and blocking slots.
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// Copyright Douglas Gregor 2001-2004.
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// Copyright Frank Mori Hess 2009.
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//
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// Use, modification and
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// distribution is subject to the Boost Software License, Version
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// 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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// For more information, see http://www.boost.org
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#include <iostream>
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#include <boost/signals2/signal.hpp>
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#include <boost/signals2/shared_connection_block.hpp>
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struct HelloWorld
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{
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void operator()() const
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{
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std::cout << "Hello, World!" << std::endl;
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}
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};
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void disconnect_example()
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{
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boost::signals2::signal<void ()> sig;
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//[ disconnect_code_snippet
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boost::signals2::connection c = sig.connect(HelloWorld());
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std::cout << "c is connected\n";
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sig(); // Prints "Hello, World!"
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c.disconnect(); // Disconnect the HelloWorld object
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std::cout << "c is disconnected\n";
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sig(); // Does nothing: there are no connected slots
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//]
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}
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void block_example()
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{
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boost::signals2::signal<void ()> sig;
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//[ block_code_snippet
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boost::signals2::connection c = sig.connect(HelloWorld());
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std::cout << "c is not blocked.\n";
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sig(); // Prints "Hello, World!"
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{
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boost::signals2::shared_connection_block block(c); // block the slot
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std::cout << "c is blocked.\n";
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sig(); // No output: the slot is blocked
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} // shared_connection_block going out of scope unblocks the slot
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std::cout << "c is not blocked.\n";
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sig(); // Prints "Hello, World!"}
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//]
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}
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struct ShortLived
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{
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void operator()() const
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{
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std::cout << "Life is short!" << std::endl;
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}
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};
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void scoped_connection_example()
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{
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boost::signals2::signal<void ()> sig;
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//[ scoped_connection_code_snippet
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{
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boost::signals2::scoped_connection c(sig.connect(ShortLived()));
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sig(); // will call ShortLived function object
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} // scoped_connection goes out of scope and disconnects
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sig(); // ShortLived function object no longer connected to sig
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//]
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}
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//[ disconnect_by_slot_def_code_snippet
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void foo() { std::cout << "foo"; }
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void bar() { std::cout << "bar\n"; }
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//]
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void disconnect_by_slot_example()
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{
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boost::signals2::signal<void()> sig;
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//[ disconnect_by_slot_usage_code_snippet
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sig.connect(&foo);
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sig.connect(&bar);
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sig();
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// disconnects foo, but not bar
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sig.disconnect(&foo);
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sig();
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//]
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}
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int main()
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{
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std::cout << "Disconnect example:\n";
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disconnect_example();
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std::cout << "\nBlock example:\n";
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block_example();
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std::cout << "\nScoped connection example:\n";
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scoped_connection_example();
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std::cout << "\nDisconnect by slot example:\n";
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disconnect_by_slot_example();
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return 0;
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}
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