diff options
Diffstat (limited to 'plugingui/notifier.h')
-rw-r--r-- | plugingui/notifier.h | 163 |
1 files changed, 163 insertions, 0 deletions
diff --git a/plugingui/notifier.h b/plugingui/notifier.h new file mode 100644 index 0000000..328ab7d --- /dev/null +++ b/plugingui/notifier.h @@ -0,0 +1,163 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/*************************************************************************** + * notifier.h + * + * Thu Sep 3 15:48:39 CEST 2015 + * Copyright 2015 Bent Bisballe Nyeng + * deva@aasimon.org + ****************************************************************************/ + +/* + * This file is part of DrumGizmo. + * + * DrumGizmo is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * DrumGizmo is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with DrumGizmo; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. + */ +#pragma once + +#include <functional> +#include <vector> +#include <map> +#include <set> +#include <memory> + +namespace aux +{ + template<int> + struct placeholder + { + }; +} + +namespace std +{ + template<int N> + struct is_placeholder<aux::placeholder<N>> + : integral_constant<int, N+1> + { + }; +} + +namespace aux +{ + // std::integer_sequence introduced in C++14 so remove this once we start requiring that. + + template<int... Ns> + struct int_sequence + { + }; + + template<int N, int... Ns> + struct gen_int_sequence + : gen_int_sequence<N-1, N-1, Ns...> + { + }; + + template<int... Ns> + struct gen_int_sequence<0, Ns...> + : int_sequence<Ns...> + { + }; +}; + + +namespace GUI { + +class Listener; +class NotifierBase { +public: + virtual void disconnect(Listener* object) {} +}; + +class Listener { +public: + virtual ~Listener() + { + for(auto signal : signals) + { + signal->disconnect(this); + } + } + + void registerNotifier(NotifierBase* signal) + { + signals.insert(signal); + } + + void unregisterNotifier(NotifierBase* signal) + { + signals.erase(signal); + } + +private: + std::set<NotifierBase*> signals; +}; + +template<typename... Args> +class Notifier : public NotifierBase { +public: + Notifier() {} + + //! \brief When dtor is called it will automatically disconnect all its listeners. + ~Notifier() + { + for(auto& slot : slots) + { + slot.first->unregisterNotifier(this); + } + } + + using callback_type = std::function<void(Args...)>; + + //! \brief Connect object to this Notifier. + template<typename O, typename F> + void connect(O* p, const F& fn) + { + slots[p] = std::move(construct_mem_fn(fn, p, aux::gen_int_sequence<sizeof...(Args)>{})); + if(p && dynamic_cast<Listener*>(p)) + { + dynamic_cast<Listener*>(p)->registerNotifier(this); + } + } + + //! \brief Disconnect object from this Notifier. + void disconnect(Listener* object) + { + slots.erase(object); + } + + //! \brief Activate this notifier by pretending it is a function. + //! Example: Notifier<int> foo; foo(42); + void operator()(Args... args) + { + for(auto& slot : slots) + { + slot.second(args...); + } + } + +private: + std::map<Listener*, callback_type> slots; + + template<typename F, typename O, int... Ns> + callback_type construct_mem_fn(const F& fn, O* p, aux::int_sequence<Ns...>) const + { + return std::bind(fn, p, aux::placeholder<Ns>{}...); + } + +}; + +} // GUI:: + +#define CONNECT(SRC, SIG, TAR, SLO) (SRC)->SIG.connect(TAR, SLO) |