Introduce new Notifier and use it in the Knob class.

1 files changed, 149 insertions, 0 deletions

diff --git a/plugingui/notifier.h b/plugingui/notifier.h
new file mode 100644
index 0000000..d68e28c
--- /dev/null
+++ b/plugingui/notifier.h
@@ -0,0 +1,149 @@
+/* -*- 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 <iostream>
+#include <functional>
+#include <vector>
+#include <map>
+#include <set>
+#include <type_traits>
+#include <utility>
+
+namespace GUI {
+
+class Listener;
+class NotifierBase {
+public:
+	virtual void disconnect(Listener* object) {}
+};
+
+class Listener {
+public:
+	virtual ~Listener()
+	{
+		for(auto signal = signals.begin(); signal != signals.end(); ++signal) {
+			(*signal)->disconnect(this);
+		}
+	}
+
+	void registerNotifier(NotifierBase* signal)
+	{
+		signals.insert(signal);
+	}
+
+	void unregisterNotifier(NotifierBase* signal)
+	{
+		signals.erase(signal);
+	}
+
+	std::set<NotifierBase*> signals;
+};
+
+template<typename T, typename... Args>
+class Notifier : public NotifierBase {
+public:
+	Notifier() {}
+	~Notifier()
+	{
+		for(auto slot = slots.begin(); slot != slots.end(); ++slot) {
+			(*slot).first->unregisterNotifier(this);
+		}
+	}
+
+	void connect(Listener* object, std::function<void(T, Args...)> slot)
+	{
+		slots[object] = slot;
+		if(object) {
+			object->registerNotifier(this);
+		}
+	}
+
+	void disconnect(Listener* object)
+	{
+		slots.erase(object);
+	}
+
+	void notify(T t, Args...args)
+	{
+		for(auto slot = slots.begin(); slot != slots.end(); ++slot) {
+			(*slot).second(t, args...);
+		}
+	}
+
+	std::map<Listener*, std::function<void(T, Args...)>> slots;
+};
+
+} // GUI::
+
+template<unsigned... Is> struct seq{};
+template<unsigned I, unsigned... Is>
+struct gen_seq : gen_seq<I-1, I-1, Is...>{};
+template<unsigned... Is>
+struct gen_seq<0, Is...> : seq<Is...>{};
+
+template<unsigned I> struct placeholder{};
+
+namespace std{
+template<unsigned I>
+struct is_placeholder< ::placeholder<I> > : integral_constant<int, I>{};
+} // std::
+
+namespace aux{
+template<unsigned... Is, class F, class... Ts>
+auto easy_bind(seq<Is...>, F&& f, Ts&&... vs)
+	-> decltype(std::bind(std::forward<F>(f), std::forward<Ts>(vs)..., ::placeholder<1 + Is>()...))
+{
+    return std::bind(std::forward<F>(f), std::forward<Ts>(vs)..., ::placeholder<1 + Is>()...);
+}
+} // aux::
+
+template<class R, class C, class... FArgs, class... Args>
+auto mem_bind(R (C::*ptmf)(FArgs...), Args&&... vs)
+	-> decltype(aux::easy_bind(gen_seq<(sizeof...(FArgs) + 1) - sizeof...(Args)>(), ptmf, std::forward<Args>(vs)...))
+{
+    // the +1s for 'this' argument
+    static_assert(sizeof...(Args) <= sizeof...(FArgs) + 1, "too many arguments to mem_bind");
+    return aux::easy_bind(gen_seq<(sizeof...(FArgs) + 1) - sizeof...(Args)>(), ptmf, std::forward<Args>(vs)...);
+}
+
+template<class T, class C, class... Args>
+auto mem_bind(T C::*ptmd, Args&&... vs)
+	-> decltype(aux::easy_bind(gen_seq<1 - sizeof...(Args)>(), ptmd, std::forward<Args>(vs)...))
+{
+    // just 'this' argument
+    static_assert(sizeof...(Args) <= 1, "too many arguments to mem_bind");
+    return aux::easy_bind(gen_seq<1 - sizeof...(Args)>(), ptmd, std::forward<Args>(vs)...);
+}
+
+//#define obj_connect_old(SRC, SIG, TAR, SLO) (SRC).SIG.connect(&(TAR), mem_bind(&decltype(TAR)::SLO, TAR))
+
+#define fun_connect(SRC, SIG, SLO) \
+	(SRC).SIG.connect(nullptr, SLO)
+
+#define obj_connect(SRC, SIG, TAR, SLO) \
+  (SRC)->SIG.connect(TAR, mem_bind(&SLO, std::ref(*TAR)))