From 24bb55371a5d8d81b23521ebdfcde68f0035697c Mon Sep 17 00:00:00 2001
From: Bent Bisballe Nyeng <deva@aasimon.org>
Date: Sun, 20 Sep 2015 11:36:22 +0200
Subject: Basic project based on DrumGizmo.

---
 plugingui/test.cc | 172 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 172 insertions(+)
 create mode 100644 plugingui/test.cc

(limited to 'plugingui/test.cc')

diff --git a/plugingui/test.cc b/plugingui/test.cc
new file mode 100644
index 0000000..2f60d37
--- /dev/null
+++ b/plugingui/test.cc
@@ -0,0 +1,172 @@
+#include <iostream>
+#include <functional>
+#include <vector>
+#include <map>
+#include <set>
+#include <type_traits>
+#include <utility>
+ 
+/////////////////////////////////////////
+//
+// Listener and Notifier classes:
+//
+/////////////////////////////////////////
+ 
+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);
+        }
+ 
+        std::set<NotifierBase*> signals;
+};
+ 
+template<typename T, typename... Args>
+class Notifier : public NotifierBase {
+public:
+        Notifier() {}
+        ~Notifier()
+        {
+                for (auto slot: slots) {
+                        slot.first->unregisterNotifier(this);
+                }
+        }
+ 
+        void connect(Listener* object, std::function<void(T, Args...)> slot)
+        {
+                slots[object] = slot;
+                object->registerNotifier(this);
+        }
+ 
+        void disconnect(Listener* object)
+        {
+                slots.erase(object);
+        }
+ 
+        void notify(T t, Args...args)
+        {
+                for (auto slot: slots) {
+                        slot.second(t, args...);
+                }
+        }
+ 
+        std::map<Listener*, std::function<void(T, Args...)>> slots;
+};
+ 
+/////////////////////////////////////////
+//
+// Code which I don't understand but does something clever and produces a compile warning:
+//
+/////////////////////////////////////////
+ 
+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)...);
+}
+ 
+ 
+ 
+/////////////////////////////////////////
+//
+//  Example:
+//
+/////////////////////////////////////////
+ 
+class MyObject : public Listener {
+public:
+        void onMouseMoved(int x, int y)
+        {
+                std::cout << __PRETTY_FUNCTION__ << std::endl;
+                std::cout << "Mouse moved: " << x << "," << y << std::endl;
+        }
+};
+ 
+class MyObject2 : public Listener {
+public:
+        void mouseMoved(int x, int y)
+        {
+                std::cout << __PRETTY_FUNCTION__ << std::endl;
+                std::cout << "Mouse moved: " << x << "," << y << std::endl;
+        }
+};
+ 
+class Button {
+public:
+        Notifier<int, int> mouseMove; // arguments: (int x, int y)
+ 
+        void emulateMouseMove(int x, int y)
+        {
+                mouseMove.notify(x, y);
+        }
+};
+ 
+ 
+#define CONN(O, M) &O, mem_bind(&decltype(O)::M, O)
+#define _connect(SRC, SIG, TAR, SLO) SRC.SIG.connect(&TAR, mem_bind(&decltype(TAR)::SLO, TAR))
+ 
+int main()
+{
+        Button btn;
+ 
+        MyObject object;
+        //btn.mouseMove.connect(&object, std::bind(&MyObject::onMouseMoved, std::ref(object), _1, _2 )); // 'Vanilla' interface
+        //btn.mouseMove.connect(&object, std::bind(&decltype::onMouseMoved, std::ref(object), _1, _2 )); // Use decltype
+        //btn.mouseMove.connect(&object, mem_bind(&decltype(object)::onMouseMoved, object)); // Use clever mem_bind construct
+        btn.mouseMove.connect(CONN(object, onMouseMoved)); // Use convenience macro
+ 
+        _connect(btn, mouseMove, object, onMouseMoved);
+ 
+        MyObject2 object2;
+        btn.mouseMove.connect(CONN(object2, mouseMoved));
+ 
+        // Now trigger the notification
+        btn.emulateMouseMove(10,10);
+}
-- 
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