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-rw-r--r--plugingui/test.cc172
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diff --git a/plugingui/test.cc b/plugingui/test.cc
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+++ b/plugingui/test.cc
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+#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);
+}