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Diffstat (limited to 'plugingui/test.cc')
-rw-r--r-- | plugingui/test.cc | 172 |
1 files changed, 172 insertions, 0 deletions
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); +} |