Signal.hpp

//
// TGUI - Texus' Graphical User Interface
// Copyright (C) 2012-2025 Bruno Van de Velde (vdv_b@tgui.eu)
//
// This software is provided 'as-is', without any express or implied warranty.
// In no event will the authors be held liable for any damages arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it freely,
// subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented;
//    you must not claim that you wrote the original software.
//    If you use this software in a product, an acknowledgment
//    in the product documentation would be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such,
//    and must not be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source distribution.
//
 
#ifndef TGUI_SIGNAL_HPP
#define TGUI_SIGNAL_HPP

 
#include <TGUI/Global.hpp>
#include <TGUI/String.hpp>
#include <TGUI/Color.hpp>
#include <TGUI/Vector2.hpp>
#include <TGUI/Animation.hpp>
#include <TGUI/Filesystem.hpp>
 
#include <unordered_map>
#include <type_traits>
#include <functional>
#include <typeindex>
#include <memory>
#include <vector>
#include <deque>
 
#undef MessageBox  // windows.h defines MessageBox when NOMB isn't defined before including windows.h

 
namespace tgui
{
    class Widget;
    class ChildWindow;
    class Panel;

    class TGUI_API Signal
    {
    public:

        virtual ~Signal() = default;

        Signal(String&& name, std::size_t extraParameters = 0) :
            m_name{std::move(name)}
        {
            if (1 + extraParameters > m_parameters.size())
                m_parameters.resize(1 + extraParameters);
        }

        Signal(const Signal& other);

        Signal(Signal&& other) noexcept = default;

        Signal& operator=(const Signal& other);

        Signal& operator=(Signal&& other) noexcept = default;

        template <typename Func, typename... BoundArgs>
        unsigned int operator()(const Func& func, const BoundArgs&... args)
        {
            return connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            const auto id = ++m_lastSignalId;
#if defined(__cpp_if_constexpr) && (__cpp_if_constexpr >= 201606L)
            if constexpr(sizeof...(BoundArgs) == 0)
                m_handlers[id] = func;
            else
#endif
            {
                m_handlers[id] = [=]{ invokeFunc(func, args...); };
            }
 
            return id;
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const std::shared_ptr<Widget>&, const String&)>>::value>* = nullptr>
        unsigned int connectEx(const Func& func, const BoundArgs&... args)
        {
            // The name is copied so that the lambda does not depend on the 'this' pointer
            return connect([func, name=m_name, args...](){ invokeFunc(func, args..., getWidget(), name); });
        }

        bool disconnect(unsigned int id);

        void disconnectAll();

        bool emit(const Widget* widget);

        TGUI_NODISCARD String getName() const
        {
            return m_name;
        }

        void setEnabled(bool enabled)
        {
            m_enabled = enabled;
        }

        TGUI_NODISCARD bool isEnabled() const
        {
            return m_enabled;
        }

    protected:

        static std::shared_ptr<Widget> getWidget();

        template <typename Type>
        TGUI_NODISCARD static const std::decay_t<Type>& dereferenceParam(std::size_t paramIndex)
        {
            return *static_cast<const std::decay_t<Type>*>(m_parameters[paramIndex]);
        }
 
#if defined(__cpp_lib_invoke) && (__cpp_lib_invoke >= 201411L)
        template <typename Func, typename... Args>
        static void invokeFunc(Func&& func, Args&&... args)
        {
            std::invoke(std::forward<Func>(func), std::forward<Args>(args)...);
        }
#else
        // std::invoke only exists in c++17 so we use our own implementation to support c++14 compilers
        template <typename Func, typename... Args, typename std::enable_if_t<std::is_member_pointer<std::decay_t<Func>>::value>* = nullptr>
        static void invokeFunc(Func&& func, Args&&... args)
        {
            (std::mem_fn(func))(std::forward<Args>(args)...);
        }
 
        template <typename Func, typename... Args, typename std::enable_if_t<!std::is_member_pointer<std::decay_t<Func>>::value>* = nullptr>
        static void invokeFunc(Func&& func, Args&&... args)
        {
            std::forward<Func>(func)(std::forward<Args>(args)...);
        }
#endif

    protected:
 
        bool m_enabled = true;
        String m_name;
        std::unordered_map<unsigned int, std::function<void()>> m_handlers;
 
        static unsigned int m_lastSignalId;
        static std::deque<const void*> m_parameters;
    };

    template <typename T>
    class SignalTyped : public Signal
    {
    public:

        SignalTyped(String&& name) :
            Signal{std::move(name), 1}
        {
        }

        template <typename Func, typename... BoundArgs>
        unsigned int operator()(const Func& func, const BoundArgs&... args)
        {
            return connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., T)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<T>(1)); });
        }

        bool emit(const Widget* widget, T param)
        {
            if (m_handlers.empty())
                return false;
 
            m_parameters[1] = static_cast<const void*>(&param);
            return Signal::emit(widget);
        }
    };

    template <typename T1, typename T2>
    class SignalTyped2 : public Signal
    {
    public:

        SignalTyped2(String&& name) :
            Signal{std::move(name), 2}
        {
        }

        template <typename Func, typename... BoundArgs>
        unsigned int operator()(const Func& func, const BoundArgs&... args)
        {
            return connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., T1, T2)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<T1>(1), dereferenceParam<T2>(2)); });
        }

        bool emit(const Widget* widget, T1 param1, T2 param2)
        {
            if (m_handlers.empty())
                return false;
 
            m_parameters[1] = static_cast<const void*>(&param1);
            m_parameters[2] = static_cast<const void*>(&param2);
            return Signal::emit(widget);
        }
    };
 
    using SignalInt = SignalTyped<int>; 
    using SignalUInt = SignalTyped<unsigned int>; 
    using SignalBool = SignalTyped<bool>; 
    using SignalFloat = SignalTyped<float>; 
    using SignalColor = SignalTyped<Color>; 
    using SignalString = SignalTyped<const String&>; 
    using SignalVector2f = SignalTyped<Vector2f>; 
    using SignalFloatRect = SignalTyped<FloatRect>; 
    using SignalRange = SignalTyped2<float, float>; 

    class TGUI_API SignalChildWindow : public Signal
    {
    public:

        SignalChildWindow(String&& name) :
            Signal{std::move(name), 1}
        {
        }

        template <typename Func, typename... BoundArgs>
        unsigned int operator()(const Func& func, const BoundArgs&... args)
        {
            return connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const std::shared_ptr<ChildWindow>&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceChildWindow()); });
        }

        bool emit(ChildWindow* param);

    private:

        static std::shared_ptr<ChildWindow> dereferenceChildWindow();

    };

    class TGUI_API SignalItem : public Signal
    {
    public:

        SignalItem(String&& name) :
            Signal{std::move(name), 3}
        {
        }

        template <typename Func, typename... BoundArgs>
        unsigned int operator()(const Func& func, const BoundArgs&... args)
        {
            return connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., int)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<int>(1)); });
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const String&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<String>(2)); });
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const String&, const String&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<String>(2), dereferenceParam<String>(3)); });
        }

        bool emit(const Widget* widget, int index, const String& item, const String& id);

    };

    class TGUI_API SignalPanelListBoxItem : public Signal
    {
    public:
        SignalPanelListBoxItem(String&& name) :
            Signal{std::move(name), 3}
        { }

        template<typename Func, typename... BoundArgs>
        unsigned int operator()(const Func& func, const BoundArgs&... args)
        {
            return connect(func, args...);
        }

        template<typename Func, typename... BoundArgs, std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect(func, args...);
        }

        template<typename Func, typename... BoundArgs, std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., int)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=] { invokeFunc(func, args..., dereferenceParam<int>(1)); });
        }

        template<typename Func, typename... BoundArgs, std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const std::shared_ptr<Panel>&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=] { invokeFunc(func, args..., dereferencePanel()); });
        }

        template<typename Func, typename... BoundArgs, std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const String&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=] { invokeFunc(func, args..., dereferenceParam<String>(3)); });
        }

        template<typename Func, typename... BoundArgs, std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., int, const std::shared_ptr<Panel>&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=] { invokeFunc(func, args..., dereferenceParam<int>(1), dereferencePanel()); });
        }

        template<typename Func, typename... BoundArgs, std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const std::shared_ptr<Panel>&, const String&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=] { invokeFunc(func, args..., dereferencePanel(), dereferenceParam<String>(3)); });
        }

        template<typename Func, typename... BoundArgs, std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., int, const std::shared_ptr<Panel>&, const String&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=] { invokeFunc(func, args..., dereferenceParam<int>(1), dereferencePanel(), dereferenceParam<String>(3)); });
        }

        bool emit(const Widget* widget, int index, const std::shared_ptr<Panel>& panel, const String& id);

    private:

        static std::shared_ptr<Panel> dereferencePanel();

    };

    class TGUI_API SignalFileDialogPaths : public Signal
    {
    public:

        SignalFileDialogPaths(String&& name) :
            Signal{std::move(name), 3}
        {
        }

        template <typename Func, typename... BoundArgs>
        unsigned int operator()(const Func& func, const BoundArgs&... args)
        {
            return connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const String&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<String>(1)); });
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const Filesystem::Path&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<Filesystem::Path>(2)); });
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const std::vector<Filesystem::Path>&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<std::vector<Filesystem::Path>>(3)); });
        }

        bool emit(const Widget* widget, const std::vector<Filesystem::Path>& paths);
    };

    class TGUI_API SignalShowEffect : public Signal
    {
    public:

        SignalShowEffect(String&& name) :
            Signal{std::move(name), 2}
        {
        }

        template <typename Func, typename... BoundArgs>
        unsigned int operator()(const Func& func, const BoundArgs&... args)
        {
            return connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., ShowEffectType)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<ShowEffectType>(1)); });
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., bool)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<bool>(2)); });
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., ShowEffectType, bool)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<ShowEffectType>(1), dereferenceParam<bool>(2)); });
        }

        bool emit(const Widget* widget, ShowEffectType type, bool visible);

    };

    class TGUI_API SignalAnimationType : public Signal
    {
    public:

        SignalAnimationType(String&& name) :
            Signal{std::move(name), 1}
        {
        }

        template <typename Func, typename... BoundArgs>
        unsigned int operator()(const Func& func, const BoundArgs&... args)
        {
            return connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., AnimationType)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<AnimationType>(1)); });
        }

        bool emit(const Widget* widget, AnimationType type);

    };

    class TGUI_API SignalItemHierarchy : public Signal
    {
    public:

        SignalItemHierarchy(String&& name) :
            Signal{std::move(name), 2}
        {
        }

        template <typename Func, typename... BoundArgs>
        unsigned int operator()(const Func& func, const BoundArgs&... args)
        {
            return connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect(func, args...);
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const String&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<String>(1)); });
        }

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const BoundArgs&..., const std::vector<String>&)>>::value>* = nullptr>
        unsigned int connect(const Func& func, const BoundArgs&... args)
        {
            return Signal::connect([=]{ invokeFunc(func, args..., dereferenceParam<std::vector<String>>(2)); });
        }

        bool emit(const Widget* widget, const String& item, const std::vector<String>& fullItem);

    };

}

 
#endif // TGUI_SIGNAL_HPP