SignalManager.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_MANAGER_HPP
#define TGUI_SIGNAL_MANAGER_HPP
 
#include <TGUI/Widget.hpp>
 
#include <unordered_map>
#include <memory>

 
namespace tgui
{
 
    class TGUI_API SignalManager
    {
    public:
 
        using Ptr = std::shared_ptr<SignalManager>; 
        using ConstPtr = std::shared_ptr<const SignalManager>; 
 
        using Delegate = std::function<void()>;
        using DelegateEx = std::function<void(std::shared_ptr<Widget>, const String&)>;
 
        using Weak = std::weak_ptr<Widget>;
        using SignalID = unsigned int;
 
        struct SignalTuple
        {
            String widgetName;
            String signalName;
            std::pair<Delegate, DelegateEx> func;
        };
 
        struct ConnectedSignalTuple
        {
            SignalID signalId;
            Weak widget;
            unsigned int signalWidgetID;
 
            ConnectedSignalTuple(SignalID sigId, Weak widgetPtr, unsigned int widgetId) :
                signalId(sigId),
                widget(std::move(widgetPtr)),
                signalWidgetID(widgetId)
            {
            }
        };

        SignalManager() = default;

        virtual ~SignalManager() = default;

        static void setDefaultSignalManager(const SignalManager::Ptr& manager);

        TGUI_NODISCARD static SignalManager::Ptr getSignalManager();
 
#if defined(__cpp_if_constexpr) && (__cpp_if_constexpr >= 201606L)
        template <typename Func, typename... BoundArgs>
        unsigned int connect(String widgetName, String signalName, Func&& handler, const BoundArgs&... args);
 
#else
        template <typename Func, typename... Args, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const Args&...)>>::value>* = nullptr>
        unsigned int connect(String widgetName, String signalName, Func&& handler, const Args&... args);

        template <typename Func, typename... BoundArgs, typename std::enable_if_t<!std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value // Ambigious otherwise when passing bind expression
                                                                                && std::is_convertible<Func, std::function<void(const BoundArgs&..., std::shared_ptr<Widget>, const String&)>>::value>* = nullptr>
        unsigned int connect(String widgetName, String signalName, Func&& handler, BoundArgs&&... args);
#endif

        virtual bool disconnect(unsigned int id);

        virtual void disconnectAll();

        virtual void add(const Widget::Ptr& widgetPtr);

        virtual void remove(Widget* widget);

    private:
        unsigned int generateUniqueId();
 
        unsigned int m_lastId = 0;

    protected:

        TGUI_NODISCARD std::pair<Delegate, DelegateEx> makeSignal(const Delegate&);

        TGUI_NODISCARD std::pair<Delegate, DelegateEx> makeSignalEx(const DelegateEx&);

        virtual void connect(SignalID id);

 
        static SignalManager::Ptr m_manager;
 
        std::vector<Weak> m_widgets;
        std::unordered_map<SignalID, SignalTuple> m_signals;
        std::vector<ConnectedSignalTuple> m_connectedSignals;
    };

 
#if defined(__cpp_if_constexpr) && (__cpp_if_constexpr >= 201606L)
    template <typename Func, typename... BoundArgs>
    unsigned int SignalManager::connect(String widgetName, String signalName, Func&& handler, const BoundArgs&... args)
    {
        const unsigned int id = generateUniqueId();
 
        if constexpr (std::is_convertible_v<Func, std::function<void(const BoundArgs&...)>>
                   && std::is_invocable_v<decltype(&handler), BoundArgs...>
                   && !std::is_function_v<Func>)
        {
            // Reference to function
            m_signals[id] = {widgetName, signalName, makeSignal([=, f=std::function<void(const BoundArgs&...)>(handler)]{ std::invoke(f, args...); })};
        }
        else if constexpr (std::is_convertible_v<Func, std::function<void(const BoundArgs&...)>>)
        {
            // Function pointer
            m_signals[id] = {widgetName, signalName, makeSignal([=]{ std::invoke(handler, args...); })};
        }
        else if constexpr (std::is_convertible_v<Func, std::function<void(const BoundArgs&..., const std::shared_ptr<Widget>&, const String&)>>
                        && std::is_invocable_v<decltype(&handler), BoundArgs..., const std::shared_ptr<Widget>&, const String&>
                        && !std::is_function_v<Func>)
        {
            // Reference to function with caller arguments
            m_signals[id] = {widgetName, signalName, makeSignalEx([=, f=std::function<void(const BoundArgs&..., const std::shared_ptr<Widget>& w, const String& s)>(handler)](const std::shared_ptr<Widget>& w, const String& s){ std::invoke(f, args..., w, s); })};
        }
        else
        {
            // Function pointer with caller arguments
            m_signals[id] = {widgetName, signalName, makeSignalEx([=](const std::shared_ptr<Widget>& w, const String& s){ std::invoke(handler, args..., w, s); })};
        }
 
        connect(id);
        return id;
    }
#else
    template <typename Func, typename... Args, typename std::enable_if_t<std::is_convertible<Func, std::function<void(const Args&...)>>::value>*>
    unsigned int SignalManager::connect(String widgetName, String signalName, Func&& handler, const Args&... args)
    {
        const unsigned int id = generateUniqueId();
        m_signals[id] = {widgetName, signalName, makeSignal([f=std::function<void(const Args&...)>(handler),args...](){ f(args...); })};
 
        connect(id);
        return id;
    }
 
    template <typename Func, typename... BoundArgs, typename std::enable_if_t<!std::is_convertible<Func, std::function<void(const BoundArgs&...)>>::value // Ambigious otherwise when passing bind expression
                                                                            && std::is_convertible<Func, std::function<void(const BoundArgs&..., std::shared_ptr<Widget>, const String&)>>::value>*>
    unsigned int SignalManager::connect(String widgetName, String signalName, Func&& handler, BoundArgs&&... args)
    {
        const unsigned int id = generateUniqueId();
        m_signals[id] = {widgetName, signalName, makeSignalEx(
                [f=std::function<void(const BoundArgs&..., const std::shared_ptr<Widget>&, const String&)>(handler), args...]
                        (const std::shared_ptr<Widget>& w, const String& s)
                { f(args..., w, s); }
        )};
 
        connect(id);
        return id;
    }
#endif

}

 
#endif // TGUI_SIGNAL_MANAGER_HPP