BackendGuiSDL.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_BACKEND_GUI_SDL_HPP
#define TGUI_BACKEND_GUI_SDL_HPP
 
#include <TGUI/extlibs/IncludeSDL.hpp>
#if SDL_MAJOR_VERSION < 3
    #include <SDL_touch.h>
#endif
 
#include <TGUI/Backend/Window/BackendGui.hpp>

 
namespace tgui
{
 
    class TGUI_API BackendGuiSDL : public BackendGui
    {
    public:

        BackendGuiSDL() = default;

        bool handleEvent(const SDL_Event& event);
        using BackendGui::handleEvent;

        void mainLoop(Color clearColor = {240, 240, 240}) override;

        TGUI_NODISCARD bool convertEvent(const SDL_Event& eventSDL, Event& eventTGUI);

        SDL_Window* getWindow() const;

        void startTextInput(FloatRect inputRect) override;

        void stopTextInput() override;

        void updateTextCursorPosition(FloatRect inputRect, Vector2f caretPos) override;

        TGUI_NODISCARD bool isKeyboardModifierPressed(Event::KeyModifier modifierKey) const override;

    protected:

        void setGuiWindow(SDL_Window* window);

        // Updates the view and changes the size of the root container when needed
        void updateContainerSize() override;

    protected:

        virtual void renderFrame(Color clearColor);

        virtual void presentScreen() = 0;
 
#if ((SDL_MAJOR_VERSION == 2) && (SDL_MINOR_VERSION < 26))
        virtual void updateFramebufferSize() = 0;
#endif

    protected:
 
        SDL_Window* m_window = nullptr;
        float m_dpiScale = 1;
 
        bool m_textInputStarted = false;
        SDL_Rect m_textInputRect = {};
 
        bool m_touchFirstFingerDown = false;
        SDL_FingerID m_touchFirstFingerId = 0;      // Only valid if m_touchFirstFingerDown is true
        SDL_TouchID  m_touchFirstFingerTouchId = 0; // Only valid if m_touchFirstFingerDown is true

    };
}

 
#endif // TGUI_BACKEND_GUI_SDL_HPP