text: #ifndef Magnum_Platform_AbstractXApplication_h
  #define Magnum_Platform_AbstractXApplication_h
  /*
      This file is part of Magnum.
  
      Copyright © 2010, 2011, 2012, 2013, 2014, 2015, 2016, 2017, 2018, 2019
                Vladimír Vondruš <mosra@centrum.cz>
  
      Permission is hereby granted, free of charge, to any person obtaining a
      copy of this software and associated documentation files (the "Software"),
      to deal in the Software without restriction, including without limitation
      the rights to use, copy, modify, merge, publish, distribute, sublicense,
      and/or sell copies of the Software, and to permit persons to whom the
      Software is furnished to do so, subject to the following conditions:
  
      The above copyright notice and this permission notice shall be included
      in all copies or substantial portions of the Software.
  
      THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
      IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
      FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
      THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
      LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
      FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
      DEALINGS IN THE SOFTWARE.
  */
  
  /** @file
   * @brief Class @ref Magnum::Platform::AbstractXApplication
   */
  
  #include <memory>
  #include <Corrade/Containers/EnumSet.h>
  
  #include <X11/Xlib.h>
  #include <X11/Xutil.h>
  /* undef Xlib nonsense to avoid conflicts */
  #undef Always
  #undef Complex
  #undef None
  #undef Status
  
  #include "Magnum/Magnum.h"
  #include "Magnum/Tags.h"
  #include "Magnum/GL/GL.h"
  #include "Magnum/Math/Vector2.h"
  #include "Magnum/Platform/Platform.h"
  
  namespace Magnum { namespace Platform {
  
  namespace Implementation {
      template<class, class, class, class> class AbstractContextHandler;
  }
  
  /** @nosubgrouping
  @brief Base for X11-based applications
  
  Supports keyboard and mouse handling. See @ref platform for brief introduction.
  
  @note Not meant to be used directly, see the @ref GlxApplication and
      @ref XEglApplication subclasses instead.
  */
  class AbstractXApplication {
      public:
          /** @brief Application arguments */
          struct Arguments {
              /** @brief Constructor */
              /*implicit*/ constexpr Arguments(int& argc, char** argv) noexcept: argc{argc}, argv{argv} {}
  
              int& argc;      /**< @brief Argument count */
              char** argv;    /**< @brief Argument values */
          };
  
          class Configuration;
          class GLConfiguration;
          class ViewportEvent;
          class InputEvent;
          class KeyEvent;
          class MouseEvent;
          class MouseMoveEvent;
  
          /** @brief Copying is not allowed */
          AbstractXApplication(const AbstractXApplication&) = delete;
  
          /** @brief Moving is not allowed */
          AbstractXApplication(AbstractXApplication&&) = delete;
  
          /** @brief Copying is not allowed */
          AbstractXApplication& operator=(const AbstractXApplication&) = delete;
  
          /** @brief Moving is not allowed */
          AbstractXApplication& operator=(AbstractXApplication&&) = delete;
  
          /**
           * @brief Execute main loop
           * @return Value for returning from @cpp main() @ce
           *
           * See @ref MAGNUM_GLXAPPLICATION_MAIN() or
           * @ref MAGNUM_XEGLAPPLICATION_MAIN() for usage information.
           */
          int exec();
  
          /** @brief Exit application main loop */
          void exit() { _flags |= Flag::Exit; }
  
      protected:
          /* Nobody will need to have (and delete) AbstractXApplication*, thus
             this is faster than public pure virtual destructor */
          ~AbstractXApplication();
  
          /**
           * @brief Create a window with given configuration for OpenGL context
           * @param configuration     Application configuration
           * @param glConfiguration   OpenGL context configuration
           *
           * Must be called only if the context wasn't created by the constructor
           * itself, i.e. when passing @ref NoCreate to it. Error message is
           * printed and the program exits if the context cannot be created, see
           * @ref tryCreate() for an alternative.
           */
          void create(const Configuration& configuration, const GLConfiguration& glConfiguration);
  
          /**
           * @brief Create a window with given configuration and OpenGL context
           *
           * Equivalent to calling @ref create(const Configuration&, const GLConfiguration&)
           * with default-constructed @ref GLConfiguration.
           */
          void create(const Configuration& configuration);
  
          /**
           * @brief Create a window with default configuration and OpenGL context
           *
           * Equivalent to calling @ref create(const Configuration&) with
           * default-constructed @ref Configuration.
           */
          void create();
  
          #ifdef MAGNUM_BUILD_DEPRECATED
          /** @brief @copybrief create(const Configuration&, const GLConfiguration&)
           * @deprecated Use @ref create(const Configuration&, const GLConfiguration&) instead.
           */
          CORRADE_DEPRECATED("use create(const Configuration&, const GLConfiguration&) instead") void createContext(const Configuration& configuration) {
              create(configuration);
          }
  
          /** @brief @copybrief create()
           * @deprecated Use @ref create() instead.
           */
          CORRADE_DEPRECATED("use create() instead") void createContext() {
              create();
          }
          #endif
  
          /**
           * @brief Try to create context with given configuration for OpenGL context
           *
           * Unlike @ref create(const Configuration&, const GLConfiguration&)
           * returns @cpp false @ce if the context cannot be created,
           * @cpp true @ce otherwise.
           */
          bool tryCreate(const Configuration& configuration, const GLConfiguration& glConfiguration);
  
          /**
           * @brief Try to create context with given configuration and OpenGL context
           *
           * Unlike @ref create(const Configuration&) returns @cpp false @ce if
           * the context cannot be created, @cpp true @ce otherwise.
           */
          bool tryCreate(const Configuration& configuration);
  
          #ifdef MAGNUM_BUILD_DEPRECATED
          /** @brief @copybrief tryCreate(const Configuration&, const GLConfiguration&)
           * @deprecated Use @ref tryCreate(const Configuration&, const GLConfiguration&) instead.
           */
          CORRADE_DEPRECATED("use tryCreate(const Configuration&) instead") bool tryCreateContext(const Configuration& configuration) {
              return tryCreate(configuration);
          }
          #endif
  
          /** @{ @name Screen handling */
  
      public:
          /**
           * @brief Window size
           *
           * Window size to which all input event coordinates can be related.
           * Same as @ref framebufferSize().
           */
          Vector2i windowSize() const { return _windowSize; }
  
          /**
           * @brief Framebuffer size
           *
           * Size of the default framebuffer. Same as @ref windowSize().
           */
          Vector2i framebufferSize() const { return _windowSize; }
  
      protected:
          /**
           * @brief Swap buffers
           *
           * Paints currently rendered framebuffer on screen.
           */
          void swapBuffers();
  
          /** @copydoc Sdl2Application::redraw() */
          void redraw() { _flags |= Flag::Redraw; }
  
      private:
          /**
           * @brief Viewport event
           *
           * Called when window size changes. The default implementation does
           * nothing. If you want to respond to size changes, you should pass the
           * new size to @ref GL::DefaultFramebuffer::setViewport() (if using
           * OpenGL) and possibly elsewhere (to
           * @ref SceneGraph::Camera::setViewport(), other framebuffers...).
           *
           * Note that this function might not get called at all if the window
           * size doesn't change. You should configure the initial state of your
           * cameras, framebuffers etc. in application constructor rather than
           * relying on this function to be called. Size of the window can be
           * retrieved using @ref windowSize().
           */
          virtual void viewportEvent(ViewportEvent& event);
  
          #ifdef MAGNUM_BUILD_DEPRECATED
          /** @copydoc GlfwApplication::viewportEvent(const Vector2i&) */
          virtual CORRADE_DEPRECATED("use viewportEvent(ViewportEvent&) instead") void viewportEvent(const Vector2i& size);
          #endif
  
          /** @copydoc Sdl2Application::drawEvent() */
          virtual void drawEvent() = 0;
  
          /*@}*/
  
          /** @{ @name Keyboard handling */
  
          /** @copydoc Sdl2Application::keyPressEvent() */
          virtual void keyPressEvent(KeyEvent& event);
  
          /** @copydoc Sdl2Application::keyReleaseEvent() */
          virtual void keyReleaseEvent(KeyEvent& event);
  
          /*@}*/
  
          /** @{ @name Mouse handling */
  
          /** @copydoc Sdl2Application::mousePressEvent() */
          virtual void mousePressEvent(MouseEvent& event);
  
          /** @copydoc Sdl2Application::mouseReleaseEvent() */
          virtual void mouseReleaseEvent(MouseEvent& event);
  
          /** @copydoc Sdl2Application::mouseMoveEvent() */
          virtual void mouseMoveEvent(MouseMoveEvent& event);
  
          /*@}*/
  
      #ifdef DOXYGEN_GENERATING_OUTPUT
      private:
      #else
      protected:
      #endif
          explicit AbstractXApplication(Implementation::AbstractContextHandler<GLConfiguration, Display*, VisualID, Window>* contextHandler, const Arguments& arguments, const Configuration& configuration, const GLConfiguration& glConfiguration);
  
          explicit AbstractXApplication(Implementation::AbstractContextHandler<GLConfiguration, Display*, VisualID, Window>* contextHandler, const Arguments& arguments, NoCreateT);
  
      private:
          enum class Flag: unsigned int {
              Redraw = 1 << 0,
              Exit = 1 << 1
          };
  
          typedef Containers::EnumSet<Flag> Flags;
          CORRADE_ENUMSET_FRIEND_OPERATORS(Flags)
  
          Display* _display{};
          Window _window{};
          Atom _deleteWindow{};
  
          std::unique_ptr<Implementation::AbstractContextHandler<GLConfiguration, Display*, VisualID, Window>> _contextHandler;
          std::unique_ptr<Platform::GLContext> _context;
  
          /** @todo Get this from the created window */
          Vector2i _windowSize;
  
          Flags _flags;
  };
  
  CORRADE_ENUMSET_OPERATORS(AbstractXApplication::Flags)
  
  /**
  @brief OpenGL context configuration
  
  Double-buffered OpenGL context.
  @see @ref GlxApplication::GlxApplication(), @ref XEglApplication::XEglApplication(),
      @ref Configuration, @ref create(), @ref tryCreate()
  @todo GLX_ARB_create_context_robustness/EGL_EXT_create_context_robustness
  */
  class AbstractXApplication::GLConfiguration {
      public:
          explicit GLConfiguration();
          ~GLConfiguration();
  
          /** @copydoc Sdl2Application::GLConfiguration::version() */
          GL::Version version() const { return _version; }
  
          /** @copydoc Sdl2Application::GLConfiguration::setVersion() */
          GLConfiguration& setVersion(GL::Version version) {
              _version = version;
              return *this;
          }
  
      private:
          GL::Version _version;
  };
  
  /**
  @brief Configuration
  
  @see @ref GlxApplication::GlxApplication(), @ref XEglApplication::XEglApplication(),
      @ref GLConfiguration, @ref create(), @ref tryCreate()
  */
  class AbstractXApplication::Configuration {
      public:
          /*implicit*/ Configuration();
          ~Configuration();
  
          /** @brief Window title */
          std::string title() const { return _title; }
  
          /**
           * @brief Set window title
           * @return Reference to self (for method chaining)
           *
           * Default is @cpp "Magnum X Application" @ce.
           */
          Configuration& setTitle(std::string title) {
              _title = std::move(title);
              return *this;
          }
  
          /** @copydoc Sdl2Application::Configuration::size() */
          Vector2i size() const { return _size; }
  
          /**
           * @brief Set window size
           * @return Reference to self (for method chaining)
           *
           * Default is @cpp {800, 600} @ce.
           */
          Configuration& setSize(const Vector2i& size) {
              _size = size;
              return *this;
          }
  
          #ifdef MAGNUM_BUILD_DEPRECATED
          /** @brief @copybrief GLConfiguration::version()
           * @deprecated Use @ref GLConfiguration::version() instead.
           */
          CORRADE_DEPRECATED("use GLConfiguration::version() instead") GL::Version version() const { return _version; }
  
          /** @brief @copybrief GLConfiguration::setVersion()
           * @deprecated Use @ref GLConfiguration::setVersion() instead.
           */
          CORRADE_DEPRECATED("use GLConfiguration::setVersion() instead") Configuration& setVersion(GL::Version version) {
              _version = version;
              return *this;
          }
          #endif
  
      private:
          std::string _title;
          Vector2i _size;
          #ifdef MAGNUM_BUILD_DEPRECATED
          GL::Version _version;
          #endif
  };
  
  /**
  @brief Viewport event
  
  @see @ref viewportEvent()
  */
  class AbstractXApplication::ViewportEvent {
      public:
          /** @brief Copying is not allowed */
          ViewportEvent(const ViewportEvent&) = delete;
  
          /** @brief Moving is not allowed */
          ViewportEvent(ViewportEvent&&) = delete;
  
          /** @brief Copying is not allowed */
          ViewportEvent& operator=(const ViewportEvent&) = delete;
  
          /** @brief Moving is not allowed */
          ViewportEvent& operator=(ViewportEvent&&) = delete;
  
          /**
           * @brief Window size
           *
           * Same as @ref framebufferSize().
           * @see @ref AbstractXApplication::windowSize()
           */
          Vector2i windowSize() const { return _size; }
  
          /**
           * @brief Framebuffer size
           *
           * Same as @ref windowSize().
           * @see @ref AbstractXApplication::framebufferSize()
           */
          Vector2i framebufferSize() const { return _size; }
  
      private:
          friend AbstractXApplication;
  
          explicit ViewportEvent(const Vector2i& size): _size{size} {}
  
          const Vector2i _size;
  };
  
  /**
  @brief Base for input events
  
  @see @ref KeyEvent, @ref MouseEvent, @ref MouseMoveEvent, @ref keyPressEvent(),
      @ref keyReleaseEvent(), @ref mousePressEvent(), @ref mouseReleaseEvent(),
      @ref mouseMoveEvent()
  */
  class AbstractXApplication::InputEvent {
      public:
          /**
           * @brief Modifier
           *
           * @see @ref Modifiers, @ref modifiers()
           */
          enum class Modifier: unsigned int {
              Shift = ShiftMask,          /**< Shift */
              Ctrl = ControlMask,         /**< Ctrl */
              Alt = Mod1Mask,             /**< Alt */
              AltGr = Mod5Mask,           /**< AltGr */
              CapsLock = LockMask,        /**< Caps lock */
              NumLock = Mod2Mask          /**< Num lock */
          };
  
          /**
           * @brief Set of modifiers
           *
           * @see @ref modifiers()
           */
          typedef Containers::EnumSet<Modifier> Modifiers;
  
          /**
           * @brief Mouse button
           *
           * @see @ref Buttons, @ref buttons()
           */
          enum class Button: unsigned int {
              Left = Button1Mask,     /**< Left button */
              Middle = Button2Mask,   /**< Middle button */
              Right = Button3Mask     /**< Right button */
          };
  
          /**
           * @brief Set of mouse buttons
           *
           * @see @ref buttons()
           */
          typedef Containers::EnumSet<Button> Buttons;
  
          /** @brief Copying is not allowed */
          InputEvent(const InputEvent&) = delete;
  
          /** @brief Moving is not allowed */
          InputEvent(InputEvent&&) = delete;
  
          /** @brief Copying is not allowed */
          InputEvent& operator=(const InputEvent&) = delete;
  
          /** @brief Moving is not allowed */
          InputEvent& operator=(InputEvent&&) = delete;
  
          /** @copydoc Sdl2Application::InputEvent::setAccepted() */
          void setAccepted(bool accepted = true) { _accepted = accepted; }
  
          /** @copydoc Sdl2Application::InputEvent::isAccepted() */
          bool isAccepted() const { return _accepted; }
  
          /** @brief Modifiers */
          Modifiers modifiers() const { return _modifiers; }
  
          /** @brief Mouse buttons */
          Buttons buttons() const { return Button(static_cast<unsigned int>(_modifiers)); }
  
      #ifndef DOXYGEN_GENERATING_OUTPUT
      protected:
          explicit InputEvent(Modifiers modifiers): _modifiers(modifiers), _accepted(false) {}
  
          ~InputEvent() = default;
      #endif
  
      private:
          Modifiers _modifiers;
          bool _accepted;
  };
  
  CORRADE_ENUMSET_OPERATORS(AbstractXApplication::InputEvent::Modifiers)
  CORRADE_ENUMSET_OPERATORS(AbstractXApplication::InputEvent::Buttons)
  
  /**
  @brief Key event
  
  @see @ref keyPressEvent(), @ref keyReleaseEvent()
  */
  class AbstractXApplication::KeyEvent: public AbstractXApplication::InputEvent {
      friend AbstractXApplication;
  
      public:
          /**
           * @brief Key
           *
           * @see @ref key()
           */
          enum class Key: KeySym {
              Enter = XK_Return,          /**< Enter */
              Esc = XK_Escape,            /**< Escape */
  
              Up = XK_Up,                 /**< Up arrow */
              Down = XK_Down,             /**< Down arrow */
              Left = XK_Left,             /**< Left arrow */
              Right = XK_Right,           /**< Right arrow */
              F1 = XK_F1,                 /**< F1 */
              F2 = XK_F2,                 /**< F2 */
              F3 = XK_F3,                 /**< F3 */
              F4 = XK_F4,                 /**< F4 */
              F5 = XK_F5,                 /**< F5 */
              F6 = XK_F6,                 /**< F6 */
              F7 = XK_F7,                 /**< F7 */
              F8 = XK_F8,                 /**< F8 */
              F9 = XK_F9,                 /**< F9 */
              F10 = XK_F10,               /**< F10 */
              F11 = XK_F11,               /**< F11 */
              F12 = XK_F12,               /**< F12 */
              Home = XK_Home,             /**< Home */
              End = XK_End,               /**< End */
              PageUp = XK_Page_Up,        /**< Page up */
              PageDown = XK_Page_Down,    /**< Page down */
  
              Space = XK_space,           /**< Space */
              Comma = XK_comma,           /**< Comma */
              Period = XK_period,         /**< Period */
              Minus = XK_minus,           /**< Minus */
              Plus = XK_plus,             /**< Plus */
              Slash = XK_slash,           /**< Slash */
              Percent = XK_percent,       /**< Percent */
              Equal = XK_equal,           /**< Equal */
  
              Zero = XK_0,                /**< Zero */
              One = XK_1,                 /**< One */
              Two = XK_2,                 /**< Two */
              Three = XK_3,               /**< Three */
              Four = XK_4,                /**< Four */
              Five = XK_5,                /**< Five */
              Six = XK_6,                 /**< Six */
              Seven = XK_7,               /**< Seven */
              Eight = XK_8,               /**< Eight */
              Nine = XK_9,                /**< Nine */
  
              A = XK_a,                   /**< Small letter A */
              B = XK_b,                   /**< Small letter B */
              C = XK_c,                   /**< Small letter C */
              D = XK_d,                   /**< Small letter D */
              E = XK_e,                   /**< Small letter E */
              F = XK_f,                   /**< Small letter F */
              G = XK_g,                   /**< Small letter G */
              H = XK_h,                   /**< Small letter H */
              I = XK_i,                   /**< Small letter I */
              J = XK_j,                   /**< Small letter J */
              K = XK_k,                   /**< Small letter K */
              L = XK_l,                   /**< Small letter L */
              M = XK_m,                   /**< Small letter M */
              N = XK_n,                   /**< Small letter N */
              O = XK_o,                   /**< Small letter O */
              P = XK_p,                   /**< Small letter P */
              Q = XK_q,                   /**< Small letter Q */
              R = XK_r,                   /**< Small letter R */
              S = XK_s,                   /**< Small letter S */
              T = XK_t,                   /**< Small letter T */
              U = XK_u,                   /**< Small letter U */
              V = XK_v,                   /**< Small letter V */
              W = XK_w,                   /**< Small letter W */
              X = XK_x,                   /**< Small letter X */
              Y = XK_y,                   /**< Small letter Y */
              Z = XK_z                    /**< Small letter Z */
          };
  
          /** @brief Key */
          Key key() const { return _key; }
  
          /** @brief Position */
          Vector2i position() const { return _position; }
  
      private:
          explicit KeyEvent(Key key, Modifiers modifiers, const Vector2i& position): InputEvent(modifiers), _key(key), _position(position) {}
  
          const Key _key;
          const Vector2i _position;
  };
  
  /**
  @brief Mouse event
  
  @see @ref MouseMoveEvent, @ref mousePressEvent(), @ref mouseReleaseEvent()
  */
  class AbstractXApplication::MouseEvent: public AbstractXApplication::InputEvent {
      friend AbstractXApplication;
  
      public:
          /**
           * @brief Mouse button
           *
           * @see @ref button()
           */
          enum class Button: unsigned int {
              Left = Button1,         /**< Left button */
              Middle = Button2,       /**< Middle button */
              Right = Button3,        /**< Right button */
              WheelUp = Button4,      /**< Wheel up */
              WheelDown = Button5     /**< Wheel down */
          };
  
          /** @brief Button */
          Button button() const { return _button; }
  
          /** @brief Position */
          Vector2i position() const { return _position; }
  
      private:
          explicit MouseEvent(Button button, Modifiers modifiers, const Vector2i& position): InputEvent(modifiers), _button(button), _position(position) {}
  
          const Button _button;
          const Vector2i _position;
  };
  
  /**
  @brief Mouse move event
  
  @see @ref MouseEvent, @ref mouseMoveEvent()
  */
  class AbstractXApplication::MouseMoveEvent: public AbstractXApplication::InputEvent {
      friend AbstractXApplication;
  
      public:
          /** @brief Position */
          Vector2i position() const { return _position; }
  
      private:
          explicit MouseMoveEvent(Modifiers modifiers, const Vector2i& position): InputEvent(modifiers), _position(position) {}
  
          const Vector2i _position;
  };
  
  }}
  
  #endif
  