/* first include the standard headers that we're likely to need */
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/Xresource.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* create a namespace with title @gui */
namespace gui {

    typedef struct {
        Window window;
        unsigned int w, h;
        unsigned long background, border;
    } CWindow;

    typedef struct {
        int function;            /* logical operation */
        unsigned long plane_mask;/* plane mask */
        unsigned long foreground;/* foreground pixel */
        unsigned long background;/* background pixel */
        int line_width;          /* line width (in pixels) */
        int line_style;          /* LineSolid, LineOnOffDash, LineDoubleDash */
        int cap_style;           /* CapNotLast, CapButt, CapRound, CapProjecting */
        int join_style;          /* JoinMiter, JoinRound, JoinBevel */
        int fill_style;          /* FillSolid, FillTiled, FillStippled FillOpaqueStippled*/
        int fill_rule;           /* EvenOddRule, WindingRule */
        int arc_mode;            /* ArcChord, ArcPieSlice */
        Pixmap tile;             /* tile pixmap for tiling operations */
        Pixmap stipple;          /* stipple 1 plane pixmap for stippling */
        int ts_x_origin;         /* offset for tile or stipple operations */
        int ts_y_origin;
        Font font;               /* default text font for text operations */
        int subwindow_mode;      /* ClipByChildren, IncludeInferiors */
        Bool graphics_exposures; /* boolean, should exposures be generated */
        int clip_x_origin;       /* origin for clipping */
        int clip_y_origin;
        Pixmap clip_mask;        /* bitmap clipping; other calls for rects */
        int dash_offset;         /* patterned/dashed line information */
        char dashes;
    } CMask;

    typedef struct {
      XColor x, y;
    } CColor;

    struct Root {
        Display *display;
        int id;
    } disp;

    /* client class */
    class Client {

        friend class Draw;

        public :

            /* create a new screen */
            void init()
            {
                disp.display = XOpenDisplay(NULL);
                if (!disp.display)
                    fprintf(stderr, "unable to connect to displayn");

                disp.id = DefaultScreen(disp.display);
            }

            /* close the window and screen */
            void close()
            {
                XCloseDisplay(disp.display);
            }

            /* create a new window, and listen events */
            void create_window(CWindow &win;)
            {
                win.window = XCreateSimpleWindow(disp.display, DefaultRootWindow(disp.display), /* display, parent */
                0,0, /* x, y: the window manager will place the window elsewhere */
                win.w,win.h, /* width, height */
                2, win.border, /* border width & colour, unless you have a window manager */
                win.background); /* background colour */


                XSelectInput(disp.display, win.window, 
                             ButtonPressMask|StructureNotifyMask|ExposureMask );
            }

            /* set a a new background color for window */
            void set_background(CWindow &win;)
            {
                win.background = BlackPixel(disp.display, disp.id);
            }

            /* set a new window broder */
            void set_border(CWindow &win;)
            {
                 win.border = BlackPixel(disp.display, disp.id);
            }
            /* set a new window size */
            void set_size(CWindow &win;, int x, int y)
            {
                 win.w = x;
                 win.h = y;
            }

            /* put the window on the screen */
            void show_window(CWindow win)
            {
                XMapWindow(disp.display, win.window);
            }

            /* clear the window */
            void clear_window(XEvent ev)
            {
                XClearWindow(disp.display, ev.xany.window);
            }

            /* print next event in x quene*/
            void getevent(XEvent &ev;)
            {
                XNextEvent(disp.display, &ev;);
            }

    };

    /* drawing class*/
    class Draw : public Client
    {

        public:

        /* fill a CColor value with a colorcode*/
        CColor fill_with_color(char arr[])
        {
            Colormap cmap;
            CColor x;

            cmap = DefaultColormap(disp.display, disp.id);
            XAllocNamedColor(disp.display, cmap, arr, &x.x, &x.y);

            return x;
        }

        /* draw a line */
        void draw_line(CWindow &win;, int begin_y, int begin_x, int end_x, int end_y)
        {
            GC pen;
            CMask mask;

            CColor x = fill_with_color("Red");

            mask.foreground = x.x.pixel;
            mask.line_width = 10;
            mask.line_style = LineSolid;


            pen = XCreateGC(disp.display, win.window, 
                            GCForeground|GCLineWidth|GCLineStyle, (XGCValues*)&mask;);
            XDrawLine(disp.display,  win.window, pen, begin_x, begin_y, end_y, end_x);
        }

    };

}

using namespace gui;

/* example */
int main(int argc, char ** argv)
{
    Client c;
    Draw d;
    CWindow win;
 XEvent ev;

    c.init();

    c.set_background(win);
 c.set_border(win);

 c.set_size(win, 400,400);

 c.create_window(win);
    c.show_window(win);

 while(1){

        c.getevent(ev);


  switch(ev.type){
  case Expose:

            d.draw_line(win, 90, 70, 90, 170);

        break;
  case ConfigureNotify:
   if (win.w != ev.xconfigure.width
     || win.h != ev.xconfigure.height) {
    win.w = ev.xconfigure.width;
    win.h = ev.xconfigure.height;
                c.clear_window(ev);
    printf("Size changed to: %d by %dn", win.w, win.h);
   }
   break;

  case ButtonPress:
   c.close();
   return 0;
  }

 }

}