/*
CS 349 Hello X Windows

- - - - - - - - - - - - - - - - - - - - - -

Commands to compile and run:

    g++ -o drawing.min drawing.min.cpp -L/usr/X11R6/lib -lX11 -lstdc++
    ./drawing.min

Note: the -L option and -lstdc++ may not be needed on some machines.

*/

#include <unistd.h>
#include <cstdlib>
#include <iostream>
#include <X11/Xlib.h>

Display* display;
Window window;

int main( int argc, char* argv[] ) {

  // open display
  display = XOpenDisplay("");
  if (!display) exit (-1);
  int screen = DefaultScreen(display);
  int w = 200;
  int h = 100;
  window = XCreateSimpleWindow(display, DefaultRootWindow(display),
                               10, 10, w, h, 2,
                               BlackPixel(display, screen), WhitePixel(display, screen));
  XMapRaised(display, window);
  XFlush(display);

  // give server 10ms to get set up before sending drawing commands
  usleep(10 * 1000);           

  // drawing demo with graphics context here ...
  GC gc = XCreateGC(display, window, 0, 0);       // create a graphics context
  XSetForeground(display, gc, BlackPixel(display, screen));
  XSetBackground(display, gc, WhitePixel(display, screen));

  // load a larger font
  XFontStruct * font;
  font = XLoadQueryFont (display, "12x24");
  XSetFont (display, gc, font->fid);

  // draw text
  std::string text("hello X Windows");
  XDrawImageString( display, window, gc,
                    10, h / 2, text.c_str(), text.length());

  XFlush(display);
  std::cout << "ENTER2exit"; std::cin.get(); // wait for input
  XCloseDisplay(display);

}