#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <X11/Xlib.h>
#include <X11/Xutil.h>
#include <X11/extensions/shape.h>
#include <X11/xpm.h>

int main(int argc, char *argv[]) {
  Display *display;
  Window win, root;
  XEvent event;
  GC gc;
  XSetWindowAttributes a;
  int screen, depth, white, black, press;
  int x1, x2, y1, y2, x, y, w, h, m, quit;
  char buffer[10];
  XpmAttributes xa;
  Pixmap pixmap, shape;
  Colormap colormap;
 
  if (!(display = XOpenDisplay(getenv("DISPLAY")))) {
    fprintf(stderr, "%s: unable to open display: %s\n", argv[0], getenv("DISPLAY"));
    exit(1);
  }

  screen = DefaultScreen(display);
  root = RootWindow(display, screen);
  depth = DefaultDepth(display, screen);
  colormap = DefaultColormap(display, screen);
  white = WhitePixel(display, screen);
  black = BlackPixel(display, screen);
  m = quit = 0;

  memset(&xa, 0, sizeof(XpmAttributes));
  xa.valuemask = (XpmVisual | XpmDepth | XpmColormap);
  xa.visual = DefaultVisual(display, DefaultScreen(display));
  xa.depth = depth;
  xa.colormap = colormap;

  XpmReadFileToPixmap(display, root, argv[1], &pixmap, &shape, &xa);

  x = y = 100;
  w = xa.width;
  h = xa.height;

  win = XCreateSimpleWindow(display, root, x, y, w, h, 0, black, black);
  XShapeCombineMask(display, win, ShapeBounding, 0, 0, shape, ShapeSet);
  gc = XCreateGC(display, pixmap, 0, 0);

  a.override_redirect = True;
  XChangeWindowAttributes(display, win, CWOverrideRedirect, &a);

  XSelectInput(display, win, ExposureMask | ButtonPressMask | ButtonReleaseMask | ButtonMotionMask);
  XMapWindow(display, win);

  while (!quit) {
    XNextEvent(display, &event);
    switch(event.type) {
    case Expose:
	XCopyArea(display, pixmap, win, gc, 0, 0, w, h, 0, 0);
	break;
    case ButtonPress:
	press = 1;
	x1 = event.xbutton.x;
	y1 = event.xbutton.y;

	break;
    case ButtonRelease:
	press = 0;
	x1 = y1 = 0;
	break;
    case MotionNotify:
	x += event.xmotion.x-x1;
	y += event.xmotion.y-y1;

	XMoveWindow(display, win, x, y);
	break;
    }
  }

  printf("done\n");
  XCloseDisplay(display);

  return 0;
}