//
// file name : X_func.C
// written by Ting-jen Yen
//
#include "window.h"
#include <X11/cursorfont.h>
extern int byte_per_pixel;

// W-init initialize the X system, opens a window. Then it does
// all the setup for the window with the X interface.
void W_init(int x,int y)
{
  char *display_name = NULL, *font_name="8x13";
  XSetWindowAttributes attributes;
  XVisualInfo vTemplate;
  XVisualInfo * visualList;
  int visualsMatched;
  int i,j;
  XGCValues xgcvalues;
  XColor xcolor[256];
  if ((display=XOpenDisplay(display_name)) == NULL)
  {
     cerr << "W-init: cannot connect to X server "<<XDisplayName(display_name);
     exit(-1);
  }
  screen = DefaultScreen(display);
  vTemplate.screen = screen;
//  vTemplate.depth = 8;

//  Try to get some proper visual mode with 256 colors

  visualList = XGetVisualInfo(display, VisualScreenMask,
			& vTemplate, &visualsMatched);
  for (i = 0, j = -1; i < visualsMatched; i ++)
  {
    if (visualList[i].c_class >= StaticColor &&
	visualList[i].c_class <= TrueColor)
      if (i > j) j = i;
  }

  if (j == -1)
  {
    cerr << "No visual mode available" << endl;
    if (visualList) XFree(visualList);
    XCloseDisplay(display);
    exit(-1);
  }

  visual = visualList[j].visual;
  byte_per_pixel = visualList[j].depth / 8;

//  Now, create a private colormap, and initial colors with R:G:B = 3:3:2 bits
//  And get default black and white color. We initiate the colors from
//  the default system colormap to reduce the difference of the colormaps.

  colormap = XCreateColormap(display, RootWindow(display,screen), visual,
		AllocNone);
  
  if (visualList[j].c_class <= PseudoColor)
  {
    for (i = 0 ; i < 256; i ++)
      xcolor[i].pixel = i;
    XQueryColors(display, DefaultColormap(display,screen), xcolor, 256);
    for (i = 0 ; i < 256; i ++)
    {
      if (xcolor[i].red == 0xff00 &&	// if it is white color already,
  	xcolor[i].green == 0xff00 &&	// don't do any modify
  	xcolor[i].blue == 0xff00)
        continue;
      xcolor[i].red &= 0xe000;
      xcolor[i].green &= 0xe000;
      xcolor[i].blue &= 0xc000;
    }
    for (i = 0; i < 256; i ++)
      XAllocColor(display, colormap, &xcolor[i]);
    B = BlackPixel(display, screen);
    W = WhitePixel(display, screen);
  }
  else
  {
    xcolor[0].red = 0xff00;
    xcolor[0].green = 0xff00;
    xcolor[0].blue = 0xff00;
    xcolor[0].flags = DoRed | DoGreen | DoBlue;
    XAllocColor(display, colormap, xcolor);
    W = xcolor[0].pixel;		// get white color pixel value

    xcolor[0].red = 0;
    xcolor[0].green = 0;
    xcolor[0].blue = 0;
    xcolor[0].flags = DoRed | DoGreen | DoBlue;
    XAllocColor(display, colormap, xcolor);
    B = xcolor[0].pixel;		// get black color pixel value

  }

//  Set properties of the new window then open the window.

  attributes.colormap = colormap;
  attributes.background_pixel = W;
  attributes.border_pixel = B;

  window = XCreateWindow(display, RootWindow(display, screen),
	    0, 0, x, y, 5, visualList[j].depth, InputOutput,
	    visual, CWBorderPixel|CWBackPixel|CWColormap,
	    &attributes);
 
  XSetWindowColormap(display, window, colormap);

// This window will not any events except expose event and
// resize event.

  XSelectInput(display, window,ExposureMask | StructureNotifyMask);
 
// Create a "Graphics Context" and then set some basic components
//  of it.

  gcx = XCreateGC(display, window,0L , &xgcvalues);
  gc_inv = XCreateGC(display, window,0L , &xgcvalues);

  XSetFunction(display, gcx, GXcopy);
  XSetFunction(display, gc_inv, GXcopy);
  XSetForeground(display, gcx, B);
  XSetForeground(display, gc_inv, W);
  XSetBackground(display, gcx, W);
  XSetBackground(display, gc_inv, B);
  XSetFillStyle(display, gcx, FillSolid);
  XSetLineAttributes(display,gcx, 1, LineSolid, CapRound, JoinRound);
  XSetLineAttributes(display,gc_inv, 1, LineSolid, CapRound, JoinRound);
  XFree(visualList);

// Allocate a font.

  if ((font_info1 = XLoadQueryFont(display, font_name)) == NULL)
    exit(-1);
  XSetFont(display, gcx, font_info1->fid);
  hand_cursor = XCreateFontCursor(display, XC_hand2);
}
 
//
// CreateButton will open a window on the parent
// window with given position, and with size enough
// enclose the given name. No other things are done.
// The event handler will have to handle redraw and
// call back function of this button explicitly.
//

Window CreateButton(int x, int y, Window parent, char *name)
{
  Window button;
  int w, h;
  w = XTextWidth(font_info1, name, strlen(name)) + 6;
  h = font_info1->max_bounds.ascent+font_info1->max_bounds.descent+6;
  button = XCreateSimpleWindow(display, parent, x, y, w, h, 2,
	   B, W);
  XDrawString(display, button, gcx, 3, h-font_info1->max_bounds.descent,
	   name, strlen(name));
  XSelectInput(display, button, ButtonPressMask | ButtonReleaseMask |
	   ExposureMask | EnterWindowMask | LeaveWindowMask);
  return button;
}

//
// CreateCanvas will simply create a window of given position
// and given size, and setup the event it would accept.
// 
Window CreateCanvas(int x, int y, int w, int h, Window parent, long event_mask)
{
  Window canvas;
  canvas = XCreateSimpleWindow(display, parent, x, y, w, h, 1,
	  B, W);
  XSelectInput(display, canvas, event_mask);
  return canvas;
}