/* help.c         program info, keyboard shortcuts */

/*
 * xcheckers:     a point and click checkerboard
 * (C):           1999, 2000 Peter Chiocchetti <girbal@tacheles.de>
 */


#include <stdlib.h>
#include <string.h>
#include <stdio.h>
#include <X11/Xlib.h>
#include "xcheckers.h"
#include "help.h"
#include "xcheckers.xbm"
#include "resource.h"
#include "child.h"


#define border 1
#define hline(i) ((font->ascent + font->descent) * i)
#define shift (font->descent + 1)
#define gutter (XTextWidth (font, "n", 1))

#define header (icon_height + shift + gutter)
#define hheight (header + hline (5) + gutter)

#define MAX 12
#define maxlen(str) (str ? (strlen(str) >= MAX ? MAX : strlen (str)) : 0)
#define safeGet(id) (resGet (id) ? resGet (id) : "")

#define HELPMASK (ButtonPressMask | ButtonReleaseMask \
		  | PointerMotionMask | ButtonMotionMask \
		  | EnterWindowMask | LeaveWindowMask \
		  | ExposureMask)
#define HGCMASK (GCBackground | GCForeground | GCFont)

#define nlabels (sizeof (labels) / sizeof (macro))


int             help = 0;
macro          *labelp;
Pixmap          icon;
GC              hgc;
int             hwidth, mwidth;


/*
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 *                                                                program info
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 */


/* return the button column the pointer is over */
static int
mcol(int x)
{
  if (x > gutter && x < gutter + mwidth)
    return 0;
  if (x > gutter + mwidth + gutter && x < gutter + mwidth + gutter + mwidth)
    return 1;
  return -1;
}


/* return the button row the pointer is over */
static int
mrow(int y)
{
  y -= header;

  if (y > 0 && y < hline(5))
    return (y / hline(1));
  return -1;
}


/* invert button the pointer is over */
void
helpSel(int curx, int cury)
{
  static int      oldx = 0;
  static int      oldy = 0;

  cury -= shift;

  if ((mcol(curx) == mcol(oldx)) && (mrow(cury) == mrow(oldy)))
    return;

  if (mcol(oldx) >= 0 && mrow(oldy) >= 0)
    XFillRectangle(dpy, hwin, hgc,
		   gutter + (gutter + mwidth) * mcol(oldx),
		   header + shift + hline(mrow(oldy)), mwidth, hline(1));

  if (mcol(curx) < 0 || mrow(cury) < 0) {
    oldx = 0;
    oldy = 0;
    return;
  }
  XFillRectangle(dpy, hwin, hgc,
		 gutter + (gutter + mwidth) * mcol(curx),
		 header + shift + hline(mrow(cury)), mwidth, hline(1));
  oldx = curx;
  oldy = cury;
}


/* display help window */
void
showHelp(void)
{
  if (!help) {
    XMoveWindow(dpy,hwin,
		(board_width - hwidth) / 2 - border,
		(board_height - hheight) / 2 - border);
    XMapWindow(dpy, hwin);
    help = 1;
  } else {
    helpSel(0, 0);
    XUnmapWindow(dpy, hwin);
    help = 0;
  }
}


/* send message from button that was clicked */
void
helpBut(int x, int y)
{
  y -= shift;
  x = mcol(x);
  y = mrow(y);

  if (x >= 0 && y >= 0) {
    showHelp();
    y += x * 5;
    message(strdup((labelp + y)->call));
  }
}


/* draw into the help window */
void
drawHelp(void)
{
  int             i;
  macro          *tmp;

  /* header: program icon, program name */
  XCopyArea(dpy, icon, hwin, gc, 0, 0, icon_width, icon_height,
	    gutter, header - icon_height - shift);
  XDrawString(dpy, hwin, gc,
	      gutter + icon_width + gutter, header - shift,
	      progname, maxlen(progname));
  XDrawLine(dpy, hwin, gc, gutter, header, hwidth - gutter, header);

  /* buttons */
  for (i = 1, tmp = labelp; i <= 5; i++, tmp++) {
    XDrawString(dpy, hwin, gc,
		gutter, header + hline(i), tmp->label,
		maxlen(tmp->label));
    XDrawString(dpy, hwin, gc,
		gutter + mwidth + gutter, header + hline(i),
		(tmp + 5)->label, maxlen((tmp + 5)->label));
  }
}


/* prepare help window */
void
initHelp(unsigned long paper, unsigned long pen)
{
  int             tmp;
  int             i;
  macro           labels[] = {
    {safeGet("button0_label"), safeGet("button0_call")},
    {safeGet("button1_label"), safeGet("button1_call")},
    {safeGet("button2_label"), safeGet("button2_call")},
    {safeGet("button3_label"), safeGet("button3_call")},
    {safeGet("button4_label"), safeGet("button4_call")},
    {safeGet("button5_label"), safeGet("button5_call")},
    {safeGet("button6_label"), safeGet("button6_call")},
    {safeGet("button7_label"), safeGet("button7_call")},
    {safeGet("button8_label"), safeGet("button8_call")},
    {safeGet("button9_label"), safeGet("button9_call")},
  };

  labelp = (macro *) malloc(sizeof(labels));
  memcpy(labelp, labels, sizeof(labels));

  for (mwidth = 0, i = 0; i < nlabels; i++)
    if ((tmp = XTextWidth(font, labels[i].label,
			  maxlen(labels[i].label))) > mwidth)
      mwidth = tmp;

  hwidth = gutter + mwidth + gutter + mwidth + gutter;
  if ((tmp = gutter + icon_width + gutter
       + XTextWidth(font, "progname", maxlen(progname)) + gutter) > hwidth)
    hwidth = tmp;

  hwin = XCreateSimpleWindow(dpy, win,
			     (board_width - hwidth) / 2,
			     (board_height - hheight) / 2,
			     hwidth, hheight, border, pen, paper);

  icon = XCreatePixmapFromBitmapData(dpy, hwin, icon_bits,
				     icon_width, icon_height,
				     pen, paper, DefaultDepth(dpy, screen));

  hgc = XCreateGC(dpy, hwin, 0, NULL);
  XCopyGC(dpy, gc, HGCMASK, hgc);
  XSetForeground(dpy, hgc, pen ^ paper);
  XSetFunction(dpy, hgc, GXxor);
  XSelectInput(dpy, hwin, HELPMASK);

  showHelp();
}