text: 
  static Systray *systray = NULL;
  static unsigned long systrayorientation = _NET_SYSTEM_TRAY_ORIENTATION_HORZ;
  
  unsigned int
  getsystraywidth()
  {
  	unsigned int w = 0;
  	Client *i;
  	if (showsystray)
  		for (i = systray->icons; i; w += i->w + systrayspacing, i = i->next);
  	return w ? w + systrayspacing : 0;
  }
  
  void
  removesystrayicon(Client *i)
  {
  	Client **ii;
  
  	if (!showsystray || !i)
  		return;
  	for (ii = &systray->icons; *ii && *ii != i; ii = &(*ii)->next);
  	if (ii)
  		*ii = i->next;
  	free(i);
  }
  
  void
  resizerequest(XEvent *e)
  {
  	XResizeRequestEvent *ev = &e->xresizerequest;
  	Client *i;
  
  	if ((i = wintosystrayicon(ev->window))) {
  		updatesystrayicongeom(i, ev->width, ev->height);
  		updatesystray();
  	}
  }
  
  Monitor *
  systraytomon(Monitor *m)
  {
  	Monitor *t;
  	int i, n;
  	if (!systraypinning) {
  		if (!m)
  			return selmon;
  		return m == selmon ? m : NULL;
  	}
  	for (n = 1, t = mons; t && t->next; n++, t = t->next);
  	for (i = 1, t = mons; t && t->next && i < systraypinning; i++, t = t->next);
  	if (systraypinningfailfirst && n < systraypinning)
  		return mons;
  	return t;
  }
  
  void
  updatesystray(void)
  {
  	XSetWindowAttributes wa;
  	XWindowChanges wc;
  	Client *i;
  	Monitor *m = systraytomon(NULL);
  	unsigned int x = m->mx + m->mw;
  	unsigned int w = 1, xpad = 0, ypad = 0;
  	#if BARPADDING_PATCH
  	xpad = sp;
  	ypad = vp;
  	#endif // BARPADDING_PATCH
  
  	if (!showsystray)
  		return;
  	if (!systray) {
  		/* init systray */
  		if (!(systray = (Systray *)calloc(1, sizeof(Systray))))
  			die("fatal: could not malloc() %u bytes\n", sizeof(Systray));
  
  		wa.override_redirect = True;
  		wa.event_mask = ButtonPressMask|ExposureMask;
  		wa.border_pixel = 0;
  		#if ALPHA_PATCH
  		wa.background_pixel = 0;
  		wa.colormap = cmap;
  		systray->win = XCreateWindow(dpy, root, x - xpad, m->by + ypad, w, bh, 0, depth,
  						InputOutput, visual,
  						CWOverrideRedirect|CWBackPixel|CWBorderPixel|CWColormap|CWEventMask, &wa);
  		#else
  		wa.background_pixel = scheme[SchemeNorm][ColBg].pixel;
  		systray->win = XCreateSimpleWindow(dpy, root, x - xpad, m->by + ypad, w, bh, 0, 0, scheme[SchemeNorm][ColBg].pixel);
  		XChangeWindowAttributes(dpy, systray->win, CWOverrideRedirect|CWBackPixel|CWBorderPixel|CWEventMask, &wa);
  		#endif // ALPHA_PATCH
  		XSelectInput(dpy, systray->win, SubstructureNotifyMask);
  		XChangeProperty(dpy, systray->win, netatom[NetSystemTrayOrientation], XA_CARDINAL, 32,
  				PropModeReplace, (unsigned char *)&systrayorientation, 1);
  		#if ALPHA_PATCH
  		XChangeProperty(dpy, systray->win, netatom[NetSystemTrayVisual], XA_VISUALID, 32,
  				PropModeReplace, (unsigned char *)&visual->visualid, 1);
  		#endif // ALPHA_PATCH
  		XChangeProperty(dpy, systray->win, netatom[NetWMWindowType], XA_ATOM, 32,
  				PropModeReplace, (unsigned char *)&netatom[NetWMWindowTypeDock], 1);
  		XMapRaised(dpy, systray->win);
  		XSetSelectionOwner(dpy, netatom[NetSystemTray], systray->win, CurrentTime);
  		if (XGetSelectionOwner(dpy, netatom[NetSystemTray]) == systray->win) {
  			sendevent(root, xatom[Manager], StructureNotifyMask, CurrentTime, netatom[NetSystemTray], systray->win, 0, 0);
  			XSync(dpy, False);
  		}
  		else {
  			fprintf(stderr, "dwm: unable to obtain system tray.\n");
  			free(systray);
  			systray = NULL;
  			return;
  		}
  	}
  
  	drw_setscheme(drw, scheme[SchemeNorm]);
  	for (w = 0, i = systray->icons; i; i = i->next) {
  		/* make sure the background color stays the same */
  		#if ALPHA_PATCH
  		wa.background_pixel = 0;
  		#else
  		wa.background_pixel = scheme[SchemeNorm][ColBg].pixel;
  		#endif // ALPHA_PATCH
  		XChangeWindowAttributes(dpy, i->win, CWBackPixel, &wa);
  		XMapRaised(dpy, i->win);
  		w += systrayspacing;
  		i->x = w;
  		XMoveResizeWindow(dpy, i->win, i->x, 0, i->w, i->h);
  		w += i->w;
  		if (i->mon != m)
  			i->mon = m;
  	}
  	w = w ? w + systrayspacing : 1;
   	x -= w;
  	XMoveResizeWindow(dpy, systray->win, x - xpad, m->by + ypad, w, bh);
  	wc.x = x - xpad;
  	wc.y = m->by + ypad;
  	wc.width = w;
  	wc.height = bh;
  	wc.stack_mode = Above; wc.sibling = m->barwin;
  	XConfigureWindow(dpy, systray->win, CWX|CWY|CWWidth|CWHeight|CWSibling|CWStackMode, &wc);
  	XMapWindow(dpy, systray->win);
  	XMapSubwindows(dpy, systray->win);
  	/* redraw background */
  	XSetForeground(dpy, drw->gc, scheme[SchemeNorm][ColBg].pixel);
  	XFillRectangle(dpy, systray->win, drw->gc, 0, 0, w, bh);
  	XSync(dpy, False);
  }
  
  void
  updatesystrayicongeom(Client *i, int w, int h)
  {
  	if (i) {
  		i->h = bh;
  		if (w == h)
  			i->w = bh;
  		else if (h == bh)
  			i->w = w;
  		else
  			i->w = (int) ((float)bh * ((float)w / (float)h));
  		applysizehints(i, &(i->x), &(i->y), &(i->w), &(i->h), False);
  		/* force icons into the systray dimensions if they don't want to */
  		if (i->h > bh) {
  			if (i->w == i->h)
  				i->w = bh;
  			else
  				i->w = (int) ((float)bh * ((float)i->w / (float)i->h));
  			i->h = bh;
  		}
  		if (i->w > 2*bh)
  			i->w = bh;
  	}
  }
  
  void
  updatesystrayiconstate(Client *i, XPropertyEvent *ev)
  {
  	long flags;
  	int code = 0;
  
  	if (!showsystray || !i || ev->atom != xatom[XembedInfo] ||
  			!(flags = getatomprop(i, xatom[XembedInfo])))
  		return;
  
  	if (flags & XEMBED_MAPPED && !i->tags) {
  		i->tags = 1;
  		code = XEMBED_WINDOW_ACTIVATE;
  		XMapRaised(dpy, i->win);
  		setclientstate(i, NormalState);
  	}
  	else if (!(flags & XEMBED_MAPPED) && i->tags) {
  		i->tags = 0;
  		code = XEMBED_WINDOW_DEACTIVATE;
  		XUnmapWindow(dpy, i->win);
  		setclientstate(i, WithdrawnState);
  	}
  	else
  		return;
  	sendevent(i->win, xatom[Xembed], StructureNotifyMask, CurrentTime, code, 0,
  			systray->win, XEMBED_EMBEDDED_VERSION);
  }
  
  Client *
  wintosystrayicon(Window w)
  {
  	Client *i = NULL;
  
  	if (!showsystray || !w)
  		return i;
  	for (i = systray->icons; i && i->win != w; i = i->next);
  	return i;
  }