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.background_pixel = scheme[SchemeNorm][ColBg].pixel;
		wa.border_pixel = 0;
		#if ALPHA_PATCH
		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
		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 */
		wa.background_pixel = scheme[SchemeNorm][ColBg].pixel;
		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;
}