func

void
buttonpress(XEvent *e)
{
	unsigned int i, x, click;
	Arg arg = {0};
	Client *c;
	Monitor *m;
	XButtonPressedEvent *ev = &e->xbutton;
    char *text, *s, ch;
    click = ClkRootWin;
	/* focus monitor if necessary */
	if ((m = wintomon(ev->window)) && m != selmon) {
		unfocus(selmon->sel, 1);
		selmon = m;
		focus(NULL);
	}
	if (ev->window == selmon->barwin) {
		i = x = 0;
		unsigned int occ = 0;
		for(c = m->clients; c; c=c->next)
			occ |= c->tags == TAGMASK ? 0 : c->tags;
		do {
			/* Do not reserve space for vacant tags */
			if (!(occ & 1 << i || m->tagset[m->seltags] & 1 << i))
				continue;
			x += TEXTW(tags[i]);
		} while (ev->x >= x && ++i < LENGTH(tags));
		if (i < LENGTH(tags)) {
			click = ClkTagBar;
			arg.ui = 1 << i;
		} else if (ev->x < x + TEXTW(selmon->ltsymbol))
			click = ClkLtSymbol;
		/* 2px right padding */
		//else if (ev->x > selmon->ww - TEXTW(stext) + lrpad - 2)
		else if (ev->x > selmon->ww - statusw) {
            x = selmon->ww - statusw;
            click = ClkStatusText;
		                       statussig = 0;
                       for (text = s = stext; *s && x <= ev->x; s++) {
                               if ((unsigned char)(*s) < ' ') {
                                       ch = *s;
                                       *s = '\0';
                                       x += TEXTW(text) - lrpad;
                                       *s = ch;
                                       text = s + 1;
                                       if (x >= ev->x)
                                               break;
                                       /* reset on matching signal raw byte */
                                       if (ch == statussig)
                                               statussig = 0;
                                       else
                                               statussig = ch;
                               }
                       }
               }
        else {
			x += TEXTW(selmon->ltsymbol);
			c = m->clients;

			if (c) {
				do {
					if (!ISVISIBLE(c))
						continue;
					else
						x +=(1.0 / (double)m->bt) * m->btw;
				} while (ev->x > x && (c = c->next));

				click = ClkWinTitle;
				arg.v = c;
			}
		}
	} else if ((c = wintoclient(ev->window))) {
		focus(c);
		restack(selmon);
		XAllowEvents(dpy, ReplayPointer, CurrentTime);
		click = ClkClientWin;
	}
	for (i = 0; i < LENGTH(buttons); i++)
		if (click == buttons[i].click && buttons[i].func && buttons[i].button == ev->button
		&& CLEANMASK(buttons[i].mask) == CLEANMASK(ev->state))
			buttons[i].func((click == ClkTagBar || click == ClkWinTitle) && buttons[i].arg.i == 0 ? &arg : &buttons[i].arg);
}