text: /*
   * See LICENSE file for copyright and license details.
   */
  
  #include <sys/wait.h>
  #include <locale.h>
  #include <stdarg.h>
  #include <unistd.h>
  #include <signal.h>
  #include <stdio.h>
  #include <string.h>
  #include <stdlib.h>
  #include <X11/Xatom.h>
  #include <X11/Xlib.h>
  #include <X11/Xproto.h>
  #include <X11/Xutil.h>
  #include <X11/XKBlib.h>
  #include <X11/Xft/Xft.h>
  
  #include "arg.h"
  
  /* XEMBED messages */
  #define XEMBED_EMBEDDED_NOTIFY          0
  #define XEMBED_WINDOW_ACTIVATE          1
  #define XEMBED_WINDOW_DEACTIVATE        2
  #define XEMBED_REQUEST_FOCUS            3
  #define XEMBED_FOCUS_IN                 4
  #define XEMBED_FOCUS_OUT                5
  #define XEMBED_FOCUS_NEXT               6
  #define XEMBED_FOCUS_PREV               7
  /* 8-9 were used for XEMBED_GRAB_KEY/XEMBED_UNGRAB_KEY */
  #define XEMBED_MODALITY_ON              10
  #define XEMBED_MODALITY_OFF             11
  #define XEMBED_REGISTER_ACCELERATOR     12
  #define XEMBED_UNREGISTER_ACCELERATOR   13
  #define XEMBED_ACTIVATE_ACCELERATOR     14
  
  /* Details for  XEMBED_FOCUS_IN: */
  #define XEMBED_FOCUS_CURRENT            0
  #define XEMBED_FOCUS_FIRST              1
  #define XEMBED_FOCUS_LAST               2
  
  /* Macros */
  #define MAX(a, b)                ((a) > (b) ? (a) : (b))
  #define MIN(a, b)                ((a) < (b) ? (a) : (b))
  #define LENGTH(x)                (sizeof((x)) / sizeof(*(x)))
  #define CLEANMASK(mask)          (mask & ~(numlockmask|LockMask))
  #define TEXTW(x)                 (textnw(x, strlen(x)) + dc.font.height)
  
  enum { ColFG, ColBG, ColLast };                         /* color */
  enum { WMProtocols, WMDelete, WMName, WMState, WMFullscreen,
  	XEmbed, WMSelectTab, WMLast };                      /* default atoms */
  
  typedef union {
  	int i;
  	const void *v;
  } Arg;
  
  typedef struct {
  	unsigned int mod;
  	KeySym keysym;
  	void (*func)(const Arg *);
  	const Arg arg;
  } Key;
  
  typedef struct {
  	int x, y, w, h;
  	XftColor norm[ColLast];
  	XftColor sel[ColLast];
  	Drawable drawable;
  	GC gc;
  	struct {
  		int ascent;
  		int descent;
  		int height;
  		XftFont *xfont;
  	} font;
  } DC; /* draw context */
  
  typedef struct Client {
  	char name[256];
  	Window win;
  	int tabx;
  	Bool mapped;
  	Bool closed;
  } Client;
  
  /* function declarations */
  static void buttonpress(const XEvent *e);
  static void cleanup(void);
  static void clientmessage(const XEvent *e);
  static void configurenotify(const XEvent *e);
  static void configurerequest(const XEvent *e);
  static void createnotify(const XEvent *e);
  static void destroynotify(const XEvent *e);
  static void die(const char *errstr, ...);
  static void drawbar(void);
  static void drawtext(const char *text, XftColor col[ColLast]);
  static void *emallocz(size_t size);
  static void *erealloc(void *o, size_t size);
  static void expose(const XEvent *e);
  static void focus(int c);
  static void focusin(const XEvent *e);
  static void focusonce(const Arg *arg);
  static void fullscreen(const Arg *arg);
  static char* getatom(int a);
  static int getclient(Window w);
  static XftColor getcolor(const char *colstr);
  static int getfirsttab(void);
  static Bool gettextprop(Window w, Atom atom, char *text, unsigned int size);
  static void initfont(const char *fontstr);
  static Bool isprotodel(int c);
  static void keypress(const XEvent *e);
  static void killclient(const Arg *arg);
  static void manage(Window win);
  static void maprequest(const XEvent *e);
  static void move(const Arg *arg);
  static void movetab(const Arg *arg);
  static void propertynotify(const XEvent *e);
  static void resize(int c, int w, int h);
  static void rotate(const Arg *arg);
  static void run(void);
  static void sendxembed(int c, long msg, long detail, long d1, long d2);
  static void setup(void);
  static void setcmd(int argc, char *argv[], int);
  static void sigchld(int unused);
  static void spawn(const Arg *arg);
  static int textnw(const char *text, unsigned int len);
  static void unmanage(int c);
  static void updatenumlockmask(void);
  static void updatetitle(int c);
  static int xerror(Display *dpy, XErrorEvent *ee);
  static void xsettitle(Window w, const char *str);
  
  /* variables */
  static int screen;
  static void (*handler[LASTEvent]) (const XEvent *) = {
  	[ButtonPress] = buttonpress,
  	[ClientMessage] = clientmessage,
  	[ConfigureNotify] = configurenotify,
  	[ConfigureRequest] = configurerequest,
  	[CreateNotify] = createnotify,
  	[DestroyNotify] = destroynotify,
  	[Expose] = expose,
  	[FocusIn] = focusin,
  	[KeyPress] = keypress,
  	[MapRequest] = maprequest,
  	[PropertyNotify] = propertynotify,
  };
  static int bh, wx, wy, ww, wh;
  static unsigned int numlockmask = 0;
  static Bool running = True, nextfocus, doinitspawn = True,
  	    fillagain = False, closelastclient = False;
  static Display *dpy;
  static DC dc;
  static Atom wmatom[WMLast];
  static Window root, win;
  static Client **clients = NULL;
  static int nclients = 0, sel = -1, lastsel = -1;
  static int (*xerrorxlib)(Display *, XErrorEvent *);
  static int cmd_append_pos = 0;
  static char winid[64];
  static char **cmd = NULL;
  static char *wmname = "tabbed";
  static const char *geometry = NULL;
  
  char *argv0;
  
  /* configuration, allows nested code to access above variables */
  #include "config.h"
  
  void
  buttonpress(const XEvent *e) {
  	const XButtonPressedEvent *ev = &e->xbutton;
  	int i;
  	int fc;
  	Arg arg;
  
  	fc = getfirsttab();
  
  	if((fc > 0 && ev->x < TEXTW(before)) || ev->x < 0)
  		return;
  
  	if(ev->y < 0 || ev-> y > bh)
  		return;
  
  	for(i = (fc > 0) ? fc : 0; i < nclients; i++) {
  		if(clients[i]->tabx > ev->x) {
  			switch(ev->button) {
  			case Button1:
  				focus(i);
  				break;
  			case Button2:
  				focus(i);
  				killclient(NULL);
  				break;
  			case Button4:
  			case Button5:
  				arg.i = ev->button == Button4 ? -1 : 1;
  				rotate(&arg);
  				break;
  			}
  			break;
  		}
  	}
  }
  
  void
  cleanup(void) {
  	int i;
  
  	for(i = 0; i < nclients; i++) {
  		focus(i);
  		killclient(NULL);
  		killclient(NULL);
  		XReparentWindow(dpy, clients[i]->win, root, 0, 0);
  		unmanage(i);
  	}
  	free(clients);
  	clients = NULL;
  
  	XFreePixmap(dpy, dc.drawable);
  	XFreeGC(dpy, dc.gc);
  	XDestroyWindow(dpy, win);
  	XSync(dpy, False);
  	free(cmd);
  }
  
  void
  clientmessage(const XEvent *e) {
  	const XClientMessageEvent *ev = &e->xclient;
  
  	if(ev->message_type == wmatom[WMProtocols]
  			&& ev->data.l[0] == wmatom[WMDelete]) {
  		running = False;
  	}
  }
  
  void
  configurenotify(const XEvent *e) {
  	const XConfigureEvent *ev = &e->xconfigure;
  
  	if(ev->window == win && (ev->width != ww || ev->height != wh)) {
  		ww = ev->width;
  		wh = ev->height;
  		XFreePixmap(dpy, dc.drawable);
  		dc.drawable = XCreatePixmap(dpy, root, ww, wh,
  				DefaultDepth(dpy, screen));
  		if(sel > -1)
  			resize(sel, ww, wh - bh);
  		XSync(dpy, False);
  	}
  }
  
  void
  configurerequest(const XEvent *e) {
  	const XConfigureRequestEvent *ev = &e->xconfigurerequest;
  	XWindowChanges wc;
  	int c;
  
  	if((c = getclient(ev->window)) > -1) {
  		wc.x = 0;
  		wc.y = bh;
  		wc.width = ww;
  		wc.height = wh - bh;
  		wc.border_width = 0;
  		wc.sibling = ev->above;
  		wc.stack_mode = ev->detail;
  		XConfigureWindow(dpy, clients[c]->win, ev->value_mask, &wc);
  	}
  }
  
  void
  createnotify(const XEvent *e) {
  	const XCreateWindowEvent *ev = &e->xcreatewindow;
  
  	if(ev->window != win && getclient(ev->window) < 0)
  		manage(ev->window);
  }
  
  void
  destroynotify(const XEvent *e) {
  	const XDestroyWindowEvent *ev = &e->xdestroywindow;
  	int c;
  
  	if((c = getclient(ev->window)) > -1)
  		unmanage(c);
  }
  
  void
  die(const char *errstr, ...) {
  	va_list ap;
  
  	va_start(ap, errstr);
  	vfprintf(stderr, errstr, ap);
  	va_end(ap);
  	exit(EXIT_FAILURE);
  }
  
  void
  drawbar(void) {
  	XftColor *col;
  	int c, fc, width, n = 0;
  	char *name = NULL;
  	char tabtitle[256];
  
  	if(nclients == 0) {
  		dc.x = 0;
  		dc.w = ww;
  		XFetchName(dpy, win, &name);
  		drawtext(name ? name : "", dc.norm);
  		XCopyArea(dpy, dc.drawable, win, dc.gc, 0, 0, ww, bh, 0, 0);
  		XSync(dpy, False);
  
  		return;
  	}
  
  	width = ww;
  	clients[nclients-1]->tabx = -1;
  	fc = getfirsttab();
  	if(fc > -1)
  		n = nclients - fc;
  
  	if((n * tabwidth) > width) {
  		dc.w = TEXTW(after);
  		dc.x = width - dc.w;
  		drawtext(after, dc.sel);
  		width -= dc.w;
  	}
  	dc.x = 0;
  
  	if(fc > 0) {
  		dc.w = TEXTW(before);
  		drawtext(before, dc.sel);
  		dc.x += dc.w;
  		width -= dc.w;
  	}
  
  	for(c = (fc > 0)? fc : 0; c < nclients && dc.x < width; c++) {
  		dc.w = tabwidth;
  		if(c == sel) {
  			col = dc.sel;
  			if((n * tabwidth) > width) {
  				dc.w += width % tabwidth;
  			} else {
  				dc.w = width - (n - 1) * tabwidth;
  			}
  		} else {
  			col = dc.norm;
  		}
  		snprintf(tabtitle, sizeof(tabtitle), "%d: %s",
  		         c + 1, clients[c]->name);
  		drawtext(tabtitle, col);
  		dc.x += dc.w;
  		clients[c]->tabx = dc.x;
  	}
  	XCopyArea(dpy, dc.drawable, win, dc.gc, 0, 0, ww, bh, 0, 0);
  	XSync(dpy, False);
  }
  
  void
  drawtext(const char *text, XftColor col[ColLast]) {
  	int i, x, y, h, len, olen;
  	char buf[256];
  	XftDraw *d;
  	XRectangle r = { dc.x, dc.y, dc.w, dc.h };
  
  	XSetForeground(dpy, dc.gc, col[ColBG].pixel);
  	XFillRectangles(dpy, dc.drawable, dc.gc, &r, 1);
  	if(!text)
  		return;
  
  	olen = strlen(text);
  	h = dc.font.ascent + dc.font.descent;
  	y = dc.y + (dc.h / 2) - (h / 2) + dc.font.ascent;
  	x = dc.x + (h / 2);
  
  	/* shorten text if necessary */
  	for(len = MIN(olen, sizeof(buf));
  			len && textnw(text, len) > dc.w - h; len--);
  	if(!len)
  		return;
  
  	memcpy(buf, text, len);
  	if(len < olen) {
  		for(i = len; i && i > len - 3; buf[--i] = '.');
  	}
  
  	d = XftDrawCreate(dpy, dc.drawable, DefaultVisual(dpy, screen), DefaultColormap(dpy, screen));
  
  	XftDrawStringUtf8(d, &col[ColFG], dc.font.xfont, x, y, (XftChar8 *) buf, len);
  	XftDrawDestroy(d);
  }
  
  void *
  emallocz(size_t size) {
  	void *p;
  
  	if(!(p = calloc(1, size)))
  		die("tabbed: cannot malloc\n");
  	return p;
  }
  
  void *
  erealloc(void *o, size_t size) {
  	void *p;
  
  	if(!(p = realloc(o, size)))
  		die("tabbed: cannot realloc\n");
  	return p;
  }
  
  void
  expose(const XEvent *e) {
  	const XExposeEvent *ev = &e->xexpose;
  
  	if(ev->count == 0 && win == ev->window)
  		drawbar();
  }
  
  void
  focus(int c) {
  	char buf[BUFSIZ] = "tabbed-"VERSION" ::";
  	size_t i, n;
  
  	/* If c, sel and clients are -1, raise tabbed-win itself */
  	if(nclients == 0) {
  		cmd[cmd_append_pos] = NULL;
  		for(i = 0, n = strlen(buf); cmd[i] && n < sizeof(buf); i++)
  			n += snprintf(&buf[n], sizeof(buf) - n, " %s", cmd[i]);
  
  		xsettitle(win, buf);
  		XRaiseWindow(dpy, win);
  
  		return;
  	}
  
  	if(c < 0 || c >= nclients)
  		return;
  
  	resize(c, ww, wh - bh);
  	XRaiseWindow(dpy, clients[c]->win);
  	XSetInputFocus(dpy, clients[c]->win, RevertToParent, CurrentTime);
  	sendxembed(c, XEMBED_FOCUS_IN, XEMBED_FOCUS_CURRENT, 0, 0);
  	sendxembed(c, XEMBED_WINDOW_ACTIVATE, 0, 0, 0);
  	xsettitle(win, clients[c]->name);
  
  	/* If sel is already c, change nothing. */
  	if(sel != c) {
  		lastsel = sel;
  		sel = c;
  	}
  
  	drawbar();
  	XSync(dpy, False);
  }
  
  void
  focusin(const XEvent *e) {
  	const XFocusChangeEvent *ev = &e->xfocus;
  	int dummy;
  	Window focused;
  
  	if(ev->mode != NotifyUngrab) {
  		XGetInputFocus(dpy, &focused, &dummy);
  		if(focused == win)
  			focus(sel);
  	}
  }
  
  void
  focusonce(const Arg *arg) {
  	nextfocus = True;
  }
  
  void
  fullscreen(const Arg *arg) {
  	XEvent e;
  
  	e.type = ClientMessage;
  	e.xclient.window = win;
  	e.xclient.message_type = wmatom[WMState];
  	e.xclient.format = 32;
  	e.xclient.data.l[0] = 2;
  	e.xclient.data.l[1] = wmatom[WMFullscreen];
  	e.xclient.data.l[2] = 0;
  	XSendEvent(dpy, root, False, SubstructureNotifyMask, &e);
  }
  
  char *
  getatom(int a) {
  	static char buf[BUFSIZ];
  	Atom adummy;
  	int idummy;
  	unsigned long ldummy;
  	unsigned char *p = NULL;
  
  	XGetWindowProperty(dpy, win, wmatom[a], 0L, BUFSIZ, False, XA_STRING,
  			&adummy, &idummy, &ldummy, &ldummy, &p);
  	if(p) {
  		strncpy(buf, (char *)p, LENGTH(buf)-1);
  	} else {
  		buf[0] = '\0';
  	}
  	XFree(p);
  
  	return buf;
  }
  
  int
  getclient(Window w) {
  	int i;
  
  	for(i = 0; i < nclients; i++) {
  		if(clients[i]->win == w)
  			return i;
  	}
  
  	return -1;
  }
  
  XftColor
  getcolor(const char *colstr) {
  	XftColor color;
  
  	if(!XftColorAllocName(dpy, DefaultVisual(dpy, screen), DefaultColormap(dpy, screen), colstr, &color))
  		die("tabbed: cannot allocate color '%s'\n", colstr);
  
  	return color;
  }
  
  int
  getfirsttab(void) {
  	int c, n, fc;
  
  	if(sel < 0)
  		return -1;
  
  	c = sel;
  	fc = 0;
  	n = nclients;
  	if((n * tabwidth) > ww) {
  		for(; (c * tabwidth) > (ww / 2)
  				&& (n * tabwidth) > ww;
  				c--, n--, fc++);
  	}
  
  	return fc;
  }
  
  Bool
  gettextprop(Window w, Atom atom, char *text, unsigned int size) {
  	char **list = NULL;
  	int n;
  	XTextProperty name;
  
  	if(!text || size == 0)
  		return False;
  
  	text[0] = '\0';
  	XGetTextProperty(dpy, w, &name, atom);
  	if(!name.nitems)
  		return False;
  
  	if(name.encoding == XA_STRING) {
  		strncpy(text, (char *)name.value, size - 1);
  	} else {
  		if(XmbTextPropertyToTextList(dpy, &name, &list, &n) >= Success
  				&& n > 0 && *list) {
  			strncpy(text, *list, size - 1);
  			XFreeStringList(list);
  		}
  	}
  	text[size - 1] = '\0';
  	XFree(name.value);
  
  	return True;
  }
  
  void
  initfont(const char *fontstr) {
  	if(!(dc.font.xfont = XftFontOpenName(dpy, screen, fontstr))
  	&& !(dc.font.xfont = XftFontOpenName(dpy, screen, "fixed")))
  		die("error, cannot load font: '%s'\n", fontstr);
  
  	dc.font.ascent = dc.font.xfont->ascent;
  	dc.font.descent = dc.font.xfont->descent;
  	dc.font.height = dc.font.ascent + dc.font.descent;
  }
  
  Bool
  isprotodel(int c) {
  	int i, n;
  	Atom *protocols;
  	Bool ret = False;
  
  	if(XGetWMProtocols(dpy, clients[c]->win, &protocols, &n)) {
  		for(i = 0; !ret && i < n; i++) {
  			if(protocols[i] == wmatom[WMDelete])
  				ret = True;
  		}
  		XFree(protocols);
  	}
  
  	return ret;
  }
  
  void
  keypress(const XEvent *e) {
  	const XKeyEvent *ev = &e->xkey;
  	unsigned int i;
  	KeySym keysym;
  
  	keysym = XkbKeycodeToKeysym(dpy, (KeyCode)ev->keycode, 0, 0);
  	for(i = 0; i < LENGTH(keys); i++) {
  		if(keysym == keys[i].keysym
  				&& CLEANMASK(keys[i].mod) == CLEANMASK(ev->state)
  				&& keys[i].func) {
  			keys[i].func(&(keys[i].arg));
  		}
  	}
  }
  
  void
  killclient(const Arg *arg) {
  	XEvent ev;
  
  	if(sel < 0)
  		return;
  
  	if(isprotodel(sel) && !clients[sel]->closed) {
  		ev.type = ClientMessage;
  		ev.xclient.window = clients[sel]->win;
  		ev.xclient.message_type = wmatom[WMProtocols];
  		ev.xclient.format = 32;
  		ev.xclient.data.l[0] = wmatom[WMDelete];
  		ev.xclient.data.l[1] = CurrentTime;
  		XSendEvent(dpy, clients[sel]->win, False, NoEventMask, &ev);
  		clients[sel]->closed = True;
  	} else {
  		XKillClient(dpy, clients[sel]->win);
  	}
  }
  
  void
  manage(Window w) {
  	updatenumlockmask();
  	{
  		int i, j, nextpos;
  		unsigned int modifiers[] = { 0, LockMask, numlockmask,
  			numlockmask|LockMask };
  		KeyCode code;
  		Client *c;
  		XEvent e;
  
  		XWithdrawWindow(dpy, w, 0);
  		XReparentWindow(dpy, w, win, 0, bh);
  		XSelectInput(dpy, w, PropertyChangeMask
  				|StructureNotifyMask|EnterWindowMask);
  		XSync(dpy, False);
  
  		for(i = 0; i < LENGTH(keys); i++) {
  			if((code = XKeysymToKeycode(dpy, keys[i].keysym))) {
  				for(j = 0; j < LENGTH(modifiers); j++) {
  					XGrabKey(dpy, code, keys[i].mod
  							| modifiers[j], w,
  						 True, GrabModeAsync,
  						 GrabModeAsync);
  				}
  			}
  		}
  
  		c = emallocz(sizeof(*c));
  		c->win = w;
  
  		nclients++;
  		clients = erealloc(clients, sizeof(Client *) * nclients);
  
  		if(npisrelative) {
  			nextpos = sel + newposition;
  		} else {
  			if(newposition < 0) {
  				nextpos = nclients - newposition;
  			} else {
  				nextpos = newposition;
  			}
  		}
  		if(nextpos >= nclients)
  			nextpos = nclients - 1;
  		if(nextpos < 0)
  			nextpos = 0;
  
  		if(nclients > 1 && nextpos < nclients - 1) {
  			memmove(&clients[nextpos + 1], &clients[nextpos],
  					sizeof(Client *) *
  					(nclients - nextpos - 1));
  		}
  		clients[nextpos] = c;
  		updatetitle(nextpos);
  
  		XLowerWindow(dpy, w);
  		XMapWindow(dpy, w);
  
  		e.xclient.window = w;
  		e.xclient.type = ClientMessage;
  		e.xclient.message_type = wmatom[XEmbed];
  		e.xclient.format = 32;
  		e.xclient.data.l[0] = CurrentTime;
  		e.xclient.data.l[1] = XEMBED_EMBEDDED_NOTIFY;
  		e.xclient.data.l[2] = 0;
  		e.xclient.data.l[3] = win;
  		e.xclient.data.l[4] = 0;
  		XSendEvent(dpy, root, False, NoEventMask, &e);
  
  		XSync(dpy, False);
  
  		/* Adjust sel before focus does set it to lastsel. */
  		if(sel >= nextpos)
  			sel++;
  		focus((nextfocus)? nextpos : ((sel < 0)? 0 : sel));
  		nextfocus = foreground;
  	}
  }
  
  void
  maprequest(const XEvent *e) {
  	const XMapRequestEvent *ev = &e->xmaprequest;
  
  	if(getclient(ev->window) < 0)
  		manage(ev->window);
  }
  
  void
  move(const Arg *arg) {
  	if(arg->i >= 0 && arg->i < nclients)
  		focus(arg->i);
  }
  
  void
  movetab(const Arg *arg) {
  	int c;
  	Client *new;
  
  	if(sel < 0 || (arg->i == 0))
  		return;
  
  	c = sel + arg->i;
  	while(c >= nclients)
  		c -= nclients;
  	while(c < 0)
  		c += nclients;
  
  	new = clients[c];
  	clients[c] = clients[sel];
  	clients[sel] = new;
  
  	sel = c;
  
  	drawbar();
  }
  
  void
  propertynotify(const XEvent *e) {
  	const XPropertyEvent *ev = &e->xproperty;
  	int c;
  	char* selection = NULL;
  	Arg arg;
  
  	if(ev->state == PropertyNewValue && ev->atom == wmatom[WMSelectTab]) {
  		selection = getatom(WMSelectTab);
  		if(!strncmp(selection, "0x", 2)) {
  			arg.i = getclient(strtoul(selection, NULL, 0));
  			move(&arg);
  		} else {
  			cmd[cmd_append_pos] = selection;
  			arg.v = cmd;
  			spawn(&arg);
  		}
  	} else if(ev->state != PropertyDelete && ev->atom == XA_WM_NAME
  			&& (c = getclient(ev->window)) > -1) {
  		updatetitle(c);
  	}
  }
  
  void
  resize(int c, int w, int h) {
  	XConfigureEvent ce;
  	XWindowChanges wc;
  
  	ce.x = 0;
  	ce.y = bh;
  	ce.width = wc.width = w;
  	ce.height = wc.height = h;
  	ce.type = ConfigureNotify;
  	ce.display = dpy;
  	ce.event = clients[c]->win;
  	ce.window = clients[c]->win;
  	ce.above = None;
  	ce.override_redirect = False;
  	ce.border_width = 0;
  
  	XConfigureWindow(dpy, clients[c]->win, CWWidth|CWHeight, &wc);
  	XSendEvent(dpy, clients[c]->win, False, StructureNotifyMask,
  			(XEvent *)&ce);
  }
  
  void
  rotate(const Arg *arg) {
  	int nsel = -1;
  
  	if(sel < 0)
  		return;
  
  	if(arg->i == 0) {
  		if(lastsel > -1)
  			focus(lastsel);
  	} else if(sel > -1) {
  		/* Rotating in an arg->i step around the clients. */
  		nsel = sel + arg->i;
  		while(nsel >= nclients)
  			nsel -= nclients;
  		while(nsel < 0)
  			nsel += nclients;
  		focus(nsel);
  	}
  }
  
  void
  run(void) {
  	XEvent ev;
  
  	/* main event loop */
  	XSync(dpy, False);
  	drawbar();
  	if(doinitspawn == True)
  		spawn(NULL);
  
  	while(running) {
  		XNextEvent(dpy, &ev);
  		if(handler[ev.type])
  			(handler[ev.type])(&ev); /* call handler */
  	}
  }
  
  void
  sendxembed(int c, long msg, long detail, long d1, long d2) {
  	XEvent e = { 0 };
  
  	e.xclient.window = clients[c]->win;
  	e.xclient.type = ClientMessage;
  	e.xclient.message_type = wmatom[XEmbed];
  	e.xclient.format = 32;
  	e.xclient.data.l[0] = CurrentTime;
  	e.xclient.data.l[1] = msg;
  	e.xclient.data.l[2] = detail;
  	e.xclient.data.l[3] = d1;
  	e.xclient.data.l[4] = d2;
  	XSendEvent(dpy, clients[c]->win, False, NoEventMask, &e);
  }
  
  void
  setcmd(int argc, char *argv[], int replace) {
  	int i;
  
  	cmd = emallocz((argc+3) * sizeof(*cmd));
  	if (argc == 0)
  		return;
  	for(i = 0; i < argc; i++)
  		cmd[i] = argv[i];
  	cmd[(replace > 0)? replace : argc] = winid;
  	cmd_append_pos = argc + !replace;
  	cmd[cmd_append_pos] = cmd[cmd_append_pos+1] = NULL;
  }
  
  void
  setup(void) {
  	int bitm, tx, ty, tw, th, dh, dw, isfixed;
  	XClassHint class_hint;
  	XSizeHints *size_hint;
  
  	/* clean up any zombies immediately */
  	sigchld(0);
  
  	/* init screen */
  	screen = DefaultScreen(dpy);
  	root = RootWindow(dpy, screen);
  	initfont(font);
  	bh = dc.h = dc.font.height + 2;
  
  	/* init atoms */
  	wmatom[WMProtocols] = XInternAtom(dpy, "WM_PROTOCOLS", False);
  	wmatom[WMDelete] = XInternAtom(dpy, "WM_DELETE_WINDOW", False);
  	wmatom[XEmbed] = XInternAtom(dpy, "_XEMBED", False);
  	wmatom[WMName] = XInternAtom(dpy, "_NET_WM_NAME", False);
  	wmatom[WMState] = XInternAtom(dpy, "_NET_WM_STATE", False);
  	wmatom[WMFullscreen] = XInternAtom(dpy, "_NET_WM_STATE_FULLSCREEN", False);
  	wmatom[WMSelectTab] = XInternAtom(dpy, "_TABBED_SELECT_TAB", False);
  
  	/* init appearance */
  	wx = 0;
  	wy = 0;
  	ww = 800;
  	wh = 600;
  	isfixed = 0;
  
  	if(geometry) {
  		tx = ty = tw = th = 0;
  		bitm = XParseGeometry(geometry, &tx, &ty, (unsigned *)&tw,
  				(unsigned *)&th);
  		if(bitm & XValue)
  			wx = tx;
  		if(bitm & YValue)
  			wy = ty;
  		if(bitm & WidthValue)
  			ww = tw;
  		if(bitm & HeightValue)
  			wh = th;
  		if(bitm & XNegative && wx == 0)
  			wx = -1;
  		if(bitm & YNegative && wy == 0)
  			wy = -1;
  		if(bitm & (HeightValue|WidthValue))
  			isfixed = 1;
  
  		dw = DisplayWidth(dpy, screen);
  		dh = DisplayHeight(dpy, screen);
  		if(wx < 0)
  			wx = dw + wx - ww - 1;
  		if(wy < 0)
  			wy = dh + wy - wh - 1;
  	}
  
  	dc.norm[ColBG] = getcolor(normbgcolor);
  	dc.norm[ColFG] = getcolor(normfgcolor);
  	dc.sel[ColBG] = getcolor(selbgcolor);
  	dc.sel[ColFG] = getcolor(selfgcolor);
  	dc.drawable = XCreatePixmap(dpy, root, ww, wh,
  			DefaultDepth(dpy, screen));
  	dc.gc = XCreateGC(dpy, root, 0, 0);
  
  	win = XCreateSimpleWindow(dpy, root, wx, wy, ww, wh, 0,
  			dc.norm[ColFG].pixel, dc.norm[ColBG].pixel);
  	XMapRaised(dpy, win);
  	XSelectInput(dpy, win, SubstructureNotifyMask|FocusChangeMask|
  			ButtonPressMask|ExposureMask|KeyPressMask|PropertyChangeMask|
  			StructureNotifyMask|SubstructureRedirectMask);
  	xerrorxlib = XSetErrorHandler(xerror);
  
  	class_hint.res_name = wmname;
  	class_hint.res_class = wmclass;
  	XSetClassHint(dpy, win, &class_hint);
  
  	size_hint = XAllocSizeHints();
  	if(!isfixed) {
  		size_hint->flags = PSize;
  		size_hint->height = wh;
  		size_hint->width = ww;
  	} else {
  		size_hint->flags = PMaxSize | PMinSize;
  		size_hint->min_width = size_hint->max_width = ww;
  		size_hint->min_height = size_hint->max_height = wh;
  	}
  	XSetWMProperties(dpy, win, NULL, NULL, NULL, 0, size_hint, NULL, NULL);
  	XFree(size_hint);
  
  	XSetWMProtocols(dpy, win, &wmatom[WMDelete], 1);
  
  	snprintf(winid, sizeof(winid), "%lu", win);
  	setenv("XEMBED", winid, 1);
  
  	nextfocus = foreground;
  	focus(-1);
  }
  
  void
  sigchld(int unused) {
  	if(signal(SIGCHLD, sigchld) == SIG_ERR)
  		die("tabbed: cannot install SIGCHLD handler");
  
  	while(0 < waitpid(-1, NULL, WNOHANG));
  }
  
  void
  spawn(const Arg *arg) {
  	if(fork() == 0) {
  		if(dpy)
  			close(ConnectionNumber(dpy));
  
  		setsid();
  		if(arg && arg->v) {
  			execvp(((char **)arg->v)[0], (char **)arg->v);
  			fprintf(stderr, "tabbed: execvp %s",
  					((char **)arg->v)[0]);
  		} else {
  			cmd[cmd_append_pos] = NULL;
  			execvp(cmd[0], cmd);
  			fprintf(stderr, "tabbed: execvp %s", cmd[0]);
  		}
  		perror(" failed");
  		exit(0);
  	}
  }
  
  int
  textnw(const char *text, unsigned int len) {
  	XGlyphInfo ext;
  	XftTextExtentsUtf8(dpy, dc.font.xfont, (XftChar8 *) text, len, &ext);
  	return ext.xOff;
  }
  
  void
  unmanage(int c) {
  	if(c < 0 || c >= nclients) {
  		drawbar();
  		XSync(dpy, False);
  		return;
  	}
  
  	if(!nclients) {
  		return;
  	} else if(c == 0) {
  		/* First client. */
  		nclients--;
  		free(clients[0]);
  		memmove(&clients[0], &clients[1], sizeof(Client *) * nclients);
  	} else if(c == nclients - 1) {
  		/* Last client. */
  		nclients--;
  		free(clients[c]);
  		clients = erealloc(clients, sizeof(Client *) * nclients);
  	} else {
  		/* Somewhere inbetween. */
  		free(clients[c]);
  		memmove(&clients[c], &clients[c+1],
  				sizeof(Client *) * (nclients - (c + 1)));
  		nclients--;
  	}
  
  	if(nclients <= 0) {
  		sel = -1;
  		lastsel = -1;
  
  		if (closelastclient) {
  			running = False;
  		} else if (fillagain && running) {
  			spawn(NULL);
  		}
  	} else {
  		if(c == lastsel) {
  			lastsel = -1;
  		} else if(lastsel > c) {
  			lastsel--;
  		}
  		lastsel = MIN(lastsel, nclients - 1);
  
  		if(c == sel) {
  			/* Note that focus() will never set lastsel == sel,
  			 * so if here lastsel == sel, it was decreased by above if() clause
  			 * and was actually (sel + 1) before.
  			 */
  			if(lastsel > 0) {
  				focus(lastsel);
  			} else {
  				focus(0);
  				lastsel = 1;
  			}
  		} else {
  			if(sel > c)
  				sel -= 1;
  			if(sel >= nclients)
  				sel = nclients - 1;
  
  			focus(sel);
  		}
  	}
  
  	drawbar();
  	XSync(dpy, False);
  }
  
  void
  updatenumlockmask(void) {
  	unsigned int i, j;
  	XModifierKeymap *modmap;
  
  	numlockmask = 0;
  	modmap = XGetModifierMapping(dpy);
  	for(i = 0; i < 8; i++) {
  		for(j = 0; j < modmap->max_keypermod; j++) {
  			if(modmap->modifiermap[i * modmap->max_keypermod + j]
  					== XKeysymToKeycode(dpy,
  						XK_Num_Lock)) {
  				numlockmask = (1 << i);
  			}
  		}
  	}
  	XFreeModifiermap(modmap);
  }
  
  void
  updatetitle(int c) {
  	if(!gettextprop(clients[c]->win, wmatom[WMName],
  				clients[c]->name, sizeof(clients[c]->name))) {
  		gettextprop(clients[c]->win, XA_WM_NAME,
  				clients[c]->name, sizeof(clients[c]->name));
  	}
  	if(sel == c)
  		xsettitle(win, clients[c]->name);
  	drawbar();
  }
  
  /* There's no way to check accesses to destroyed windows, thus those cases are
   * ignored (especially on UnmapNotify's).  Other types of errors call Xlibs
   * default error handler, which may call exit.  */
  int
  xerror(Display *dpy, XErrorEvent *ee) {
  	if(ee->error_code == BadWindow
  			|| (ee->request_code == X_SetInputFocus
  				&& ee->error_code == BadMatch)
  			|| (ee->request_code == X_PolyText8
  				&& ee->error_code == BadDrawable)
  			|| (ee->request_code == X_PolyFillRectangle
  				&& ee->error_code == BadDrawable)
  			|| (ee->request_code == X_PolySegment
  				&& ee->error_code == BadDrawable)
  			|| (ee->request_code == X_ConfigureWindow
  				&& ee->error_code == BadMatch)
  			|| (ee->request_code == X_GrabButton
  				&& ee->error_code == BadAccess)
  			|| (ee->request_code == X_GrabKey
  				&& ee->error_code == BadAccess)
  			|| (ee->request_code == X_CopyArea
  				&& ee->error_code == BadDrawable)) {
  		return 0;
  	}
  
  	fprintf(stderr, "tabbed: fatal error: request code=%d, error code=%d\n",
  			ee->request_code, ee->error_code);
  	return xerrorxlib(dpy, ee); /* may call exit */
  }
  
  void
  xsettitle(Window w, const char *str) {
  	XTextProperty xtp;
  
  	if(XmbTextListToTextProperty(dpy, (char **)&str, 1, XCompoundTextStyle,
  				&xtp) == Success) {
  		XSetTextProperty(dpy, w, &xtp, wmatom[WMName]);
  		XSetTextProperty(dpy, w, &xtp, XA_WM_NAME);
  		XFree(xtp.value);
  	}
  }
  
  char *argv0;
  
  void
  usage(void) {
  	die("usage: %s [-dfhsv] [-g geometry] [-n name] [-w wmclass] [-p [s+/-]pos] [-r narg] "
  		"[-u color] [-U color] [-t color] [-T color] command...\n", argv0);
  }
  
  int
  main(int argc, char *argv[]) {
  	Bool detach = False;
  	int replace = 0;
  	char *pstr;
  
  	ARGBEGIN {
  	case 'c':
  		closelastclient = True;
  		fillagain = False;
  		break;
  	case 'd':
  		detach = True;
  		break;
  	case 'f':
  		fillagain = True;
  		break;
  	case 'g':
  		geometry = EARGF(usage());
  		break;
  	case 'n':
  		wmname = EARGF(usage());
  		break;
  	case 'p':
  		pstr = EARGF(usage());
  		if(pstr[0] == 's') {
  			npisrelative = True;
  			newposition = atoi(&pstr[1]);
  		} else {
  			newposition = atoi(pstr);
  		}
  		break;
  	case 'r':
  		replace = atoi(EARGF(usage()));
  		break;
  	case 's':
  		doinitspawn = False;
  		break;
  	case 'v':
  		die("tabbed-"VERSION", © 2009-2012"
  			" tabbed engineers, see LICENSE"
  			" for details.\n");
  		break;
  	case 't':
  		selbgcolor = EARGF(usage());
  		break;
  	case 'T':
  		selfgcolor = EARGF(usage());
  		break;
  	case 'u':
  		normbgcolor = EARGF(usage());
  		break;
  	case 'U':
  		normfgcolor = EARGF(usage());
  		break;
  	case 'w':
  		wmclass = EARGF(usage());
  		break;
  	default:
  	case 'h':
  		usage();
  	} ARGEND;
  
  	if(argc < 1) {
  		doinitspawn = False;
  		fillagain = False;
  	}
  
  	setcmd(argc, argv, replace);
  
  	if(!setlocale(LC_CTYPE, "") || !XSupportsLocale())
  		fprintf(stderr, "tabbed: no locale support\n");
  	if(!(dpy = XOpenDisplay(NULL)))
  		die("tabbed: cannot open display\n");
  
  	setup();
  	printf("0x%lx\n", win);
  	fflush(NULL);
  
  	if(detach) {
  		if(fork() == 0) {
  			fclose(stdout);
  		} else {
  			if(dpy)
  				close(ConnectionNumber(dpy));
  			return EXIT_SUCCESS;
  		}
  	}
  
  	run();
  	cleanup();
  	XCloseDisplay(dpy);
  
  	return EXIT_SUCCESS;
  }
  
  