text: /* See LICENSE file for copyright and license details.
   *
   * dynamic window manager is designed like any other X client as well. It is
   * driven through handling X events. In contrast to other X clients, a window
   * manager selects for SubstructureRedirectMask on the root window, to receive
   * events about window (dis-)appearance. Only one X connection at a time is
   * allowed to select for this event mask.
   *
   * The event handlers of dwm are organized in an array which is accessed
   * whenever a new event has been fetched. This allows event dispatching
   * in O(1) time.
   *
   * Each child of the root window is called a client, except windows which have
   * set the override_redirect flag. Clients are organized in a linked client
   * list on each monitor, the focus history is remembered through a stack list
   * on each monitor. Each client contains a bit array to indicate the tags of a
   * client.
   *
   * Keys and tagging rules are organized as arrays and defined in config.h.
   *
   * To understand everything else, start reading main().
   */
  #include <errno.h>
  #include <locale.h>
  #include <signal.h>
  #include <stdarg.h>
  #include <stdio.h>
  #include <stdlib.h>
  #include <string.h>
  #include <unistd.h>
  #include <sys/types.h>
  #include <sys/wait.h>
  #include <X11/cursorfont.h>
  #include <X11/keysym.h>
  #include <X11/Xatom.h>
  #include <X11/Xlib.h>
  #include <X11/Xproto.h>
  #include <X11/Xutil.h>
  #ifdef XINERAMA
  #include <X11/extensions/Xinerama.h>
  #endif /* XINERAMA */
  #include <X11/Xft/Xft.h>
  
  #include "drw.h"
  #include "util.h"
  
  /* macros */
  #define BUTTONMASK              (ButtonPressMask|ButtonReleaseMask)
  #define CLEANMASK(mask)         (mask & ~(numlockmask|LockMask) & (ShiftMask|ControlMask|Mod1Mask|Mod2Mask|Mod3Mask|Mod4Mask|Mod5Mask))
  #define INTERSECT(x,y,w,h,m)    (MAX(0, MIN((x)+(w),(m)->wx+(m)->ww) - MAX((x),(m)->wx)) \
                                 * MAX(0, MIN((y)+(h),(m)->wy+(m)->wh) - MAX((y),(m)->wy)))
  #define ISVISIBLE(C)            ((C->tags & C->mon->tagset[C->mon->seltags]))
  #define LENGTH(X)               (sizeof X / sizeof X[0])
  #define MOUSEMASK               (BUTTONMASK|PointerMotionMask)
  #define WIDTH(X)                ((X)->w + 2 * (X)->bw)
  #define HEIGHT(X)               ((X)->h + 2 * (X)->bw)
  #define TAGMASK                 ((1 << LENGTH(tags)) - 1)
  #define TEXTW(X)                (drw_fontset_getwidth(drw, (X)) + lrpad)
  
  /* enums */
  enum { CurNormal, CurResize, CurMove, CurLast }; /* cursor */
  enum { SchemeNorm, SchemeSel }; /* color schemes */
  enum { NetSupported, NetWMName, NetWMState, NetWMCheck,
         NetWMFullscreen, NetActiveWindow, NetWMWindowType,
         NetWMWindowTypeDialog, NetClientList, NetLast }; /* EWMH atoms */
  enum { WMProtocols, WMDelete, WMState, WMTakeFocus, WMLast }; /* default atoms */
  enum { ClkTagBar, ClkLtSymbol, ClkStatusText, ClkWinTitle,
         ClkClientWin, ClkRootWin, ClkLast }; /* clicks */
  
  typedef union {
    int i;
    unsigned int ui;
    float f;
    const void *v;
  } Arg;
  
  typedef struct {
    unsigned int click;
    unsigned int mask;
    unsigned int button;
    void (*func)(const Arg *arg);
    const Arg arg;
  } Button;
  
  typedef struct Monitor Monitor;
  typedef struct Client Client;
  struct Client {
    char name[256];
    float mina, maxa;
    int x, y, w, h;
    int oldx, oldy, oldw, oldh;
    int basew, baseh, incw, inch, maxw, maxh, minw, minh;
    int bw, oldbw;
    unsigned int tags;
    int isfixed, isfloating, isurgent, neverfocus, oldstate, isfullscreen;
    Client *next;
    Client *snext;
    Monitor *mon;
    Window win;
  };
  
  typedef struct {
    unsigned int mod;
    KeySym keysym;
    void (*func)(const Arg *);
    const Arg arg;
  } Key;
  
  typedef struct {
    const char *symbol;
    void (*arrange)(Monitor *);
  } Layout;
  
  struct Monitor {
    char ltsymbol[16];
    float mfact;
    int nmaster;
    int num;
    int by;               /* bar geometry */
    int mx, my, mw, mh;   /* screen size */
    int wx, wy, ww, wh;   /* window area  */
    unsigned int seltags;
    unsigned int sellt;
    unsigned int tagset[2];
    int showbar;
    int topbar;
    Client *clients;
    Client *sel;
    Client *stack;
    Monitor *next;
    Window barwin;
    const Layout *lt[2];
  };
  
  typedef struct {
    const char *class;
    const char *instance;
    const char *title;
    unsigned int tags;
    int isfloating;
    int monitor;
  } Rule;
  
  /* function declarations */
  static void applyrules(Client *c);
  static int applysizehints(Client *c, int *x, int *y, int *w, int *h, int interact);
  static void arrange(Monitor *m);
  static void arrangemon(Monitor *m);
  static void attach(Client *c);
  static void attachstack(Client *c);
  static void buttonpress(XEvent *e);
  static void checkotherwm(void);
  static void cleanup(void);
  static void cleanupmon(Monitor *mon);
  static void clientmessage(XEvent *e);
  static void configure(Client *c);
  static void configurenotify(XEvent *e);
  static void configurerequest(XEvent *e);
  static Monitor *createmon(void);
  static void destroynotify(XEvent *e);
  static void detach(Client *c);
  static void detachstack(Client *c);
  static Monitor *dirtomon(int dir);
  static void drawbar(Monitor *m);
  static void drawbars(void);
  static void enternotify(XEvent *e);
  static void expose(XEvent *e);
  static void focus(Client *c);
  static void focusin(XEvent *e);
  static void focusmon(const Arg *arg);
  static void focusstack(const Arg *arg);
  static Atom getatomprop(Client *c, Atom prop);
  static int getrootptr(int *x, int *y);
  static long getstate(Window w);
  static int gettextprop(Window w, Atom atom, char *text, unsigned int size);
  static void grabbuttons(Client *c, int focused);
  static void grabkeys(void);
  static void incnmaster(const Arg *arg);
  static void keypress(XEvent *e);
  static void killclient(const Arg *arg);
  static void manage(Window w, XWindowAttributes *wa);
  static void mappingnotify(XEvent *e);
  static void maprequest(XEvent *e);
  static void monocle(Monitor *m);
  static void motionnotify(XEvent *e);
  static void movemouse(const Arg *arg);
  static Client *nexttiled(Client *c);
  static void pop(Client *);
  static void propertynotify(XEvent *e);
  static void quit(const Arg *arg);
  static Monitor *recttomon(int x, int y, int w, int h);
  static void resize(Client *c, int x, int y, int w, int h, int interact);
  static void resizeclient(Client *c, int x, int y, int w, int h);
  static void resizemouse(const Arg *arg);
  static void restack(Monitor *m);
  static void run(void);
  static void scan(void);
  static int sendevent(Client *c, Atom proto);
  static void sendmon(Client *c, Monitor *m);
  static void setclientstate(Client *c, long state);
  static void setfocus(Client *c);
  static void setfullscreen(Client *c, int fullscreen);
  static void setlayout(const Arg *arg);
  static void setmfact(const Arg *arg);
  static void setup(void);
  static void seturgent(Client *c, int urg);
  static void showhide(Client *c);
  static void sigchld(int unused);
  static void spawn(const Arg *arg);
  static void tag(const Arg *arg);
  static void tagmon(const Arg *arg);
  static void tile(Monitor *);
  static void togglebar(const Arg *arg);
  static void togglefloating(const Arg *arg);
  static void toggletag(const Arg *arg);
  static void toggleview(const Arg *arg);
  static void unfocus(Client *c, int setfocus);
  static void unmanage(Client *c, int destroyed);
  static void unmapnotify(XEvent *e);
  static void updatebarpos(Monitor *m);
  static void updatebars(void);
  static void updateclientlist(void);
  static int updategeom(void);
  static void updatenumlockmask(void);
  static void updatesizehints(Client *c);
  static void updatestatus(void);
  static void updatetitle(Client *c);
  static void updatewindowtype(Client *c);
  static void updatewmhints(Client *c);
  static void view(const Arg *arg);
  static Client *wintoclient(Window w);
  static Monitor *wintomon(Window w);
  static int xerror(Display *dpy, XErrorEvent *ee);
  static int xerrordummy(Display *dpy, XErrorEvent *ee);
  static int xerrorstart(Display *dpy, XErrorEvent *ee);
  static void zoom(const Arg *arg);
  
  /* variables */
  static const char broken[] = "broken";
  static char stext[256];
  static int screen;
  static int sw, sh;           /* X display screen geometry width, height */
  static int bh, blw = 0;      /* bar geometry */
  static int lrpad;            /* sum of left and right padding for text */
  static int (*xerrorxlib)(Display *, XErrorEvent *);
  static unsigned int numlockmask = 0;
  static void (*handler[LASTEvent]) (XEvent *) = {
    [ButtonPress] = buttonpress,
    [ClientMessage] = clientmessage,
    [ConfigureRequest] = configurerequest,
    [ConfigureNotify] = configurenotify,
    [DestroyNotify] = destroynotify,
    [EnterNotify] = enternotify,
    [Expose] = expose,
    [FocusIn] = focusin,
    [KeyPress] = keypress,
    [MappingNotify] = mappingnotify,
    [MapRequest] = maprequest,
    [MotionNotify] = motionnotify,
    [PropertyNotify] = propertynotify,
    [UnmapNotify] = unmapnotify
  };
  static Atom wmatom[WMLast], netatom[NetLast];
  static int running = 1;
  static Cur *cursor[CurLast];
  static Clr **scheme;
  static Display *dpy;
  static Drw *drw;
  static Monitor *mons, *selmon;
  static Window root, wmcheckwin;
  
  /* configuration, allows nested code to access above variables */
  #include "config.h"
  
  /* compile-time check if all tags fit into an unsigned int bit array. */
  struct NumTags { char limitexceeded[LENGTH(tags) > 31 ? -1 : 1]; };
  
  /* function implementations */
  void
  applyrules(Client *c)
  {
    const char *class, *instance;
    unsigned int i;
    const Rule *r;
    Monitor *m;
    XClassHint ch = { NULL, NULL };
  
    /* rule matching */
    c->isfloating = 0;
    c->tags = 0;
    XGetClassHint(dpy, c->win, &ch);
    class    = ch.res_class ? ch.res_class : broken;
    instance = ch.res_name  ? ch.res_name  : broken;
  
    for (i = 0; i < LENGTH(rules); i++) {
      r = &rules[i];
      if ((!r->title || strstr(c->name, r->title))
      && (!r->class || strstr(class, r->class))
      && (!r->instance || strstr(instance, r->instance)))
      {
        c->isfloating = r->isfloating;
        c->tags |= r->tags;
        for (m = mons; m && m->num != r->monitor; m = m->next);
        if (m)
          c->mon = m;
      }
    }
    if (ch.res_class)
      XFree(ch.res_class);
    if (ch.res_name)
      XFree(ch.res_name);
    c->tags = c->tags & TAGMASK ? c->tags & TAGMASK : c->mon->tagset[c->mon->seltags];
  }
  
  int
  applysizehints(Client *c, int *x, int *y, int *w, int *h, int interact)
  {
    int baseismin;
    Monitor *m = c->mon;
  
    /* set minimum possible */
    *w = MAX(1, *w);
    *h = MAX(1, *h);
    if (interact) {
      if (*x > sw)
        *x = sw - WIDTH(c);
      if (*y > sh)
        *y = sh - HEIGHT(c);
      if (*x + *w + 2 * c->bw < 0)
        *x = 0;
      if (*y + *h + 2 * c->bw < 0)
        *y = 0;
    } else {
      if (*x >= m->wx + m->ww)
        *x = m->wx + m->ww - WIDTH(c);
      if (*y >= m->wy + m->wh)
        *y = m->wy + m->wh - HEIGHT(c);
      if (*x + *w + 2 * c->bw <= m->wx)
        *x = m->wx;
      if (*y + *h + 2 * c->bw <= m->wy)
        *y = m->wy;
    }
    if (*h < bh)
      *h = bh;
    if (*w < bh)
      *w = bh;
    if (resizehints || c->isfloating || !c->mon->lt[c->mon->sellt]->arrange) {
      /* see last two sentences in ICCCM 4.1.2.3 */
      baseismin = c->basew == c->minw && c->baseh == c->minh;
      if (!baseismin) { /* temporarily remove base dimensions */
        *w -= c->basew;
        *h -= c->baseh;
      }
      /* adjust for aspect limits */
      if (c->mina > 0 && c->maxa > 0) {
        if (c->maxa < (float)*w / *h)
          *w = *h * c->maxa + 0.5;
        else if (c->mina < (float)*h / *w)
          *h = *w * c->mina + 0.5;
      }
      if (baseismin) { /* increment calculation requires this */
        *w -= c->basew;
        *h -= c->baseh;
      }
      /* adjust for increment value */
      if (c->incw)
        *w -= *w % c->incw;
      if (c->inch)
        *h -= *h % c->inch;
      /* restore base dimensions */
      *w = MAX(*w + c->basew, c->minw);
      *h = MAX(*h + c->baseh, c->minh);
      if (c->maxw)
        *w = MIN(*w, c->maxw);
      if (c->maxh)
        *h = MIN(*h, c->maxh);
    }
    return *x != c->x || *y != c->y || *w != c->w || *h != c->h;
  }
  
  void
  arrange(Monitor *m)
  {
    if (m)
      showhide(m->stack);
    else for (m = mons; m; m = m->next)
      showhide(m->stack);
    if (m) {
      arrangemon(m);
      restack(m);
    } else for (m = mons; m; m = m->next)
      arrangemon(m);
  }
  
  void
  arrangemon(Monitor *m)
  {
    strncpy(m->ltsymbol, m->lt[m->sellt]->symbol, sizeof m->ltsymbol);
    if (m->lt[m->sellt]->arrange)
      m->lt[m->sellt]->arrange(m);
  }
  
  void
  attach(Client *c)
  {
    c->next = c->mon->clients;
    c->mon->clients = c;
  }
  
  void
  attachstack(Client *c)
  {
    c->snext = c->mon->stack;
    c->mon->stack = c;
  }
  
  void
  buttonpress(XEvent *e)
  {
    unsigned int i, x, click;
    Arg arg = {0};
    Client *c;
    Monitor *m;
    XButtonPressedEvent *ev = &e->xbutton;
  
    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;
      do
        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 + blw)
        click = ClkLtSymbol;
      else if (ev->x > selmon->ww - (int)TEXTW(stext))
        click = ClkStatusText;
      else
        click = ClkWinTitle;
    } 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 && buttons[i].arg.i == 0 ? &arg : &buttons[i].arg);
  }
  
  void
  checkotherwm(void)
  {
    xerrorxlib = XSetErrorHandler(xerrorstart);
    /* this causes an error if some other window manager is running */
    XSelectInput(dpy, DefaultRootWindow(dpy), SubstructureRedirectMask);
    XSync(dpy, False);
    XSetErrorHandler(xerror);
    XSync(dpy, False);
  }
  
  void
  cleanup(void)
  {
    Arg a = {.ui = ~0};
    Layout foo = { "", NULL };
    Monitor *m;
    size_t i;
  
    view(&a);
    selmon->lt[selmon->sellt] = &foo;
    for (m = mons; m; m = m->next)
      while (m->stack)
        unmanage(m->stack, 0);
    XUngrabKey(dpy, AnyKey, AnyModifier, root);
    while (mons)
      cleanupmon(mons);
    for (i = 0; i < CurLast; i++)
      drw_cur_free(drw, cursor[i]);
    for (i = 0; i < LENGTH(colors); i++)
      free(scheme[i]);
    XDestroyWindow(dpy, wmcheckwin);
    drw_free(drw);
    XSync(dpy, False);
    XSetInputFocus(dpy, PointerRoot, RevertToPointerRoot, CurrentTime);
    XDeleteProperty(dpy, root, netatom[NetActiveWindow]);
  }
  
  void
  cleanupmon(Monitor *mon)
  {
    Monitor *m;
  
    if (mon == mons)
      mons = mons->next;
    else {
      for (m = mons; m && m->next != mon; m = m->next);
      m->next = mon->next;
    }
    XUnmapWindow(dpy, mon->barwin);
    XDestroyWindow(dpy, mon->barwin);
    free(mon);
  }
  
  void
  clientmessage(XEvent *e)
  {
    XClientMessageEvent *cme = &e->xclient;
    Client *c = wintoclient(cme->window);
  
    if (!c)
      return;
    if (cme->message_type == netatom[NetWMState]) {
      if (cme->data.l[1] == netatom[NetWMFullscreen]
      || cme->data.l[2] == netatom[NetWMFullscreen])
        setfullscreen(c, (cme->data.l[0] == 1 /* _NET_WM_STATE_ADD    */
          || (cme->data.l[0] == 2 /* _NET_WM_STATE_TOGGLE */ && !c->isfullscreen)));
    } else if (cme->message_type == netatom[NetActiveWindow]) {
      if (c != selmon->sel && !c->isurgent)
        seturgent(c, 1);
    }
  }
  
  void
  configure(Client *c)
  {
    XConfigureEvent ce;
  
    ce.type = ConfigureNotify;
    ce.display = dpy;
    ce.event = c->win;
    ce.window = c->win;
    ce.x = c->x;
    ce.y = c->y;
    ce.width = c->w;
    ce.height = c->h;
    ce.border_width = c->bw;
    ce.above = None;
    ce.override_redirect = False;
    XSendEvent(dpy, c->win, False, StructureNotifyMask, (XEvent *)&ce);
  }
  
  void
  configurenotify(XEvent *e)
  {
    Monitor *m;
    Client *c;
    XConfigureEvent *ev = &e->xconfigure;
    int dirty;
  
    /* TODO: updategeom handling sucks, needs to be simplified */
    if (ev->window == root) {
      dirty = (sw != ev->width || sh != ev->height);
      sw = ev->width;
      sh = ev->height;
      if (updategeom() || dirty) {
        drw_resize(drw, sw, bh);
        updatebars();
        for (m = mons; m; m = m->next) {
          for (c = m->clients; c; c = c->next)
            if (c->isfullscreen)
              resizeclient(c, m->mx, m->my, m->mw, m->mh);
          XMoveResizeWindow(dpy, m->barwin, m->wx, m->by, m->ww, bh);
        }
        focus(NULL);
        arrange(NULL);
      }
    }
  }
  
  void
  configurerequest(XEvent *e)
  {
    Client *c;
    Monitor *m;
    XConfigureRequestEvent *ev = &e->xconfigurerequest;
    XWindowChanges wc;
  
    if ((c = wintoclient(ev->window))) {
      if (ev->value_mask & CWBorderWidth)
        c->bw = ev->border_width;
      else if (c->isfloating || !selmon->lt[selmon->sellt]->arrange) {
        m = c->mon;
        if (ev->value_mask & CWX) {
          c->oldx = c->x;
          c->x = m->mx + ev->x;
        }
        if (ev->value_mask & CWY) {
          c->oldy = c->y;
          c->y = m->my + ev->y;
        }
        if (ev->value_mask & CWWidth) {
          c->oldw = c->w;
          c->w = ev->width;
        }
        if (ev->value_mask & CWHeight) {
          c->oldh = c->h;
          c->h = ev->height;
        }
        if ((c->x + c->w) > m->mx + m->mw && c->isfloating)
          c->x = m->mx + (m->mw / 2 - WIDTH(c) / 2); /* center in x direction */
        if ((c->y + c->h) > m->my + m->mh && c->isfloating)
          c->y = m->my + (m->mh / 2 - HEIGHT(c) / 2); /* center in y direction */
        if ((ev->value_mask & (CWX|CWY)) && !(ev->value_mask & (CWWidth|CWHeight)))
          configure(c);
        if (ISVISIBLE(c))
          XMoveResizeWindow(dpy, c->win, c->x, c->y, c->w, c->h);
      } else
        configure(c);
    } else {
      wc.x = ev->x;
      wc.y = ev->y;
      wc.width = ev->width;
      wc.height = ev->height;
      wc.border_width = ev->border_width;
      wc.sibling = ev->above;
      wc.stack_mode = ev->detail;
      XConfigureWindow(dpy, ev->window, ev->value_mask, &wc);
    }
    XSync(dpy, False);
  }
  
  Monitor *
  createmon(void)
  {
    Monitor *m;
  
    m = ecalloc(1, sizeof(Monitor));
    m->tagset[0] = m->tagset[1] = 1;
    m->mfact = mfact;
    m->nmaster = nmaster;
    m->showbar = showbar;
    m->topbar = topbar;
    m->lt[0] = &layouts[0];
    m->lt[1] = &layouts[1 % LENGTH(layouts)];
    strncpy(m->ltsymbol, layouts[0].symbol, sizeof m->ltsymbol);
    return m;
  }
  
  void
  destroynotify(XEvent *e)
  {
    Client *c;
    XDestroyWindowEvent *ev = &e->xdestroywindow;
  
    if ((c = wintoclient(ev->window)))
      unmanage(c, 1);
  }
  
  void
  detach(Client *c)
  {
    Client **tc;
  
    for (tc = &c->mon->clients; *tc && *tc != c; tc = &(*tc)->next);
    *tc = c->next;
  }
  
  void
  detachstack(Client *c)
  {
    Client **tc, *t;
  
    for (tc = &c->mon->stack; *tc && *tc != c; tc = &(*tc)->snext);
    *tc = c->snext;
  
    if (c == c->mon->sel) {
      for (t = c->mon->stack; t && !ISVISIBLE(t); t = t->snext);
      c->mon->sel = t;
    }
  }
  
  Monitor *
  dirtomon(int dir)
  {
    Monitor *m = NULL;
  
    if (dir > 0) {
      if (!(m = selmon->next))
        m = mons;
    } else if (selmon == mons)
      for (m = mons; m->next; m = m->next);
    else
      for (m = mons; m->next != selmon; m = m->next);
    return m;
  }
  
  void
  drawbar(Monitor *m)
  {
    int x, w, tw = 0;
    int boxs = drw->fonts->h / 9;
    int boxw = drw->fonts->h / 6 + 2;
    unsigned int i, occ = 0, urg = 0;
    Client *c;
  
    /* draw status first so it can be overdrawn by tags later */
    if (m == selmon) { /* status is only drawn on selected monitor */
      drw_setscheme(drw, scheme[SchemeNorm]);
      tw = TEXTW(stext) - lrpad + 2; /* 2px right padding */
      drw_text(drw, m->ww - tw, 0, tw, bh, 0, stext, 0);
    }
  
    for (c = m->clients; c; c = c->next) {
      occ |= c->tags;
      if (c->isurgent)
        urg |= c->tags;
    }
    x = 0;
    for (i = 0; i < LENGTH(tags); i++) {
      w = TEXTW(tags[i]);
      drw_setscheme(drw, scheme[m->tagset[m->seltags] & 1 << i ? SchemeSel : SchemeNorm]);
      drw_text(drw, x, 0, w, bh, lrpad / 2, tags[i], urg & 1 << i);
      if (occ & 1 << i)
        drw_rect(drw, x + boxs, boxs, boxw, boxw,
          m == selmon && selmon->sel && selmon->sel->tags & 1 << i,
          urg & 1 << i);
      x += w;
    }
    w = blw = TEXTW(m->ltsymbol);
    drw_setscheme(drw, scheme[SchemeNorm]);
    x = drw_text(drw, x, 0, w, bh, lrpad / 2, m->ltsymbol, 0);
  
    if ((w = m->ww - tw - x) > bh) {
      if (m->sel) {
        drw_setscheme(drw, scheme[m == selmon ? SchemeSel : SchemeNorm]);
        drw_text(drw, x, 0, w, bh, lrpad / 2, m->sel->name, 0);
        if (m->sel->isfloating)
          drw_rect(drw, x + boxs, boxs, boxw, boxw, m->sel->isfixed, 0);
      } else {
        drw_setscheme(drw, scheme[SchemeNorm]);
        drw_rect(drw, x, 0, w, bh, 1, 1);
      }
    }
    drw_map(drw, m->barwin, 0, 0, m->ww, bh);
  }
  
  void
  drawbars(void)
  {
    Monitor *m;
  
    for (m = mons; m; m = m->next)
      drawbar(m);
  }
  
  void
  enternotify(XEvent *e)
  {
    Client *c;
    Monitor *m;
    XCrossingEvent *ev = &e->xcrossing;
  
    if ((ev->mode != NotifyNormal || ev->detail == NotifyInferior) && ev->window != root)
      return;
    c = wintoclient(ev->window);
    m = c ? c->mon : wintomon(ev->window);
    if (m != selmon) {
      unfocus(selmon->sel, 1);
      selmon = m;
    } else if (!c || c == selmon->sel)
      return;
    focus(c);
  }
  
  void
  expose(XEvent *e)
  {
    Monitor *m;
    XExposeEvent *ev = &e->xexpose;
  
    if (ev->count == 0 && (m = wintomon(ev->window)))
      drawbar(m);
  }
  
  void
  focus(Client *c)
  {
    if (!c || !ISVISIBLE(c))
      for (c = selmon->stack; c && !ISVISIBLE(c); c = c->snext);
    if (selmon->sel && selmon->sel != c)
      unfocus(selmon->sel, 0);
    if (c) {
      if (c->mon != selmon)
        selmon = c->mon;
      if (c->isurgent)
        seturgent(c, 0);
      detachstack(c);
      attachstack(c);
      grabbuttons(c, 1);
      XSetWindowBorder(dpy, c->win, scheme[SchemeSel][ColBorder].pixel);
      setfocus(c);
    } else {
      XSetInputFocus(dpy, root, RevertToPointerRoot, CurrentTime);
      XDeleteProperty(dpy, root, netatom[NetActiveWindow]);
    }
    selmon->sel = c;
    drawbars();
  }
  
  /* there are some broken focus acquiring clients needing extra handling */
  void
  focusin(XEvent *e)
  {
    XFocusChangeEvent *ev = &e->xfocus;
  
    if (selmon->sel && ev->window != selmon->sel->win)
      setfocus(selmon->sel);
  }
  
  void
  focusmon(const Arg *arg)
  {
    Monitor *m;
  
    if (!mons->next)
      return;
    if ((m = dirtomon(arg->i)) == selmon)
      return;
    unfocus(selmon->sel, 0);
    selmon = m;
    focus(NULL);
  }
  
  void
  focusstack(const Arg *arg)
  {
    Client *c = NULL, *i;
  
    if (!selmon->sel)
      return;
    if (arg->i > 0) {
      for (c = selmon->sel->next; c && !ISVISIBLE(c); c = c->next);
      if (!c)
        for (c = selmon->clients; c && !ISVISIBLE(c); c = c->next);
    } else {
      for (i = selmon->clients; i != selmon->sel; i = i->next)
        if (ISVISIBLE(i))
          c = i;
      if (!c)
        for (; i; i = i->next)
          if (ISVISIBLE(i))
            c = i;
    }
    if (c) {
      focus(c);
      restack(selmon);
    }
  }
  
  Atom
  getatomprop(Client *c, Atom prop)
  {
    int di;
    unsigned long dl;
    unsigned char *p = NULL;
    Atom da, atom = None;
  
    if (XGetWindowProperty(dpy, c->win, prop, 0L, sizeof atom, False, XA_ATOM,
      &da, &di, &dl, &dl, &p) == Success && p) {
      atom = *(Atom *)p;
      XFree(p);
    }
    return atom;
  }
  
  int
  getrootptr(int *x, int *y)
  {
    int di;
    unsigned int dui;
    Window dummy;
  
    return XQueryPointer(dpy, root, &dummy, &dummy, x, y, &di, &di, &dui);
  }
  
  long
  getstate(Window w)
  {
    int format;
    long result = -1;
    unsigned char *p = NULL;
    unsigned long n, extra;
    Atom real;
  
    if (XGetWindowProperty(dpy, w, wmatom[WMState], 0L, 2L, False, wmatom[WMState],
      &real, &format, &n, &extra, (unsigned char **)&p) != Success)
      return -1;
    if (n != 0)
      result = *p;
    XFree(p);
    return result;
  }
  
  int
  gettextprop(Window w, Atom atom, char *text, unsigned int size)
  {
    char **list = NULL;
    int n;
    XTextProperty name;
  
    if (!text || size == 0)
      return 0;
    text[0] = '\0';
    if (!XGetTextProperty(dpy, w, &name, atom) || !name.nitems)
      return 0;
    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 1;
  }
  
  void
  grabbuttons(Client *c, int focused)
  {
    updatenumlockmask();
    {
      unsigned int i, j;
      unsigned int modifiers[] = { 0, LockMask, numlockmask, numlockmask|LockMask };
      XUngrabButton(dpy, AnyButton, AnyModifier, c->win);
      if (!focused)
        XGrabButton(dpy, AnyButton, AnyModifier, c->win, False,
          BUTTONMASK, GrabModeSync, GrabModeSync, None, None);
      for (i = 0; i < LENGTH(buttons); i++)
        if (buttons[i].click == ClkClientWin)
          for (j = 0; j < LENGTH(modifiers); j++)
            XGrabButton(dpy, buttons[i].button,
              buttons[i].mask | modifiers[j],
              c->win, False, BUTTONMASK,
              GrabModeAsync, GrabModeSync, None, None);
    }
  }
  
  void
  grabkeys(void)
  {
    updatenumlockmask();
    {
      unsigned int i, j;
      unsigned int modifiers[] = { 0, LockMask, numlockmask, numlockmask|LockMask };
      KeyCode code;
  
      XUngrabKey(dpy, AnyKey, AnyModifier, root);
      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], root,
              True, GrabModeAsync, GrabModeAsync);
    }
  }
  
  void
  incnmaster(const Arg *arg)
  {
    selmon->nmaster = MAX(selmon->nmaster + arg->i, 0);
    arrange(selmon);
  }
  
  #ifdef XINERAMA
  static int
  isuniquegeom(XineramaScreenInfo *unique, size_t n, XineramaScreenInfo *info)
  {
    while (n--)
      if (unique[n].x_org == info->x_org && unique[n].y_org == info->y_org
      && unique[n].width == info->width && unique[n].height == info->height)
        return 0;
    return 1;
  }
  #endif /* XINERAMA */
  
  void
  keypress(XEvent *e)
  {
    unsigned int i;
    KeySym keysym;
    XKeyEvent *ev;
  
    ev = &e->xkey;
    keysym = XKeycodeToKeysym(dpy, (KeyCode)ev->keycode, 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)
  {
    if (!selmon->sel)
      return;
    if (!sendevent(selmon->sel, wmatom[WMDelete])) {
      XGrabServer(dpy);
      XSetErrorHandler(xerrordummy);
      XSetCloseDownMode(dpy, DestroyAll);
      XKillClient(dpy, selmon->sel->win);
      XSync(dpy, False);
      XSetErrorHandler(xerror);
      XUngrabServer(dpy);
    }
  }
  
  void
  manage(Window w, XWindowAttributes *wa)
  {
    Client *c, *t = NULL;
    Window trans = None;
    XWindowChanges wc;
  
    c = ecalloc(1, sizeof(Client));
    c->win = w;
    /* geometry */
    c->x = c->oldx = wa->x;
    c->y = c->oldy = wa->y;
    c->w = c->oldw = wa->width;
    c->h = c->oldh = wa->height;
    c->oldbw = wa->border_width;
  
    updatetitle(c);
    if (XGetTransientForHint(dpy, w, &trans) && (t = wintoclient(trans))) {
      c->mon = t->mon;
      c->tags = t->tags;
    } else {
      c->mon = selmon;
      applyrules(c);
    }
  
    if (c->x + WIDTH(c) > c->mon->mx + c->mon->mw)
      c->x = c->mon->mx + c->mon->mw - WIDTH(c);
    if (c->y + HEIGHT(c) > c->mon->my + c->mon->mh)
      c->y = c->mon->my + c->mon->mh - HEIGHT(c);
    c->x = MAX(c->x, c->mon->mx);
    /* only fix client y-offset, if the client center might cover the bar */
    c->y = MAX(c->y, ((c->mon->by == c->mon->my) && (c->x + (c->w / 2) >= c->mon->wx)
      && (c->x + (c->w / 2) < c->mon->wx + c->mon->ww)) ? bh : c->mon->my);
    c->bw = borderpx;
  
    wc.border_width = c->bw;
    XConfigureWindow(dpy, w, CWBorderWidth, &wc);
    XSetWindowBorder(dpy, w, scheme[SchemeNorm][ColBorder].pixel);
    configure(c); /* propagates border_width, if size doesn't change */
    updatewindowtype(c);
    updatesizehints(c);
    updatewmhints(c);
    XSelectInput(dpy, w, EnterWindowMask|FocusChangeMask|PropertyChangeMask|StructureNotifyMask);
    grabbuttons(c, 0);
    if (!c->isfloating)
      c->isfloating = c->oldstate = trans != None || c->isfixed;
    if (c->isfloating)
      XRaiseWindow(dpy, c->win);
    attach(c);
    attachstack(c);
    XChangeProperty(dpy, root, netatom[NetClientList], XA_WINDOW, 32, PropModeAppend,
      (unsigned char *) &(c->win), 1);
    XMoveResizeWindow(dpy, c->win, c->x + 2 * sw, c->y, c->w, c->h); /* some windows require this */
    setclientstate(c, NormalState);
    if (c->mon == selmon)
      unfocus(selmon->sel, 0);
    c->mon->sel = c;
    arrange(c->mon);
    XMapWindow(dpy, c->win);
    focus(NULL);
  }
  
  void
  mappingnotify(XEvent *e)
  {
    XMappingEvent *ev = &e->xmapping;
  
    XRefreshKeyboardMapping(ev);
    if (ev->request == MappingKeyboard)
      grabkeys();
  }
  
  void
  maprequest(XEvent *e)
  {
    static XWindowAttributes wa;
    XMapRequestEvent *ev = &e->xmaprequest;
  
    if (!XGetWindowAttributes(dpy, ev->window, &wa))
      return;
    if (wa.override_redirect)
      return;
    if (!wintoclient(ev->window))
      manage(ev->window, &wa);
  }
  
  void
  monocle(Monitor *m)
  {
    unsigned int n = 0;
    Client *c;
  
    for (c = m->clients; c; c = c->next)
      if (ISVISIBLE(c))
        n++;
    if (n > 0) /* override layout symbol */
      snprintf(m->ltsymbol, sizeof m->ltsymbol, "[%d]", n);
    for (c = nexttiled(m->clients); c; c = nexttiled(c->next))
      resize(c, m->wx, m->wy, m->ww - 2 * c->bw, m->wh - 2 * c->bw, 0);
  }
  
  void
  motionnotify(XEvent *e)
  {
    static Monitor *mon = NULL;
    Monitor *m;
    XMotionEvent *ev = &e->xmotion;
  
    if (ev->window != root)
      return;
    if ((m = recttomon(ev->x_root, ev->y_root, 1, 1)) != mon && mon) {
      unfocus(selmon->sel, 1);
      selmon = m;
      focus(NULL);
    }
    mon = m;
  }
  
  void
  movemouse(const Arg *arg)
  {
    int x, y, ocx, ocy, nx, ny;
    Client *c;
    Monitor *m;
    XEvent ev;
    Time lasttime = 0;
  
    if (!(c = selmon->sel))
      return;
    if (c->isfullscreen) /* no support moving fullscreen windows by mouse */
      return;
    restack(selmon);
    ocx = c->x;
    ocy = c->y;
    if (XGrabPointer(dpy, root, False, MOUSEMASK, GrabModeAsync, GrabModeAsync,
      None, cursor[CurMove]->cursor, CurrentTime) != GrabSuccess)
      return;
    if (!getrootptr(&x, &y))
      return;
    do {
      XMaskEvent(dpy, MOUSEMASK|ExposureMask|SubstructureRedirectMask, &ev);
      switch(ev.type) {
      case ConfigureRequest:
      case Expose:
      case MapRequest:
        handler[ev.type](&ev);
        break;
      case MotionNotify:
        if ((ev.xmotion.time - lasttime) <= (1000 / 60))
          continue;
        lasttime = ev.xmotion.time;
  
        nx = ocx + (ev.xmotion.x - x);
        ny = ocy + (ev.xmotion.y - y);
        if (abs(selmon->wx - nx) < snap)
          nx = selmon->wx;
        else if (abs((selmon->wx + selmon->ww) - (nx + WIDTH(c))) < snap)
          nx = selmon->wx + selmon->ww - WIDTH(c);
        if (abs(selmon->wy - ny) < snap)
          ny = selmon->wy;
        else if (abs((selmon->wy + selmon->wh) - (ny + HEIGHT(c))) < snap)
          ny = selmon->wy + selmon->wh - HEIGHT(c);
        if (!c->isfloating && selmon->lt[selmon->sellt]->arrange
        && (abs(nx - c->x) > snap || abs(ny - c->y) > snap))
          togglefloating(NULL);
        if (!selmon->lt[selmon->sellt]->arrange || c->isfloating)
          resize(c, nx, ny, c->w, c->h, 1);
        break;
      }
    } while (ev.type != ButtonRelease);
    XUngrabPointer(dpy, CurrentTime);
    if ((m = recttomon(c->x, c->y, c->w, c->h)) != selmon) {
      sendmon(c, m);
      selmon = m;
      focus(NULL);
    }
  }
  
  Client *
  nexttiled(Client *c)
  {
    for (; c && (c->isfloating || !ISVISIBLE(c)); c = c->next);
    return c;
  }
  
  void
  pop(Client *c)
  {
    detach(c);
    attach(c);
    focus(c);
    arrange(c->mon);
  }
  
  void
  propertynotify(XEvent *e)
  {
    Client *c;
    Window trans;
    XPropertyEvent *ev = &e->xproperty;
  
    if ((ev->window == root) && (ev->atom == XA_WM_NAME))
      updatestatus();
    else if (ev->state == PropertyDelete)
      return; /* ignore */
    else if ((c = wintoclient(ev->window))) {
      switch(ev->atom) {
      default: break;
      case XA_WM_TRANSIENT_FOR:
        if (!c->isfloating && (XGetTransientForHint(dpy, c->win, &trans)) &&
          (c->isfloating = (wintoclient(trans)) != NULL))
          arrange(c->mon);
        break;
      case XA_WM_NORMAL_HINTS:
        updatesizehints(c);
        break;
      case XA_WM_HINTS:
        updatewmhints(c);
        drawbars();
        break;
      }
      if (ev->atom == XA_WM_NAME || ev->atom == netatom[NetWMName]) {
        updatetitle(c);
        if (c == c->mon->sel)
          drawbar(c->mon);
      }
      if (ev->atom == netatom[NetWMWindowType])
        updatewindowtype(c);
    }
  }
  
  void
  quit(const Arg *arg)
  {
    running = 0;
  }
  
  Monitor *
  recttomon(int x, int y, int w, int h)
  {
    Monitor *m, *r = selmon;
    int a, area = 0;
  
    for (m = mons; m; m = m->next)
      if ((a = INTERSECT(x, y, w, h, m)) > area) {
        area = a;
        r = m;
      }
    return r;
  }
  
  void
  resize(Client *c, int x, int y, int w, int h, int interact)
  {
    if (applysizehints(c, &x, &y, &w, &h, interact))
      resizeclient(c, x, y, w, h);
  }
  
  void
  resizeclient(Client *c, int x, int y, int w, int h)
  {
    XWindowChanges wc;
  
    c->oldx = c->x; c->x = wc.x = x;
    c->oldy = c->y; c->y = wc.y = y;
    c->oldw = c->w; c->w = wc.width = w;
    c->oldh = c->h; c->h = wc.height = h;
    wc.border_width = c->bw;
    XConfigureWindow(dpy, c->win, CWX|CWY|CWWidth|CWHeight|CWBorderWidth, &wc);
    configure(c);
    XSync(dpy, False);
  }
  
  void
  resizemouse(const Arg *arg)
  {
    int ocx, ocy, nw, nh;
    Client *c;
    Monitor *m;
    XEvent ev;
    Time lasttime = 0;
  
    if (!(c = selmon->sel))
      return;
    if (c->isfullscreen) /* no support resizing fullscreen windows by mouse */
      return;
    restack(selmon);
    ocx = c->x;
    ocy = c->y;
    if (XGrabPointer(dpy, root, False, MOUSEMASK, GrabModeAsync, GrabModeAsync,
      None, cursor[CurResize]->cursor, CurrentTime) != GrabSuccess)
      return;
    XWarpPointer(dpy, None, c->win, 0, 0, 0, 0, c->w + c->bw - 1, c->h + c->bw - 1);
    do {
      XMaskEvent(dpy, MOUSEMASK|ExposureMask|SubstructureRedirectMask, &ev);
      switch(ev.type) {
      case ConfigureRequest:
      case Expose:
      case MapRequest:
        handler[ev.type](&ev);
        break;
      case MotionNotify:
        if ((ev.xmotion.time - lasttime) <= (1000 / 60))
          continue;
        lasttime = ev.xmotion.time;
  
        nw = MAX(ev.xmotion.x - ocx - 2 * c->bw + 1, 1);
        nh = MAX(ev.xmotion.y - ocy - 2 * c->bw + 1, 1);
        if (c->mon->wx + nw >= selmon->wx && c->mon->wx + nw <= selmon->wx + selmon->ww
        && c->mon->wy + nh >= selmon->wy && c->mon->wy + nh <= selmon->wy + selmon->wh)
        {
          if (!c->isfloating && selmon->lt[selmon->sellt]->arrange
          && (abs(nw - c->w) > snap || abs(nh - c->h) > snap))
            togglefloating(NULL);
        }
        if (!selmon->lt[selmon->sellt]->arrange || c->isfloating)
          resize(c, c->x, c->y, nw, nh, 1);
        break;
      }
    } while (ev.type != ButtonRelease);
    XWarpPointer(dpy, None, c->win, 0, 0, 0, 0, c->w + c->bw - 1, c->h + c->bw - 1);
    XUngrabPointer(dpy, CurrentTime);
    while (XCheckMaskEvent(dpy, EnterWindowMask, &ev));
    if ((m = recttomon(c->x, c->y, c->w, c->h)) != selmon) {
      sendmon(c, m);
      selmon = m;
      focus(NULL);
    }
  }
  
  void
  restack(Monitor *m)
  {
    Client *c;
    XEvent ev;
    XWindowChanges wc;
  
    drawbar(m);
    if (!m->sel)
      return;
    if (m->sel->isfloating || !m->lt[m->sellt]->arrange)
      XRaiseWindow(dpy, m->sel->win);
    if (m->lt[m->sellt]->arrange) {
      wc.stack_mode = Below;
      wc.sibling = m->barwin;
      for (c = m->stack; c; c = c->snext)
        if (!c->isfloating && ISVISIBLE(c)) {
          XConfigureWindow(dpy, c->win, CWSibling|CWStackMode, &wc);
          wc.sibling = c->win;
        }
    }
    XSync(dpy, False);
    while (XCheckMaskEvent(dpy, EnterWindowMask, &ev));
  }
  
  void
  run(void)
  {
    XEvent ev;
    /* main event loop */
    XSync(dpy, False);
    while (running && !XNextEvent(dpy, &ev))
      if (handler[ev.type])
        handler[ev.type](&ev); /* call handler */
  }
  
  void
  scan(void)
  {
    unsigned int i, num;
    Window d1, d2, *wins = NULL;
    XWindowAttributes wa;
  
    if (XQueryTree(dpy, root, &d1, &d2, &wins, &num)) {
      for (i = 0; i < num; i++) {
        if (!XGetWindowAttributes(dpy, wins[i], &wa)
        || wa.override_redirect || XGetTransientForHint(dpy, wins[i], &d1))
          continue;
        if (wa.map_state == IsViewable || getstate(wins[i]) == IconicState)
          manage(wins[i], &wa);
      }
      for (i = 0; i < num; i++) { /* now the transients */
        if (!XGetWindowAttributes(dpy, wins[i], &wa))
          continue;
        if (XGetTransientForHint(dpy, wins[i], &d1)
        && (wa.map_state == IsViewable || getstate(wins[i]) == IconicState))
          manage(wins[i], &wa);
      }
      if (wins)
        XFree(wins);
    }
  }
  
  void
  sendmon(Client *c, Monitor *m)
  {
    if (c->mon == m)
      return;
    unfocus(c, 1);
    detach(c);
    detachstack(c);
    c->mon = m;
    c->tags = m->tagset[m->seltags]; /* assign tags of target monitor */
    attach(c);
    attachstack(c);
    focus(NULL);
    arrange(NULL);
  }
  
  void
  setclientstate(Client *c, long state)
  {
    long data[] = { state, None };
  
    XChangeProperty(dpy, c->win, wmatom[WMState], wmatom[WMState], 32,
      PropModeReplace, (unsigned char *)data, 2);
  }
  
  int
  sendevent(Client *c, Atom proto)
  {
    int n;
    Atom *protocols;
    int exists = 0;
    XEvent ev;
  
    if (XGetWMProtocols(dpy, c->win, &protocols, &n)) {
      while (!exists && n--)
        exists = protocols[n] == proto;
      XFree(protocols);
    }
    if (exists) {
      ev.type = ClientMessage;
      ev.xclient.window = c->win;
      ev.xclient.message_type = wmatom[WMProtocols];
      ev.xclient.format = 32;
      ev.xclient.data.l[0] = proto;
      ev.xclient.data.l[1] = CurrentTime;
      XSendEvent(dpy, c->win, False, NoEventMask, &ev);
    }
    return exists;
  }
  
  void
  setfocus(Client *c)
  {
    if (!c->neverfocus) {
      XSetInputFocus(dpy, c->win, RevertToPointerRoot, CurrentTime);
      XChangeProperty(dpy, root, netatom[NetActiveWindow],
        XA_WINDOW, 32, PropModeReplace,
        (unsigned char *) &(c->win), 1);
    }
    sendevent(c, wmatom[WMTakeFocus]);
  }
  
  void
  setfullscreen(Client *c, int fullscreen)
  {
    if (fullscreen && !c->isfullscreen) {
      XChangeProperty(dpy, c->win, netatom[NetWMState], XA_ATOM, 32,
        PropModeReplace, (unsigned char*)&netatom[NetWMFullscreen], 1);
      c->isfullscreen = 1;
      c->oldstate = c->isfloating;
      c->oldbw = c->bw;
      c->bw = 0;
      c->isfloating = 1;
      resizeclient(c, c->mon->mx, c->mon->my, c->mon->mw, c->mon->mh);
      XRaiseWindow(dpy, c->win);
    } else if (!fullscreen && c->isfullscreen){
      XChangeProperty(dpy, c->win, netatom[NetWMState], XA_ATOM, 32,
        PropModeReplace, (unsigned char*)0, 0);
      c->isfullscreen = 0;
      c->isfloating = c->oldstate;
      c->bw = c->oldbw;
      c->x = c->oldx;
      c->y = c->oldy;
      c->w = c->oldw;
      c->h = c->oldh;
      resizeclient(c, c->x, c->y, c->w, c->h);
      arrange(c->mon);
    }
  }
  
  void
  setlayout(const Arg *arg)
  {
    if (!arg || !arg->v || arg->v != selmon->lt[selmon->sellt])
      selmon->sellt ^= 1;
    if (arg && arg->v)
      selmon->lt[selmon->sellt] = (Layout *)arg->v;
    strncpy(selmon->ltsymbol, selmon->lt[selmon->sellt]->symbol, sizeof selmon->ltsymbol);
    if (selmon->sel)
      arrange(selmon);
    else
      drawbar(selmon);
  }
  
  /* arg > 1.0 will set mfact absolutely */
  void
  setmfact(const Arg *arg)
  {
    float f;
  
    if (!arg || !selmon->lt[selmon->sellt]->arrange)
      return;
    f = arg->f < 1.0 ? arg->f + selmon->mfact : arg->f - 1.0;
    if (f < 0.05 || f > 0.95)
      return;
    selmon->mfact = f;
    arrange(selmon);
  }
  
  void
  setup(void)
  {
    int i;
    XSetWindowAttributes wa;
    Atom utf8string;
  
    /* clean up any zombies immediately */
    sigchld(0);
  
    /* init screen */
    screen = DefaultScreen(dpy);
    sw = DisplayWidth(dpy, screen);
    sh = DisplayHeight(dpy, screen);
    root = RootWindow(dpy, screen);
    drw = drw_create(dpy, screen, root, sw, sh);
    if (!drw_fontset_create(drw, fonts, LENGTH(fonts)))
      die("no fonts could be loaded.");
    lrpad = drw->fonts->h;
    bh = drw->fonts->h + 2;
    updategeom();
    /* init atoms */
    utf8string = XInternAtom(dpy, "UTF8_STRING", False);
    wmatom[WMProtocols] = XInternAtom(dpy, "WM_PROTOCOLS", False);
    wmatom[WMDelete] = XInternAtom(dpy, "WM_DELETE_WINDOW", False);
    wmatom[WMState] = XInternAtom(dpy, "WM_STATE", False);
    wmatom[WMTakeFocus] = XInternAtom(dpy, "WM_TAKE_FOCUS", False);
    netatom[NetActiveWindow] = XInternAtom(dpy, "_NET_ACTIVE_WINDOW", False);
    netatom[NetSupported] = XInternAtom(dpy, "_NET_SUPPORTED", False);
    netatom[NetWMName] = XInternAtom(dpy, "_NET_WM_NAME", False);
    netatom[NetWMState] = XInternAtom(dpy, "_NET_WM_STATE", False);
    netatom[NetWMCheck] = XInternAtom(dpy, "_NET_SUPPORTING_WM_CHECK", False);
    netatom[NetWMFullscreen] = XInternAtom(dpy, "_NET_WM_STATE_FULLSCREEN", False);
    netatom[NetWMWindowType] = XInternAtom(dpy, "_NET_WM_WINDOW_TYPE", False);
    netatom[NetWMWindowTypeDialog] = XInternAtom(dpy, "_NET_WM_WINDOW_TYPE_DIALOG", False);
    netatom[NetClientList] = XInternAtom(dpy, "_NET_CLIENT_LIST", False);
    /* init cursors */
    cursor[CurNormal] = drw_cur_create(drw, XC_left_ptr);
    cursor[CurResize] = drw_cur_create(drw, XC_sizing);
    cursor[CurMove] = drw_cur_create(drw, XC_fleur);
    /* init appearance */
    scheme = ecalloc(LENGTH(colors), sizeof(Clr *));
    for (i = 0; i < LENGTH(colors); i++)
      scheme[i] = drw_scm_create(drw, colors[i], 3);
    /* init bars */
    updatebars();
    updatestatus();
    /* supporting window for NetWMCheck */
    wmcheckwin = XCreateSimpleWindow(dpy, root, 0, 0, 1, 1, 0, 0, 0);
    XChangeProperty(dpy, wmcheckwin, netatom[NetWMCheck], XA_WINDOW, 32,
      PropModeReplace, (unsigned char *) &wmcheckwin, 1);
    XChangeProperty(dpy, wmcheckwin, netatom[NetWMName], utf8string, 8,
      PropModeReplace, (unsigned char *) "dwm", 3);
    XChangeProperty(dpy, root, netatom[NetWMCheck], XA_WINDOW, 32,
      PropModeReplace, (unsigned char *) &wmcheckwin, 1);
    /* EWMH support per view */
    XChangeProperty(dpy, root, netatom[NetSupported], XA_ATOM, 32,
      PropModeReplace, (unsigned char *) netatom, NetLast);
    XDeleteProperty(dpy, root, netatom[NetClientList]);
    /* select events */
    wa.cursor = cursor[CurNormal]->cursor;
    wa.event_mask = SubstructureRedirectMask|SubstructureNotifyMask
      |ButtonPressMask|PointerMotionMask|EnterWindowMask
      |LeaveWindowMask|StructureNotifyMask|PropertyChangeMask;
    XChangeWindowAttributes(dpy, root, CWEventMask|CWCursor, &wa);
    XSelectInput(dpy, root, wa.event_mask);
    grabkeys();
    focus(NULL);
  }
  
  
  void
  seturgent(Client *c, int urg)
  {
    XWMHints *wmh;
  
    c->isurgent = urg;
    if (!(wmh = XGetWMHints(dpy, c->win)))
      return;
    wmh->flags = urg ? (wmh->flags | XUrgencyHint) : (wmh->flags & ~XUrgencyHint);
    XSetWMHints(dpy, c->win, wmh);
    XFree(wmh);
  }
  
  void
  showhide(Client *c)
  {
    if (!c)
      return;
    if (ISVISIBLE(c)) {
      /* show clients top down */
      XMoveWindow(dpy, c->win, c->x, c->y);
      if ((!c->mon->lt[c->mon->sellt]->arrange || c->isfloating) && !c->isfullscreen)
        resize(c, c->x, c->y, c->w, c->h, 0);
      showhide(c->snext);
    } else {
      /* hide clients bottom up */
      showhide(c->snext);
      XMoveWindow(dpy, c->win, WIDTH(c) * -2, c->y);
    }
  }
  
  void
  sigchld(int unused)
  {
    if (signal(SIGCHLD, sigchld) == SIG_ERR)
      die("can't install SIGCHLD handler:");
    while (0 < waitpid(-1, NULL, WNOHANG));
  }
  
  void
  spawn(const Arg *arg)
  {
    if (arg->v == dmenucmd)
      dmenumon[0] = '0' + selmon->num;
    if (fork() == 0) {
      if (dpy)
        close(ConnectionNumber(dpy));
      setsid();
      execvp(((char **)arg->v)[0], (char **)arg->v);
      fprintf(stderr, "dwm: execvp %s", ((char **)arg->v)[0]);
      perror(" failed");
      exit(EXIT_SUCCESS);
    }
  }
  
  void
  tag(const Arg *arg)
  {
    if (selmon->sel && arg->ui & TAGMASK) {
      selmon->sel->tags = arg->ui & TAGMASK;
      focus(NULL);
      arrange(selmon);
    }
  }
  
  void
  tagmon(const Arg *arg)
  {
    if (!selmon->sel || !mons->next)
      return;
    sendmon(selmon->sel, dirtomon(arg->i));
  }
  
  void
  tile(Monitor *m)
  {
    unsigned int i, n, h, mw, my, ty;
    Client *c;
  
    for (n = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next), n++);
    if (n == 0)
      return;
  
    if (n > m->nmaster)
      mw = m->nmaster ? m->ww * m->mfact : 0;
    else
      mw = m->ww;
    for (i = my = ty = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next), i++)
      if (i < m->nmaster) {
        h = (m->wh - my) / (MIN(n, m->nmaster) - i);
        resize(c, m->wx, m->wy + my, mw - (2*c->bw), h - (2*c->bw), 0);
        if (my + HEIGHT(c) < m->wh)
          my += HEIGHT(c);
      } else {
        h = (m->wh - ty) / (n - i);
        resize(c, m->wx + mw, m->wy + ty, m->ww - mw - (2*c->bw), h - (2*c->bw), 0);
        if (ty + HEIGHT(c) < m->wh)
          ty += HEIGHT(c);
      }
  }
  
  void
  togglebar(const Arg *arg)
  {
    selmon->showbar = !selmon->showbar;
    updatebarpos(selmon);
    XMoveResizeWindow(dpy, selmon->barwin, selmon->wx, selmon->by, selmon->ww, bh);
    arrange(selmon);
  }
  
  void
  togglefloating(const Arg *arg)
  {
    if (!selmon->sel)
      return;
    if (selmon->sel->isfullscreen) /* no support for fullscreen windows */
      return;
    selmon->sel->isfloating = !selmon->sel->isfloating || selmon->sel->isfixed;
    if (selmon->sel->isfloating)
      resize(selmon->sel, selmon->sel->x, selmon->sel->y,
        selmon->sel->w, selmon->sel->h, 0);
    arrange(selmon);
  }
  
  void
  toggletag(const Arg *arg)
  {
    unsigned int newtags;
  
    if (!selmon->sel)
      return;
    newtags = selmon->sel->tags ^ (arg->ui & TAGMASK);
    if (newtags) {
      selmon->sel->tags = newtags;
      focus(NULL);
      arrange(selmon);
    }
  }
  
  void
  toggleview(const Arg *arg)
  {
    unsigned int newtagset = selmon->tagset[selmon->seltags] ^ (arg->ui & TAGMASK);
  
    if (newtagset) {
      selmon->tagset[selmon->seltags] = newtagset;
      focus(NULL);
      arrange(selmon);
    }
  }
  
  void
  unfocus(Client *c, int setfocus)
  {
    if (!c)
      return;
    grabbuttons(c, 0);
    XSetWindowBorder(dpy, c->win, scheme[SchemeNorm][ColBorder].pixel);
    if (setfocus) {
      XSetInputFocus(dpy, root, RevertToPointerRoot, CurrentTime);
      XDeleteProperty(dpy, root, netatom[NetActiveWindow]);
    }
  }
  
  void
  unmanage(Client *c, int destroyed)
  {
    Monitor *m = c->mon;
    XWindowChanges wc;
  
    detach(c);
    detachstack(c);
    if (!destroyed) {
      wc.border_width = c->oldbw;
      XGrabServer(dpy); /* avoid race conditions */
      XSetErrorHandler(xerrordummy);
      XConfigureWindow(dpy, c->win, CWBorderWidth, &wc); /* restore border */
      XUngrabButton(dpy, AnyButton, AnyModifier, c->win);
      setclientstate(c, WithdrawnState);
      XSync(dpy, False);
      XSetErrorHandler(xerror);
      XUngrabServer(dpy);
    }
    free(c);
    focus(NULL);
    updateclientlist();
    arrange(m);
  }
  
  void
  unmapnotify(XEvent *e)
  {
    Client *c;
    XUnmapEvent *ev = &e->xunmap;
  
    if ((c = wintoclient(ev->window))) {
      if (ev->send_event)
        setclientstate(c, WithdrawnState);
      else
        unmanage(c, 0);
    }
  }
  
  void
  updatebars(void)
  {
    Monitor *m;
    XSetWindowAttributes wa = {
      .override_redirect = True,
      .background_pixmap = ParentRelative,
      .event_mask = ButtonPressMask|ExposureMask
    };
    XClassHint ch = {"dwm", "dwm"};
    for (m = mons; m; m = m->next) {
      if (m->barwin)
        continue;
      m->barwin = XCreateWindow(dpy, root, m->wx, m->by, m->ww, bh, 0, DefaultDepth(dpy, screen),
          CopyFromParent, DefaultVisual(dpy, screen),
          CWOverrideRedirect|CWBackPixmap|CWEventMask, &wa);
      XDefineCursor(dpy, m->barwin, cursor[CurNormal]->cursor);
      XMapRaised(dpy, m->barwin);
      XSetClassHint(dpy, m->barwin, &ch);
    }
  }
  
  void
  updatebarpos(Monitor *m)
  {
    m->wy = m->my;
    m->wh = m->mh;
    if (m->showbar) {
      m->wh -= bh;
      m->by = m->topbar ? m->wy : m->wy + m->wh;
      m->wy = m->topbar ? m->wy + bh : m->wy;
    } else
      m->by = -bh;
  }
  
  void
  updateclientlist()
  {
    Client *c;
    Monitor *m;
  
    XDeleteProperty(dpy, root, netatom[NetClientList]);
    for (m = mons; m; m = m->next)
      for (c = m->clients; c; c = c->next)
        XChangeProperty(dpy, root, netatom[NetClientList],
          XA_WINDOW, 32, PropModeAppend,
          (unsigned char *) &(c->win), 1);
  }
  
  int
  updategeom(void)
  {
    int dirty = 0;
  
  #ifdef XINERAMA
    if (XineramaIsActive(dpy)) {
      int i, j, n, nn;
      Client *c;
      Monitor *m;
      XineramaScreenInfo *info = XineramaQueryScreens(dpy, &nn);
      XineramaScreenInfo *unique = NULL;
  
      for (n = 0, m = mons; m; m = m->next, n++);
      /* only consider unique geometries as separate screens */
      unique = ecalloc(nn, sizeof(XineramaScreenInfo));
      for (i = 0, j = 0; i < nn; i++)
        if (isuniquegeom(unique, j, &info[i]))
          memcpy(&unique[j++], &info[i], sizeof(XineramaScreenInfo));
      XFree(info);
      nn = j;
      if (n <= nn) { /* new monitors available */
        for (i = 0; i < (nn - n); i++) {
          for (m = mons; m && m->next; m = m->next);
          if (m)
            m->next = createmon();
          else
            mons = createmon();
        }
        for (i = 0, m = mons; i < nn && m; m = m->next, i++)
          if (i >= n
          || unique[i].x_org != m->mx || unique[i].y_org != m->my
          || unique[i].width != m->mw || unique[i].height != m->mh)
          {
            dirty = 1;
            m->num = i;
            m->mx = m->wx = unique[i].x_org;
            m->my = m->wy = unique[i].y_org;
            m->mw = m->ww = unique[i].width;
            m->mh = m->wh = unique[i].height;
            updatebarpos(m);
          }
      } else { /* less monitors available nn < n */
        for (i = nn; i < n; i++) {
          for (m = mons; m && m->next; m = m->next);
          while ((c = m->clients)) {
            dirty = 1;
            m->clients = c->next;
            detachstack(c);
            c->mon = mons;
            attach(c);
            attachstack(c);
          }
          if (m == selmon)
            selmon = mons;
          cleanupmon(m);
        }
      }
      free(unique);
    } else
  #endif /* XINERAMA */
    { /* default monitor setup */
      if (!mons)
        mons = createmon();
      if (mons->mw != sw || mons->mh != sh) {
        dirty = 1;
        mons->mw = mons->ww = sw;
        mons->mh = mons->wh = sh;
        updatebarpos(mons);
      }
    }
    if (dirty) {
      selmon = mons;
      selmon = wintomon(root);
    }
    return dirty;
  }
  
  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
  updatesizehints(Client *c)
  {
    long msize;
    XSizeHints size;
  
    if (!XGetWMNormalHints(dpy, c->win, &size, &msize))
      /* size is uninitialized, ensure that size.flags aren't used */
      size.flags = PSize;
    if (size.flags & PBaseSize) {
      c->basew = size.base_width;
      c->baseh = size.base_height;
    } else if (size.flags & PMinSize) {
      c->basew = size.min_width;
      c->baseh = size.min_height;
    } else
      c->basew = c->baseh = 0;
    if (size.flags & PResizeInc) {
      c->incw = size.width_inc;
      c->inch = size.height_inc;
    } else
      c->incw = c->inch = 0;
    if (size.flags & PMaxSize) {
      c->maxw = size.max_width;
      c->maxh = size.max_height;
    } else
      c->maxw = c->maxh = 0;
    if (size.flags & PMinSize) {
      c->minw = size.min_width;
      c->minh = size.min_height;
    } else if (size.flags & PBaseSize) {
      c->minw = size.base_width;
      c->minh = size.base_height;
    } else
      c->minw = c->minh = 0;
    if (size.flags & PAspect) {
      c->mina = (float)size.min_aspect.y / size.min_aspect.x;
      c->maxa = (float)size.max_aspect.x / size.max_aspect.y;
    } else
      c->maxa = c->mina = 0.0;
    c->isfixed = (c->maxw && c->maxh && c->maxw == c->minw && c->maxh == c->minh);
  }
  
  void
  updatestatus(void)
  {
    if (!gettextprop(root, XA_WM_NAME, stext, sizeof(stext)))
      strcpy(stext, "dwm-"VERSION);
    drawbar(selmon);
  }
  
  void
  updatetitle(Client *c)
  {
    if (!gettextprop(c->win, netatom[NetWMName], c->name, sizeof c->name))
      gettextprop(c->win, XA_WM_NAME, c->name, sizeof c->name);
    if (c->name[0] == '\0') /* hack to mark broken clients */
      strcpy(c->name, broken);
  }
  
  void
  updatewindowtype(Client *c)
  {
    Atom state = getatomprop(c, netatom[NetWMState]);
    Atom wtype = getatomprop(c, netatom[NetWMWindowType]);
  
    if (state == netatom[NetWMFullscreen])
      setfullscreen(c, 1);
    if (wtype == netatom[NetWMWindowTypeDialog])
      c->isfloating = 1;
  }
  
  void
  updatewmhints(Client *c)
  {
    XWMHints *wmh;
  
    if ((wmh = XGetWMHints(dpy, c->win))) {
      if (c == selmon->sel && wmh->flags & XUrgencyHint) {
        wmh->flags &= ~XUrgencyHint;
        XSetWMHints(dpy, c->win, wmh);
      } else
        c->isurgent = (wmh->flags & XUrgencyHint) ? 1 : 0;
      if (wmh->flags & InputHint)
        c->neverfocus = !wmh->input;
      else
        c->neverfocus = 0;
      XFree(wmh);
    }
  }
  
  void
  view(const Arg *arg)
  {
    if ((arg->ui & TAGMASK) == selmon->tagset[selmon->seltags])
      return;
    selmon->seltags ^= 1; /* toggle sel tagset */
    if (arg->ui & TAGMASK)
      selmon->tagset[selmon->seltags] = arg->ui & TAGMASK;
    focus(NULL);
    arrange(selmon);
  }
  
  Client *
  wintoclient(Window w)
  {
    Client *c;
    Monitor *m;
  
    for (m = mons; m; m = m->next)
      for (c = m->clients; c; c = c->next)
        if (c->win == w)
          return c;
    return NULL;
  }
  
  Monitor *
  wintomon(Window w)
  {
    int x, y;
    Client *c;
    Monitor *m;
  
    if (w == root && getrootptr(&x, &y))
      return recttomon(x, y, 1, 1);
    for (m = mons; m; m = m->next)
      if (w == m->barwin)
        return m;
    if ((c = wintoclient(w)))
      return c->mon;
    return selmon;
  }
  
  /* 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, "dwm: fatal error: request code=%d, error code=%d\n",
      ee->request_code, ee->error_code);
    return xerrorxlib(dpy, ee); /* may call exit */
  }
  
  int
  xerrordummy(Display *dpy, XErrorEvent *ee)
  {
    return 0;
  }
  
  /* Startup Error handler to check if another window manager
   * is already running. */
  int
  xerrorstart(Display *dpy, XErrorEvent *ee)
  {
    die("dwm: another window manager is already running");
    return -1;
  }
  
  void
  zoom(const Arg *arg)
  {
    Client *c = selmon->sel;
  
    if (!selmon->lt[selmon->sellt]->arrange
    || (selmon->sel && selmon->sel->isfloating))
      return;
    if (c == nexttiled(selmon->clients))
      if (!c || !(c = nexttiled(c->next)))
        return;
    pop(c);
  }
  
  int
  main(int argc, char *argv[])
  {
    if (argc == 2 && !strcmp("-v", argv[1]))
      die("dwm-"VERSION);
    else if (argc != 1)
      die("usage: dwm [-v]");
    if (!setlocale(LC_CTYPE, "") || !XSupportsLocale())
      fputs("warning: no locale support\n", stderr);
    if (!(dpy = XOpenDisplay(NULL)))
      die("dwm: cannot open display");
    checkotherwm();
    setup();
  #ifdef __OpenBSD__
    if (pledge("stdio rpath proc exec", NULL) == -1)
      die("pledge");
  #endif /* __OpenBSD__ */
    scan();
    run();
    cleanup();
    XCloseDisplay(dpy);
    return EXIT_SUCCESS;
  }
  