dwm.c

// -*- indent-tabs-mode: t; -*-

/* 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 <X11/Xlib-xcb.h>
#include <xcb/res.h>
#include <pango/pango.h>
#include <pango/pangoxft.h>
#include <time.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 ISVISIBLEONTAG(C, T)    ((C->tags & T))
#define ISVISIBLE(C)            ISVISIBLEONTAG(C, 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 + gappx)
#define HEIGHT(X)               ((X)->h + 2 * (X)->bw + gappx)
#define TAGMASK                 ((1 << LENGTH(tags)) - 1)
#define TEXTW(X)                (drw_text(drw, 0, 0, 0, 0, (X), 0) + drw->fonts[0]->h)

/* enums */
enum { CurNormal, CurResize, CurMove, CurLast }; /* cursor */
enum { SchemeNorm, SchemeSel, SchemeLast }; /* color schemes */
enum { NetSupported, NetWMName, NetWMState,
       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;
    float cfact;
    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, isterminal, noswallow;
    pid_t pid;
    Client *next;
    Client *snext;
    Client *swallowing;
    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 isterminal;
    int noswallow;
    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 attachaside(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 clearurgent(Client *c);
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 pid_t getparentprocess(pid_t p);
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 int isdescprocess(pid_t p, pid_t c);
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 *nexttagged(Client *c);
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 runorraise(const Arg *arg);
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 setcfact(const Arg *arg);
static void setmfact(const Arg *arg);
static void setup(void);
static void showhide(Client *c);
static void sigchld(int unused);
static void spawn(const Arg *arg);
static Client *swallowingclient(Window w);
static void tag(const Arg *arg);
static void tagmon(const Arg *arg);
static Client *termforwin(const Client *c);
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 int updategeom(void);
static void updatebarpos(Monitor *m);
static void updatebars(void);
static void updateclientlist(void);
static void updatenumlockmask(void);
static void updatesizehints(Client *c);
static void updatestatus(void);
static void updatewindowtype(Client *c);
static void updatetitle(Client *c);
static void updatewmhints(Client *c);
static void view(const Arg *arg);
static pid_t winpid(Window w);
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);

/* user defined functions */
static void banishpointer();
static void grid(Monitor *m);
static void htile(Monitor *m);

/* variables */
static const char broken[] = "broken";
static char stext[1024];
static int screen;
static int sw, sh;           /* X display screen geometry width, height */
static int bh, blw = 0;      /* bar geometry */
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 ClrScheme scheme[SchemeLast];
static Display *dpy;
static Drw *drw;
static Monitor *mons, *selmon;
static Window root;
static int gap;
static xcb_connection_t *xcon;

/* 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->isterminal = r->isterminal;
            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
attachaside(Client *c) {
   Client *at = nexttagged(c);
   if(!at) {
         attach(c);
         return;
   }
   c->next = at->next;
   at->next = c;
}

void
attachstack(Client *c)
{
    c->snext = c->mon->stack;
    c->mon->stack = c;
}

void
swallow(Client *p, Client *c)
{
    if (c->noswallow || c->isterminal)
        return;

    detach(c);
    detachstack(c);

    setclientstate(c, WithdrawnState);
    XUnmapWindow(dpy, p->win);

    p->swallowing = c;
    c->mon = p->mon;

    Window w = p->win;
    p->win = c->win;
    c->win = w;
    updatetitle(p);
    arrange(p->mon);
    configure(p);
    updateclientlist();
}

void
unswallow(Client *c)
{
    c->win = c->swallowing->win;

    free(c->swallowing);
    c->swallowing = NULL;

    updatetitle(c);
    arrange(c->mon);
    XMapWindow(dpy, c->win);
    XMoveResizeWindow(dpy, c->win, c->x, c->y, c->w, c->h);
    configure(c);
    setclientstate(c, NormalState);
}

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 - TEXTW(stext))
            click = ClkStatusText;
        else
            click = ClkWinTitle;
    } else if ((c = wintoclient(ev->window))) {
        focus(c);
        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); // XXX - unmanage swallowing windows too
    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 < SchemeLast; i++) {
        drw_clr_free(scheme[i].border);
        drw_clr_free(scheme[i].bg);
        drw_clr_free(scheme[i].fg);
    }
    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
clearurgent(Client *c)
{
    XWMHints *wmh;

    c->isurgent = 0;
    if (!(wmh = XGetWMHints(dpy, c->win)))
        return;
    wmh->flags &= ~XUrgencyHint;
    XSetWMHints(dpy, c->win, wmh);
    XFree(wmh);
}

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 (!ISVISIBLE(c)) {
            c->mon->seltags ^= 1;
            c->mon->tagset[c->mon->seltags] = c->tags;
        }
        pop(c);
    }
}

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;
    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)
                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);

    else if ((c = swallowingclient(ev->window)))
        unmanage(c->swallowing, 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 dx, x, xx, w, clockw;
    time_t current;
    char clock[38];
    unsigned int i, occ = 0, urg = 0;
    Client *c;

    dx = (drw->fonts[0]->ascent + drw->fonts[0]->descent + 2) / 4;

    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, m->tagset[m->seltags] & 1 << i ? &scheme[SchemeSel] : &scheme[SchemeNorm]);
        drw_text(drw, x, 0, w, bh, tags[i], urg & 1 << i);
        drw_rect(drw, x + 1, 1, dx, dx, m == selmon && selmon->sel && selmon->sel->tags & 1 << i,
                   occ & 1 << i, urg & 1 << i);
        x += w;
    }
    w = blw = TEXTW(m->ltsymbol);
    drw_setscheme(drw, &scheme[SchemeNorm]);
    drw_text(drw, x, 0, w, bh, m->ltsymbol, 0);
    x += w;
    xx = x;
    if (m == selmon) { /* status is only drawn on selected monitor */
        w = TEXTW(stext);
        x = m->ww - w;
        if (x < xx) {
            x = xx;
            w = m->ww - xx;
        }
        drw_text(drw, x, 0, w, bh, stext, 0);
    } else
        x = m->ww;
    if ((w = x - xx) > bh) {
        x = xx;

        time(&current);
        strftime(clock, 38, clock_fmt, localtime(&current));
        clockw = TEXTW(clock);

        drw_text(drw, x, 0, w, bh, "", 0);
        w = MIN(w, clockw);
        x = MAX(x, (m->mw / 2) - (clockw / 2));
        drw_text(drw, x, 0, w, bh, clock, 0);

    }
    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);
    /* was if (selmon->sel) */
    if (selmon->sel && selmon->sel != c)
        unfocus(selmon->sel, 0);
    if (c) {
        if (c->mon != selmon)
            selmon = c->mon;
        if (c->isurgent)
            clearurgent(c);
        detachstack(c);
        attachstack(c);
        grabbuttons(c, 1);
        XSetWindowBorder(dpy, c->win, scheme[SchemeSel].border->pix);
        setfocus(c);
    } else {
        XSetInputFocus(dpy, root, RevertToPointerRoot, CurrentTime);
        XDeleteProperty(dpy, root, netatom[NetActiveWindow]);
    }
    selmon->sel = c;
    drawbars();
}

/* there are some broken focus acquiring clients */
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); /* s/1/0/ fixes input focus issues
                    in gedit and anjuta */
    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';
    XGetTextProperty(dpy, w, &name, atom);
    if (!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) {
            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);
        } else
            XGrabButton(dpy, AnyButton, AnyModifier, 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, *term = NULL;
    Window trans = None;
    XWindowChanges wc;

    c = ecalloc(1, sizeof(Client));
    c->win = w;
    c->pid = winpid(w);
    updatetitle(c);
    if (XGetTransientForHint(dpy, w, &trans) && (t = wintoclient(trans))) {
        c->mon = t->mon;
        c->tags = t->tags;
    } else {
        c->mon = selmon;
        applyrules(c);
        term = termforwin(c);
    }

    /* 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;
    c->cfact = 1.0;

    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].border->pix);
    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);
    attachaside(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);
    if (term)
        swallow(term, c);
    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 (nx >= selmon->wx && nx <= selmon->wx + selmon->ww
            && ny >= selmon->wy && ny <= selmon->wy + selmon->wh) {
                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 *
nexttagged(Client *c) {
    Client *walked = c->mon->clients;
    for(;
        walked && (walked->isfloating || !ISVISIBLEONTAG(walked, c->tags));
        walked = walked->next
    );
    return walked;
}

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;
    unsigned int n;
    unsigned int gapoffset;
    unsigned int gapincr;
    Client *nbc;

    wc.border_width = c->bw;
    gap = c->isfloating ? 0 : gappx;

    /* Get number of clients for the selected monitor */
    for (n = 0, nbc = nexttiled(selmon->clients); nbc; nbc = nexttiled(nbc->next), n++);

    /* Do nothing if layout is floating */
    if (c->isfloating || selmon->lt[selmon->sellt]->arrange == NULL) {
        gapincr = gapoffset = 0;
    } else {
        /* Remove border and gap if layout is monocle */
        if (selmon->lt[selmon->sellt]->arrange == monocle) {
            gapoffset = 0;
            gapincr = -2 * borderpx;
            wc.border_width = 0;
        } else if (n == 1) {
          gapoffset = gappx;
          gapincr = gappx;
        } else {
          gapoffset = gappx;
          gapincr = 2 * gappx;
        }
    }

    c->oldx = c->x; c->x = wc.x = x + (gapoffset/2);
    c->oldy = c->y; c->y = wc.y = y + (gapoffset/2);
    c->oldw = c->w; c->w = wc.width = w - gapincr;
    c->oldh = c->h; c->h = wc.height = h - gapincr;

    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
runorraise(const Arg *arg)
{
    char *app = ((char **)arg->v)[4];
    Arg a = { .ui = ~0 };
    Monitor *mon;
    Client *c;
    XClassHint hint = { NULL, NULL };
    /* Tries to find the client */
    for (mon = mons; mon; mon = mon->next) {
        for (c = mon->clients; c; c = c->next) {
            XGetClassHint(dpy, c->win, &hint);
            if (hint.res_class && strcmp(app, hint.res_class) == 0) {
                a.ui = c->tags;
                view(&a);
                focus(c);
                XRaiseWindow(dpy, c->win);
                return;
            }
        }
    }

    /* Client not found: spawn it */
    spawn(arg);
}

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 */
    attachaside(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);
}

void
setcfact(const Arg *arg) {
    float f;
    Client *c;

    c = selmon->sel;

    if(!arg || !c || !selmon->lt[selmon->sellt]->arrange)
        return;
    f = arg->f + c->cfact;
    if(arg->f == 0.0)
        f = 1.0;
    else if(f < 0.25 || f > 4.0)
        return;
    c->cfact = f;
    arrange(selmon);
}

/* arg > 1.0 will set mfact absolutly */
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 < 0.1 || f > 0.9)
        return;
    selmon->mfact = f;
    arrange(selmon);
}

void
setup(void)
{
    XSetWindowAttributes wa;

    /* 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);
    drw_load_fonts(drw, fonts, LENGTH(fonts));
    if (!drw->fontcount)
        die("no fonts could be loaded.\n");
    bh = drw->fonts[0]->h + 8;
    updategeom();
    /* init atoms */
    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[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[SchemeNorm].border = drw_clr_create(drw, normbordercolor);
    scheme[SchemeNorm].bg = drw_clr_create(drw, normbgcolor);
    scheme[SchemeNorm].fg = drw_clr_create(drw, normfgcolor);
    scheme[SchemeSel].border = drw_clr_create(drw, selbordercolor);
    scheme[SchemeSel].bg = drw_clr_create(drw, selbgcolor);
    scheme[SchemeSel].fg = drw_clr_create(drw, selfgcolor);
    /* init bars */
    updatebars();
    updatestatus();
    /* EWMH support per view */
    XChangeProperty(dpy, root, netatom[NetSupported], XA_ATOM, 32,
            PropModeReplace, (unsigned char *) netatom, NetLast);
    XDeleteProperty(dpy, root, netatom[NetClientList]);
    /* select for 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
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;
    float mfacts = 0, sfacts = 0;
    Client *c;
    static int gap = 0;

    for(n = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next), n++) {
        if(n < m->nmaster)
            mfacts += c->cfact;
        else
            sfacts += c->cfact;
    }

    if(n == 0) {
        return;
    } else if(n == 1) {
        monocle(m);
        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) * (c->cfact / mfacts) + gappx;
            resize(c, m->wx, m->wy + my, mw - (2*c->bw), h - (2*c->bw), False);
            my += HEIGHT(c) + gap;
            mfacts -= c->cfact;
        }
        else {
            h = (m->wh - ty) * (c->cfact / sfacts) + gappx;
            resize(c, m->wx + mw - gappx, m->wy + ty, m->ww - mw - (2*c->bw) + 2*gappx, h - (2*c->bw), False);
            ty += HEIGHT(c) + gap;
            sfacts -= c->cfact;
        }
}

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].border->pix);
    if (setfocus) {
        XSetInputFocus(dpy, root, RevertToPointerRoot, CurrentTime);
        XDeleteProperty(dpy, root, netatom[NetActiveWindow]);
    }
}

void
unmanage(Client *c, int destroyed)
{
    Monitor *m = c->mon;
    XWindowChanges wc;

    if (c->swallowing) {
        unswallow(c);
        return;
    }

    Client *s = swallowingclient(c->win);
    if (s) {
        free(s->swallowing);
        s->swallowing = NULL;
        arrange(m);
        focus(NULL);
        return;
    }

    /* The server grab construct avoids race conditions. */
    detach(c);
    detachstack(c);
    if (!destroyed) {
        wc.border_width = c->oldbw;
        XGrabServer(dpy);
        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);

    if (!s) {
        arrange(m);
        focus(NULL);
        updateclientlist();
    }
}

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
    };
    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);
    }
}

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) {
            for (i = 0; i < (nn - n); i++) { /* new monitors available */
                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 (m->clients) {
                    dirty = 1;
                    c = m->clients;
                    m->clients = c->next;
                    detachstack(c);
                    c->mon = mons;
                    attachaside(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->minw && c->maxh && c->minh
                 && c->maxw == c->minw && c->maxh == c->minh);
}

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
updatestatus(void)
{
    if (!gettextprop(root, XA_WM_NAME, stext, sizeof(stext)))
        strcpy(stext, "dwm-"VERSION);
    drawbar(selmon);
}

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);
}

pid_t
winpid(Window w)
{
    pid_t result = 0;

    xcb_res_client_id_spec_t spec = {0};
    spec.client = w;
    spec.mask = XCB_RES_CLIENT_ID_MASK_LOCAL_CLIENT_PID;

    xcb_generic_error_t *e = NULL;
    xcb_res_query_client_ids_cookie_t c = xcb_res_query_client_ids(xcon, 1, &spec);
    xcb_res_query_client_ids_reply_t *r = xcb_res_query_client_ids_reply(xcon, c, &e);

    if (!r)
        return (pid_t)0;

    xcb_res_client_id_value_iterator_t i = xcb_res_query_client_ids_ids_iterator(r);
    for (; i.rem; xcb_res_client_id_value_next(&i)) {
        spec = i.data->spec;
        if (spec.mask & XCB_RES_CLIENT_ID_MASK_LOCAL_CLIENT_PID) {
            uint32_t *t = xcb_res_client_id_value_value(i.data);
            result = *t;
            break;
        }
    }

    free(r);

    if (result == (pid_t)-1)
        result = 0;
    return result;
}

pid_t
getparentprocess(pid_t p)
{
    unsigned int v = 0;

#ifdef __linux__
    FILE *f;
    char buf[256];
    snprintf(buf, sizeof(buf) - 1, "/proc/%u/stat", (unsigned)p);

    if (!(f = fopen(buf, "r")))
        return 0;

    fscanf(f, "%*u %*s %*c %u", &v);
    fclose(f);
#endif /* __linux__ */

    return (pid_t)v;
}

int
isdescprocess(pid_t p, pid_t c)
{
    while (p != c && c != 0)
        c = getparentprocess(c);

    return (int)c;
}

Client *
termforwin(const Client *w)
{
    Client *c;
    Monitor *m;

    if (!w->pid || w->isterminal)
        return NULL;

    for (m = mons; m; m = m->next) {
        for (c = m->clients; c; c = c->next) {
            if (c->isterminal && !c->swallowing && c->pid && isdescprocess(c->pid, w->pid))
                return c;
        }
    }

    return NULL;
}

Client *
swallowingclient(Window w)
{
    Client *c;
    Monitor *m;

    for (m = mons; m; m = m->next) {
        for (c = m->clients; c; c = c->next) {
            if (c->swallowing && c->swallowing->win == w)
                return c;
        }
    }

    return NULL;
}

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\n");
    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 "\n");
    else if (argc != 1)
        die("usage: dwm [-v]\n");
    if (!setlocale(LC_CTYPE, "") || !XSupportsLocale())
        fputs("warning: no locale support\n", stderr);
    if (!(dpy = XOpenDisplay(NULL)))
        die("dwm: cannot open display\n");
    if (!(xcon = XGetXCBConnection(dpy)))
        die("dwm: cannot get xcb connection\n");
    checkotherwm();
    setup();
    scan();
    run();
    cleanup();
    XCloseDisplay(dpy);
    return EXIT_SUCCESS;
}

void
banishpointer(const Arg *arg) {
    XWarpPointer(dpy, None, root, 0, 0, 0, 0, selmon->ww - borderpx,
            selmon->wh + bh - borderpx);
    XFlush(dpy);
}


void
htile(Monitor *m) {
    unsigned int i, n, w, mh, mx, tx;
    Client *c;

    for(n = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next), n++);
    if(n == 0)
        return;

    if(n > m->nmaster)
        mh = m->nmaster ? m->wh * m->mfact : 0;
    else
        mh = m->wh;

    for(i = mx = tx = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next), i++)

        if(i < m->nmaster) {
            w = (m->ww - mx) / (MIN(n, m->nmaster) - i);
            resize(c, m->wx + mx, m->wy, w - (2*c->bw) + gappx, mh - (2*c->bw), False);
            mx += WIDTH(c);
        } else {
            w = (m->ww - tx) / (n - i);
            resize(c, m->wx + tx, m->wy + mh - gappx, w - (2*c->bw) + gappx,
                    m->wh - mh - (2*c->bw) + 2*gappx, False);
            tx += WIDTH(c);
        }
}

void
grid(Monitor *m) {
    unsigned int i, n, cx, cy, cw, ch, aw, ah, cols, rows;
    Client *c;

    for(n = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next))
        n++;

    /* grid dimensions */
    for(rows = 0; rows <= n/2; rows++)
        if(rows*rows >= n)
            break;
    cols = (rows && (rows - 1) * rows >= n) ? rows - 1 : rows;

    /* window geoms (cell height/width) */
    ch = m->wh / (rows ? rows : 1);
    cw = m->ww / (cols ? cols : 1);
    for(i = 0, c = nexttiled(m->clients); c; c = nexttiled(c->next)) {
        cx = m->wx + (i / rows) * cw;
        cy = m->wy + (i % rows) * ch;
        /* adjust height/width of last row/column's windows */
        ah = ((i + 1) % rows == 0) ? m->wh - ch * rows : 0;
        aw = (i >= rows * (cols - 1)) ? m->ww - cw * cols : 0;
        resize(c, cx, cy, cw - 2 * c->bw + aw + gappx, ch - 2 * c->bw + ah + gappx, False);
        i++;
    }
}