/* 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 <stdarg.h>
#include <signal.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 */

/* macros */
#define BUTTONMASK              (ButtonPressMask|ButtonReleaseMask)
#define CLEANMASK(mask)         (mask & ~(numlockmask|LockMask))
#define INRECT(X,Y,RX,RY,RW,RH) ((X) >= (RX) && (X) < (RX) + (RW) && (Y) >= (RY) && (Y) < (RY) + (RH))
#define ISVISIBLE(C)            ((C->tags & C->mon->tagset[C->mon->seltags]))
#define LENGTH(X)               (sizeof X / sizeof X[0])
#define MAX(A, B)               ((A) > (B) ? (A) : (B))
#define MIN(A, B)               ((A) < (B) ? (A) : (B))
#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)                (textnw(X, strlen(X)) + dc.font.height)

/* enums */
enum { CurNormal, CurResize, CurMove, CurLast };        /* cursor */
enum { ColBorder, ColFG, ColBG, ColLast };              /* color */
enum { NetSupported, NetWMName, NetWMState,
       NetWMFullscreen, NetLast
     };                      /* EWMH atoms */
enum { WMProtocols, WMDelete, WMState, 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;
      Bool isfixed, isfloating, isurgent, oldstate;
      Client *next;
      Client *snext;
      Monitor *mon;
      Window win;
};

typedef struct {
      int x, y, w, h;
      unsigned long norm[ColLast];
      unsigned long sel[ColLast];
      Drawable drawable;
      GC gc;

      struct {
            int ascent;
            int descent;
            int height;
            XFontSet set;
            XFontStruct *xfont;
      } font;
} DC; /* draw context */

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 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];
      Bool showbar;
      Bool 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;
      Bool isfloating;
      int monitor;
} Rule;

/* function declarations */
static void applyrules(Client *c);
static Bool applysizehints(Client *c, int *x, int *y, int *w, int *h, Bool 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 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 void die(const char *errstr, ...);
static Monitor *dirtomon(int dir);
static void drawbar(Monitor *m);
static void drawbars(void);
static void drawsquare(Bool filled, Bool empty, Bool invert, unsigned long col[ColLast]);
static void drawtext(const char *text, unsigned long col[ColLast], Bool invert);
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 unsigned long getcolor(const char *colstr);
static Bool getrootptr(int *x, int *y);
static long getstate(Window w);
static Bool gettextprop(Window w, Atom atom, char *text, unsigned int size);
static void grabbuttons(Client *c, Bool focused);
static void grabkeys(void);
static void initfont(const char *fontstr);
static Bool isprotodel(Client *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 movemouse(const Arg *arg);
static Client *nexttiled(Client *c);
static Monitor *ptrtomon(int x, int y);
static void propertynotify(XEvent *e);
static void quit(const Arg *arg);
static void resize(Client *c, int x, int y, int w, int h, Bool 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 void sendmon(Client *c, Monitor *m);
static void setclientstate(Client *c, long state);
static void setlayout(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 void tag(const Arg *arg);
static void tagmon(const Arg *arg);
static int textnw(const char *text, unsigned int len);
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, Bool setfocus);
static void unmanage(Client *c, Bool destroyed);
static void unmapnotify(XEvent *e);
static Bool updategeom(void);
static void updatebarpos(Monitor *m);
static void updatebars(void);
static void updatenumlockmask(void);
static void updatesizehints(Client *c);
static void updatestatus(void);
static void updatetitle(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 (*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,
      [PropertyNotify] = propertynotify,
      [UnmapNotify] = unmapnotify
};
static Atom wmatom[WMLast], netatom[NetLast];
static Bool otherwm;
static Bool running = True;
static Cursor cursor[CurLast];
static Display *dpy;
static DC dc;
static Monitor *mons = NULL, *selmon = NULL;
static Window root;

/* 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];
};

Bool fixConky(Client * c)
{

      const char *class=0;
      XClassHint ch = { 0 };

      if (XGetClassHint(dpy, c->win, &ch)) {
            if (strstr(class, "conky")) {
                  unmanage(c,False);
                  return True;
            }
      }

      return False;
}

/* function implementations */
void
applyrules(Client *c)
{

      const char *class, *instance;
      unsigned int i;
      const Rule *r;
      Monitor *m;
      XClassHint ch = { 0 };

      /* rule matching */
      c->isfloating = c->tags = 0;

      if (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];

//	fixConky(c);
}

Bool
applysizehints(Client *c, int *x, int *y, int *w, int *h, Bool interact)
{
      Bool 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->mx + m->mw)
                  *x = m->mx + m->mw - WIDTH(c);

            if (*y > m->my + m->mh)
                  *y = m->my + m->mh - HEIGHT(c);

            if (*x + *w + 2 * c->bw < m->mx)
                  *x = m->mx;

            if (*y + *h + 2 * c->bw < m->my)
                  *y = m->my;
      }

      if (*h < bh)
            *h = bh;

      if (*w < bh)
            *w = bh;

      if (resizehints || c->isfloating) {
            /* 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 += c->basew;

            *h += c->baseh;

            *w = MAX(*w, c->minw);

            *h = MAX(*h, 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);

      focus(NULL);

      if (m)
            arrangemon(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);

      restack(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, True);
            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->wx + 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)
{
      otherwm = False;
      xerrorxlib = XSetErrorHandler(xerrorstart);
      /* this causes an error if some other window manager is running */
      XSelectInput(dpy, DefaultRootWindow(dpy), SubstructureRedirectMask);
      XSync(dpy, False);

      if (otherwm)
            die("dwm: another window manager is already running\n");

      XSetErrorHandler(xerror);

      XSync(dpy, False);
}

void
cleanup(void)
{
      Arg a = {.ui = ~0};
      Layout foo = { "", NULL };
      Monitor *m;

      view(&a);
      selmon->lt[selmon->sellt] = &foo;

      for (m = mons; m; m = m->next)
            while (m->stack)
                  unmanage(m->stack, False);

      if (dc.font.set)
            XFreeFontSet(dpy, dc.font.set);
      else
            XFreeFont(dpy, dc.font.xfont);

      XUngrabKey(dpy, AnyKey, AnyModifier, root);

      XFreePixmap(dpy, dc.drawable);

      XFreeGC(dpy, dc.gc);

      XFreeCursor(dpy, cursor[CurNormal]);

      XFreeCursor(dpy, cursor[CurResize]);

      XFreeCursor(dpy, cursor[CurMove]);

      while (mons)
            cleanupmon(mons);

      XSync(dpy, False);

      XSetInputFocus(dpy, PointerRoot, RevertToPointerRoot, CurrentTime);
}

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 = False;

      if (!(wmh = XGetWMHints(dpy, c->win)))
            return;

      wmh->flags &= ~XUrgencyHint;

      XSetWMHints(dpy, c->win, wmh);

      XFree(wmh);
}

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;

      if (ev->window == root) {
            sw = ev->width;
            sh = ev->height;

            if (updategeom()) {
                  if (dc.drawable != 0)
                        XFreePixmap(dpy, dc.drawable);

                  dc.drawable = XCreatePixmap(dpy, root, sw, bh, DefaultDepth(dpy, screen));

                  updatebars();

                  for (m = mons; m; m = m->next)
                        XMoveResizeWindow(dpy, m->barwin, m->wx, m->by, m->ww, bh);

                  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->x = m->mx + ev->x;

                  if (ev->value_mask & CWY)
                        c->y = m->my + ev->y;

                  if (ev->value_mask & CWWidth)
                        c->w = ev->width;

                  if (ev->value_mask & CWHeight)
                        c->h = ev->height;

                  if ((c->x + c->w) > m->mx + m->mw && c->isfloating)
                        c->x = m->mx + (m->mw / 2 - c->w / 2); /* center in x direction */

                  if ((c->y + c->h) > m->my + m->mh && c->isfloating)
                        c->y = m->my + (m->mh / 2 - c->h / 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;

      if (!(m = (Monitor *)calloc(1, sizeof(Monitor))))
            die("fatal: could not malloc() %u bytes\n", sizeof(Monitor));

      m->tagset[0] = m->tagset[1] = 1;

      m->mfact = mfact;

      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, True);
}

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;
      }
}

void
die(const char *errstr, ...)
{
      va_list ap;

      va_start(ap, errstr);
      vfprintf(stderr, errstr, ap);
      va_end(ap);
      exit(EXIT_FAILURE);
}

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;
      unsigned int i, occ = 0, urg = 0;
      unsigned long *col;
      Client *c;

      for (c = m->clients; c; c = c->next) {
            occ |= c->tags;

            if (c->isurgent)
                  urg |= c->tags;
      }

      dc.x = 0;

      for (i = 0; i < LENGTH(tags); i++) {
            dc.w = TEXTW(tags[i]);
            col = m->tagset[m->seltags] & 1 << i ? dc.sel : dc.norm;
            drawtext(tags[i], col, urg & 1 << i);
            drawsquare(m == selmon && selmon->sel && selmon->sel->tags & 1 << i,
                       occ & 1 << i, urg & 1 << i, col);
            dc.x += dc.w;
      }

      dc.w = blw = TEXTW(m->ltsymbol);

      drawtext(m->ltsymbol, dc.norm, False);
      dc.x += dc.w;
      x = dc.x;

      if (m == selmon) { /* status is only drawn on selected monitor */
            dc.w = TEXTW(stext);
            dc.x = m->ww - dc.w;

            if (dc.x < x) {
                  dc.x = x;
                  dc.w = m->ww - x;
            }

            drawtext(stext, dc.norm, False);
      } else
            dc.x = m->ww;

      if ((dc.w = dc.x - x) > bh) {
            dc.x = x;

            if (m->sel) {
                  col = m == selmon ? dc.sel : dc.norm;
                  drawtext(m->sel->name, col, False);
                  drawsquare(m->sel->isfixed, m->sel->isfloating, False, col);
            } else
                  drawtext(NULL, dc.norm, False);
      }

      XCopyArea(dpy, dc.drawable, m->barwin, dc.gc, 0, 0, m->ww, bh, 0, 0);

      XSync(dpy, False);
}

void
drawbars(void)
{
      Monitor *m;

      for (m = mons; m; m = m->next)
            drawbar(m);
}

void
drawsquare(Bool filled, Bool empty, Bool invert, unsigned long col[ColLast])
{
      int x;
      XGCValues gcv;
      XRectangle r = { dc.x, dc.y, dc.w, dc.h };

      gcv.foreground = col[invert ? ColBG : ColFG];
      XChangeGC(dpy, dc.gc, GCForeground, &gcv);
      x = (dc.font.ascent + dc.font.descent + 2) / 4;
      r.x = dc.x + 1;
      r.y = dc.y + 1;

      if (filled) {
            r.width = r.height = x + 1;
            XFillRectangles(dpy, dc.drawable, dc.gc, &r, 1);
      } else if (empty) {
            r.width = r.height = x;
            XDrawRectangles(dpy, dc.drawable, dc.gc, &r, 1);
      }
}

void
drawtext(const char *text, unsigned long col[ColLast], Bool invert)
{
      char buf[256];
      int i, x, y, h, len, olen;
      XRectangle r = { dc.x, dc.y, dc.w, dc.h };

      XSetForeground(dpy, dc.gc, col[invert ? ColFG : ColBG]);
      XFillRectangles(dpy, dc.drawable, dc.gc, &r, 1);

      if (!text)
            return;

      olen = strlen(text);

      h = dc.font.ascent + dc.font.descent;

      y = dc.y + (dc.h / 2) - (h / 2) + dc.font.ascent;

      x = dc.x + (h / 2);

      /* shorten text if necessary */
      for (len = MIN(olen, sizeof buf); len && textnw(text, len) > dc.w - h; len--);

      if (!len)
            return;

      memcpy(buf, text, len);

      if (len < olen)
            for (i = len; i && i > len - 3; buf[--i] = '.');

      XSetForeground(dpy, dc.gc, col[invert ? ColBG : ColFG]);

      if (dc.font.set)
            XmbDrawString(dpy, dc.drawable, dc.font.set, dc.gc, x, y, buf, len);
      else
            XDrawString(dpy, dc.drawable, dc.gc, x, y, buf, len);
}

void
enternotify(XEvent *e)
{
      Client *c;
      Monitor *m;
      XCrossingEvent *ev = &e->xcrossing;

      if ((ev->mode != NotifyNormal || ev->detail == NotifyInferior) && ev->window != root)
            return;

      if ((m = wintomon(ev->window)) && m != selmon) {
            unfocus(selmon->sel, True);
            selmon = m;
      }

      if ((c = wintoclient(ev->window)))
            focus(c);
      else
            focus(NULL);
}

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, False);

      if (c) {
            if (c->mon != selmon)
                  selmon = c->mon;

            if (c->isurgent)
                  clearurgent(c);

            detachstack(c);

            attachstack(c);

            grabbuttons(c, True);

            XSetWindowBorder(dpy, c->win, dc.sel[ColBorder]);

            XSetInputFocus(dpy, c->win, RevertToPointerRoot, CurrentTime);
      } else
            XSetInputFocus(dpy, root, RevertToPointerRoot, CurrentTime);

      selmon->sel = c;

      drawbars();
}

void
focusin(XEvent *e)   /* there are some broken focus acquiring clients */
{
      XFocusChangeEvent *ev = &e->xfocus;

      if (selmon->sel && ev->window != selmon->sel->win)
            XSetInputFocus(dpy, selmon->sel->win, RevertToPointerRoot, CurrentTime);
}

void
focusmon(const Arg *arg)
{
      Monitor *m = NULL;

      if (!mons->next)
            return;

      if ((m = dirtomon(arg->i)) == selmon)
            return;

      unfocus(selmon->sel, True);

      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);
      }
}

unsigned long
getcolor(const char *colstr)
{
      Colormap cmap = DefaultColormap(dpy, screen);
      XColor color;

      if (!XAllocNamedColor(dpy, cmap, colstr, &color, &color))
            die("error, cannot allocate color '%s'\n", colstr);

      return color.pixel;
}

Bool
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;
}

Bool
gettextprop(Window w, Atom atom, char *text, unsigned int size)
{
      char **list = NULL;
      int n;
      XTextProperty name;

      if (!text || size == 0)
            return False;

      text[0] = '\0';

      XGetTextProperty(dpy, w, &name, atom);

      if (!name.nitems)
            return False;

      if (name.encoding == XA_STRING)
            strncpy(text, (char *)name.value, size - 1);
      else {
            if (XmbTextPropertyToTextList(dpy, &name, &list, &n) >= Success && n > 0 && *list) {
                  strncpy(text, *list, size - 1);
                  XFreeStringList(list);
            }
      }

      text[size - 1] = '\0';

      XFree(name.value);
      return True;
}

void
grabbuttons(Client *c, Bool 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
initfont(const char *fontstr)
{
      char *def, **missing;
      int i, n;

      missing = NULL;
      dc.font.set = XCreateFontSet(dpy, fontstr, &missing, &n, &def);

      if (missing) {
            while (n--)
                  fprintf(stderr, "dwm: missing fontset: %s\n", missing[n]);

            XFreeStringList(missing);
      }

      if (dc.font.set) {
            XFontSetExtents *font_extents;
            XFontStruct **xfonts;
            char **font_names;

            dc.font.ascent = dc.font.descent = 0;
            font_extents = XExtentsOfFontSet(dc.font.set);
            n = XFontsOfFontSet(dc.font.set, &xfonts, &font_names);

            for (i = 0, dc.font.ascent = 0, dc.font.descent = 0; i < n; i++) {
                  dc.font.ascent = MAX(dc.font.ascent, (*xfonts)->ascent);
                  dc.font.descent = MAX(dc.font.descent,(*xfonts)->descent);
                  xfonts++;
            }
      } else {
            if (!(dc.font.xfont = XLoadQueryFont(dpy, fontstr))
                        && !(dc.font.xfont = XLoadQueryFont(dpy, "fixed")))
                  die("error, cannot load font: '%s'\n", fontstr);

            dc.font.ascent = dc.font.xfont->ascent;

            dc.font.descent = dc.font.xfont->descent;
      }

      dc.font.height = dc.font.ascent + dc.font.descent;
}

Bool
isprotodel(Client *c)
{
      int i, n;
      Atom *protocols;
      Bool ret = False;

      if (XGetWMProtocols(dpy, c->win, &protocols, &n)) {
            for (i = 0; !ret && i < n; i++)
                  if (protocols[i] == wmatom[WMDelete])
                        ret = True;

            XFree(protocols);
      }

      return ret;
}

#ifdef XINERAMA
static Bool
isuniquegeom(XineramaScreenInfo *unique, size_t len, XineramaScreenInfo *info)
{
      unsigned int i;

      for (i = 0; i < len; i++)
            if (unique[i].x_org == info->x_org && unique[i].y_org == info->y_org
                        && unique[i].width == info->width && unique[i].height == info->height)
                  return False;

      return True;
}

#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)
{
      XEvent ev;

      if (!selmon->sel)
            return;

      if (isprotodel(selmon->sel)) {
            ev.type = ClientMessage;
            ev.xclient.window = selmon->sel->win;
            ev.xclient.message_type = wmatom[WMProtocols];
            ev.xclient.format = 32;
            ev.xclient.data.l[0] = wmatom[WMDelete];
            ev.xclient.data.l[1] = CurrentTime;
            XSendEvent(dpy, selmon->sel->win, False, NoEventMask, &ev);
      } else {
            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)
{
      static Client cz;
      Client *c, *t = NULL;
      Window trans = None;
      XWindowChanges wc;

      if (!(c = malloc(sizeof(Client))))
            die("fatal: could not malloc() %u bytes\n", sizeof(Client));

      *c = cz;

      c->win = w;

      updatetitle(c);

      if (XGetTransientForHint(dpy, w, &trans))
            t = wintoclient(trans);

      if (t) {
            c->mon = t->mon;
            c->tags = t->tags;
      } else {
            c->mon = selmon;
            applyrules(c);
      }

      /* geometry */
      c->x = c->oldx = wa->x + c->mon->wx;

      c->y = c->oldy = wa->y + c->mon->wy;

      c->w = c->oldw = wa->width;

      c->h = c->oldh = wa->height;

      c->oldbw = wa->border_width;

      if (c->w == c->mon->mw && c->h == c->mon->mh) {
            c->isfloating = 1;
            c->x = c->mon->mx;
            c->y = c->mon->my;
            c->bw = 0;
      } else {
            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 == 0) && (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, dc.norm[ColBorder]);
      configure(c); /* propagates border_width, if size doesn't change */
      updatesizehints(c);
      XSelectInput(dpy, w, EnterWindowMask|FocusChangeMask|PropertyChangeMask|StructureNotifyMask);
      grabbuttons(c, False);

      if (!c->isfloating)
            c->isfloating = c->oldstate = trans != None || c->isfixed;

      if (c->isfloating)
            XRaiseWindow(dpy, c->win);

      attach(c);

      attachstack(c);

      XMoveResizeWindow(dpy, c->win, c->x + 2 * sw, c->y, c->w, c->h); /* some windows require this */

      XMapWindow(dpy, c->win);

      setclientstate(c, NormalState);

      arrange(c->mon);
}

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, False);
}

void
movemouse(const Arg *arg)
{
      int x, y, ocx, ocy, nx, ny;
      Client *c;
      Monitor *m;
      XEvent ev;

      if (!(c = selmon->sel))
            return;

      restack(selmon);

      ocx = c->x;

      ocy = c->y;

      if (XGrabPointer(dpy, root, False, MOUSEMASK, GrabModeAsync, GrabModeAsync,
                       None, cursor[CurMove], 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:
                        nx = ocx + (ev.xmotion.x - x);
                        ny = ocy + (ev.xmotion.y - y);

                        if (snap && 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, True);

                        break;
            }
      } while (ev.type != ButtonRelease);

      XUngrabPointer(dpy, CurrentTime);

      if ((m = ptrtomon(c->x + c->w / 2, c->y + c->h / 2)) != selmon) {
            sendmon(c, m);
            selmon = m;
            focus(NULL);
      }
}

Client *
nexttiled(Client *c)
{
      for (; c && (c->isfloating || !ISVISIBLE(c)); c = c->next);

      return c;
}

Monitor *
ptrtomon(int x, int y)
{
      Monitor *m;

      for (m = mons; m; m = m->next)
            if (INRECT(x, y, m->wx, m->wy, m->ww, m->wh))
                  return m;

      return selmon;
}

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:
                        XGetTransientForHint(dpy, c->win, &trans);

                        if (!c->isfloating && (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);
            }
      }
}

void
clientmessage(XEvent *e)
{
      XClientMessageEvent *cme = &e->xclient;
      Client *c;

      if ((c = wintoclient(cme->window))
                  && (cme->message_type == netatom[NetWMState] && cme->data.l[1] == netatom[NetWMFullscreen])) {
            if (cme->data.l[0]) {
                  XChangeProperty(dpy, cme->window, netatom[NetWMState], XA_ATOM, 32,
                                  PropModeReplace, (unsigned char*)&netatom[NetWMFullscreen], 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 {
                  XChangeProperty(dpy, cme->window, netatom[NetWMState], XA_ATOM, 32,
                                  PropModeReplace, (unsigned char*)0, 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
quit(const Arg *arg)
{
      running = False;
}

void
resize(Client *c, int x, int y, int w, int h, Bool 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;
      int nw, nh;
      Client *c;
      Monitor *m;
      XEvent ev;

      if (!(c = selmon->sel))
            return;

      restack(selmon);

      ocx = c->x;

      ocy = c->y;

      if (XGrabPointer(dpy, root, False, MOUSEMASK, GrabModeAsync, GrabModeAsync,
                       None, cursor[CurResize], 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:
                        nw = MAX(ev.xmotion.x - ocx - 2 * c->bw + 1, 1);
                        nh = MAX(ev.xmotion.y - ocy - 2 * c->bw + 1, 1);

                        if (snap && nw >= selmon->wx && nw <= selmon->wx + selmon->ww
                                    && nh >= selmon->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, True);

                        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 = ptrtomon(c->x + c->w / 2, c->y + c->h / 2)) != 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, True);

      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);
}

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 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);
      root = RootWindow(dpy, screen);
      initfont(font);
      sw = DisplayWidth(dpy, screen);
      sh = DisplayHeight(dpy, screen);
      bh = dc.h = dc.font.height + 2;
      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);
      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);
      /* init cursors */
      cursor[CurNormal] = XCreateFontCursor(dpy, XC_left_ptr);
      cursor[CurResize] = XCreateFontCursor(dpy, XC_sizing);
      cursor[CurMove] = XCreateFontCursor(dpy, XC_fleur);
      /* init appearance */
      dc.norm[ColBorder] = getcolor(normbordercolor);
      dc.norm[ColBG] = getcolor(normbgcolor);
      dc.norm[ColFG] = getcolor(normfgcolor);
      dc.sel[ColBorder] = getcolor(selbordercolor);
      dc.sel[ColBG] = getcolor(selbgcolor);
      dc.sel[ColFG] = getcolor(selfgcolor);
      dc.drawable = XCreatePixmap(dpy, root, DisplayWidth(dpy, screen), bh, DefaultDepth(dpy, screen));
      dc.gc = XCreateGC(dpy, root, 0, NULL);
      XSetLineAttributes(dpy, dc.gc, 1, LineSolid, CapButt, JoinMiter);

      if (!dc.font.set)
            XSetFont(dpy, dc.gc, dc.font.xfont->fid);

      /* init bars */
      updatebars();

      updatestatus();

      /* EWMH support per view */
      XChangeProperty(dpy, root, netatom[NetSupported], XA_ATOM, 32,
                      PropModeReplace, (unsigned char *) netatom, NetLast);

      /* select for events */
      wa.cursor = cursor[CurNormal];

      wa.event_mask = SubstructureRedirectMask|SubstructureNotifyMask|ButtonPressMask
                      |EnterWindowMask|LeaveWindowMask|StructureNotifyMask
                      |PropertyChangeMask;

      XChangeWindowAttributes(dpy, root, CWEventMask|CWCursor, &wa);

      XSelectInput(dpy, root, wa.event_mask);

      grabkeys();
}

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)
                  resize(c, c->x, c->y, c->w, c->h, False);

            showhide(c->snext);
      } else { /* hide clients bottom up */
            showhide(c->snext);
            XMoveWindow(dpy, c->win, c->x + 2 * sw, 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 (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(0);
      }
}

void
tag(const Arg *arg)
{
      if (selmon->sel && arg->ui & TAGMASK) {
            selmon->sel->tags = arg->ui & TAGMASK;
            arrange(selmon);
      }
}

void
tagmon(const Arg *arg)
{
      if (!selmon->sel || !mons->next)
            return;

      sendmon(selmon->sel, dirtomon(arg->i));
}

int
textnw(const char *text, unsigned int len)
{
      XRectangle r;

      if (dc.font.set) {
            XmbTextExtents(dc.font.set, text, len, NULL, &r);
            return r.width;
      }

      return XTextWidth(dc.font.xfont, text, len);
}

void
tile(Monitor *m)
{
      int x, y, h, w,mh;
      unsigned int i, n;
      Client *c;

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

      if (n == 0)
            return;

      /* master */
      c = nexttiled(m->clients);

      mh = (int)(m->mfact * (double)m->wh);

      resize(c, m->wx , (n==1)?m->wy:(m->wy + mh) , m->ww - c->bw,  (n==1)?(m->wh-(2*c->bw)):(m->wh - mh-(2*c->bw))  , False);

      if (--n == 0)
            return;

      /* tile stack */
      x = m->wx;

      y = m->wy;

      w = m->ww /n;

      h = mh;

      if (h < bh)
            h = m->wh;

      for (i = 0, c = nexttiled(c->next); c; c = nexttiled(c->next), i++) {
            resize(c, x, y,(i + 1 == n)? (m->wx + m->ww - x -  (2*c->bw)) : (w -  (2*c->bw)) ,h - (2*c->bw), False);

            if (w != m->ww)
                  x = c->x + WIDTH(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;

      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, False);

      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;
            arrange(selmon);
      }
}

void
toggleview(const Arg *arg)
{
      unsigned int newtagset = selmon->tagset[selmon->seltags] ^ (arg->ui & TAGMASK);

      if (newtagset) {
            selmon->tagset[selmon->seltags] = newtagset;
            arrange(selmon);
      }
}

void
unfocus(Client *c, Bool setfocus)
{
      if (!c)
            return;

      grabbuttons(c, False);

      XSetWindowBorder(dpy, c->win, dc.norm[ColBorder]);

      if (setfocus)
            XSetInputFocus(dpy, root, RevertToPointerRoot, CurrentTime);
}

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

      /* 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);

      focus(NULL);
      arrange(m);
}

void
unmapnotify(XEvent *e)
{
      Client *c;
      XUnmapEvent *ev = &e->xunmap;

      if ((c = wintoclient(ev->window)))
            unmanage(c, False);
}

void
updatebars(void)
{
      Monitor *m;
      XSetWindowAttributes wa;

      wa.override_redirect = True;
      wa.background_pixmap = ParentRelative;
      wa.event_mask = ButtonPressMask|ExposureMask;

      for (m = mons; m; m = m->next) {
            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]);
            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;
}

Bool
updategeom(void)
{
      Bool dirty = False;

#ifdef XINERAMA

      if (XineramaIsActive(dpy)) {
            int i, j, n, nn;
            Client *c;
            Monitor *m;
            XineramaScreenInfo *info = XineramaQueryScreens(dpy, &nn);
            XineramaScreenInfo *unique = NULL;

            info = XineramaQueryScreens(dpy, &nn);

            for (n = 0, m = mons; m; m = m->next, n++);

            /* only consider unique geometries as separate screens */
            if (!(unique = (XineramaScreenInfo *)malloc(sizeof(XineramaScreenInfo) * nn)))
                  die("fatal: could not malloc() %u bytes\n", sizeof(XineramaScreenInfo) * nn);

            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 = True;
                              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 = True;
                              c = m->clients;
                              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 = True;
                  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
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) ? True : False;

            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;

      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 ptrtomon(x, y);

      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)
{
      otherwm = True;
      return -1;
}

void
zoom(const Arg *arg)
{
      Client *c = selmon->sel;

      if (!selmon->lt[selmon->sellt]->arrange
                  || selmon->lt[selmon->sellt]->arrange == monocle
                  || (selmon->sel && selmon->sel->isfloating))
            return;

      if (c == nexttiled(selmon->clients))
            if (!c || !(c = nexttiled(c->next)))
                  return;

      detach(c);

      attach(c);

      focus(c);

      arrange(c->mon);
}

int
main(int argc, char *argv[])
{
      if (argc == 2 && !strcmp("-v", argv[1]))
            die("dwm-"VERSION", © 2006-2010 dwm engineers, see LICENSE for details\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");

      checkotherwm();

      setup();

      scan();

      run();

      cleanup();

      XCloseDisplay(dpy);

      return 0;
}
