/* (C)opyright MMVI-MMVII Anselm R. Garbe <garbeam at gmail dot com>
 * (C)opyright MMVIII markus schnalke <meillo at marmaro dot de>
 * See LICENSE file for 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 global
 * doubly-linked client list, the focus history is remembered through a global
 * stack list. [...]
 *
 * Keys and tagging rules are organized as arrays and defined in the config.h
 * file. [...] The current mode is represented by the arrange() function
 * pointer, which wether points to [domax()] or dotile().
 *
 * To understand everything else, start reading main.c:main().
 *
 * -- and now about aewl --
 *
 * aewl is a stripped down dwm. It stated as a patchset, but finally forked off
 * completely. The reason for this was the increasing gap between my wish to
 * stay where dwm was, and dwm direction to go further. Further more did I
 * always use only a small subset of dwm's features, so condencing dwm had been
 * my wish for a long time.
 *
 * In aewl clients are either tagged or not (only one tag). Visible are either
 * all tagged clients or all without the tag.
 */


#include <errno.h>
#include <locale.h>
#include <stdio.h>
#include <stdarg.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/signal.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>

#include "config.h"


/* mask shorthands, used in event.c and client.c */
#define BUTTONMASK		(ButtonPressMask | ButtonReleaseMask)

enum { NetSupported, NetWMName, NetLast };		/* EWMH atoms */
enum { WMProtocols, WMDelete, WMState, WMLast };	/* default atoms */
enum { CurNormal, CurResize, CurMove, CurLast };	/* cursor */
enum { ColFG, ColBG, ColLast };		/* color */

typedef struct {
	int ascent;
	int descent;
	int height;
	XFontSet set;
	XFontStruct *xfont;
} Fnt;

typedef struct {
	int x, y, w, h;
	unsigned long norm[ColLast];
	unsigned long sel[ColLast];
	Drawable drawable;
	Fnt font;
	GC gc;
} DC; /* draw context */

typedef struct Client Client;
struct Client {
	char name[256];
	int x, y, w, h;
	int rx, ry, rw, rh; /* revert geometry */
	int basew, baseh, incw, inch, maxw, maxh, minw, minh;
	int minax, minay, maxax, maxay;
	long flags;
	unsigned int border;
	Bool isfixed, isfloat, ismax;
	Bool tag;
	Client *next;
	Client *prev;
	Client *snext;
	Window win;
};

typedef struct {
	const char* class;
	const char* instance;
	const char* title;
	int tag;
	Bool isfloat;
} Rule;


typedef struct {
	unsigned long mod;
	KeySym keysym;
	void (*func)(const char* cmd);
	const char* cmd;
} Key;


#define CLEANMASK(mask) (mask & ~(numlockmask | LockMask))
#define MOUSEMASK		(BUTTONMASK | PointerMotionMask)



char stext[256];				/* status text */
int bh;				/* bar height */
int screen, sx, sy, sw, sh;		/* screen geometry */
int wax, way, wah, waw;			/* windowarea geometry */
unsigned int nmaster;		/* number of master clients */
unsigned int numlockmask;		/* dynamic lock mask */
void (*handler[LASTEvent])(XEvent *);	/* event handler */
void arrange(void);			/* arrange */
void (*arrange1)(void);			/* arrange function, indicates mode  */
void (*arrange2)(void);			/* arrange function, indicates mode  */
Atom wmatom[WMLast], netatom[NetLast];
Bool running = True;
Bool selscreen = True;
Bool seltag;
Bool viewfloats;
Client* clients = NULL;		/* global client list */
Client* stack = NULL;		/* global client stack */
Client* sel = NULL;		/* selected client */
Cursor cursor[CurLast];
DC dc = {0};					/* global draw context */
Display *dpy;
Window root, barwin;

static int (*xerrorxlib)(Display *, XErrorEvent *);
static Bool otherwm;
static unsigned int len = 0;



void configure(Client *c);		/* send synthetic configure event */
void focus(Client *c);			/* focus c, c may be NULL */
Client *getclient(Window w);		/* return client of w */
Bool isprotodel(Client *c);		/* returns True if c->win supports wmatom[WMDelete] */
void manage(Window w, XWindowAttributes *wa);	/* manage new client */
void resize(Client *c, Bool sizehints);	/* resize c*/
void updatesizehints(Client *c);		/* update the size hint variables of c */
void updatetitle(Client *c);		/* update the name of c */
void unmanage(Client *c);		/* destroy c */

void drawbar(void);			/* draw the bar */
unsigned long getcolor(const char *colstr);	/* return color of colstr */
void setfont(const char *fontstr);	/* set the font for DC */
unsigned int textw(const char *text);	/* return the width of text in px*/

void grabkeys(void);			/* grab all keys defined in config.h */

void sendevent(Window w, Atom a, long value);	/* send synthetic event to w */
int xerror(Display *dsply, XErrorEvent *ee);	/* X error handler */

Client *getnext(Client *c);		/* returns next visible client */
void settag(Client *c, Client *trans);	/* sets tag of c */

void *emallocz(unsigned int size);	/* allocates zero-initialized memory, exits on error */
void die(const char *errstr, ...);	/* prints errstr and exits with 1 */

void detach(Client *c);			/* detaches c from global client list */
void dotile(void);			/* arranges all windows tiled */
void domax(void);            /* arranges all windows fullscreen */
Bool isvisible(Client *c);		/* returns True if client is visible */
void restack(void);			/* restores z layers of all clients */

void toggleview(void);			/* toggle the view */
void floattoggle();			/* toggle floatsview */
void focusnext(void);		/* focuses next visible client  */
void zoom(void);			/* zooms the focused client to master area */
void killclient(void);		/* kill c nicely */
void quit(void);			/* quit nicely */
void togglemode(void);		/* toggles arrange function (dotile/domax) */
void togglefloat(void);		/* toggles focusesd client between floating/non-floating state */
void incnmaster(void);		/* increments nmaster */
void decnmaster(void);		/* decrements nmaster */
void toggletag(void);		/* toggles tag of c */
void spawn(const char* cmd);			/* forks a new subprocess with cmd */

void updatestatus(void);		/* update the status text */


RULES
KEYS









/* from view.c */

Client *
nexttiled(Client *c) {
	for(c = getnext(c); c && c->isfloat; c = getnext(c->next));
	return c;
}

void
togglemax(Client *c) {
	XEvent ev;
		
	if(c->isfixed)
		return;

	if((c->ismax = !c->ismax)) {
		c->rx = c->x;
		c->ry = c->y;
		c->rw = c->w;
		c->rh = c->h;
		c->x = wax;
		c->y = way;
		c->w = waw - 2 * BORDERPX;
		c->h = wah - 2 * BORDERPX;
	} else {
		c->x = c->rx;
		c->y = c->ry;
		c->w = c->rw;
		c->h = c->rh;
	}
	resize(c, False);
	while(XCheckMaskEvent(dpy, EnterWindowMask, &ev));
}




void
detach(Client *c) {
	if(c->prev)
		c->prev->next = c->next;
	if(c->next)
		c->next->prev = c->prev;
	if(c == clients)
		clients = c->next;
	c->next = c->prev = NULL;
}

void
dotile(void) {
	unsigned int i, n, mw, mh, tw, th;
	Client *c;

	for(n = 0, c = nexttiled(clients); c; c = nexttiled(c->next))
		n++;
	/* window geoms */
	mh = (n > nmaster) ? wah / nmaster : wah / (n > 0 ? n : 1);
	mw = (n > nmaster) ? waw / 2 : waw;
	th = (n > nmaster) ? wah / (n - nmaster) : 0;
	tw = waw - mw;

	for(i = 0, c = clients; c; c = c->next)
		if(isvisible(c)) {
			if(c->isfloat) {
				resize(c, True);
				continue;
			}
			c->ismax = False;
			c->x = wax;
			c->y = way;
			if(i < nmaster) {
				c->y += i * mh;
				c->w = mw - 2 * BORDERPX;
				c->h = mh - 2 * BORDERPX;
			}
			else {  /* tile window */
				c->x += mw;
				c->w = tw - 2 * BORDERPX;
				if(th > 2 * BORDERPX) {
					c->y += (i - nmaster) * th;
					c->h = th - 2 * BORDERPX;
				}
				else /* fallback if th <= 2 * BORDERPX */
					c->h = wah - 2 * BORDERPX;
			}
			resize(c, False);
			i++;
		}
		else
			XMoveWindow(dpy, c->win, c->x + 2 * sw, c->y);
	if(!sel || !isvisible(sel)) {
		for(c = stack; c && !isvisible(c); c = c->snext);
		focus(c);
	}
	restack();
}

void
domax(void) {
  Client *c;

  for(c = clients; c; c = c->next) {
    if(isvisible(c)) {
      if(c->isfloat) {
        resize(c, True);
        continue;
      }
			c->ismax = True;
			c->x = wax;
			c->y = way;
			c->w = waw - 2 * BORDERPX;
			c->h = wah - 2 * BORDERPX;
			resize(c, False);
    } else {
      XMoveWindow(dpy, c->win, c->x + 2 * sw, c->y);
    }
  }
  if(!sel || !isvisible(sel)) {
    for(c = stack; c && !isvisible(c); c = c->snext);
    focus(c);
  }
  restack();
}

void
focusnext() {
	Client *c;

	if(!sel)
		return;
	if(!(c = getnext(sel->next)))
		c = getnext(clients);
	if(c) {
		focus(c);
		restack();
	}
}

void
incnmaster() {
	if(wah / (nmaster + 1) <= 2 * BORDERPX)
		return;
	nmaster++;
	if(sel)
		arrange();
}

void
decnmaster() {
	if(nmaster <= 1)
		return;
	nmaster--;
	if(sel)
		arrange();
}

Bool
isvisible(Client *c) {
	if (c->isfloat) {
		return viewfloats;
	}
	return (!viewfloats && c->tag == seltag);
}

void
restack(void) {
	Client *c;
	XEvent ev;

	drawbar();
	if(!sel)
		return;
	/*if(sel->isfloat)*/
		XRaiseWindow(dpy, sel->win);

	/*
	if(!sel->isfloat)
		XLowerWindow(dpy, sel->win);
	for(c = nexttiled(clients); c; c = nexttiled(c->next)) {
		if(c == sel)
			continue;
		XLowerWindow(dpy, c->win);
	}
	*/

	XSync(dpy, False);
	while(XCheckMaskEvent(dpy, EnterWindowMask, &ev));
}

void
togglefloat() {
	if (!sel)
		return;
	sel->isfloat = !sel->isfloat;
	floattoggle();
}

void
togglemode() {
	/* toggle between tile and max */
	if (viewfloats) {
		return;
	}
	if (seltag) {
		arrange1 = (arrange1 == dotile) ? domax : dotile;
	} else {
		arrange2 = (arrange2 == dotile) ? domax : dotile;
	}
	if(sel)
		arrange();
	zoom();
}

void
arrange() {
	if (seltag) {
		arrange1();
	} else {
		arrange2();
	}
}

void
toggleview() {
	if (viewfloats) {
		return;
	}
	seltag = !seltag;
	arrange();
}

void
floattoggle() {
	viewfloats = !viewfloats;
	arrange();
}

void
zoom() {
	unsigned int n;
	Client *c;

	if(!sel)
		return;
	if(sel->isfloat) {
		togglemax(sel);
		return;
	}
	for(n = 0, c = nexttiled(clients); c; c = nexttiled(c->next))
		n++;

	if((c = sel) == nexttiled(clients))
		if(!(c = nexttiled(c->next)))
			return;
	detach(c);
	if(clients)
		clients->prev = c;
	c->next = clients;
	clients = c;
	focus(c);
	arrange();
}

/* from util.c */

void *
emallocz(unsigned int size) {
	void *res = calloc(1, size);

	if(!res)
		die("fatal: could not malloc() %u bytes\n", size);
	return res;
}

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

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

void
spawn(const char* cmd) {
	static char *shell = NULL;

	if(!cmd)
		return;
	if(!(shell = getenv("SHELL")))
		shell = "/bin/sh";
	/* The double-fork construct avoids zombie processes and keeps the code
	 * clean from stupid signal handlers. */
	if(fork() == 0) {
		if(fork() == 0) {
			if(dpy)
				close(ConnectionNumber(dpy));
			setsid();
			execl(shell, shell, "-c", cmd, (char *)NULL);
			fprintf(stderr, "aewl: execl '%s -c %s'", shell, cmd);
			perror(" failed");
		}
		exit(0);
	}
	wait(0);
}

/* from tag.c */

Client *
getnext(Client *c) {
	while(c && !isvisible(c)) {
		c = c->next;
	}
	return c;
}

void
settag(Client *c, Client *trans) {
	unsigned int i;
	XClassHint ch = { 0 };

	if(trans) {
		c->tag = trans->tag;
		return;
	}
	c->tag = seltag;  /* default */
	XGetClassHint(dpy, c->win, &ch);
	len = sizeof rule / sizeof rule[0];
	for(i = 0; i < len; i++) {
		if((rule[i].title && strstr(c->name, rule[i].title))
		   || (ch.res_class && rule[i].class && strstr(ch.res_class, rule[i].class))
		   || (ch.res_name && rule[i].instance && strstr(ch.res_name, rule[i].instance))) {
			c->isfloat = rule[i].isfloat;
			if (rule[i].tag < 0) {
				c->tag = seltag;
			} else if (rule[i].tag) {
				c->tag = True;
			} else {
				c->tag = False;
			}
			break;
		}
	}
	if(ch.res_class)
		XFree(ch.res_class);
	if(ch.res_name)
		XFree(ch.res_name);
}

void
toggletag() {
	if(!sel)
		return;
	sel->tag = !sel->tag;
	toggleview();
}

/* from event.c */

void
movemouse(Client *c) {
	int x1, y1, ocx, ocy, di;
	unsigned int dui;
	Window dummy;
	XEvent ev;

	ocx = c->x;
	ocy = c->y;
	if(XGrabPointer(dpy, root, False, MOUSEMASK, GrabModeAsync, GrabModeAsync,
			None, cursor[CurMove], CurrentTime) != GrabSuccess)
		return;
	c->ismax = False;
	XQueryPointer(dpy, root, &dummy, &dummy, &x1, &y1, &di, &di, &dui);
	for(;;) {
		XMaskEvent(dpy, MOUSEMASK | ExposureMask | SubstructureRedirectMask, &ev);
		switch (ev.type) {
		case ButtonRelease:
			resize(c, True);
			XUngrabPointer(dpy, CurrentTime);
			return;
		case ConfigureRequest:
		case Expose:
		case MapRequest:
			handler[ev.type](&ev);
			break;
		case MotionNotify:
			XSync(dpy, False);
			c->x = ocx + (ev.xmotion.x - x1);
			c->y = ocy + (ev.xmotion.y - y1);
			if(abs(wax + c->x) < SNAP)
				c->x = wax;
			else if(abs((wax + waw) - (c->x + c->w + 2 * c->border)) < SNAP)
				c->x = wax + waw - c->w - 2 * c->border;
			if(abs(way - c->y) < SNAP)
				c->y = way;
			else if(abs((way + wah) - (c->y + c->h + 2 * c->border)) < SNAP)
				c->y = way + wah - c->h - 2 * c->border;
			resize(c, False);
			break;
		}
	}
}

void
resizemouse(Client *c) {
	int ocx, ocy;
	int nw, nh;
	XEvent ev;

	ocx = c->x;
	ocy = c->y;
	if(XGrabPointer(dpy, root, False, MOUSEMASK, GrabModeAsync, GrabModeAsync,
			None, cursor[CurResize], CurrentTime) != GrabSuccess)
		return;
	c->ismax = False;
	XWarpPointer(dpy, None, c->win, 0, 0, 0, 0, c->w + c->border - 1, c->h + c->border - 1);
	for(;;) {
		XMaskEvent(dpy, MOUSEMASK | ExposureMask | SubstructureRedirectMask , &ev);
		switch(ev.type) {
		case ButtonRelease:
			resize(c, True);
			XUngrabPointer(dpy, CurrentTime);
			return;
		case ConfigureRequest:
		case Expose:
		case MapRequest:
			handler[ev.type](&ev);
			break;
		case MotionNotify:
			XSync(dpy, False);
			nw = ev.xmotion.x - ocx - 2 * c->border + 1;
			c->w = nw > 0 ? nw : 1;
			nh = ev.xmotion.y - ocy - 2 * c->border + 1;
			c->h = nh > 0 ? nh : 1;
			resize(c, True);
			break;
		}
	}
}

void
buttonpress(XEvent *e) {
	Client *c;
	XButtonPressedEvent *ev = &e->xbutton;

	if(barwin == ev->window) {
		return;
	}
	if((c = getclient(ev->window))) {
		focus(c);
		if(CLEANMASK(ev->state) != MODKEY)
			return;
		if(ev->button == Button1 && c->isfloat) {
			restack();
			movemouse(c);
		} else if(ev->button == Button3 && c->isfloat && !c->isfixed) {
			restack();
			resizemouse(c);
		}
	}
}

void
configurerequest(XEvent *e) {
	unsigned long newmask;
	Client *c;
	XConfigureRequestEvent *ev = &e->xconfigurerequest;
	XWindowChanges wc;

	if((c = getclient(ev->window))) {
		c->ismax = False;
		if(ev->value_mask & CWX)
			c->x = ev->x;
		if(ev->value_mask & CWY)
			c->y = ev->y;
		if(ev->value_mask & CWWidth)
			c->w = ev->width;
		if(ev->value_mask & CWHeight)
			c->h = ev->height;
		if(ev->value_mask & CWBorderWidth)
			c->border = ev->border_width;
		wc.x = c->x;
		wc.y = c->y;
		wc.width = c->w;
		wc.height = c->h;
		newmask = ev->value_mask & (~(CWSibling | CWStackMode | CWBorderWidth));
		if(newmask)
			XConfigureWindow(dpy, c->win, newmask, &wc);
		else
			configure(c);
		XSync(dpy, False);
		if(c->isfloat) {
			resize(c, False);
			if(!isvisible(c))
				XMoveWindow(dpy, c->win, c->x + 2 * sw, c->y);
		}
		else
			arrange();
	} 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);
	}
}

void
destroynotify(XEvent *e) {
	Client *c;
	XDestroyWindowEvent *ev = &e->xdestroywindow;

	if((c = getclient(ev->window)))
		unmanage(c);
}

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

	if(ev->mode != NotifyNormal || ev->detail == NotifyInferior)
		return;
	if((c = getclient(ev->window)) && isvisible(c))
		focus(c);
	else if(ev->window == root) {
		selscreen = True;
		for(c = stack; c && !isvisible(c); c = c->snext);
		focus(c);
	}
}

void
expose(XEvent *e) {
	XExposeEvent *ev = &e->xexpose;

	if(ev->count == 0) {
		if(barwin == ev->window)
			drawbar();
	}
}

void
keypress(XEvent *e) {
	static unsigned int len = sizeof key / sizeof key[0];
	unsigned int i;
	KeySym keysym;
	XKeyEvent *ev = &e->xkey;

	keysym = XKeycodeToKeysym(dpy, (KeyCode)ev->keycode, 0);
	for(i = 0; i < len; i++) {
		if(keysym == key[i].keysym && CLEANMASK(key[i].mod) == CLEANMASK(ev->state)) {
			if(key[i].func)
				key[i].func(key[i].cmd);
		}
	}
}

void
leavenotify(XEvent *e) {
	XCrossingEvent *ev = &e->xcrossing;

	if((ev->window == root) && !ev->same_screen) {
		selscreen = False;
		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) {
		XSelectInput(dpy, ev->window,
				(StructureNotifyMask | PropertyChangeMask));
		return;
	}
	if(!getclient(ev->window))
		manage(ev->window, &wa);
}

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 = getclient(ev->window))) {
		switch (ev->atom) {
			default: break;
			case XA_WM_TRANSIENT_FOR:
				XGetTransientForHint(dpy, c->win, &trans);
				if(!c->isfloat && (c->isfloat = (trans != 0)))
					arrange();
				break;
			case XA_WM_NORMAL_HINTS:
				updatesizehints(c);
				break;
		}
		if(ev->atom == XA_WM_NAME || ev->atom == netatom[NetWMName]) {
			updatetitle(c);
			if(c == sel)
				drawbar();
		}
	}
}

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

	if((c = getclient(ev->window)))
		unmanage(c);
}



void (*handler[LASTEvent]) (XEvent *) = {
	[ButtonPress] = buttonpress,
	[ConfigureRequest] = configurerequest,
	[DestroyNotify] = destroynotify,
	[EnterNotify] = enternotify,
	[LeaveNotify] = leavenotify,
	[Expose] = expose,
	[KeyPress] = keypress,
	[MappingNotify] = mappingnotify,
	[MapRequest] = maprequest,
	[PropertyNotify] = propertynotify,
	[UnmapNotify] = unmapnotify
};

void
grabkeys(void) {
	static unsigned int len = sizeof key / sizeof key[0];
	unsigned int i;
	KeyCode code;

	XUngrabKey(dpy, AnyKey, AnyModifier, root);
	for(i = 0; i < len; i++) {
		code = XKeysymToKeycode(dpy, key[i].keysym);
		XGrabKey(dpy, code, key[i].mod, root, True,
				GrabModeAsync, GrabModeAsync);
		XGrabKey(dpy, code, key[i].mod | LockMask, root, True,
				GrabModeAsync, GrabModeAsync);
		XGrabKey(dpy, code, key[i].mod | numlockmask, root, True,
				GrabModeAsync, GrabModeAsync);
		XGrabKey(dpy, code, key[i].mod | numlockmask | LockMask, root, True,
				GrabModeAsync, GrabModeAsync);
	}
}

/* from draw.c */

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

	XSetForeground(dpy, dc.gc, col[ColBG]);
	XFillRectangles(dpy, dc.drawable, dc.gc, &r, 1);
	if(!text)
		return;
	w = 0;
	olen = len = strlen(text);
	if(len >= sizeof buf)
		len = sizeof buf - 1;
	memcpy(buf, text, len);
	buf[len] = 0;
	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 */
	while(len && (w = textnw(buf, len)) > dc.w - h)
		buf[--len] = 0;
	if(len < olen) {
		if(len > 1)
			buf[len - 1] = '.';
		if(len > 2)
			buf[len - 2] = '.';
		if(len > 3)
			buf[len - 3] = '.';
	}
	if(w > dc.w)
		return; /* too long */
	gcv.foreground = col[ColFG];
	if(dc.font.set) {
		XChangeGC(dpy, dc.gc, GCForeground, &gcv);
		XmbDrawString(dpy, dc.drawable, dc.font.set, dc.gc, x, y, buf, len);
	} else {
		gcv.font = dc.font.xfont->fid;
		XChangeGC(dpy, dc.gc, GCForeground | GCFont, &gcv);
		XDrawString(dpy, dc.drawable, dc.gc, x, y, buf, len);
	}
}

void
drawbar(void) {
	int x;
	unsigned long black[ColLast];
	black[ColBG] = getcolor("#000000");
	black[ColFG] = getcolor("#ffffff");

	/* views */
	dc.x = dc.y = 0;
	dc.w = textw(NAMETAGGED);
	drawtext(NAMETAGGED, ( (seltag&&!viewfloats) ? dc.sel : dc.norm ));

	dc.x += dc.w;
	dc.w = BORDERPX;
	drawtext(NULL, black);

	dc.x += dc.w;
	dc.w = textw(NAMEUNTAGGED);
	drawtext(NAMEUNTAGGED, ( (!seltag&&!viewfloats) ? dc.sel : dc.norm ));

	dc.x += dc.w;
	dc.w = BORDERPX;
	drawtext(NULL, black);

	/* status text */
	x = dc.x + dc.w;
	dc.w = textw(stext);
	dc.x = sw - dc.w;
	if(dc.x < x) {
		dc.x = x;
		dc.w = sw - x;
	}
	drawtext(stext, dc.norm);

	/* client title */
	if((dc.w = dc.x - x) > bh) {
		dc.x = x;
		drawtext(sel ? sel->name : NULL, dc.norm);

		dc.x += dc.w;
		dc.w = BORDERPX;
		drawtext(NULL, black);
	}

	XCopyArea(dpy, dc.drawable, barwin, dc.gc, 0, 0, sw, bh, 0, 0);
	XSync(dpy, False);
}

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;
}

void
setfont(const char *fontstr) {
	char *def, **missing;
	int i, n;

	missing = NULL;
	if(dc.font.set)
		XFreeFontSet(dpy, dc.font.set);
	dc.font.set = XCreateFontSet(dpy, fontstr, &missing, &n, &def);
	if(missing) {
		while(n--)
			fprintf(stderr, "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++) {
			if(dc.font.ascent < (*xfonts)->ascent)
				dc.font.ascent = (*xfonts)->ascent;
			if(dc.font.descent < (*xfonts)->descent)
				dc.font.descent = (*xfonts)->descent;
			xfonts++;
		}
	} else {
		if(dc.font.xfont)
			XFreeFont(dpy, dc.font.xfont);
		dc.font.xfont = NULL;
		if(!(dc.font.xfont = XLoadQueryFont(dpy, fontstr)))
			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;
}

unsigned int
textw(const char *text) {
	return textnw(text, strlen(text)) + dc.font.height;
}

/* from client.c */

void
detachstack(Client *c) {
	Client **tc;
	for(tc=&stack; *tc && *tc != c; tc=&(*tc)->snext);
	*tc = c->snext;
}

void
grabbuttons(Client *c, Bool focused) {
	XUngrabButton(dpy, AnyButton, AnyModifier, c->win);

	if(focused) {
		XGrabButton(dpy, Button1, MODKEY, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button1, MODKEY | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button1, MODKEY | numlockmask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button1, MODKEY | numlockmask | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);

		XGrabButton(dpy, Button2, MODKEY, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button2, MODKEY | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button2, MODKEY | numlockmask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button2, MODKEY | numlockmask | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);

		XGrabButton(dpy, Button3, MODKEY, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button3, MODKEY | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button3, MODKEY | numlockmask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
		XGrabButton(dpy, Button3, MODKEY | numlockmask | LockMask, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
	} else {
		XGrabButton(dpy, AnyButton, AnyModifier, c->win, False, BUTTONMASK,
				GrabModeAsync, GrabModeSync, None, None);
	}
}

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
xerrordummy(Display *dsply, XErrorEvent *ee) {
	return 0;
}

void
configure(Client *c) {
	XEvent synev;

	synev.type = ConfigureNotify;
	synev.xconfigure.display = dpy;
	synev.xconfigure.event = c->win;
	synev.xconfigure.window = c->win;
	synev.xconfigure.x = c->x;
	synev.xconfigure.y = c->y;
	synev.xconfigure.width = c->w;
	synev.xconfigure.height = c->h;
	synev.xconfigure.border_width = c->border;
	synev.xconfigure.above = None;
	XSendEvent(dpy, c->win, True, NoEventMask, &synev);
}

void
focus(Client *c) {
	if(c && !isvisible(c))
		return;
	if(sel && sel != c) {
		grabbuttons(sel, False);
		XSetWindowBorder(dpy, sel->win, dc.norm[ColBG]);
	}
	if(c) {
		detachstack(c);
		c->snext = stack;
		stack = c;
		grabbuttons(c, True);
	}
	sel = c;
	drawbar();
	if(!selscreen)
		return;
	if(c) {
		XSetWindowBorder(dpy, c->win, dc.sel[ColBG]);
		XSetInputFocus(dpy, c->win, RevertToPointerRoot, CurrentTime);
	} else {
		XSetInputFocus(dpy, root, RevertToPointerRoot, CurrentTime);
	}
}

Client *
getclient(Window w) {
	Client *c;

	for(c = clients; c; c = c->next) {
		if(c->win == w) {
			return c;
		}
	}
	return NULL;
}

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;
}

void
killclient() {
	if(!sel)
		return;
	if(isprotodel(sel))
		sendevent(sel->win, wmatom[WMProtocols], wmatom[WMDelete]);
	else
		XKillClient(dpy, sel->win);
}

void
manage(Window w, XWindowAttributes *wa) {
	Client *c;
	Window trans;

	c = emallocz(sizeof(Client));
	c->tag = True;
	c->win = w;
	c->x = wa->x;
	c->y = wa->y;
	c->w = wa->width;
	c->h = wa->height;
	if(c->w == sw && c->h == sh) {
		c->border = 0;
		c->x = sx;
		c->y = sy;
	} else {
		c->border = BORDERPX;
		if(c->x + c->w + 2 * c->border > wax + waw)
			c->x = wax + waw - c->w - 2 * c->border;
		if(c->y + c->h + 2 * c->border > way + wah)
			c->y = way + wah - c->h - 2 * c->border;
		if(c->x < wax)
			c->x = wax;
		if(c->y < way)
			c->y = way;
	}
	updatesizehints(c);
	XSelectInput(dpy, c->win,
		StructureNotifyMask | PropertyChangeMask | EnterWindowMask);
	XGetTransientForHint(dpy, c->win, &trans);
	grabbuttons(c, False);
	XSetWindowBorder(dpy, c->win, dc.norm[ColBG]);
	updatetitle(c);
	settag(c, getclient(trans));
	if(!c->isfloat)
		c->isfloat = trans || c->isfixed;
	if(clients)
		clients->prev = c;
	c->next = clients;
	c->snext = stack;
	stack = clients = c;
	XMoveWindow(dpy, c->win, c->x + 2 * sw, c->y);
	XMapWindow(dpy, c->win);
	setclientstate(c, NormalState);
	if(isvisible(c))
		focus(c);
	arrange();
}

void
resize(Client *c, Bool sizehints) {
	float actual, dx, dy, max, min;
	XWindowChanges wc;

	if(c->w <= 0 || c->h <= 0)
		return;
	if(sizehints) {
		if(c->minw && c->w < c->minw)
			c->w = c->minw;
		if(c->minh && c->h < c->minh)
			c->h = c->minh;
		if(c->maxw && c->w > c->maxw)
			c->w = c->maxw;
		if(c->maxh && c->h > c->maxh)
			c->h = c->maxh;
		/* inspired by algorithm from fluxbox */
		if(c->minay > 0 && c->maxay && (c->h - c->baseh) > 0) {
			dx = (float)(c->w - c->basew);
			dy = (float)(c->h - c->baseh);
			min = (float)(c->minax) / (float)(c->minay);
			max = (float)(c->maxax) / (float)(c->maxay);
			actual = dx / dy;
			if(max > 0 && min > 0 && actual > 0) {
				if(actual < min) {
					dy = (dx * min + dy) / (min * min + 1);
					dx = dy * min;
					c->w = (int)dx + c->basew;
					c->h = (int)dy + c->baseh;
				}
				else if(actual > max) {
					dy = (dx * min + dy) / (max * max + 1);
					dx = dy * min;
					c->w = (int)dx + c->basew;
					c->h = (int)dy + c->baseh;
				}
			}
		}
		if(c->incw)
			c->w -= (c->w - c->basew) % c->incw;
		if(c->inch)
			c->h -= (c->h - c->baseh) % c->inch;
	}
	if(c->w == sw && c->h == sh)
		c->border = 0;
	else
		c->border = BORDERPX;
	/* offscreen appearance fixes */
	if(c->x > sw)
		c->x = sw - c->w - 2 * c->border;
	if(c->y > sh)
		c->y = sh - c->h - 2 * c->border;
	if(c->x + c->w + 2 * c->border < sx)
		c->x = sx;
	if(c->y + c->h + 2 * c->border < sy)
		c->y = sy;
	wc.x = c->x;
	wc.y = c->y;
	wc.width = c->w;
	wc.height = c->h;
	wc.border_width = c->border;
	XConfigureWindow(dpy, c->win, CWX | CWY | CWWidth | CWHeight | CWBorderWidth, &wc);
	configure(c);
	XSync(dpy, False);
}

void
updatesizehints(Client *c) {
	long msize;
	XSizeHints size;

	if(!XGetWMNormalHints(dpy, c->win, &size, &msize) || !size.flags)
		size.flags = PSize;
	c->flags = size.flags;
	if(c->flags & PBaseSize) {
		c->basew = size.base_width;
		c->baseh = size.base_height;
	} else {
		c->basew = c->baseh = 0;
	}
	if(c->flags & PResizeInc) {
		c->incw = size.width_inc;
		c->inch = size.height_inc;
	} else {
		c->incw = c->inch = 0;
	}
	if(c->flags & PMaxSize) {
		c->maxw = size.max_width;
		c->maxh = size.max_height;
	} else {
		c->maxw = c->maxh = 0;
	}
	if(c->flags & PMinSize) {
		c->minw = size.min_width;
		c->minh = size.min_height;
	} else {
		c->minw = c->minh = 0;
	}
	if(c->flags & PAspect) {
		c->minax = size.min_aspect.x;
		c->minay = size.min_aspect.y;
		c->maxax = size.max_aspect.x;
		c->maxay = size.max_aspect.y;
	} else {
		c->minax = c->minay = c->maxax = c->maxay = 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);
	}
}


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
unmanage(Client *c) {
	Client *nc;

	/* The server grab construct avoids race conditions. */
	XGrabServer(dpy);
	XSetErrorHandler(xerrordummy);
	detach(c);
	detachstack(c);
	if(sel == c) {
		for(nc = stack; nc && !isvisible(nc); nc = nc->snext);
		focus(nc);
	}
	XUngrabButton(dpy, AnyButton, AnyModifier, c->win);
	setclientstate(c, WithdrawnState);
	free(c);
	XSync(dpy, False);
	XSetErrorHandler(xerror);
	XUngrabServer(dpy);
	arrange();
}

/* from main.c */

void
cleanup(void) {
	while(stack) {
		resize(stack, True);
		unmanage(stack);
	}
	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);
	XDestroyWindow(dpy, barwin);
	XFreeCursor(dpy, cursor[CurNormal]);
	XFreeCursor(dpy, cursor[CurResize]);
	XFreeCursor(dpy, cursor[CurMove]);
	XSetInputFocus(dpy, PointerRoot, RevertToPointerRoot, CurrentTime);
	XSync(dpy, False);
}

void
scan(void) {
	unsigned int i, num;
	Window *wins, d1, d2;
	XWindowAttributes wa;

	wins = NULL;
	if(XQueryTree(dpy, root, &d1, &d2, &wins, &num)) {
		for(i = 0; i < num; i++) {
			if(!XGetWindowAttributes(dpy, wins[i], &wa))
				continue;
			if(wa.override_redirect || XGetTransientForHint(dpy, wins[i], &d1))
				continue;
			if(wa.map_state == IsViewable)
				manage(wins[i], &wa);
		}
	}
	if(wins)
		XFree(wins);
}

void
setup(void) {
	int i, j;
	unsigned int mask;
	Window w;
	XModifierKeymap *modmap;
	XSetWindowAttributes wa;

	screen = DefaultScreen(dpy);
	root = RootWindow(dpy, screen);

	/* 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);
	XChangeProperty(dpy, root, netatom[NetSupported], XA_ATOM, 32,
			PropModeReplace, (unsigned char *) netatom, NetLast);
	/* init cursors */
	cursor[CurNormal] = XCreateFontCursor(dpy, XC_left_ptr);
	cursor[CurResize] = XCreateFontCursor(dpy, XC_sizing);
	cursor[CurMove] = XCreateFontCursor(dpy, XC_fleur);
	/* init modifier map */
	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);
	/* select for events */
	wa.event_mask = SubstructureRedirectMask | SubstructureNotifyMask
		| EnterWindowMask | LeaveWindowMask | PropertyChangeMask;
	wa.cursor = cursor[CurNormal];
	XChangeWindowAttributes(dpy, root, CWEventMask | CWCursor, &wa);
	grabkeys();
	seltag = False;
	viewfloats = False;
	/* style */
	dc.norm[ColBG] = getcolor(NORMBGCOLOR);
	dc.norm[ColFG] = getcolor(NORMFGCOLOR);
	dc.sel[ColBG] = getcolor(SELBGCOLOR);
	dc.sel[ColFG] = getcolor(SELFGCOLOR);
	setfont(FONT);
	/* geometry */
	sx = sy = 0;
	sw = DisplayWidth(dpy, screen);
	sh = DisplayHeight(dpy, screen);
	nmaster = NMASTER;
	arrange1 = DEFMODE;
	arrange2 = DEFMODE;
	/* bar */
	dc.h = bh = dc.font.height + 2;
	wa.override_redirect = 1;
	wa.background_pixmap = ParentRelative;
	wa.event_mask = ButtonPressMask | ExposureMask;
	barwin = XCreateWindow(dpy, root, sx, sy, sw, bh, 0,
			DefaultDepth(dpy, screen), CopyFromParent, DefaultVisual(dpy, screen),
			CWOverrideRedirect | CWBackPixmap | CWEventMask, &wa);
	XDefineCursor(dpy, barwin, cursor[CurNormal]);
	XMapRaised(dpy, barwin);
	/* windowarea */
	wax = sx;
	way = sy + bh;
	wah = sh - bh;
	waw = sw;
	/* pixmap for everything */
	dc.drawable = XCreatePixmap(dpy, root, sw, bh, DefaultDepth(dpy, screen));
	dc.gc = XCreateGC(dpy, root, 0, 0);
	XSetLineAttributes(dpy, dc.gc, 1, LineSolid, CapButt, JoinMiter);
	/* multihead support */
	selscreen = XQueryPointer(dpy, root, &w, &w, &i, &i, &i, &i, &mask);

	updatestatus();
}

/*
 * Startup Error handler to check if another window manager
 * is already running.
 */
int
xerrorstart(Display *dsply, XErrorEvent *ee) {
	otherwm = True;
	return -1;
}

void
sendevent(Window w, Atom a, long value) {
	XEvent e;

	e.type = ClientMessage;
	e.xclient.window = w;
	e.xclient.message_type = a;
	e.xclient.format = 32;
	e.xclient.data.l[0] = value;
	e.xclient.data.l[1] = CurrentTime;
	XSendEvent(dpy, w, False, NoEventMask, &e);
	XSync(dpy, False);
}

void
quit() {
	running = False;
}

/* 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_GrabKey && ee->error_code == BadAccess)
	|| (ee->request_code == X_CopyArea && ee->error_code == BadDrawable))
		return 0;
	fprintf(stderr, "aewl: fatal error: request code=%d, error code=%d\n",
		ee->request_code, ee->error_code);
	return xerrorxlib(dpy, ee); /* may call exit */
}

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("aewl: another window manager is already running\n");
	}

	XSetErrorHandler(xerror);
	XSync(dpy, False);
}

void
run(void) {
	XEvent ev;

	XSync(dpy, False);
	/* main event loop */
	while(running && !XNextEvent(dpy, &ev)) {
		if(handler[ev.type]) {
			(handler[ev.type])(&ev); /* call handler */
		}
	}
}

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

int
main(int argc, char *argv[]) {

	if(argc == 2 && !strncmp("-v", argv[1], 3)) {
		fputs("aewl-"VERSION", Copyright 2008  markus schnalke <meillo@marmaro.de>\n", stdout);
		fputs("forked off dwm-3.4, (C)opyright MMVI-MMVII Anselm R. Garbe\n", stdout);
		exit(EXIT_SUCCESS);
	} else if(argc != 1) {
		die("usage: aewl [-v]\n");
	}
	setlocale(LC_CTYPE, "");
	dpy = XOpenDisplay(0);
	if(!dpy) {
		die("aewl: cannot open display\n");
	}

	checkotherwm();
	setup();
	scan();
	run();
	cleanup();

	XCloseDisplay(dpy);
	return 0;
}