/* (C)opyright MMVI-MMVII Anselm R. Garbe <garbeam at gmail dot com>

 * 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.

 *

 * Calls to fetch an X event from the event queue are blocking.  Due reading

 * status text from standard input, a select()-driven main loop has been

 * implemented which selects for reads on the X connection and STDIN_FILENO to

 * handle all data smoothly. 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. Each client contains an array of Bools of the same size as the

 * global tags array to indicate the tags of a client.  For each client dwm

 * creates a small title window, which is resized whenever the (_NET_)WM_NAME

 * properties are updated or the client is moved/resized.

 *

 * Keys and tagging rules are organized as arrays and defined in the config.h

 * file. These arrays are kept static in event.o and tag.o respectively,

 * because no other part of dwm needs access to them.  The current layout is

 * represented by the lt pointer.

 *

 * To understand everything else, start reading main.c:main().

 */

#include "config.h"

#include <X11/Xlib.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 { ColBorder, ColFG, ColBG, ColLast };		/* color */

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 isbanned, isfixed, ismax, isfloating;

	Bool *tags;

	Client *next;

	Client *prev;

	Client *snext;

	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 {

	const char *symbol;

	void (*arrange)(void);

} Layout;

extern const char *tags[];		/* all tags */

char stext[256];			/* status text */

int screen, sx, sy, sw, sh;		/* screen geometry */

int wax, way, wah, waw;			/* windowarea geometry */

unsigned int bh, blw;			/* bar height, bar layout label width */

unsigned int ntags, numlockmask;	/* number of tags, dynamic lock mask */

void (*handler[LASTEvent])(XEvent *);	/* event handler */

Atom wmatom[WMLast], netatom[NetLast];

Bool selscreen, *seltag;		/* seltag is array of Bool */

Client *clients, *sel, *stack;		/* global client list and stack */

Cursor cursor[CurLast];

DC dc;					/* global draw context */

Display *dpy;

Layout *lt;

Window root, barwin;

/* client.c */

void attach(Client *c);			/* attaches c to global client list */

void configure(Client *c);		/* send synthetic configure event */

void detach(Client *c);			/* detaches c from global client list */

void focus(Client *c);			/* focus c, c may be NULL */

void killclient(const char *arg);		/* kill c nicely */

void manage(Window w, XWindowAttributes *wa);	/* manage new client */

void resize(Client *c, int x, int y,

		int w, int h, Bool sizehints);	/* resize with given coordinates c*/

void togglefloating(const char *arg);	/* toggles focused client between floating/tiled state */

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 */

/* draw.c */

void drawstatus(void);			/* draw the bar */

void drawtext(const char *text, unsigned long col[ColLast]);	/* draw text */

unsigned int textw(const char *text);	/* return the width of text in px*/

/* event.c */

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

/* layout.c */

void floating(void);			/* arranges all windows floating */

void focusclient(const char *arg);	/* focuses next(1)/previous(-1) visible client */

void incmasterw(const char *arg);	/* increments the master width with arg's index value */

void incnmaster(const char *arg);	/* increments nmaster with arg's index value */

void initlayouts(void);			/* initialize layout array */

Client *nexttiled(Client *c);		/* returns tiled successor of c */

void restack(void);			/* restores z layers of all clients */

void setlayout(const char *arg);		/* sets layout, -1 toggles */

void togglemax(const char *arg);		/* toggles maximization of floating client */

void zoom(const char *arg);		/* zooms the focused client to master area, arg is ignored */

/* main.c */

void quit(const char *arg);		/* quit dwm nicely */

void sendevent(Window w, Atom a, long value);	/* send synthetic event to w */

int xerror(Display *dsply, XErrorEvent *ee);	/* dwm's X error handler */

/* tag.c */

void compileregs(void);			/* initialize regexps of rules defined in config.h */

Bool isvisible(Client *c);		/* returns True if client is visible */

void settags(Client *c, Client *trans);	/* sets tags of c */

void tag(const char *arg);		/* tags c with arg's index */

void toggletag(const char *arg);		/* toggles c tags with arg's index */

void toggleview(const char *arg);	/* toggles the tag with arg's index (in)visible */

void view(const char *arg);		/* views the tag with arg's index */

/* util.c */

void *emallocz(unsigned int size);	/* allocates zero-initialized memory, exits on error */

void eprint(const char *errstr, ...);	/* prints errstr and exits with 1 */

void spawn(const char *arg);		/* forks a new subprocess with arg's cmd */