/* 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.

 *

 * 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.

 *

 * 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 <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

#include <sys/select.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

/* macros */

#define MAX(a, b)       ((a) > (b) ? (a) : (b))

#define MIN(a, b)       ((a) < (b) ? (a) : (b))

#define BUTTONMASK      (ButtonPressMask|ButtonReleaseMask)

#define CLEANMASK(mask) (mask & ~(numlockmask|LockMask))

#define LENGTH(x)       (sizeof x / sizeof x[0])

#define MAXTAGLEN       16

#define MOUSEMASK       (BUTTONMASK|PointerMotionMask)

#define TAGMASK         ((int)((1LL << LENGTH(tags)) - 1))

#define TEXTW(x)        (textnw(x, strlen(x)) + dc.font.height)

#define VISIBLE(x)      ((x)->tags & tagset[seltags])

/* enums */

enum { CurNormal, CurResize, CurMove, CurLast };        /* cursor */

enum { ColBorder, ColFG, ColBG, ColLast };              /* color */

enum { NetSupported, NetWMName, NetLast };              /* EWMH atoms */

enum { WMProtocols, WMDelete, WMName, WMState, WMLast };/* default atoms */

/* typedefs */

typedef unsigned int uint;

typedef unsigned long ulong;

typedef struct Client Client;

struct Client {

	char name[256];

	int x, y, w, h;

	int basew, baseh, incw, inch, maxw, maxh, minw, minh;

	int minax, maxax, minay, maxay;

	long flags;

	int bw, oldbw;

	Bool isbanned, isfixed, isfloating, ismax, isurgent;

	uint tags;

	Client *next;

	Client *prev;

	Client *snext;

	Window win;

};

typedef struct {

	int x, y, w, h;

	ulong norm[ColLast];

	ulong sel[ColLast];

	Drawable drawable;

	GC gc;

	struct {

		int ascent;

		int descent;

		int height;

		XFontSet set;

		XFontStruct *xfont;

	} font;

} DC; /* draw context */

typedef struct {

	uint mod;

	KeySym keysym;

	void (*func)(const void *arg);

	const void *arg;

} Key;

typedef struct {

	const char *symbol;

	void (*arrange)(void);

} Layout;

typedef struct {

	const char *class;

	const char *instance;

	const char *title;

	uint tags;

	Bool isfloating;

} Rule;

/* function declarations */

void applyrules(Client *c);

void arrange(void);

void attach(Client *c);

void attachstack(Client *c);

void buttonpress(XEvent *e);

void checkotherwm(void);

void cleanup(void);

void configure(Client *c);

void configurenotify(XEvent *e);

void configurerequest(XEvent *e);

void destroynotify(XEvent *e);

void detach(Client *c);

void detachstack(Client *c);

void drawbar(void);

void drawsquare(Bool filled, Bool empty, Bool invert, ulong col[ColLast]);

void drawtext(const char *text, ulong col[ColLast], Bool invert);

void enternotify(XEvent *e);

void eprint(const char *errstr, ...);

void expose(XEvent *e);

void focus(Client *c);

void focusin(XEvent *e);

void focusnext(const void *arg);

void focusprev(const void *arg);

Client *getclient(Window w);

ulong getcolor(const char *colstr);

long getstate(Window w);

Bool gettextprop(Window w, Atom atom, char *text, uint size);

void grabbuttons(Client *c, Bool focused);

void grabkeys(void);

void initfont(const char *fontstr);

Bool isoccupied(uint t);

Bool isprotodel(Client *c);

Bool isurgent(uint t);

void keypress(XEvent *e);

void killclient(const void *arg);

void manage(Window w, XWindowAttributes *wa);

void mappingnotify(XEvent *e);

void maprequest(XEvent *e);

void movemouse(Client *c);

Client *nexttiled(Client *c);

void propertynotify(XEvent *e);

void quit(const void *arg);

void resize(Client *c, int x, int y, int w, int h, Bool sizehints);

void resizemouse(Client *c);

void restack(void);

void run(void);

void scan(void);

void setclientstate(Client *c, long state);

void setmfact(const void *arg);

void setup(void);

void spawn(const void *arg);

void tag(const void *arg);

uint textnw(const char *text, uint len);

void tile(void);

void togglebar(const void *arg);

void togglefloating(const void *arg);

void togglelayout(const void *arg);

void togglemax(const void *arg);

void toggletag(const void *arg);

void toggleview(const void *arg);

void unmanage(Client *c);

void unmapnotify(XEvent *e);

void updatebar(void);

void updategeom(void);

void updatesizehints(Client *c);

void updatetitle(Client *c);

void updatewmhints(Client *c);

void view(const void *arg);

void viewprevtag(const void *arg);

int xerror(Display *dpy, XErrorEvent *ee);

int xerrordummy(Display *dpy, XErrorEvent *ee);

int xerrorstart(Display *dpy, XErrorEvent *ee);

void zoom(const void *arg);

/* variables */

char stext[256];

int screen, sx, sy, sw, sh;

int bx, by, bw, bh, blw, wx, wy, ww, wh;

uint seltags = 0;

int (*xerrorxlib)(Display *, XErrorEvent *);

uint numlockmask = 0;

void (*handler[LASTEvent]) (XEvent *) = {

	[ButtonPress] = buttonpress,

	[ConfigureRequest] = configurerequest,

	[ConfigureNotify] = configurenotify,

	[DestroyNotify] = destroynotify,

	[EnterNotify] = enternotify,

	[Expose] = expose,

	[FocusIn] = focusin,

	[KeyPress] = keypress,

	[MappingNotify] = mappingnotify,

	[MapRequest] = maprequest,

	[PropertyNotify] = propertynotify,

	[UnmapNotify] = unmapnotify

};

Atom wmatom[WMLast], netatom[NetLast];

Bool domax = False;

Bool otherwm, readin;

Bool running = True;

uint tagset[] = {1, 1}; /* after start, first tag is selected */

Client *clients = NULL;

Client *sel = NULL;

Client *stack = NULL;

Cursor cursor[CurLast];

Display *dpy;

DC dc = {0};

Layout layouts[];

Layout *lt = layouts;

Window root, barwin;

/* configuration, allows nested code to access above variables */

#include "config.h"

/* compile-time check if all tags fit into an uint bit array. */

struct NumTags { char limitexceeded[sizeof(uint) * 8 < LENGTH(tags) ? -1 : 1]; };

/* function implementations */

void

applyrules(Client *c) {

	uint i;

	Rule *r;

	XClassHint ch = { 0 };

	/* rule matching */

	XGetClassHint(dpy, c->win, &ch);

	for(i = 0; i < LENGTH(rules); i++) {

		r = &rules[i];

		if((!r->title || strstr(c->name, r->title))

		&& (!r->class || (ch.res_class && strstr(ch.res_class, r->class)))

		&& (!r->instance || (ch.res_name && strstr(ch.res_name, r->instance)))) {

			c->isfloating = r->isfloating;

			c->tags |= r->tags & TAGMASK;

		}

	}

	if(ch.res_class)

		XFree(ch.res_class);

	if(ch.res_name)

		XFree(ch.res_name);

	if(!c->tags)

		c->tags = tagset[seltags];

}

void

arrange(void) {

	Client *c;

	for(c = clients; c; c = c->next)

		if(VISIBLE(c)) {

			if(!lt->arrange || c->isfloating)

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

		}

		else if(!c->isbanned) {

			XMoveWindow(dpy, c->win, c->x + 2 * sw, c->y);

			c->isbanned = True;

		}

	focus(NULL);

	if(lt->arrange && !domax)

		lt->arrange();

	restack();

}

void

attach(Client *c) {

	if(clients)

		clients->prev = c;

	c->next = clients;

	clients = c;

}

void

attachstack(Client *c) {

	c->snext = stack;

	stack = c;

}

void

buttonpress(XEvent *e) {

	uint i, x, mask;

	Client *c;

	XButtonPressedEvent *ev = &e->xbutton;

	if(ev->window == barwin) {

		x = 0;

		for(i = 0; i < LENGTH(tags); i++) {

			x += TEXTW(tags[i]);

			if(ev->x < x) {

				mask = 1 << i;

				if(ev->button == Button1) {

					if(ev->state & MODKEY)

						tag(&mask);

					else

						view(&mask);

				}

				else if(ev->button == Button3) {

					if(ev->state & MODKEY)

						toggletag(&mask);

					else

						toggleview(&mask);

				}

				return;

			}

		}

		if(ev->x < x + blw) {

			if(ev->button == Button1) 

				togglelayout(NULL);

			else if(ev->button == Button3) 

				togglemax(NULL);

		}

	}

	else if((c = getclient(ev->window))) {

		focus(c);

		if(CLEANMASK(ev->state) != MODKEY || domax)

			return;

		if(ev->button == Button1)

			movemouse(c);