1/*
  2 * (C)opyright MMVI Anselm R. Garbe <garbeam at gmail dot com>
  3 * See LICENSE file for license details.
  4 *
  5 * dynamic window manager is designed like any other X client as well. It is
  6 * driven through handling X events. In contrast to other X clients, a window
  7 * manager like dwm selects for SubstructureRedirectMask on the root window, to
  8 * receive events about window appearance and disappearance.  Only one X
  9 * connection at a time is allowed to select for this event mask.
 10 *
 11 * Calls to fetch an X event from the X event queue connection are blocking.
 12 * Due reading status text from standard input, a select-driven main loop has
 13 * been implemented which selects for reads on the X connection and
 14 * STDIN_FILENO to handle all data smoothly and without busy-loop quirks. The
 15 * event handlers of dwm are organized in an array which is accessed whenever a
 16 * new event has been fetched. This allows event dispatching in O(1) time.
 17 *
 18 * Each child of the root window is called a client, except windows which have
 19 * set the override_redirect flag.  Clients are organized in a global
 20 * doubly-linked client list, the focus history is remembered through a global
 21 * stack list. Each client contains an array of Bools of the same size as the
 22 * global tags array to indicate the tags of a client.  For each client dwm
 23 * creates a small title window which is resized whenever the WM_NAME or
 24 * _NET_WM_NAME properties are updated or the client is resized.
 25 *
 26 * Keys and tagging rules are organized as arrays and defined in the config.h
 27 * file. These arrays are kept static in event.o and tag.o respectively,
 28 * because no other part of dwm needs access to them.  The current mode is
 29 * represented by the arrange function pointer which wether points to dofloat
 30 * or dotile. 
 31 *
 32 * To understand everything else, start with reading main.c:main().
 33 */
 34
 35#include "config.h"
 36#include <X11/Xlib.h>
 37
 38/* mask shorthands, used in event.c and client.c */
 39#define BUTTONMASK		(ButtonPressMask | ButtonReleaseMask)
 40#define MOUSEMASK		(BUTTONMASK | PointerMotionMask)
 41#define PROTODELWIN		1
 42
 43enum { NetSupported, NetWMName, NetLast };		/* EWMH atoms */
 44enum { WMProtocols, WMDelete, WMLast };			/* default atoms */
 45enum { CurNormal, CurResize, CurMove, CurLast };	/* cursor */
 46enum { ColFG, ColBG, ColLast };				/* color */
 47
 48typedef enum {
 49	TopLeft, TopRight, BotLeft, BotRight
 50} Corner; /* window corners */
 51
 52typedef union {
 53	const char *cmd;
 54	int i;
 55} Arg; /* argument type */
 56
 57typedef struct {
 58	int ascent;
 59	int descent;
 60	int height;
 61	XFontSet set;
 62	XFontStruct *xfont;
 63} Fnt;
 64
 65typedef struct {
 66	int x, y, w, h;
 67	unsigned long norm[ColLast];
 68	unsigned long sel[ColLast];
 69	unsigned long status[ColLast];
 70	Drawable drawable;
 71	Fnt font;
 72	GC gc;
 73} DC; /* draw context */
 74
 75typedef struct Client Client;
 76struct Client {
 77	char name[256];
 78	int proto;
 79	int x, y, w, h;
 80	int tx, ty, tw, th; /* title window geometry */
 81	int basew, baseh, incw, inch, maxw, maxh, minw, minh;
 82	int grav;
 83	long flags; 
 84	unsigned int border, weight;
 85	Bool isfloat;
 86	Bool *tags;
 87	Client *next;
 88	Client *prev;
 89	Client *snext;
 90	Window win;
 91	Window twin;
 92};
 93
 94extern const char *tags[];			/* all tags */
 95extern char stext[1024];			/* status text */
 96extern int bx, by, bw, bh, bmw;			/* bar geometry, bar mode label width */
 97extern int mw, screen, sx, sy, sw, sh;		/* screen geometry, master width */
 98extern unsigned int ntags, numlockmask;		/* number of tags, dynamic lock mask */
 99extern void (*handler[LASTEvent])(XEvent *);	/* event handler */
100extern void (*arrange)(Arg *);			/* arrange function, indicates mode  */
101extern Atom wmatom[WMLast], netatom[NetLast];
102extern Bool running, issel, maximized, *seltag;	/* seltag is array of Bool */
103extern Client *clients, *sel, *stack;		/* global cleint list and stack */
104extern Cursor cursor[CurLast];
105extern DC dc;					/* global draw context */
106extern Display *dpy;
107extern Window root, barwin;
108
109/* client.c */
110extern void ban(Client *c);			/* ban c from screen */
111extern void focus(Client *c);			/* focus c, c may be NULL */
112extern Client *getclient(Window w);		/* return client of w */
113extern Client *getctitle(Window w);		/* return client of title window */
114extern void gravitate(Client *c, Bool invert);	/* gravitate c */
115extern void killclient(Arg *arg);		/* kill c nicely */
116extern void manage(Window w, XWindowAttributes *wa);	/* manage new client */
117extern void resize(Client *c, Bool sizehints, Corner sticky); /* resize c*/
118extern void updatesize(Client *c);			/* update the size structs of c */
119extern void updatetitle(Client *c);		/* update the name of c */
120extern void togglemax(Arg *arg);		/* (un)maximize c */
121extern void unmanage(Client *c);		/* destroy c */
122
123/* draw.c */
124extern void drawall();				/* draw all visible client titles and the bar */
125extern void drawstatus();			/* draw the bar */
126extern void drawtitle(Client *c);		/* draw title of c */
127extern unsigned long getcolor(const char *colstr);	/* return color of colstr */
128extern void setfont(const char *fontstr);	/* set the font for DC */
129extern unsigned int textw(const char *text);	/* return the width of text in px*/
130
131/* event.c */
132extern void grabkeys();				/* grab all keys defined in config.h */
133extern void procevent();			/* process pending X events */
134
135/* main.c */
136extern int getproto(Window w);			/* return protocol mask of WMProtocols property of w */
137extern void quit(Arg *arg);			/* quit dwm nicely */
138extern void sendevent(Window w, Atom a, long value);	/* send synthetic event to w */
139extern int xerror(Display *dsply, XErrorEvent *ee);	/* dwm's X error handler */
140
141/* tag.c */
142extern void initrregs();			/* initialize regexps of rules defined in config.h */
143extern Client *getnext(Client *c);		/* returns next visible client */
144extern Client *getprev(Client *c);		/* returns previous visible client */
145extern void settags(Client *c, Client *trans);	/* sets tags of c */
146extern void tag(Arg *arg);			/* tags c with arg's index */
147extern void toggletag(Arg *arg);		/* toggles c tags with arg's index */
148
149/* util.c */
150extern void *emallocz(unsigned int size);	/* allocates zero-initialized memory, exits on error */
151extern void eprint(const char *errstr, ...);	/* prints errstr and exits with 1 */
152extern void *erealloc(void *ptr, unsigned int size);	/* reallocates memory, exits on error */
153extern void spawn(Arg *arg);			/* forks a new subprocess with to arg's cmd */
154
155/* view.c */
156extern void detach(Client *c);			/* detaches c from global client list */
157extern void dofloat(Arg *arg);			/* arranges all windows floating, arg is ignored */
158extern void dotile(Arg *arg);			/* arranges all windows, arg is ignored */
159extern void focusnext(Arg *arg);		/* focuses next visible client, arg is ignored  */
160extern void focusprev(Arg *arg);		/* focuses previous visible client, arg is ignored */
161extern Bool isvisible(Client *c);		/* returns True if client is visible */
162extern void resizecol(Arg *arg);		/* resizes the master width with arg's index value */
163extern void restack();				/* restores z layers of all clients */
164extern void togglemode(Arg *arg);		/* toggles global arrange function (dotile/dofloat) */
165extern void toggleview(Arg *arg);		/* toggles the tag with arg's index (in)visible */
166extern void view(Arg *arg);			/* views the tag with arg's index */
167extern void viewall(Arg *arg);			/* views all tags, arg is ignored */
168extern void zoom(Arg *arg);			/* zooms the focused client to master column, arg is ignored */