/*
* (C)opyright MMVI 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 like dwm selects for SubstructureRedirectMask on the root window, to
+ * receive events about child window appearance and disappearance. Only one X
+ * connection at a time is allowed to select for this event mask by any X
+ * server, thus only one window manager instance can be executed at a time.
+ * Any attempt to select for SubstructureRedirectMask by any connection after
+ * another connection already selected for those events, will result in an
+ * error generated by the server. Such errors are reported through calling the
+ * current X error handler.
+ *
+ * Calls to pop an X event from the event queue of the X connection are
+ * blocking. Due the fact, that dwm reads 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 and without
+ * busy-loop quirks.. The event handlers of dwm are organized in an array
+ * which is accessed whenever a new event has been popped. This allows event
+ * dispatching in O(1) time.
+ *
+ * Each child window of the root window is called a client in window manager
+ * terminology, 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. There are no other data structures to organize the clients
+ * in tag lists, because a single global list is most simple. All clients which
+ * have at least one tag enabled of the current tags viewed, will be visible on
+ * the screen, all other clients are banned to the x-location 2 * screen width.
+ * This avoids having additional layers of workspace handling.
+ *
+ * For each client dwm creates a small title window which is resized whenever
+ * the WM_NAME or _NET_WM_NAME properties are updated.
+ *
+ * Keys and tagging rules are organized as arrays as well 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 mode is represented by the arrange function pointer which wether
+ * points to dofloat or dotile.
*/
#include "config.h"
extern char stext[1024]; /* status text */
extern int bx, by, bw, bh, bmw; /* bar geometry, bar mode label width */
extern int mw, screen, sx, sy, sw, sh; /* screen geometry, master width */
-extern unsigned int ntags, numlockmask; /* number of tags, and dynamic lock mask */
+extern unsigned int ntags, numlockmask; /* number of tags, dynamic lock mask */
extern void (*handler[LASTEvent])(XEvent *); /* event handler */
extern void (*arrange)(Arg *); /* arrange function, indicates mode */
extern Atom wmatom[WMLast], netatom[NetLast];
extern Bool running, issel, maximized, *seltag; /* seltag is array of Bool */
-extern Client *clients, *sel, *stack; /* Client containers */
+extern Client *clients, *sel, *stack; /* global cleint list and stack */
extern Cursor cursor[CurLast];
-extern DC dc; /* draw context for everything */
+extern DC dc; /* global draw context */
extern Display *dpy;
extern Window root, barwin;
/* client.c */
-extern void ban(Client *c); /* ban client from screen */
+extern void ban(Client *c); /* ban c from screen */
extern void focus(Client *c); /* focus c, c may be NULL */
extern Client *getclient(Window w); /* return client of w */
extern Client *getctitle(Window w); /* return client of title window */
extern void killclient(Arg *arg); /* kill c nicely */
extern void manage(Window w, XWindowAttributes *wa); /* manage new client */
extern void resize(Client *c, Bool sizehints, Corner sticky); /* resize c*/
-extern void setsize(Client *c); /* set the size structs of c */
-extern void settitle(Client *c); /* set the name of c */
+extern void updatesize(Client *c); /* update the size structs of c */
+extern void updatetitle(Client *c); /* update the name of c */
extern void togglemax(Arg *arg); /* (un)maximize c */
extern void unmanage(Client *c); /* destroy c */
extern void drawtitle(Client *c); /* draw title of c */
extern unsigned long getcolor(const char *colstr); /* return color of colstr */
extern void setfont(const char *fontstr); /* set the font for DC */
-extern unsigned int textw(const char *text); /* return the text width of text */
+extern unsigned int textw(const char *text); /* return the width of text in px*/
/* event.c */
extern void grabkeys(); /* grab all keys defined in config.h */
extern void initrregs(); /* initialize regexps of rules defined in config.h */
extern Client *getnext(Client *c); /* returns next visible client */
extern Client *getprev(Client *c); /* returns previous visible client */
-extern void settags(Client *c, Client *trans); /* updates tags of c */
-extern void tag(Arg *arg); /* tags c accordingly to arg's index */
-extern void toggletag(Arg *arg); /* toggles c tags accordingly to arg's index */
+extern void settags(Client *c, Client *trans); /* sets tags of c */
+extern void tag(Arg *arg); /* tags c with arg's index */
+extern void toggletag(Arg *arg); /* toggles c tags with arg's index */
/* util.c */
extern void *emallocz(unsigned int size); /* allocates zero-initialized memory, exits on error */
-extern void eprint(const char *errstr, ...); /* prints error string and exits with return code 1 */
+extern void eprint(const char *errstr, ...); /* prints errstr and exits with 1 */
extern void *erealloc(void *ptr, unsigned int size); /* reallocates memory, exits on error */
-extern void spawn(Arg *arg); /* forks a new subprocess accordingly to arg's cmd */
+extern void spawn(Arg *arg); /* forks a new subprocess with to arg's cmd */
/* view.c */
extern void detach(Client *c); /* detaches c from global client list */
-extern void dofloat(Arg *arg); /* arranges all windows in a floating way, arg is ignored */
-extern void dotile(Arg *arg); /* arranges all windows in a tiled way, arg is ignored */
+extern void dofloat(Arg *arg); /* arranges all windows floating, arg is ignored */
+extern void dotile(Arg *arg); /* arranges all windows, arg is ignored */
extern void focusnext(Arg *arg); /* focuses next visible client, arg is ignored */
extern void focusprev(Arg *arg); /* focuses previous visible client, arg is ignored */
extern Bool isvisible(Client *c); /* returns True if client is visible */
-extern void resizecol(Arg *arg); /* resizes the master width accordingly to arg's index value */
+extern void resizecol(Arg *arg); /* resizes the master width with arg's index value */
extern void restack(); /* restores z layers of all clients */
-extern void togglemode(Arg *arg); /* toggles global arrange mode (between dotile and dofloat) */
-extern void toggleview(Arg *arg); /* makes the tag accordingly to arg's index (in)visible */
-extern void view(Arg *arg); /* makes the tag accordingly to arg's index visible */
-extern void viewall(Arg *arg); /* makes all tags visible, arg is ignored */
+extern void togglemode(Arg *arg); /* toggles global arrange function (dotile/dofloat) */
+extern void toggleview(Arg *arg); /* toggles the tag with arg's index (in)visible */
+extern void view(Arg *arg); /* views the tag with arg's index */
+extern void viewall(Arg *arg); /* views all tags, arg is ignored */
extern void zoom(Arg *arg); /* zooms the focused client to master column, arg is ignored */
Got questions, comments, patches, etc.? Contact Jason Woofenden