backporting my intro-comment of old dwm.h

[dwm.git] / dwm.c

diff --git a/dwm.c b/dwm.c
index d497f4c..7d2a0de 100644 (file)
--- a/dwm.c
+++ b/dwm.c
@@ -1,4 +1,33 @@
-/* See LICENSE file for copyright and license details. */
+/* 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.  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().
+ */
 #include <errno.h>
 #include <locale.h>
 #include <regex.h>
@@ -129,7 +158,6 @@ static void mappingnotify(XEvent *e);
 static void maprequest(XEvent *e);
 static void propertynotify(XEvent *e);
 static void unmapnotify(XEvent *e);
-static void grabkeys(void);
 static unsigned int idxoftag(const char *tag);
 static void floating(void); /* default floating layout */
 static void applyrules(Client *c);
@@ -1070,9 +1098,26 @@ keypress(XEvent *e) {
        KEYS
        unsigned int len = sizeof keys / sizeof keys[0];
        unsigned int i;
+       KeyCode code;
        KeySym keysym;
-       XKeyEvent *ev = &e->xkey;
-
+       XKeyEvent *ev;
+
+       if(!e) { /* grabkeys */
+               XUngrabKey(dpy, AnyKey, AnyModifier, root);
+               for(i = 0; i < len; i++) {
+                       code = XKeysymToKeycode(dpy, keys[i].keysym);
+                       XGrabKey(dpy, code, keys[i].mod, root, True,
+                                       GrabModeAsync, GrabModeAsync);
+                       XGrabKey(dpy, code, keys[i].mod | LockMask, root, True,
+                                       GrabModeAsync, GrabModeAsync);
+                       XGrabKey(dpy, code, keys[i].mod | numlockmask, root, True,
+                                       GrabModeAsync, GrabModeAsync);
+                       XGrabKey(dpy, code, keys[i].mod | numlockmask | LockMask, root, True,
+                                       GrabModeAsync, GrabModeAsync);
+               }
+               return;
+       }
+       ev = &e->xkey;
        keysym = XKeycodeToKeysym(dpy, (KeyCode)ev->keycode, 0);
        for(i = 0; i < len; i++)
                if(keysym == keys[i].keysym
@@ -1099,7 +1144,7 @@ mappingnotify(XEvent *e) {
 
        XRefreshKeyboardMapping(ev);
        if(ev->request == MappingKeyboard)
-               grabkeys();
+               keypress(NULL);
 }
 
 static void
@@ -1152,27 +1197,6 @@ unmapnotify(XEvent *e) {
                unmanage(c);
 }
 
-static void
-grabkeys(void) {
-       KEYS
-       unsigned int len = sizeof keys / sizeof keys[0];
-       unsigned int i;
-       KeyCode code;
-
-       XUngrabKey(dpy, AnyKey, AnyModifier, root);
-       for(i = 0; i < len; i++) {
-               code = XKeysymToKeycode(dpy, keys[i].keysym);
-               XGrabKey(dpy, code, keys[i].mod, root, True,
-                               GrabModeAsync, GrabModeAsync);
-               XGrabKey(dpy, code, keys[i].mod | LockMask, root, True,
-                               GrabModeAsync, GrabModeAsync);
-               XGrabKey(dpy, code, keys[i].mod | numlockmask, root, True,
-                               GrabModeAsync, GrabModeAsync);
-               XGrabKey(dpy, code, keys[i].mod | numlockmask | LockMask, root, True,
-                               GrabModeAsync, GrabModeAsync);
-       }
-}
-
 static unsigned int
 idxoftag(const char *tag) {
        unsigned int i;
@@ -1546,7 +1570,7 @@ setup(void) {
        wa.cursor = cursor[CurNormal];
        XChangeWindowAttributes(dpy, root, CWEventMask | CWCursor, &wa);
        XSelectInput(dpy, root, wa.event_mask);
-       grabkeys();
+       keypress(NULL); /* grabkeys */
        compileregs();
        for(ntags = 0; tags[ntags]; ntags++);
        seltags = emallocz(sizeof(Bool) * ntags);