Bugfix: Repeatedly try to find screens if none are available (Thanks mxf)

[i3/i3] / src / mainx.c

diff --git a/src/mainx.c b/src/mainx.c
index 5de87700076d3904fe744c1bc19ac780ecb7049b..d95ca4653dcff818b0d8cb19c82d8b49db373421 100644 (file)
--- a/src/mainx.c
+++ b/src/mainx.c
@@ -72,31 +72,34 @@ xcb_atom_t atoms[NUM_ATOMS];
 int num_screens = 0;
 
 /*
- * Callback for activity on the connection to the X server
+ * This callback is only a dummy, see xcb_prepare_cb and xcb_check_cb.
+ * See also man libev(3): "ev_prepare" and "ev_check" - customise your event loop
  *
  */
 static void xcb_got_event(EV_P_ struct ev_io *w, int revents) {
+        /* empty, because xcb_prepare_cb and xcb_check_cb are used */
+}
+
+/*
+ * Flush before blocking (and waiting for new events)
+ *
+ */
+static void xcb_prepare_cb(EV_P_ ev_prepare *w, int revents) {
+        xcb_flush(evenths.c);
+}
+
+/*
+ * Instead of polling the X connection socket we leave this to
+ * xcb_poll_for_event() which knows better than we can ever know.
+ *
+ */
+static void xcb_check_cb(EV_P_ ev_check *w, int revents) {
         xcb_generic_event_t *event;
 
-        /* When an event is available… */
         while ((event = xcb_poll_for_event(evenths.c)) != NULL) {
-                /* …we handle all events in a row: */
-                do {
-                        xcb_event_handle(&evenths, event);
-                        xcb_aux_sync(evenths.c);
-                        free(event);
-                } while ((event = xcb_poll_for_event(evenths.c)));
-
-                /* Make sure all replies are handled/discarded */
-                xcb_aux_sync(evenths.c);
-
-                /* Afterwards, there may be new events available which would
-                 * not trigger the select() (libev) immediately, so we check
-                 * again (and don’t bail out of the loop). */
+                xcb_event_handle(&evenths, event);
+                free(event);
         }
-
-        /* Make sure all replies are handled/discarded */
-        xcb_aux_sync(evenths.c);
 }
 
 int main(int argc, char *argv[], char *env[]) {
@@ -144,6 +147,9 @@ int main(int argc, char *argv[], char *env[]) {
 
         conn = xcb_connect(NULL, &screens);
 
+        if (xcb_connection_has_error(conn))
+                die("Cannot open display\n");
+
         load_configuration(conn, override_configpath);
 
         /* Place requests for the atoms we need as soon as possible */
@@ -157,6 +163,10 @@ int main(int argc, char *argv[], char *env[]) {
         REQUEST_ATOM(_NET_WM_WINDOW_TYPE);
         REQUEST_ATOM(_NET_WM_DESKTOP);
         REQUEST_ATOM(_NET_WM_WINDOW_TYPE_DOCK);
+        REQUEST_ATOM(_NET_WM_WINDOW_TYPE_DIALOG);
+        REQUEST_ATOM(_NET_WM_WINDOW_TYPE_UTILITY);
+        REQUEST_ATOM(_NET_WM_WINDOW_TYPE_TOOLBAR);
+        REQUEST_ATOM(_NET_WM_WINDOW_TYPE_SPLASH);
         REQUEST_ATOM(_NET_WM_STRUT_PARTIAL);
         REQUEST_ATOM(WM_PROTOCOLS);
         REQUEST_ATOM(WM_DELETE_WINDOW);
@@ -183,6 +193,27 @@ int main(int argc, char *argv[], char *env[]) {
         }
         /* end of ugliness */
 
+        /* Initialize event loop using libev */
+        struct ev_loop *loop = ev_default_loop(0);
+        if (loop == NULL)
+                die("Could not initialize libev. Bad LIBEV_FLAGS?\n");
+
+        struct ev_io *xcb_watcher = scalloc(sizeof(struct ev_io));
+        struct ev_check *xcb_check = scalloc(sizeof(struct ev_check));
+        struct ev_prepare *xcb_prepare = scalloc(sizeof(struct ev_prepare));
+
+        ev_io_init(xcb_watcher, xcb_got_event, xcb_get_file_descriptor(conn), EV_READ);
+        ev_io_start(loop, xcb_watcher);
+
+        ev_check_init(xcb_check, xcb_check_cb);
+        ev_check_start(loop, xcb_check);
+
+        ev_prepare_init(xcb_prepare, xcb_prepare_cb);
+        ev_prepare_start(loop, xcb_prepare);
+
+        /* Grab the server to delay any events until we enter the eventloop */
+        xcb_grab_server(conn);
+
         xcb_event_handlers_init(conn, &evenths);
 
         /* DEBUG: Trap all events and print them */
@@ -260,6 +291,10 @@ int main(int argc, char *argv[], char *env[]) {
         GET_ATOM(_NET_WM_WINDOW_TYPE);
         GET_ATOM(_NET_WM_DESKTOP);
         GET_ATOM(_NET_WM_WINDOW_TYPE_DOCK);
+        GET_ATOM(_NET_WM_WINDOW_TYPE_DIALOG);
+        GET_ATOM(_NET_WM_WINDOW_TYPE_UTILITY);
+        GET_ATOM(_NET_WM_WINDOW_TYPE_TOOLBAR);
+        GET_ATOM(_NET_WM_WINDOW_TYPE_SPLASH);
         GET_ATOM(_NET_WM_STRUT_PARTIAL);
         GET_ATOM(WM_PROTOCOLS);
         GET_ATOM(WM_DELETE_WINDOW);
@@ -272,6 +307,9 @@ int main(int argc, char *argv[], char *env[]) {
         /* Watch _NET_WM_NAME (= title of the window in UTF-8) property */
         xcb_property_set_handler(&prophs, atoms[_NET_WM_NAME], 128, handle_windowname_change, NULL);
 
+        /* Watch WM_TRANSIENT_FOR property (to which client this popup window belongs) */
+        xcb_property_set_handler(&prophs, WM_TRANSIENT_FOR, UINT_MAX, handle_transient_for, NULL);
+
         /* Watch WM_NAME (= title of the window in compound text) property for legacy applications */
         xcb_watch_wm_name(&prophs, 128, handle_windowname_change_legacy, NULL);
 
@@ -337,20 +375,11 @@ int main(int argc, char *argv[], char *env[]) {
                 c_ws = &workspaces[screen->current_workspace];
         }
 
+        /* Handle the events which arrived until now */
+        xcb_check_cb(NULL, NULL, 0);
 
-        /* Initialize event loop using libev */
-        struct ev_loop *loop = ev_default_loop(0);
-        if (loop == NULL)
-                die("Could not initialize libev. Bad LIBEV_FLAGS?\n");
-
-        ev_io xcb_watcher;
-        ev_io_init(&xcb_watcher, xcb_got_event, xcb_get_file_descriptor(conn), EV_READ);
-
-        /* Call the handler to work all events which arrived before the libev-stuff was set up */
-        xcb_got_event(NULL, &xcb_watcher, 0);
-
-        /* Enter the libev eventloop */
-        ev_io_start(loop, &xcb_watcher);
+        /* Ungrab the server to receive events and enter libev’s eventloop */
+        xcb_ungrab_server(conn);
         ev_loop(loop, 0);
 
         /* not reached */