Support _NET_WM_USER_TIME.

With this patch, we support the special value "0" for _NET_WM_USER_TIME
on a window upon managing it, which indicates that the window shall not
be focused.

fixes #2064

include/atoms.xmacro

@@ -30,6 +30,7 @@ xmacro(_NET_DESKTOP_NAMES)
 xmacro(_NET_DESKTOP_VIEWPORT)
 xmacro(_NET_ACTIVE_WINDOW)
 xmacro(_NET_CLOSE_WINDOW)
+xmacro(_NET_WM_USER_TIME)
 xmacro(_NET_STARTUP_ID)
 xmacro(_NET_WORKAREA)
 xmacro(WM_PROTOCOLS)

src/ewmh.c

@@ -263,7 +263,7 @@ void ewmh_setup_hints(void) {
     /* I’m not entirely sure if we need to keep _NET_WM_NAME on root. */
     xcb_change_property(conn, XCB_PROP_MODE_REPLACE, root, A__NET_WM_NAME, A_UTF8_STRING, 8, strlen("i3"), "i3");
 
-    /* only send the first 31 atoms (last one is _NET_CLOSE_WINDOW) increment that number when adding supported atoms */
+    /* only send the first 32 atoms (last one is _NET_CLOSE_WINDOW) increment that number when adding supported atoms */
     xcb_change_property(conn, XCB_PROP_MODE_REPLACE, root, A__NET_SUPPORTED, XCB_ATOM_ATOM, 32, /* number of atoms */ 32, supported_atoms);
 
     /* We need to map this window to be able to set the input focus to it if no other window is available to be focused. */

src/manage.c

@@ -90,7 +90,7 @@ void manage_window(xcb_window_t window, xcb_get_window_attributes_cookie_t cooki
         utf8_title_cookie, title_cookie,
         class_cookie, leader_cookie, transient_cookie,
         role_cookie, startup_id_cookie, wm_hints_cookie,
-        wm_normal_hints_cookie, motif_wm_hints_cookie;
+        wm_normal_hints_cookie, motif_wm_hints_cookie, wm_user_time_cookie;
 
     geomc = xcb_get_geometry(conn, d);
 
@@ -161,6 +161,7 @@ void manage_window(xcb_window_t window, xcb_get_window_attributes_cookie_t cooki
     wm_hints_cookie = xcb_icccm_get_wm_hints(conn, window);
     wm_normal_hints_cookie = xcb_icccm_get_wm_normal_hints(conn, window);
     motif_wm_hints_cookie = GET_PROPERTY(A__MOTIF_WM_HINTS, 5 * sizeof(uint64_t));
+    wm_user_time_cookie = GET_PROPERTY(A__NET_WM_USER_TIME, UINT32_MAX);
 
     DLOG("Managing window 0x%08x\n", window);
 
@@ -532,6 +533,23 @@ void manage_window(xcb_window_t window, xcb_get_window_attributes_cookie_t cooki
         }
     }
 
+    if (set_focus) {
+        DLOG("Checking con = %p for _NET_WM_USER_TIME.\n", nc);
+
+        uint32_t *wm_user_time;
+        xcb_get_property_reply_t *wm_user_time_reply = xcb_get_property_reply(conn, wm_user_time_cookie, NULL);
+        if (wm_user_time_reply != NULL && xcb_get_property_value_length(wm_user_time_reply) != 0 &&
+            (wm_user_time = xcb_get_property_value(wm_user_time_reply)) &&
+            wm_user_time[0] == 0) {
+            DLOG("_NET_WM_USER_TIME set to 0, not focusing con = %p.\n", nc);
+            set_focus = false;
+        }
+
+        FREE(wm_user_time_reply);
+    } else {
+        xcb_discard_reply(conn, wm_user_time_cookie.sequence);
+    }
+
     /* Defer setting focus after the 'new' event has been sent to ensure the
      * proper window event sequence. */
     if (set_focus && !nc->window->doesnt_accept_focus && nc->mapped) {

testcases/t/259-net-wm-user-time.t

@@ -0,0 +1,74 @@
+#!perl
+# vim:ts=4:sw=4:expandtab
+#
+# Please read the following documents before working on tests:
+# • http://build.i3wm.org/docs/testsuite.html
+#   (or docs/testsuite)
+#
+# • http://build.i3wm.org/docs/lib-i3test.html
+#   (alternatively: perldoc ./testcases/lib/i3test.pm)
+#
+# • http://build.i3wm.org/docs/ipc.html
+#   (or docs/ipc)
+#
+# • http://onyxneon.com/books/modern_perl/modern_perl_a4.pdf
+#   (unless you are already familiar with Perl)
+#
+# Test for _NET_WM_USER_TIME.
+# Ticket: #2064
+use i3test;
+use X11::XCB 'PROP_MODE_REPLACE';
+
+my ($ws, $other, $con);
+
+sub open_window_with_user_time {
+    my $wm_user_time = shift;
+
+    my $window = open_window(
+        before_map => sub {
+            my ($window) = @_;
+
+            my $atomname = $x->atom(name => '_NET_WM_USER_TIME');
+            my $atomtype = $x->atom(name => 'CARDINAL');
+            $x->change_property(
+                PROP_MODE_REPLACE,
+                $window->id,
+                $atomname->id,
+                $atomtype->id,
+                32,
+                1,
+                pack('L1', $wm_user_time),
+            );
+        },
+    );
+
+    return $window;
+}
+
+#####################################################################
+# 1: if _NET_WM_USER_TIME is set to 0, the window is not focused
+#    initially.
+#####################################################################
+
+$ws = fresh_workspace;
+
+open_window;
+$other = get_focused($ws);
+open_window_with_user_time(0);
+
+is(get_focused($ws), $other, 'new window is not focused');
+
+#####################################################################
+# 2: if _NET_WM_USER_TIME is set to something other than 0, the
+#    window is focused anyway.
+#####################################################################
+
+$ws = fresh_workspace;
+
+open_window;
+$other = get_focused($ws);
+open_window_with_user_time(42);
+
+isnt(get_focused($ws), $other, 'new window is focused');
+
+done_testing;