Suppress no_focus for first window on a workspace.

With this patch, the no_focus directive will be ignored if the
to-be-opened window is the first on its workspace as there's no
reason the user would not want to focus it in this case.
This improves usability when, for example, using a tabbed
workspace_layout.

fixes #1987

docs/userguide

@@ -610,6 +610,10 @@ Note that this does not apply to all cases, e.g., when feeding data into a runni
 causing it to request being focused. To configure the behavior in such cases, refer to
 <<focus_on_window_activation>>.
 
++no_focus+ will also be ignored for the first window on a workspace as there shouldn't be
+a reason to not focus the window in this case. This allows for better usability in
+combination with +workspace_layout+.
+
 *Syntax*:
 -------------------
 no_focus <criteria>

src/manage.c

@@ -524,13 +524,23 @@ void manage_window(xcb_window_t window, xcb_get_window_attributes_cookie_t cooki
     /* Send an event about window creation */
     ipc_send_window_event("new", nc);
 
+    if (set_focus && assignment_for(cwindow, A_NO_FOCUS) != NULL) {
+        /* The first window on a workspace should always be focused. We have to
+         * compare with == 1 because the container has already been inserted at
+         * this point. */
+        if (con_num_children(ws) == 1) {
+            DLOG("This is the first window on this workspace, ignoring no_focus.\n");
+        } else {
+            DLOG("no_focus was set for con = %p, not setting focus.\n", nc);
+            set_focus = false;
+        }
+    }
+
     /* 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) {
-        if (assignment_for(cwindow, A_NO_FOCUS) == NULL) {
-            DLOG("Now setting focus.\n");
-            con_focus(nc);
-        }
+        DLOG("Now setting focus.\n");
+        con_focus(nc);
     }
 
     tree_render();

testcases/t/242-no-focus.t

@@ -36,7 +36,9 @@ $first = open_window;
 $focused = get_focused($ws);
 $second = open_window;
 
+sync_with_i3;
 isnt(get_focused($ws), $focused, 'focus has changed');
+is($x->input_focus, $second->id, 'input focus has changed');
 
 exit_gracefully($pid);
 
@@ -59,7 +61,31 @@ $first = open_window;
 $focused = get_focused($ws);
 $second = open_window(wm_class => 'notme');
 
+sync_with_i3;
 is(get_focused($ws), $focused, 'focus has not changed');
+is($x->input_focus, $first->id, 'input focus has not changed');
+
+exit_gracefully($pid);
+
+#####################################################################
+## 3: no_focus doesn't affect the first window opened on a workspace
+#####################################################################
+
+$config = <<EOT;
+# i3 config file (v4)
+font -misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1
+
+no_focus [instance=focusme]
+EOT
+
+$pid = launch_with_config($config);
+
+$ws = fresh_workspace;
+$focused = get_focused($ws);
+$first = open_window(wm_class => 'focusme');
+
+sync_with_i3;
+is($x->input_focus, $first->id, 'input focus has changed');
 
 exit_gracefully($pid);