xdg-shell: handle clients launched in fullscreen

When client is lauched in fullscreen, it is placed on the
first output, because it is not mapped and
shell_surface_set_output() therefore sets default output.

Since we have no better way how to position newly created windows,
(http://lists.freedesktop.org/archives/wayland-devel/2014-May/thread.html#14568)
set the output to the one that has currently focus. Priority has
the touch focus, then pointer and then keyboard focus.

This fixes bug
https://bugs.freedesktop.org/show_bug.cgi?id=69780

Signed-off-by: Marek Chalupa <mchqwerty@gmail.com>
Tested-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>

desktop-shell/shell.c

@@ -3710,6 +3710,32 @@ xdg_surface_unset_maximized(struct wl_client *client,
 	send_configure_for_surface(shsurf);
 }
 
+static struct weston_output *
+get_focused_output(struct weston_compositor *compositor)
+{
+	struct weston_seat *seat;
+	struct weston_output *output = NULL;
+
+	wl_list_for_each(seat, &compositor->seat_list, link) {
+		/* Priority has touch focus, then pointer and
+		 * then keyboard focus. We should probably have
+		 * three for loops and check frist for touch,
+		 * then for pointer, etc. but unless somebody has some
+		 * objections, I think this is sufficient. */
+		if (seat->touch && seat->touch->focus)
+			output = seat->touch->focus->output;
+		else if (seat->pointer && seat->pointer->focus)
+			output = seat->pointer->focus->output;
+		else if (seat->keyboard && seat->keyboard->focus)
+			output = seat->keyboard->focus->output;
+
+		if (output)
+			break;
+	}
+
+	return output;
+}
+
 static void
 xdg_surface_set_fullscreen(struct wl_client *client,
 			   struct wl_resource *resource,
@@ -3726,6 +3752,13 @@ xdg_surface_set_fullscreen(struct wl_client *client,
 	else
 		output = NULL;
 
+	/* handle clients launching in fullscreen */
+	if (output == NULL && !weston_surface_is_mapped(shsurf->surface)) {
+		/* Set the output to the one that has focus currently. */
+		assert(shsurf->surface);
+		output = get_focused_output(shsurf->surface->compositor);
+	}
+
 	shell_surface_set_output(shsurf, output);
 	shsurf->fullscreen_output = shsurf->output;