[gnome-boxes/overlay-osd] display-page: Center the DnD transfer message in an overlayed osd box

[Felipe Borges <felipeborges src gnome org>]

commit c9cd4efd4273c72a31948a973a078ed520a230bd
Author: Felipe Borges <felipeborges gnome org>
Date:   Wed Aug 14 09:58:29 2019 +0200

    display-page: Center the DnD transfer message in an overlayed osd box
    
    Fixes #388

 data/ui/display-page.ui | 3 +--
 src/display-page.vala   | 5 +----
 2 files changed, 2 insertions(+), 6 deletions(-)
---
diff --git a/data/ui/display-page.ui b/data/ui/display-page.ui
index 346c3b53..c997b425 100644
--- a/data/ui/display-page.ui
+++ b/data/ui/display-page.ui
@@ -50,10 +50,9 @@
                 <property name="can_focus">False</property>
                 <property name="halign">center</property>
                 <property name="valign">center</property>
-                <property name="hexpand">true</property>
-                <property name="vexpand">true</property>
                 <style>
                   <class name="app-notification"/>
+                  <class name="overlay-box"/>
                 </style>
                 <child>
                   <object class="GtkImage">
diff --git a/src/display-page.vala b/src/display-page.vala
index b786a648..50d3d04b 100644
--- a/src/display-page.vala
+++ b/src/display-page.vala
@@ -158,10 +158,7 @@ public void replace_display (Boxes.Display display, Widget widget) {
 
                 return true;
             });
-            transfer_message_box_drag_motion_id = transfer_message_box.drag_motion.connect (() => {
-                return true;
-            });
-            transfer_message_box_drag_leave_id = transfer_message_box.drag_leave.connect (() => {
+            transfer_message_box_drag_leave_id = widget.drag_leave.connect (() => {
                 transfer_message_box.hide ();
             });
         }