fix fullscreen issues

data/ui/Window.ui

@@ -78,6 +78,7 @@
                         <property name="visible">True</property>
                         <property name="can_focus">True</property>
                         <property name="receives_default">True</property>
+                        <property name="margin_top">6</property>
                         <property name="hexpand">True</property>
                         <property name="vexpand">True</property>
                         <child>
@@ -410,8 +411,6 @@
         <property name="height_request">1</property>
         <property name="can_focus">False</property>
         <property name="valign">start</property>
-        <property name="visible_window">False</property>
-        <property name="above_child">True</property>
         <child>
           <placeholder/>
         </child>

uberwriter/headerbars.py

@@ -79,12 +79,12 @@ class FullscreenHeaderbar(BaseHeaderbar):
         self.events.connect('leave_notify_event', self.hide_fs_hb)
         self.menu_button.get_popover().connect('closed', self.hide_fs_hb)
 
-    def show_fs_hb(self, _widget, _data=None):
+    def show_fs_hb(self, _widget=None, _data=None):
         """show headerbar of the fullscreen mode
         """
         self.hb_revealer.set_reveal_child(True)
 
-    def hide_fs_hb(self, _widget, _data=None):
+    def hide_fs_hb(self, _widget=None, _data=None):
         """hide headerbar of the fullscreen mode
         """
         if self.menu_button.get_active():

uberwriter/main_window.py

@@ -210,9 +210,12 @@ class MainWindow(StyledWindow):
         if state.get_boolean():
             self.fullscreen()
             self.fs_headerbar.events.show()
+            self.fs_headerbar.hide_fs_hb()
+            self.headerbar_eventbox.hide()
         else:
             self.unfullscreen()
             self.fs_headerbar.events.hide()
+            self.headerbar_eventbox.show()
         self.text_view.grab_focus()
 
     def set_focus_mode(self, state):