titleWidget 
  The title widget to display.
When set to NULL, the header bar will display the title of the window it is contained in.
To use a different title, use class@WindowTitle:
<object class="AdwHeaderBar">
  <property name="title-widget">
    <object class="AdwWindowTitle">
      <property name="title" translatable="yes">Title</property>
    </object>
  </property>
</object>Content copied to clipboard