cd /home/idv/idv/ucar/unidata/apps/example
less idv.rbiand note the skin entry:
  <!--The different user interfaces available  -->
  <resources name="idv.resource.skin">
    <resource
       location="/ucar/unidata/apps/example/resources/skin.xml"
       label="Example>Example UI">
     <property name="view_class" value="ucar.unidata.idv.MapViewManager"/>
    </resource>
  </resources>
           <idv.view place="Center" class="${view_class}"/>
To:
        <panel layout="border" place="Center">
           <label text="Example Skin" fontsize="24" place="North"/>
           <idv.view place="Center" class="${view_class}"/>
        </panel>
java ucar.unidata.ui.XmlUi skin.xml
java ucar.unidata.apps.example.ExampleIdv
e.g.:<property name="default" value="true"/>
    <resource
       location="/ucar/unidata/apps/example/resources/skin.xml"
       label="Example>Example UI">
     <property name="view_class" value="ucar.unidata.idv.MapViewManager"/>
     <property name="default" value="true"/>
    </resource>
<resources name="idv.resource.skin" loadmore="false">
<example.label text="Example Skin" place="North"/>
public Component createComponent(Element node, String id) {
    String tagName = node.getTagName();
    if(tagName.equals("example.label")) {
        JLabel label = new JLabel(XmlUtil.getAttribute(node, XmlUi.ATTR_TEXT));
        label.setForeground(Color.red);
        return label;
     }
     return super.createComponent(node, id);
}
    public IdvWindow createNewWindow(List viewManagers, boolean notifyCollab,
                                     String title, String skinPath,
                                     Element skinRoot) {...}
        if(!testNewWindow)  {
            return super.createNewWindow(viewManagers, notifyCollab,title, skinPath, skinRoot);
        }