User Interface described by XML

<Root>

<commands>

       <cmd name="FileNew" _label="New" sensitive="0"

        _tip="Start a new document" pixtype="stock" pixname="New"/>

       <cmd name="FileOpen" _label="Open"

        _tip="Open a file" pixtype="stock" pixname="Open" accel="F3"/>

       <cmd name="FileClose" _label="Close"

        _tip="Close the current file" pixtype="stock" pixname="Close"

        accel="*Control*w"/>

       <cmd name="FileExit" _label="Exit" _tip="Exit the program"

        pixtype="stock" pixname="Exit" accel="*Control*q"/>

</commands>

<menu>

       <submenu name="File" _label="_File">

               <menuitem name="FileNew" verb="" _label="_New"/>

               <menuitem name="FileOpen" verb="" _label="_Open..."/>

               <placeholder name="FileOps"/>

               <placeholder/>

               <menuitem name="FileRevert" verb="" _label="_Revert"/>

               <separator/>

               <menuitem name="FileClose" verb="" _label="_Close"/>

               <menuitem name="FileExit" verb="" _label="E_xit"/>

       </submenu>

       <placeholder name="Component"/>

       <submenu name="Help" _label="_Help">

               <placeholder name="BuiltMenuItems"/>

               <menuitem name="HelpAbout" verb="" _label="_About..."/>

       </submenu>

</menu>

<dockitem name="Toolbar" _tip="Main toolbar">

       <toolitem name="whatever" verb="FileClose"/>

       <separator/>

       <toolitem name="bold" type="toggle" _label="Bold"

        _descr="Sets something as bold" pixtype="stock"

        pixname="Open" id="bold"/>

</dockitem>

<status>

       <item name="main">This is the staus bar text </a>

       <control name="Progress"/>

</status>

</Root>

UI XML Merging ... an example:

Merging into the container, we insert a the default placeholder: which has no name

Initial

<submenu name="File">

<item name="Open"/>

<placeholder/>

</submenu>

But we can insert before:

<submenu name="File">

<placeholder/>

<item name="Open"/>

</submenu>

Overlaid

<submenu name="File">

<item name="Close"/>

<item name="Exit"/>

</submenu>

<submenu name="File">

<item name="Close"/>

<item name="Exit"/>

</submenu>

Result

<submenu name="File">

<item name="Open"/>

<item name="Close"/>

<item name="Exit"/>

<placeholder/>

</submenu>

<submenu name="File">

<item name="Close"/>

<item name="Exit"/>

<placeholder/>

<item name="Open"/>

</submenu>