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#ifndef __com_sun_star_configuration_backend_UpdatableLayer_idl__
#define __com_sun_star_configuration_backend_UpdatableLayer_idl__

#ifndef __com_sun_star_configuration_backend_Layer_idl__
#include <com/sun/star/configuration/backend/Layer.idl>
#endif

#ifndef __com_sun_star_configuration_backend_XUpdatableLayer_idl__
#include <com/sun/star/configuration/backend/XUpdatableLayer.idl>
#endif

//==============================================================================

module com { module sun { module star { module configuration { module backend {

//==============================================================================

/**
  provides read/write access to a configuration data layer.

  <p>A layer contains the configuration setting changes to be performed
  on a default layer (or schema) to obtain the values of those settings
  for a given entity and component.
  </p>
  <p>An updatable layer can be read or replaced with another layer.
  </p>

  @since OOo 1.1.2  
  */
published service UpdatableLayer
{
    //--------------------------------------------------------------------------

    /**
        handles read access to the contents of the layer. 

        <p> If the implementation supports 
         <type scope="com::sun::star::util">XTimeStamped</type>,
         then after executing <member>XUpdatableLayer::replaceWith()</member>
         the timestamp will be the one for the replaced contents and 
         if reading after updates is supported the next read will reproduce the
         replaced data.
        </p>
      */
    service Layer ;

    //--------------------------------------------------------------------------

    /**
      provides write access to the contents of the layer. 
      
       <p> Depending of the actual type (simple, i.e pure <type>XLayer</type> or 
       composite, i.e <type>XCompositeLayer</type>) of the current layer and 
       the provided replacement layer, the operation performed 
       by <member>XUpdatableLayer::replaceWith()</member>, will vary.
       </p>
       <p> For the different current/replacement layer combinations, we have:
       <dl>
           <dt>Simple/Simple<dt> 
           <dd>the provided layer's contents replace the current one's.</dd>

           <dt>Composite/Composite<dt> 
           <dd>all layers (main and sub) present in the
               provided layer are used to replace the corresponding current
               layer contents. Sublayers present in the current layer but
               not in the provided one are left untouched. Sublayers present
               in the provided layer but not in the current one are added to
               the current layer.
            </dd>

           <dt>Simple/Composite<dt> 
           <dd>the main layer and sublayers of the provided layer 
               are merged into one whose contents replace the current layer. 
           </dd>

           <dt>Composite/Simple<dt> 
           <dd>the provided layer is split into a composite one whose contents
               are then used to replace the current layer as described above.
           </dd>

       </dl>
       <em> Not all implementations of <type>XUpdatableLayer</type>
            support conversions of the replacement layer.
            In such a case the sublayers of the provided layer may be ignored
            or all simple data be merged into the main layer.
       </em> 
       </p>
      */
    interface XUpdatableLayer ;

    //--------------------------------------------------------------------------

} ;

//==============================================================================

} ; } ; } ; } ; } ;

#endif

