UNI_Item.h

Go to the documentation of this file.

/*
 * PROPRIETARY INFORMATION.  This software is proprietary to
 * Side Effects Software Inc., and is not to be reproduced,
 * transmitted, or disclosed in any way without written permission.
 *
 * NAME:        UNI_Item.h ( UNI Library, C++)
 *
 * COMMENTS:
 *      
 */

#ifndef __UNI_Item_h__
#define __UNI_Item_h__

#include "UNI_API.h"
#include "UNI_GraphHandle.h"

// ============================================================================
template<class UNI_ID_TYPE>
class UNI_ConstItem
{
public:
    /// Constructor.
    UNI_ConstItem() = default;
    UNI_ConstItem( const UNI_ConstGraphHandle &graph_handle, UNI_ID_TYPE id )
        : myGraphHandle( graph_handle )
        , myID( id )
    {}

    /// Constructor with r-value for the intrusive graph pointer.
    UNI_ConstItem( UNI_ConstGraphHandle &&graph_handle, UNI_ID_TYPE id )
        : myGraphHandle( std::move(graph_handle) )
        , myID( id )
    {}

    /// @{ Returns true if the UNI node is valid. Ie, it has a valid API with
    /// a valid graph, and represents a valid node in that graph.
    bool                isValid() const { return graph() && 
                                                 graph()->isValid(id()); }
    explicit operator   bool()  const   { return isValid(); }
    /// @}

    /// Returns the graph inside which the node lives.
    const UNI_Graph *   graph() const   { return myGraphHandle.graph(); }

    /// Returns the ID of the node in the graph.
    UNI_ID_TYPE         id() const      { return myID; }

protected:
    /// Returns the underlying graph handle.
    const UNI_ConstGraphHandle &graphHandle() const 
    { 
        return myGraphHandle; 
    }

private:
    /// Graph interface that performs operations on nodes.
    UNI_ConstGraphHandle    myGraphHandle;

    /// The ID of the node in the graph.
    UNI_ID_TYPE             myID;
};


// ============================================================================
template<class UNI_ID_TYPE, class UNI_SESSION_ID_TYPE, class CONST_BASE_TYPE>
class UNI_Item : public CONST_BASE_TYPE
{
public:
    /// Constructor.
    UNI_Item() = default;
    UNI_Item( const UNI_GraphHandle &graph_handle, UNI_ID_TYPE id )
        : CONST_BASE_TYPE( graph_handle, id ) {}

    /// Constructor with r-value for the intrusive graph pointer.
    UNI_Item( UNI_GraphHandle &&graph_handle, UNI_ID_TYPE id )
        : CONST_BASE_TYPE( std::move(graph_handle), id ) {}

    /// @{ Other convenience constructors.
    UNI_Item( UNI_SESSION_ID_TYPE session_id )
        : UNI_Item( session_id.graphID(), session_id.localID() ) {}
    UNI_Item( UNI_GraphID graph_id, UNI_ID_TYPE id )
        : UNI_Item( UNI_GraphHandle(graph_id), id ) {}
    /// @}
   
    /// Returns the graph inside which the node lives.
    UNI_Graph *graph() const
    {
        // This sub-class constructs the base class always with 
        // a non-const graph, so we can cast away constness here.
        return const_cast<UNI_Graph*>( UNI_ConstItem<UNI_ID_TYPE>::graph() );
    }

    /// Alias the change block for use in this class, for brevity.
    using ChangeBlock = UNI_Graph::ChangeBlock;
    using ChangeType  = UNI_GraphChangeType;
};

#endif