DDD_AttributeBase.h

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#ifndef _DDD_AttributeBase_h_
#define _DDD_AttributeBase_h_

/*! \file DDD_AttributeBase.h
  
  \par Copyright Information

  Copyright (c) 2012 The DiSTI Corporation.<br>
  11301 Corporate Blvd; Suite 100<br>
  Orlando, Florida 32817<br>
  USA<br>
  <br>
  All rights reserved.<br>

  This Software contains proprietary trade secrets of DiSTI and may not be
reproduced, in whole or part, in any form, or by any means of electronic,
mechanical, or otherwise, without the written permission of DiSTI.  Said
permission may be derived through the purchase of applicable DiSTI product
licenses which detail the distribution rights of this content and any
Derivative Works based on this or other copyrighted DiSTI Software.

  NO WARRANTY. THE SOFTWARE IS PROVIDED "AS-IS," WITHOUT WARRANTY OF ANY KIND,
AND ANY USE OF THIS SOFTWARE PRODUCT IS AT YOUR OWN RISK. TO THE MAXIMUM EXTENT
PERMITTED BY APPLICABLE LAW, DISTI AND ITS SUPPLIERS DISCLAIM ALL WARRANTIES
AND CONDITIONS, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES AND CONDITIONS OF MERCHANTABILITY AND/OR FITNESS FOR A
PARTICULAR PURPOSE, TITLE, AND NON-INFRINGEMENT, WITH REGARD TO THE SOFTWARE.

  LIMITATION OF LIABILITY. TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW,
IN NO EVENT SHALL DISTI OR ITS SUPPLIERS BE LIABLE FOR ANY SPECIAL, INCIDENTAL,
INDIRECT, OR CONSEQUENTIAL DAMAGES WHATSOEVER (INCLUDING, WITHOUT LIMITATION,
DAMAGES FOR LOSS OF BUSINESS PROFITS, BUSINESS INTERRUPTION, LOSS OF BUSINESS
INFORMATION, OR ANY OTHER PECUNIARY LOSS) ARISING OUT OF THE USE OF OR
INABILITY TO USE THE SOFTWARE, EVEN IF DISTI HAS BEEN ADVISED OF THE POSSIBLITY
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  The aforementioned terms and restrictions are governed by the laws of the
State of Florida and the United States of America.

*/

#include <string>
#include "dynamic_ptr_array.h"
#include "DDD_Include.h"
#include <exception>
#include <stdexcept>

namespace disti
{
class DDD_AttributeBase;


/** \defgroup GroupAttributes DataDirector Attributes */ 

/** \brief DDD_AttributeContainer.  A virtual interface class for containers of attributes. */
class DDD_EXPORT DDD_AttributeContainer
{
public:
    virtual const char *GetName() = 0;
};

/** \brief A virtual interface class for observers of attributes.  
   AttributeObserver-derived objects are able to be notified when an attribute changes.
  */
class DDD_EXPORT DDD_AttributeObserver
{
public:
    /** A callback method that will be called when the attribute being observed changes 
      * if this observer has registered to be notified on attribute change
      * \param attribute  A pointer to the attribute that changed
      */
    virtual void OnAttributeChanged(DDD_AttributeBase *attribute) = 0;
};

/** \brief  Exception thrown whenever attempt to convert an attribute failed. */
class DDD_AttributeConversionException : public std::runtime_error
{
public:
    DDD_AttributeConversionException(const char *reason) : std::runtime_error(reason) { }
};


/** \brief  A virtual interface class for all DataDirector attribute types.
  * \ingroup GroupAttributes
  */
class DDD_EXPORT DDD_AttributeBase
{
public:

    /** The ConnectionState enum is used both to describe the current connection state 
      * of an attribute and the allowable/valid connectablity states of the attribute 
      */
    enum ConnectionState
    {
        NOT_CONNECTED = 0,           /**< The attribute is currently not connected */
        CONNECTED_INPUT     = 1<<1,  /**< The attribute is connected as an input */
        CONNECTED_OUTPUT    = 1<<2,  /**< The attribute is connected as an output */
        CONNECTED_IN_OUT    = (CONNECTED_INPUT | CONNECTED_OUTPUT) /**< The attribute is connected as both an input and output */
    };

    /** The DataType enum describes the base data type used by an attribute.  Its main purpose is to facilitate efficient
      * typed access to attribute data */
    enum DataType
    {
        STRING = 0,  /**< String datatype */
        INT,         /**< Integer datatype (32-bit) */
        UINT,        /**< Unsigned Integer datatype (32-bit) */
        DOUBLE,      /**< Double-precision floating point datatype */
        BOOLEAN,     /**< Boolean datatype */
        BYTEBUFFER   /**< ByteBuffer datatype */
    };

    /** constructor
      * \param name  The instance name of the attribute
      * \param container  The container that will own the attribute
      * \param validConnectionStates  The allowable connection states for the attribute (i.e. how can it be connected?)
      * \param persistent             True if it's a persistent attribute
      * \param revertable             If not NULL, it's a pointer to the revertable attribute for this attribute
      */
    DDD_AttributeBase(const std::string &name, DDD_AttributeContainer *container,int validConnectionStates,bool persistent,DDD_AttributeBase *revertable);

    /** destructor */
    virtual ~DDD_AttributeBase();

    /** \return Returns true if this attribute can be connected as an input */
    bool CanConnectAsInput()  { return ((_validConnectionStates&CONNECTED_INPUT) != 0);}

    /** \return Returns true if this attribute can be connected as an output */
    bool CanConnectAsOutput() {return ((_validConnectionStates&CONNECTED_OUTPUT) != 0);}

    /** \return Returns the valid connection states of the attribute as a bitmask */
    int GetValidConnectionStates() { return _validConnectionStates; }

    /** \return Returns the current connection state of the attribute as a bitmask */
    ConnectionState GetConnectionState();

    /** Sets the current connection state of the attribute
      * \param state  The connection state to set
      */
    void SetConnectionState(ConnectionState state);

    /** Adds the state to the connectability mask for this attribute  
      * \param state  The connection state to set
      */
    void AddConnectionState(ConnectionState state);

    /** \return Returns true if the connection state supports supplied connection type 
      * \param state Type of connection to check for (CONNECTED_INPUT, CONNECTED_OUTPUT)
      */
    bool ConnectionStateSupports(ConnectionState state);

    /** \return Returns the instance name of this attribute */
    const char* Name() const;

    /** \return Returns a pointer to the container that owns this attribute
      */
    DDD_AttributeContainer* GetContainer();

    /** Increases the Reference count of this attribute.  The Reference Count tracks the number of
      * connections that reference the attribute.
      */
    void IncreaseRefCount();

    /** Decreases the Reference count of this attribute.  The Reference Count tracks the number of
      * connections that reference the attribute.
      */
    void DecreaseRefCount();

    /** \return Returns the Reference count of this attribute.  The Reference Count tracks the number of
      * connections that reference the attribute.
      */
    int RefCount();

    // pure virtual methods
    /** \return Returns the value of this attribute in string format */
    virtual std::string GetValueString() const = 0;
    
    /** Sets the value of this attribute using a string value
      * \param value  The new value of the attribute
      * \param notify Whether or not to notify attribute observers
      * \throws DDD_AttributeConversionException
      */
    virtual void SetValueString(const std::string &value,bool notify, DDD_AttributeObserver *originator) = 0;

    /** \return Returns the value of this attribute as an int
      * \throws DDD_AttributeConversionException
      */
    virtual int GetValueInt(void) const = 0;

    /** Sets the value of this attribute using an int value
      * \param value  The new value of the attribute
      * \param notify Whether or not to notify attribute observers
      * \throws DDD_AttributeConversionException
      */
    virtual void SetValueInt(const int value,bool notify, DDD_AttributeObserver *originator) = 0;

    /** \return Returns the value of this attribute as an unsigned int */
    virtual unsigned int GetValueUInt(void) const = 0;

    /** Sets the value of this attribute using an unsigned int value
      * \param value  The new value of the attribute
      * \param notify Whether or not to notify attribute observers
      * \throws DDD_AttributeConversionException
      */
    virtual void SetValueUInt(const unsigned int value,bool notify, DDD_AttributeObserver *originator) = 0;

    /** \return Returns the value of this attribute as double 
      * \throws DDD_AttributeConversionException
      */
    virtual double GetValueDouble(void) const = 0;

    /** Sets the value of this attribute using a double value
      * \param value  The new value of the attribute
      * \param notify Whether or not to notify attribute observers
      * \throws DDD_AttributeConversionException
      */
    virtual void SetValueDouble(const double value,bool notify, DDD_AttributeObserver *originator) = 0;

    /** \return Returns the value of this attribute as an boolean 
      * \throws DDD_AttributeConversionException
      */
    virtual bool GetValueBool(void) const = 0;

    /** Sets the value of this attribute using a bool value
      * \param value  The new value of the attribute
      * \param notify Whether or not to notify attribute observers
      * \throws DDD_AttributeConversionException
      */
    virtual void SetValueBool(const bool value,bool notify, DDD_AttributeObserver *originator) = 0;

    /** \return Returns the value of this attribute as an byteBuffer
      * \param value Newly-allocated buffer returned
      * \length length of buffer
      * \note To avoid leaks, the data returned by value should be deleted when appropriate by the calling module.
      * \throws DDD_AttributeConversionException
      */
    virtual void GetValueByteBuffer(char **value, unsigned int &length) = 0;

    /** Sets the value of this attribute using a byte buffer value
      * \param value  The new buffer value of the attribute
      * \length length of buffer
      * \param notify Whether or not to notify attribute observers
      * \throws DDD_AttributeConversionException
      */
    virtual void SetValueByteBuffer(const char *value, unsigned int length, bool notify, DDD_AttributeObserver *originator) = 0;

    /** \return Returns the preferred data type of the attribute
      * \throws DDD_AttributeConversionException
      */
    virtual DataType GetPreferredDataType() const = 0;

    // static enum utilities
    /** \return Converts the data type enum to a string
      * \param type  The data type enum
      */
    static const char* DataTypeToString(DataType type);

    /** \return Converts the data type string to an enum
      * \param string  The data type as a string
      */
    static DataType StringToDataType(const char* string);

    /** Adds an observer to this attribute that will be notified whenever this attribute changes
      * \param observer  The observer to add.  The observer to add must not already be observing this attribute.
      * \return True if the observer was successfully added, false otherwise
      * \pre The observer to add must not already be observing this attribute.
      */
    bool AddObserver(DDD_AttributeObserver *observer);

    /** Removes an observer from the observer list
      * \param observer  The observer to remove.
      * \return True if the observer was found and removed, false if it wasn't found
      */
    bool RemoveObserver(DDD_AttributeObserver *observer);
    
    /** \return Returns the "EditorSemantic" which suggests to the editor what type of widget 
      * to use when editing this attribute
      */
    std::string EditorSemantic();

    /** Sets the "EditorSemantic" which suggests to the editor what type of widget 
      * to use when editing this attribute.
      * \param semantic The string to set
      */
    void EditorSemantic(const std::string &semantic);

    /** \return Returns a printf style format string which the editor may use when
      * editing this attribute
      */
    std::string EditorFormatString();

    /** Sets the printf style format string which the editor may use when editing this attribute
      * \param  formatStr  The format string to set
      */
    void EditorFormatString(const std::string &formatStr);

    /** \returnReturns the connectability status of the attribute as a string
      */
    std::string Connectability();

    /** Sets the "revertable" attribute for this attribute.  Revertable attributes are "reverted" to an initial value
      * whenever the Data Director is Resumed()
      * \param flag  New revertable flag
      */
    void SetRevertable(DDD_AttributeBase *attr) { _revertable = attr; }

    /** \return Gets the "revertable" attribute for this attribute.  Revertable attributes are "reverted" to an initial value
      * whenever the Data Director is Resumed()
      */
    DDD_AttributeBase *GetRevertable(void) const { return _revertable; }

    /** Sets the "persistent" flag for this attribute.  Persistent attributes are not deleted by the "DeleteDynamicAttributes"
      *  method of DDD_AttributeList
      * \param flag  New persistent flag
      */
    void SetPersistent(bool flag) { _persistent = flag; }

    /** \return Gets the "persistent" flag for this attribute.  Persistent attributes are not deleted 
      * by the "DeleteDynamicAttributes"  method of DDD_AttributeList
      */
    bool IsPersistent(void) const { return _persistent; }

    /** Causes this attribute to "revert" to it's revert value */
    void RevertValue();


    /** Notifies all observers of this attribute that the value has changed */
    void NotifyValueChanged(DDD_AttributeObserver *originator);


protected:


    typedef DynamicPtrArray<DDD_AttributeObserver*> ObserverList;

    ObserverList _observerList;         /**< The list of observers to notify when this attribute changes */
    DDD_AttributeContainer* _container; /**< The container that owns this attribute */

    int _refCount;                      /**< The number of connections that reference this attribute */
    bool _visiting;                     /**< True while attribute is being visited...prevents loops */
    std::string _name;                  /**< The instance name of this attribute */
    
    ConnectionState _connectionState;   /**< The current connection state of this attribute */
    int _validConnectionStates;         /**< The valid connectability states possible for this attribute */

    std::string _editorSemantic;        /**< String defining what type of widget to use in the editor */
    std::string _editorFormatString;    /**< printf style format string to use in the editor */

    DDD_AttributeBase *_revertable;     /**< If the attribute is a "Revertable" attribute, pointer to attribute to revert to */
    bool        _persistent;            /**< True if the attribute is a "Persistent" attribute. */
};


} // end namespace disti

#endif