ioobj.h

#ifndef ioobj_h
#define ioobj_h

/*+
________________________________________________________________________

 (C) dGB Beheer B.V.; (LICENSE) http://opendtect.org/OpendTect_license.txt
 Author:        A.H. Bril
 Date:          31-7-1995
 RCS:           $Id: ioobj.h,v 1.31 2010-04-23 05:41:41 cvsnanne Exp $
________________________________________________________________________

-*/
 
 
#include "conn.h"
#include "multiid.h"
#include "namedobj.h"
class IOPar;
class CallBack;
class ascistream;
class ascostream;
class Translator;
class IOLink;


/*\brief factory entry for IOObjs. Should deliver IOObj of certain type. */

mClass IOObjProducer
{
public:

    virtual bool        canMake(const char*) const      = 0;
    virtual IOObj*      make(const char*,const MultiID&,
                             bool fill_defs) const      = 0;

};

/*\brief object describing how to do I/O for objects

The IOMan object manager manages IODir directories of IOObj objects. These
objects contain the information needed to do the I/O needed for the storage
that is accessed in OpendTect software. IOObj objects not in the root IODir will
have a parent object, which may or may not be useful in relation to the IOObj.

In any case, every IOObj has a unique key in the form of a MultiID. This key
holds (a) the position of the IOObj in the IOMan/IODir tree (b) a unique
integer as an index in the IOObj's own IODir.

A special type of IOObj is the IOLink, which is the object that links to the
'main object' of a sub-IODir. It will usually return info as if it's the main
object itself, but will also allow changing the IOMan's dir with it.
If a link is removed, the entire tree below it is removed.

*/


mClass IOObj : public NamedObject
{
public:

    IOObj*              clone() const;
    IOObj*              getParent() const;
    virtual const MultiID& key() const                  { return key_; }

    virtual             ~IOObj();
    virtual bool        bad() const                     = 0;
    virtual bool        isLink() const                  { return false; }
    virtual void        copyFrom(const IOObj*)          = 0;
    virtual bool        hasConnType( const char* s ) const
                        { return s && !strcmp(s,connType()); }

    virtual const char* connType() const                = 0;
    virtual Conn*       getConn(Conn::State) const      = 0;
    virtual bool        slowOpen() const                { return false; }

    virtual const MultiID& parentKey() const    = 0;
    virtual void        setParentKey(const char*)       = 0;
    virtual const char* translator() const              = 0;
    virtual void        setTranslator(const char*)      = 0;
    virtual const char* group() const                   = 0;
    virtual void        setGroup(const char*)           = 0;
    virtual const char* fullUserExpr(bool forread) const= 0;

    virtual bool        implExists(bool forread) const  = 0;
    virtual bool        implReadOnly() const            { return true; }
    virtual bool        implRemove() const              { return false; }
    virtual bool        implShouldRemove() const        { return true; }
    virtual bool        implRename(const char*,const CallBack* cb=0)
                                                        { return false; }
    virtual bool        implSetReadOnly(bool) const     { return false; }
    virtual bool        removeQuery() const             { return false; }
    virtual void        genDefaultImpl()                {}

    virtual const char* dirName() const;
    bool                isStandAlone() const { return dirname_ ? true : false; }
    void                setStandAlone(const char* dirnm);
    virtual IOPar&      pars() const                    { return pars_; }

    static bool         isKey(const char*);
    static bool         isSurveyDefault(const MultiID&);

    Translator*         getTranslator() const;
    virtual void        acquireNewKey();

    static const int    tmpID()         { return  999999; }
    inline bool         isTmp() const   { return key_.leafID() == tmpID(); }
    bool                isReadDefault() const;

    static int          addProducer(IOObjProducer*);

protected:

    FileNameString*     dirname_;
    IOLink*             mylink_;
    MultiID             key_;

                        IOObj(const char* nm=0,const char* ky=0);
                        IOObj(IOObj*,const char* ky=0);
    static IOObj*       get(ascistream&,const char*,const char*);
    bool                put(ascostream&) const;
    virtual bool        getFrom(ascistream&)            = 0;
    virtual bool        putTo(ascostream&) const        = 0;
    void                setKey( const char* nm )        { key_ = nm; }

private:

    friend class        IODir;
    friend class        IOLink;

    IOPar&              pars_;
    int                 myKey() const;

    static IOObj*       produce(const char*,const char* nm=0,const char* ky=0,
                                bool initdefaults=true);

};

mGlobal bool equalIOObj(const MultiID&,const MultiID&);
mGlobal bool areEqual(const IOObj*,const IOObj*);
mGlobal bool fullImplRemove(const IOObj&);

#endif