/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-  */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#ifndef _MORKCELLOBJECT_
#define _MORKCELLOBJECT_ 1

#ifndef _MORK_
#include "mork.h"
#endif

#ifndef _MORKNODE_
#include "morkNode.h"
#endif

#ifndef _MORKOBJECT_
#include "morkObject.h"
#endif

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#define morkDerived_kCellObject  /*i*/ 0x634F /* ascii 'cO' */

class morkCellObject : public morkObject, public nsIMdbCell { // blob attribute in column scope

// public: // slots inherited from morkObject (meant to inform only)
  // nsIMdbHeap*     mNode_Heap;
  // mork_able    mNode_Mutable; // can this node be modified?
  // mork_load    mNode_Load;    // is this node clean or dirty?
  // mork_base    mNode_Base;    // must equal morkBase_kNode
  // mork_derived mNode_Derived; // depends on specific node subclass
  // mork_access  mNode_Access;  // kOpen, kClosing, kShut, or kDead
  // mork_usage   mNode_Usage;   // kHeap, kStack, kMember, kGlobal, kNone
  // mork_uses    mNode_Uses;    // refcount for strong refs
  // mork_refs    mNode_Refs;    // refcount for strong refs + weak refs

  // mork_color   mBead_Color;   // ID for this bead
  // morkHandle*  mObject_Handle;  // weak ref to handle for this object

public: // state is public because the entire Mork system is private
  NS_DECL_ISUPPORTS_INHERITED

  morkRowObject*  mCellObject_RowObject;  // strong ref to row's object
  morkRow*        mCellObject_Row;        // cell's row if still in row object
  morkCell*       mCellObject_Cell;       // cell in row if rowseed matches
  mork_column     mCellObject_Col;        // col of cell last living in pos
  mork_u2         mCellObject_RowSeed;    // copy of row's seed
  mork_u2         mCellObject_Pos;        // position of cell in row
  
// { ===== begin morkNode interface =====
public: // morkNode virtual methods
  virtual void CloseMorkNode(morkEnv* ev); // CloseCellObject() only if open
  
public: // morkCellObject construction & destruction
  morkCellObject(morkEnv* ev, const morkUsage& inUsage,
    nsIMdbHeap* ioHeap, morkRow* ioRow, morkCell* ioCell,
    mork_column inCol, mork_pos inPos);
  void CloseCellObject(morkEnv* ev); // called by CloseMorkNode();

  NS_IMETHOD SetBlob(nsIMdbEnv* ev,
    nsIMdbBlob* ioBlob); // reads inBlob slots
  // when inBlob is in the same suite, this might be fastest cell-to-cell
  
  NS_IMETHOD ClearBlob( // make empty (so content has zero length)
    nsIMdbEnv* ev);
  // clearing a yarn is like SetYarn() with empty yarn instance content
  
  NS_IMETHOD GetBlobFill(nsIMdbEnv* ev,
    mdb_fill* outFill);  // size of blob 
  // Same value that would be put into mYarn_Fill, if one called GetYarn()
  // with a yarn instance that had mYarn_Buf==nil and mYarn_Size==0.
  
  NS_IMETHOD SetYarn(nsIMdbEnv* ev, 
    const mdbYarn* inYarn);   // reads from yarn slots
  // make this text object contain content from the yarn's buffer
  
  NS_IMETHOD GetYarn(nsIMdbEnv* ev, 
    mdbYarn* outYarn);  // writes some yarn slots 
  // copy content into the yarn buffer, and update mYarn_Fill and mYarn_Form
  
  NS_IMETHOD AliasYarn(nsIMdbEnv* ev, 
    mdbYarn* outYarn); // writes ALL yarn slots
  NS_IMETHOD SetColumn(nsIMdbEnv* ev, mdb_column inColumn); 
  NS_IMETHOD GetColumn(nsIMdbEnv* ev, mdb_column* outColumn);
  
  NS_IMETHOD GetCellInfo(  // all cell metainfo except actual content
    nsIMdbEnv* ev, 
    mdb_column* outColumn,           // the column in the containing row
    mdb_fill*   outBlobFill,         // the size of text content in bytes
    mdbOid*     outChildOid,         // oid of possible row or table child
    mdb_bool*   outIsRowChild);  // nonzero if child, and a row child

  // Checking all cell metainfo is a good way to avoid forcing a large cell
  // in to memory when you don't actually want to use the content.
  
  NS_IMETHOD GetRow(nsIMdbEnv* ev, // parent row for this cell
    nsIMdbRow** acqRow);
  NS_IMETHOD GetPort(nsIMdbEnv* ev, // port containing cell
    nsIMdbPort** acqPort);
  // } ----- end attribute methods -----

  // { ----- begin children methods -----
  NS_IMETHOD HasAnyChild( // does cell have a child instead of text?
    nsIMdbEnv* ev,
    mdbOid* outOid,  // out id of row or table (or unbound if no child)
    mdb_bool* outIsRow); // nonzero if child is a row (rather than a table)

  NS_IMETHOD GetAnyChild( // access table of specific attribute
    nsIMdbEnv* ev, // context
    nsIMdbRow** acqRow, // child row (or null)
    nsIMdbTable** acqTable); // child table (or null)


  NS_IMETHOD SetChildRow( // access table of specific attribute
    nsIMdbEnv* ev, // context
    nsIMdbRow* ioRow); // inRow must be bound inside this same db port

  NS_IMETHOD GetChildRow( // access row of specific attribute
    nsIMdbEnv* ev, // context
    nsIMdbRow** acqRow); // acquire child row (or nil if no child)


  NS_IMETHOD SetChildTable( // access table of specific attribute
    nsIMdbEnv* ev, // context
    nsIMdbTable* inTable); // table must be bound inside this same db port

  NS_IMETHOD GetChildTable( // access table of specific attribute
    nsIMdbEnv* ev, // context
    nsIMdbTable** acqTable); // acquire child table (or nil if no child)
  // } ----- end children methods -----

// } ===== end nsIMdbCell methods =====
private: // copying is not allowed
  virtual ~morkCellObject(); // assert that CloseCellObject() executed earlier
  morkCellObject(const morkCellObject& other);
  morkCellObject& operator=(const morkCellObject& other);

public: // dynamic type identification
  mork_bool IsCellObject() const
  { return IsNode() && mNode_Derived == morkDerived_kCellObject; }
// } ===== end morkNode methods =====

public: // other cell node methods

  morkEnv*  CanUseCell(nsIMdbEnv* mev, mork_bool inMutable,
                       nsresult* outErr, morkCell** outCell);

  mork_bool ResyncWithRow(morkEnv* ev); // return ev->Good()
  morkAtom* GetCellAtom(morkEnv* ev) const;

  static void MissingRowColumnError(morkEnv* ev);
  static void NilRowError(morkEnv* ev);
  static void NilCellError(morkEnv* ev);
  static void NilRowObjectError(morkEnv* ev);
  static void WrongRowObjectRowError(morkEnv* ev);
  static void NonCellObjectTypeError(morkEnv* ev);

  nsIMdbCell* AcquireCellHandle(morkEnv* ev);

public: // typesafe refcounting inlines calling inherited morkNode methods
  static void SlotWeakCellObject(morkCellObject* me,
    morkEnv* ev, morkCellObject** ioSlot)
  { morkNode::SlotWeakNode((morkNode*) me, ev, (morkNode**) ioSlot); }
  
  static void SlotStrongCellObject(morkCellObject* me,
    morkEnv* ev, morkCellObject** ioSlot)
  { morkNode::SlotStrongNode((morkNode*) me, ev, (morkNode**) ioSlot); }
};

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#endif /* _MORKCELLOBJECT_ */
