//=============================================================================
// File:       fieldbdy.h
// Contents:   Declarations for DwFieldBody
// Maintainer: Doug Sauder <dwsauder@fwb.gulf.net>
// WWW:        http://www.fwb.gulf.net/~dwsauder/mimepp.html
//
// Copyright (c) 1996, 1997 Douglas W. Sauder
// All rights reserved.
//
// IN NO EVENT SHALL DOUGLAS W. SAUDER BE LIABLE TO ANY PARTY FOR DIRECT,
// INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING OUT OF
// THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF DOUGLAS W. SAUDER
// HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// DOUGLAS W. SAUDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, BUT
// NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
// PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS ON AN "AS IS"
// BASIS, AND DOUGLAS W. SAUDER HAS NO OBLIGATION TO PROVIDE MAINTENANCE,
// SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
//
//=============================================================================

#ifndef DW_FIELDBDY_H
#define DW_FIELDBDY_H

#include <iostream>

#ifndef DW_CONFIG_H
#include <mimelib/config.h>
#endif

#ifndef DW_STRING_H
#include <mimelib/string.h>
#endif

#ifndef DW_MSGCMP_H
#include <mimelib/msgcmp.h>
#endif

//=============================================================================
//+ Name DwFieldBody -- Class representing a MIME header field body
//+ Description
//. {\tt DwFieldBody} represents the field-body element in the BNF grammar
//. specified by RFC-822.  It is an abstract base class that defines the
//. interface common to all structured field bodies.
//.
//. In the tree (broken-down) representation of a message, a {\tt DwFieldBody}
//. object may be either a leaf node, having a parent but no child nodes, or
//. an intermediate node, having a parent and one or more child nodes.  The
//. parent node is the {\tt DwField} object that tqcontains it.  Child nodes,
//. if present, depend on the particular subclass of {\tt DwFieldBody} that
//. is instantiated.  A {\tt DwAddressList} object, for example, has
//. {\tt DwAddress} objects as its child nodes.
//.
//. Since {\tt DwFieldBody} is an abstract base class, you cannot create
//. instances of it directly.  Normally, objects of classes derived from
//. {\tt DwFieldBody} are obtained by calling convenience member functions
//. in the class {\tt DwHeaders}.
//.
//. Some MIME parsers are broken in that they do not handle the folding of
//. some fields properly.  {\tt DwFieldBody} folds its string representation
//. by default.  You can disable folding, however, by calling the
//. {\tt SetFolding()} member function.  To determine if folding is enabled,
//. call {\tt IsFolding()}.
//=============================================================================
// Last updated 1997-08-24
//+ Noentry ~DwFieldBody mLineOffset mDoFolding _PrintDebugInfo


class DW_EXPORT DwFieldBody : public DwMessageComponent {

    friend class DwField;

public:

    DwFieldBody();
    DwFieldBody(const DwFieldBody& aFieldBody);
    DwFieldBody(const DwString& aStr, DwMessageComponent* aParent=0);
    //. The first constructor is the default constructor, which sets the
    //. {\tt DwFieldBody} object's string representation to the empty
    //. string and sets its parent to {\tt NULL}.
    //.
    //. The second constructor is the copy constructor, which performs a
    //. deep copy of {\tt aFieldBody}.
    //. The parent of the new {\tt DwFieldBody} object is set to {\tt NULL}.
    //.
    //. The third constructor copies {\tt aStr} to the {\tt DwFieldBody}
    //. object's string representation and sets {\tt aParent} as its parent.
    //. The virtual member function {\tt Parse()} should be called immediately
    //. after this constructor in order to parse the string representation.
    //. Unless it is {\tt NULL}, {\tt aParent} should point to an object of
    //. a class derived from {\tt DwField}.

    virtual ~DwFieldBody();

    const DwFieldBody& operator = (const DwFieldBody& aFieldBody);
    //. This is the assignment operator, which performs a deep copy of
    //. {\tt aFieldBody}.  The parent node of the {\tt DwFieldBody} object
    //. is not changed.

    void SetOffset(int aOffset);
    //. Sets the offset to {\tt aOffset}.  The offset is used when folding
    //. lines.  It indicates how much the first line should be offset to
    //. account for the field name, colon, and initial white space.

    void SetFolding(DwBool aTrueOrFalse);
    //. Enables ({\tt aTrueOrFalse = DwTrue}) or disables
    //. ({\tt aTrueOrFalse = DwFalse}) the folding of fields.  The default
    //. is to fold fields.  Unfortunately, some parsers are broke and
    //. do not handle folded lines properly.  This function allows a kludge
    //. to deal with these broken parsers.

    DwBool IsFolding() const;
    //. Returns a boolean indicating if folding of fields is enabled.

protected:

    int mLineOffset;
    DwBool mDoFolding;

private:

    static const char* const sClassName;

public:

    virtual void PrintDebugInfo(std::ostream& aStrm, int aDepth=0) const;
    //. This virtual function, inherited from {\tt DwMessageComponent},
    //. prints debugging information about this object to {\tt aStrm}.
    //. It will also call {\tt PrintDebugInfo()} for any of its child
    //. components down to a level of {\tt aDepth}.
    //.
    //. This member function is available only in the debug version of
    //. the library.

    virtual void CheckInvariants() const;
    //. Aborts if one of the invariants of the object fails.  Use this
    //. member function to track down bugs.
    //.
    //. This member function is available only in the debug version of
    //. the library.

protected:

    void _PrintDebugInfo(std::ostream& aStrm) const;

};


inline void DwFieldBody::SetOffset(int aOffset)
{
    mLineOffset = aOffset;
}


inline void DwFieldBody::SetFolding(DwBool aTrueOrFalse)
{
    mDoFolding = aTrueOrFalse;
}


inline DwBool DwFieldBody::IsFolding() const
{
    return mDoFolding;
}

#endif