wxWidgets/include/wx/xtistrm.h

/////////////////////////////////////////////////////////////////////////////
// Name:        wx/xtistrm.h
// Purpose:     streaming runtime metadata information (extended class info)
// Author:      Stefan Csomor
// Modified by:
// Created:     27/07/03
// RCS-ID:      $Id$
// Copyright:   (c) 2003 Stefan Csomor
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#ifndef _WX_XTISTRMH__
#define _WX_XTISTRMH__

#if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
#pragma interface "xtistrm.h"
#endif

#include "wx/wx.h"

#if wxUSE_EXTENDED_RTTI

const int wxInvalidObjectID = -2 ;
const int wxNullObjectID = -3 ;

// Filer contains the interfaces for streaming objects in and out of XML,
// rendering them either to objects in memory, or to code.  Note:  We
// consider the process of generating code to be one of *depersisting* the
// object from xml, *not* of persisting the object to code from an object
// in memory.  This distincation can be confusing, and should be kept
// in mind when looking at the property streamers and callback interfaces
// listed below.

/*
Main interfaces for streaming out objects.
*/

// ----------------------------------------------------------------------------
// wxPersister
//
// This class will be asked during the streaming-out process about every single
// property or object instance. It can veto streaming out by returning false
// or modify the value before it is streamed-out.
// ----------------------------------------------------------------------------

class WXDLLIMPEXP_BASE wxWriter ;
class WXDLLIMPEXP_BASE wxReader ;

class WXDLLIMPEXP_BASE wxPersister
{
public :
    // will be called before an object is written, may veto by returning false
    virtual bool BeforeWriteObject( wxWriter *WXUNUSED(writer) , const wxObject *WXUNUSED(object) , const wxClassInfo *WXUNUSED(classInfo) , wxxVariantArray &WXUNUSED(metadata)) { return true ; }

    // will be called after this object has been written, may be needed for adjusting stacks
    virtual void AfterWriteObject( wxWriter *WXUNUSED(writer)  , const wxObject *WXUNUSED(object) , const wxClassInfo *WXUNUSED(classInfo) ) {}

    // will be called before a property gets written, may change the value , eg replace a concrete wxSize by wxSize( wxDefaultCoord , wxDefaultCoord ) or veto
    // writing that property at all by returning false
    virtual bool BeforeWriteProperty( wxWriter *WXUNUSED(writer)  , const wxObject *WXUNUSED(object), const wxPropertyInfo *WXUNUSED(propInfo) , wxxVariant &WXUNUSED(value) )  { return true ; }

    // will be called before a property gets written, may change the value , eg replace a concrete wxSize by wxSize( wxDefaultCoord , wxDefaultCoord ) or veto
    // writing that property at all by returning false
    virtual bool BeforeWriteProperty( wxWriter *WXUNUSED(writer)  , const wxObject *WXUNUSED(object), const wxPropertyInfo *WXUNUSED(propInfo) , wxxVariantArray &WXUNUSED(value) )  { return true ; }

    // will be called after a property has been written out, may be needed for adjusting stacks
    virtual void AfterWriteProperty( wxWriter *WXUNUSED(writer)  , const wxPropertyInfo *WXUNUSED(propInfo) ) {}

    // will be called before this delegate gets written
    virtual bool BeforeWriteDelegate( wxWriter *WXUNUSED(writer) , const wxObject *WXUNUSED(object),  const wxClassInfo* WXUNUSED(classInfo) , const wxPropertyInfo *WXUNUSED(propInfo) ,
        const wxObject *&WXUNUSED(eventSink) , const wxHandlerInfo* &WXUNUSED(handlerInfo) ) { return true ; }

        virtual void AfterWriteDelegate( wxWriter *WXUNUSED(writer) , const wxObject *WXUNUSED(object),  const wxClassInfo* WXUNUSED(classInfo) , const wxPropertyInfo *WXUNUSED(propInfo) ,
            const wxObject *&WXUNUSED(eventSink) , const wxHandlerInfo* &WXUNUSED(handlerInfo) ) { }
} ;

class WXDLLIMPEXP_BASE wxWriter : public wxObject
{
public :
    wxWriter() ;
    ~wxWriter() ;

    // with this call you start writing out a new top-level object
    void WriteObject(const wxObject *object, const wxClassInfo *classInfo , wxPersister *persister , const wxString &name , wxxVariantArray &WXUNUSED(metadata)) ;

    //
    // Managing the object identity table a.k.a context
    //
    // these methods make sure that no object gets written twice, because sometimes multiple calls to the WriteObject will be
    // made without wanting to have duplicate objects written, the object identity table will be reset manually

    virtual void ClearObjectContext() ;

    // gets the object Id for a passed in object in the context
    int GetObjectID(const wxObject *obj) ;

    // returns true if this object has already been written in this context
    bool IsObjectKnown( const wxObject *obj ) ;

    //
    // streaming callbacks
    //
    // these callbacks really write out the values in the stream format

    // begins writing out a new toplevel entry which has the indicated unique name
    virtual void DoBeginWriteTopLevelEntry( const wxString &name ) = 0 ;

    // ends writing out a new toplevel entry which has the indicated unique name
    virtual void DoEndWriteTopLevelEntry( const wxString &name ) = 0 ;

    // start of writing an object having the passed in ID
    virtual void DoBeginWriteObject(const wxObject *object, const wxClassInfo *classInfo, int objectID , wxxVariantArray &metadata ) = 0 ;

    // end of writing an toplevel object name param is used for unique identification within the container
    virtual void DoEndWriteObject(const wxObject *object, const wxClassInfo *classInfo, int objectID ) = 0 ;

    // writes a simple property in the stream format
    virtual void DoWriteSimpleType( wxxVariant &value ) = 0 ;

    // start of writing a complex property into the stream (
    virtual void DoBeginWriteProperty( const wxPropertyInfo *propInfo ) = 0 ;

    // end of writing a complex property into the stream
    virtual void DoEndWriteProperty( const wxPropertyInfo *propInfo ) = 0;

    virtual void DoBeginWriteElement() = 0 ;
    virtual void DoEndWriteElement() = 0 ;
    // insert an object reference to an already written object
    virtual void DoWriteRepeatedObject( int objectID ) = 0 ;

    // insert a null reference
    virtual void DoWriteNullObject() = 0 ;

    // writes a delegate in the stream format
    virtual void DoWriteDelegate( const wxObject *object,  const wxClassInfo* classInfo , const wxPropertyInfo *propInfo ,
        const wxObject *eventSink , int sinkObjectID , const wxClassInfo* eventSinkClassInfo , const wxHandlerInfo* handlerIndo ) = 0;
private :

    struct wxWriterInternal ;
    wxWriterInternal* m_data ;

    struct wxWriterInternalPropertiesData ;

    void WriteAllProperties( const wxObject * obj , const wxClassInfo* ci , wxPersister *persister, wxWriterInternalPropertiesData * data ) ;
    void WriteOneProperty( const wxObject *obj , const wxClassInfo* ci , const wxPropertyInfo* pi , wxPersister *persister , wxWriterInternalPropertiesData *data ) ;
    void WriteObject(const wxObject *object, const wxClassInfo *classInfo , wxPersister *persister , bool isEmbedded, wxxVariantArray &metadata ) ;
    void FindConnectEntry(const wxEvtHandler * evSource,const wxDelegateTypeInfo* dti, const wxObject* &sink , const wxHandlerInfo *&handler) ;
} ;


/*
Streaming callbacks for depersisting XML to code, or running objects
*/

class WXDLLIMPEXP_BASE wxDepersister ;

/*
wxReader handles streaming in a class from a arbitrary format. While walking through
it issues calls out to interfaces to depersist the guts from the underlying storage format.
*/

class WXDLLIMPEXP_BASE wxReader : public wxObject
{
public :
    wxReader() ;
    ~wxReader() ;

    // the only thing wxReader knows about is the class info by object ID
    wxClassInfo *GetObjectClassInfo(int objectID) ;
    bool HasObjectClassInfo( int objectID ) ;
    void SetObjectClassInfo(int objectID, wxClassInfo* classInfo);

    // Reads the component the reader is pointed at from the underlying format.
    // The return value is the root object ID, which can
    // then be used to ask the depersister about that object
    // if there was a problem you will get back wxInvalidObjectID and the current
    // error log will carry the problems encoutered
    virtual int ReadObject( const wxString &name , wxDepersister *depersist ) = 0 ;

private :
    struct wxReaderInternal;
    wxReaderInternal *m_data;
} ;

// This abstract class matches the allocate-init/create model of creation of objects.
// At runtime, these will create actual instances, and manipulate them.
// When generating code, these will just create statements of C++
// code to create the objects.

class WXDLLIMPEXP_BASE wxDepersister
{
public :
    // allocate the new object on the heap, that object will have the passed in ID
    virtual void AllocateObject(int objectID, wxClassInfo *classInfo, wxxVariantArray &metadata) = 0;

    // initialize the already allocated object having the ID objectID with the Create method
    // creation parameters which are objects are having their Ids passed in objectIDValues
    // having objectId <> wxInvalidObjectID

    virtual void CreateObject(int objectID,
        const wxClassInfo *classInfo,
        int paramCount,
        wxxVariant *VariantValues ,
        int *objectIDValues ,
        const wxClassInfo **objectClassInfos ,
        wxxVariantArray &metadata) = 0;

    // construct the new object on the heap, that object will have the passed in ID (for objects that
    // don't support allocate-create type of creation)
    // creation parameters which are objects are having their Ids passed in objectIDValues
    // having objectId <> wxInvalidObjectID

    virtual void ConstructObject(int objectID,
        const wxClassInfo *classInfo,
        int paramCount,
        wxxVariant *VariantValues ,
        int *objectIDValues ,
        const wxClassInfo **objectClassInfos ,
        wxxVariantArray &metadata) = 0;

    // destroy the heap-allocated object having the ID objectID, this may be used if an object
    // is embedded in another object and set via value semantics, so the intermediate
    // object can be destroyed after safely
    virtual void DestroyObject(int objectID, wxClassInfo *classInfo) = 0;

    // set the corresponding property
    virtual void SetProperty(int objectID,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        const wxxVariant &VariantValue) = 0;

    // sets the corresponding property (value is an object)
    virtual void SetPropertyAsObject(int objectID,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        int valueObjectId) = 0;

    // adds an element to a property collection
    virtual void AddToPropertyCollection( int objectID ,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        const wxxVariant &VariantValue) = 0;

    // sets the corresponding property (value is an object)
    virtual void AddToPropertyCollectionAsObject(int objectID,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        int valueObjectId) = 0;

    // sets the corresponding event handler
    virtual void SetConnect(int EventSourceObjectID,
        const wxClassInfo *EventSourceClassInfo,
        const wxPropertyInfo *delegateInfo ,
        const wxClassInfo *EventSinkClassInfo ,
        const wxHandlerInfo* handlerInfo ,
        int EventSinkObjectID ) = 0;
};

/*
wxRuntimeDepersister implements the callbacks that will depersist
an object into a running memory image, as opposed to writing
C++ initialization code to bring the object to life.
*/

class WXDLLIMPEXP_BASE wxRuntimeDepersister : public wxDepersister
{
    struct wxRuntimeDepersisterInternal ;
    wxRuntimeDepersisterInternal * m_data ;
public :
    wxRuntimeDepersister();
    virtual ~wxRuntimeDepersister();

    // returns the object having the corresponding ID fully constructed
    wxObject *GetObject(int objectID) ;

    // allocate the new object on the heap, that object will have the passed in ID
    virtual void AllocateObject(int objectID, wxClassInfo *classInfo ,
        wxxVariantArray &metadata) ;

    // initialize the already allocated object having the ID objectID with the Create method
    // creation parameters which are objects are having their Ids passed in objectIDValues
    // having objectId <> wxInvalidObjectID

    virtual void CreateObject(int objectID,
        const wxClassInfo *classInfo,
        int paramCount,
        wxxVariant *VariantValues ,
        int *objectIDValues,
        const wxClassInfo **objectClassInfos ,
        wxxVariantArray &metadata
        ) ;

    // construct the new object on the heap, that object will have the passed in ID (for objects that
    // don't support allocate-create type of creation)
    // creation parameters which are objects are having their Ids passed in objectIDValues
    // having objectId <> wxInvalidObjectID

    virtual void ConstructObject(int objectID,
        const wxClassInfo *classInfo,
        int paramCount,
        wxxVariant *VariantValues ,
        int *objectIDValues ,
        const wxClassInfo **objectClassInfos ,
        wxxVariantArray &metadata) ;

    // destroy the heap-allocated object having the ID objectID, this may be used if an object
    // is embedded in another object and set via value semantics, so the intermediate
    // object can be destroyed after safely
    virtual void DestroyObject(int objectID, wxClassInfo *classInfo) ;

    // set the corresponding property
    virtual void SetProperty(int objectID,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        const wxxVariant &variantValue);

    // sets the corresponding property (value is an object)
    virtual void SetPropertyAsObject(int objectId,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        int valueObjectId) ;

    // adds an element to a property collection
    virtual void AddToPropertyCollection( int objectID ,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        const wxxVariant &VariantValue) ;

    // sets the corresponding property (value is an object)
    virtual void AddToPropertyCollectionAsObject(int objectID,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        int valueObjectId) ;

    // sets the corresponding event handler
    virtual void SetConnect(int eventSourceObjectID,
        const wxClassInfo *eventSourceClassInfo,
        const wxPropertyInfo *delegateInfo ,
        const wxClassInfo *eventSinkClassInfo ,
        const wxHandlerInfo* handlerInfo ,
        int eventSinkObjectID ) ;
};

/*
wxDepersisterCode implements the callbacks that will depersist
an object into a C++ initialization function. this will move to
a utility lib soon
*/

class WXDLLIMPEXP_BASE wxTextOutputStream ;

class WXDLLIMPEXP_BASE wxCodeDepersister : public wxDepersister
{
private :
    struct wxCodeDepersisterInternal ;
    wxCodeDepersisterInternal * m_data ;
    wxTextOutputStream *m_fp;
    wxString ValueAsCode( const wxxVariant &param ) ;
public:
    wxCodeDepersister(wxTextOutputStream *out);
    virtual ~wxCodeDepersister();

    // allocate the new object on the heap, that object will have the passed in ID
    virtual void AllocateObject(int objectID, wxClassInfo *classInfo ,
        wxxVariantArray &metadata) ;

    // initialize the already allocated object having the ID objectID with the Create method
    // creation parameters which are objects are having their Ids passed in objectIDValues
    // having objectId <> wxInvalidObjectID

    virtual void CreateObject(int objectID,
        const wxClassInfo *classInfo,
        int paramCount,
        wxxVariant *variantValues ,
        int *objectIDValues,
        const wxClassInfo **objectClassInfos ,
        wxxVariantArray &metadata
        ) ;

     // construct the new object on the heap, that object will have the passed in ID (for objects that
    // don't support allocate-create type of creation)
    // creation parameters which are objects are having their Ids passed in objectIDValues
    // having objectId <> wxInvalidObjectID

    virtual void ConstructObject(int objectID,
        const wxClassInfo *classInfo,
        int paramCount,
        wxxVariant *VariantValues ,
        int *objectIDValues ,
        const wxClassInfo **objectClassInfos ,
        wxxVariantArray &metadata) ;

    // destroy the heap-allocated object having the ID objectID, this may be used if an object
    // is embedded in another object and set via value semantics, so the intermediate
    // object can be destroyed after safely
    virtual void DestroyObject(int objectID, wxClassInfo *classInfo) ;

    // set the corresponding property
    virtual void SetProperty(int objectID,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        const wxxVariant &variantValue);

    // sets the corresponding property (value is an object)
    virtual void SetPropertyAsObject(int objectId,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        int valueObjectId) ;

    // adds an element to a property collection
    virtual void AddToPropertyCollection( int objectID ,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        const wxxVariant &VariantValue) ;

    // sets the corresponding property (value is an object)
    virtual void AddToPropertyCollectionAsObject(int objectID,
        const wxClassInfo *classInfo,
        const wxPropertyInfo* propertyInfo ,
        int valueObjectId) ;

    // sets the corresponding event handler
    virtual void SetConnect(int eventSourceObjectID,
        const wxClassInfo *eventSourceClassInfo,
        const wxPropertyInfo *delegateInfo ,
        const wxClassInfo *eventSinkClassInfo ,
        const wxHandlerInfo* handlerInfo ,
        int eventSinkObjectID ) ;
};

#endif // wxUSE_EXTENDED_RTTI

#endif