dataobj.h

浙江大学的悟空嵌入式系统模拟器

///////////////////////////////////////////////////////////////////////////////
// Name:        wx/dataobj.h
// Purpose:     common data object classes
// Author:      Vadim Zeitlin, Robert Roebling
// Modified by:
// Created:     26.05.99
// RCS-ID:      $Id: dataobj.h,v 1.1 2005/03/16 06:48:49 kehc Exp $
// Copyright:   (c) wxWindows Team
// Licence:     wxWindows license
///////////////////////////////////////////////////////////////////////////////

#ifndef _WX_DATAOBJ_H_BASE_
#define _WX_DATAOBJ_H_BASE_

#if defined(__GNUG__) && !defined(__APPLE__)
    #pragma interface "dataobjbase.h"
#endif

// ----------------------------------------------------------------------------
// headers
// ----------------------------------------------------------------------------

#include "wx/defs.h"
#include "wx/string.h"
#include "wx/bitmap.h"
#include "wx/list.h"

// ============================================================================
/*
   Generic data transfer related classes. The class hierarchy is as follows:

                                - wxDataObject-
                               /               \
                              /                 \
            wxDataObjectSimple                  wxDataObjectComposite
           /           |      \
          /            |       \
   wxTextDataObject    |     wxBitmapDataObject
                       |
               wxCustomDataObject

*/
// ============================================================================

// ----------------------------------------------------------------------------
// wxDataFormat class is declared in platform-specific headers: it represents
// a format for data which may be either one of the standard ones (text,
// bitmap, ...) or a custom one which is then identified by a unique string.
// ----------------------------------------------------------------------------

/* the class interface looks like this (pseudo code):

class wxDataFormat
{
public:
    typedef <integral type> NativeFormat;

    wxDataFormat(NativeFormat format = wxDF_INVALID);
    wxDataFormat(const wxChar *format);

    wxDataFormat& operator=(NativeFormat format);
    wxDataFormat& operator=(const wxDataFormat& format);

    bool operator==(NativeFormat format) const;
    bool operator!=(NativeFormat format) const;

    void SetType(NativeFormat format);
    NativeFormat GetType() const;

    wxString GetId() const;
    void SetId(const wxChar *format);
};

*/

#if defined(__WXMSW__)
    #include "wx/msw/ole/dataform.h"
#elif defined(__WXMOTIF__)
    #include "wx/motif/dataform.h"
#elif defined(__WXGTK__)
    #include "wx/gtk/dataform.h"
#elif defined(__WXX11__)
    #include "wx/x11/dataform.h"
#elif defined(__WXMAC__)
    #include "wx/mac/dataform.h"
#elif defined(__WXPM__)
    #include "wx/os2/dataform.h"
#endif

// the value for default argument to some functions (corresponds to
// wxDF_INVALID)
extern WXDLLEXPORT const wxDataFormat& wxFormatInvalid;

// ----------------------------------------------------------------------------
// wxDataObject represents a piece of data which knows which formats it
// supports and knows how to render itself in each of them - GetDataHere(),
// and how to restore data from the buffer (SetData()).
//
// Although this class may be used directly (i.e. custom classes may be
// derived from it), in many cases it might be simpler to use either
// wxDataObjectSimple or wxDataObjectComposite classes.
//
// A data object may be "read only", i.e. support only GetData() functions or
// "read-write", i.e. support both GetData() and SetData() (in principle, it
// might be "write only" too, but this is rare). Moreover, it doesn't have to
// support the same formats in Get() and Set() directions: for example, a data
// object containing JPEG image might accept BMPs in GetData() because JPEG
// image may be easily transformed into BMP but not in SetData(). Accordingly,
// all methods dealing with formats take an additional "direction" argument
// which is either SET or GET and which tells the function if the format needs
// to be supported by SetData() or GetDataHere().
// ----------------------------------------------------------------------------

class WXDLLEXPORT wxDataObjectBase
{
public:
    enum Direction
    {
        Get  = 0x01,    // format is supported by GetDataHere()
        Set  = 0x02,    // format is supported by SetData()
        Both = 0x03     // format is supported by both (unused currently)
    };

    // this class is polymorphic, hence it needs a virtual dtor
    virtual ~wxDataObjectBase();

    // get the best suited format for rendering our data
    virtual wxDataFormat GetPreferredFormat(Direction dir = Get) const = 0;

    // get the number of formats we support
    virtual size_t GetFormatCount(Direction dir = Get) const = 0;

    // return all formats in the provided array (of size GetFormatCount())
    virtual void GetAllFormats(wxDataFormat *formats,
                               Direction dir = Get) const = 0;

    // get the (total) size of data for the given format
    virtual size_t GetDataSize(const wxDataFormat& format) const = 0;

    // copy raw data (in the specified format) to the provided buffer, return
    // TRUE if data copied successfully, FALSE otherwise
    virtual bool GetDataHere(const wxDataFormat& format, void *buf) const = 0;

    // get data from the buffer of specified length (in the given format),
    // return TRUE if the data was read successfully, FALSE otherwise
    virtual bool SetData(const wxDataFormat& WXUNUSED(format),
                         size_t WXUNUSED(len), const void * WXUNUSED(buf))
    {
        return FALSE;
    }

    // returns TRUE if this format is supported
    bool IsSupported(const wxDataFormat& format, Direction dir = Get) const;
};

// ----------------------------------------------------------------------------
// include the platform-specific declarations of wxDataObject
// ----------------------------------------------------------------------------

#if defined(__WXMSW__)
    #include "wx/msw/ole/dataobj.h"
#elif defined(__WXMOTIF__)
    #include "wx/motif/dataobj.h"
#elif defined(__WXX11__)
    #include "wx/x11/dataobj.h"
#elif defined(__WXGTK__)
    #include "wx/gtk/dataobj.h"
#elif defined(__WXMAC__)
    #include "wx/mac/dataobj.h"
#elif defined(__WXPM__)
    #include "wx/os2/dataobj.h"
#elif defined(__WXSTUBS__)
    #include "wx/stubs/dnd.h"
#endif

// ----------------------------------------------------------------------------
// wxDataObjectSimple is a wxDataObject which only supports one format (in
// both Get and Set directions, but you may return FALSE from GetDataHere() or
// SetData() if one of them is not supported). This is the simplest possible
// wxDataObject implementation.
//
// This is still an "abstract base class" (although it doesn't have any pure
// virtual functions), to use it you should derive from it and implement
// GetDataSize(), GetDataHere() and SetData() functions because the base class
// versions don't do anything - they just return "not implemented".
//
// This class should be used when you provide data in only one format (no
// conversion to/from other formats), either a standard or a custom one.
// Otherwise, you should use wxDataObjectComposite or wxDataObject directly.
// ----------------------------------------------------------------------------

class WXDLLEXPORT wxDataObjectSimple : public wxDataObject
{
public:
    // ctor takes the format we support, but it can also be set later with
    // SetFormat()
    wxDataObjectSimple(const wxDataFormat& format = wxFormatInvalid)
        : m_format(format)
        {
        }

    // get/set the format we support
    const wxDataFormat& GetFormat() const { return m_format; }
    void SetFormat(const wxDataFormat& format) { m_format = format; }

    // virtual functions to override in derived class (the base class versions
    // just return "not implemented")
    // -----------------------------------------------------------------------

    // get the size of our data
    virtual size_t GetDataSize() const
        { return 0; }

    // copy our data to the buffer
    virtual bool GetDataHere(void *WXUNUSED(buf)) const
        { return FALSE; }

    // copy data from buffer to our data
    virtual bool SetData(size_t WXUNUSED(len), const void *WXUNUSED(buf))
        { return FALSE; }

    // implement base class pure virtuals
    // ----------------------------------
    virtual wxDataFormat GetPreferredFormat(wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
        { return m_format; }
    virtual size_t GetFormatCount(wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
        { return 1; }
    virtual void GetAllFormats(wxDataFormat *formats,
                               wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
        { *formats = m_format; }
    virtual size_t GetDataSize(const wxDataFormat& WXUNUSED(format)) const
        { return GetDataSize(); }
    virtual bool GetDataHere(const wxDataFormat& WXUNUSED(format),
                             void *buf) const
        { return GetDataHere(buf); }
    virtual bool SetData(const wxDataFormat& WXUNUSED(format),
                         size_t len, const void *buf)
        { return SetData(len, buf); }

private:
    // the one and only format we support