wxWidgets/include/wx/dataobj.h

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///////////////////////////////////////////////////////////////////////////////
// Name: wx/dataobj.h
// Purpose: common data object classes
// Author: Vadim Zeitlin, Robert Roebling
// Modified by:
// Created: 26.05.99
// RCS-ID: $Id$
// Copyright: (c) wxWindows Team
// Licence: wxWindows license
///////////////////////////////////////////////////////////////////////////////
#ifndef _WX_DATAOBJ_H_BASE_
#define _WX_DATAOBJ_H_BASE_
#ifdef __GNUG__
#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(__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(__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
wxDataFormat m_format;
};
// ----------------------------------------------------------------------------
// wxDataObjectComposite is the simplest way to implement wxDataObject
// supporting multiple formats. It contains several wxDataObjectSimple and
// supports all formats supported by any of them.
//
// This class shouldn't be (normally) derived from, but may be used directly.
// If you need more flexibility than what it provides, you should probably use
// wxDataObject directly.
// ----------------------------------------------------------------------------
WX_DECLARE_EXPORTED_LIST(wxDataObjectSimple, wxSimpleDataObjectList);
class WXDLLEXPORT wxDataObjectComposite : public wxDataObject
{
public:
// ctor
wxDataObjectComposite();
// add data object (it will be deleted by wxDataObjectComposite, hence it
// must be allocated on the heap) whose format will become the preferred
// one if preferred == TRUE
void Add(wxDataObjectSimple *dataObject, bool preferred = FALSE);
// implement base class pure virtuals
// ----------------------------------
virtual wxDataFormat GetPreferredFormat(wxDataObjectBase::Direction dir = Get) const;
virtual size_t GetFormatCount(wxDataObjectBase::Direction dir = Get) const;
virtual void GetAllFormats(wxDataFormat *formats, wxDataObjectBase::Direction dir = Get) const;
virtual size_t GetDataSize(const wxDataFormat& format) const;
virtual bool GetDataHere(const wxDataFormat& format, void *buf) const;
virtual bool SetData(const wxDataFormat& format, size_t len, const void *buf);
protected:
// returns the pointer to the object which supports this format or NULL
wxDataObjectSimple *GetObject(const wxDataFormat& format) const;
#if defined(__WXMSW__)
virtual const void* GetSizeFromBuffer( const void* buffer, size_t* size,
const wxDataFormat& format );
virtual void* SetSizeInBuffer( void* buffer, size_t size,
const wxDataFormat& format );
virtual size_t GetBufferOffset( const wxDataFormat& format );
#endif
private:
// the list of all (simple) data objects whose formats we support
wxSimpleDataObjectList m_dataObjects;
// the index of the preferred one (0 initially, so by default the first
// one is the preferred)
size_t m_preferred;
};
// ============================================================================
// Standard implementations of wxDataObjectSimple which can be used directly
// (i.e. without having to derive from them) for standard data type transfers.
//
// Note that although all of them can work with provided data, you can also
// override their virtual GetXXX() functions to only provide data on demand.
// ============================================================================
// ----------------------------------------------------------------------------
// wxTextDataObject contains text data
// ----------------------------------------------------------------------------
class WXDLLEXPORT wxTextDataObject : public wxDataObjectSimple
{
public:
// ctor: you can specify the text here or in SetText(), or override
// GetText()
wxTextDataObject(const wxString& text = wxEmptyString)
: wxDataObjectSimple(wxUSE_UNICODE?wxDF_UNICODETEXT:wxDF_TEXT),
m_text(text)
{
}
// virtual functions which you may override if you want to provide text on
// demand only - otherwise, the trivial default versions will be used
virtual size_t GetTextLength() const { return m_text.Len() + 1; }
virtual wxString GetText() const { return m_text; }
virtual void SetText(const wxString& text) { m_text = text; }
// implement base class pure virtuals
// ----------------------------------
virtual size_t GetDataSize() const;
virtual bool GetDataHere(void *buf) const;
virtual bool SetData(size_t len, const void *buf);
private:
wxString m_text;
// virtual function hiding supression
size_t GetDataSize(const wxDataFormat& format) const
{ return(wxDataObjectSimple::GetDataSize(format)); }
bool GetDataHere(const wxDataFormat& format, void *pBuf) const
{ return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf)
{ return(wxDataObjectSimple::SetData(format, nLen, pBuf)); }
};
// ----------------------------------------------------------------------------
// wxBitmapDataObject contains a bitmap
// ----------------------------------------------------------------------------
class WXDLLEXPORT wxBitmapDataObjectBase : public wxDataObjectSimple
{
public:
// ctor: you can specify the bitmap here or in SetBitmap(), or override
// GetBitmap()
wxBitmapDataObjectBase(const wxBitmap& bitmap = wxNullBitmap)
: wxDataObjectSimple(wxDF_BITMAP), m_bitmap(bitmap)
{
}
// virtual functions which you may override if you want to provide data on
// demand only - otherwise, the trivial default versions will be used
virtual wxBitmap GetBitmap() const { return m_bitmap; }
virtual void SetBitmap(const wxBitmap& bitmap) { m_bitmap = bitmap; }
protected:
wxBitmap m_bitmap;
};
// ----------------------------------------------------------------------------
// wxFileDataObject contains a list of filenames
//
// NB: notice that this is a "write only" object, it can only be filled with
// data from drag and drop operation.
// ----------------------------------------------------------------------------
class WXDLLEXPORT wxFileDataObjectBase : public wxDataObjectSimple
{
public:
// ctor: use AddFile() later to fill the array
wxFileDataObjectBase() : wxDataObjectSimple(wxDF_FILENAME) { }
// get a reference to our array
const wxArrayString& GetFilenames() const { return m_filenames; }
// the Get() functions do nothing for us
virtual size_t GetDataSize() const { return 0; }
virtual bool GetDataHere(void *WXUNUSED(buf)) const { return FALSE; }
protected:
wxArrayString m_filenames;
private:
// Virtual function hiding supression
size_t GetDataSize(const wxDataFormat& format) const
{ return(wxDataObjectSimple::GetDataSize(format)); }
bool GetDataHere(const wxDataFormat& format, void* pBuf) const
{ return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
};
// ----------------------------------------------------------------------------
// wxCustomDataObject contains arbitrary untyped user data.
//
// It is understood that this data can be copied bitwise.
// ----------------------------------------------------------------------------
class WXDLLEXPORT wxCustomDataObject : public wxDataObjectSimple
{
public:
// if you don't specify the format in the ctor, you can still use
// SetFormat() later
wxCustomDataObject(const wxDataFormat& format = wxFormatInvalid);
// the dtor calls Free()
virtual ~wxCustomDataObject();
// you can call SetData() to set m_data: it will make a copy of the data
// you pass - or you can use TakeData() which won't copy anything, but
// will take ownership of data (i.e. will call Free() on it later)
void TakeData(size_t size, void *data);
// this function is called to allocate "size" bytes of memory from
// SetData(). The default version uses operator new[].
virtual void *Alloc(size_t size);
// this function is called when the data is freed, you may override it to
// anything you want (or may be nothing at all). The default version calls
// operator delete[] on m_data
virtual void Free();
// get data: you may override these functions if you wish to provide data
// only when it's requested
virtual size_t GetSize() const { return m_size; }
virtual void *GetData() const { return m_data; }
// implement base class pure virtuals
// ----------------------------------
virtual size_t GetDataSize() const;
virtual bool GetDataHere(void *buf) const;
virtual bool SetData(size_t size, const void *buf);
private:
size_t m_size;
void *m_data;
// virtual function hiding supression
size_t GetDataSize(const wxDataFormat& format) const
{ return(wxDataObjectSimple::GetDataSize(format)); }
bool GetDataHere(const wxDataFormat& format, void* pBuf) const
{ return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf)
{ return(wxDataObjectSimple::SetData(format, nLen, pBuf)); }
};
// ----------------------------------------------------------------------------
// include platform-specific declarations of wxXXXBase classes
// ----------------------------------------------------------------------------
#if defined(__WXMSW__)
#include "wx/msw/ole/dataobj2.h"
// wxURLDataObject defined in msw/ole/dataobj2.h
#else // !__WXMSW__
#if defined(__WXGTK__)
#include "wx/gtk/dataobj2.h"
#elif defined(__WXMAC__)
#include "wx/mac/dataobj2.h"
#elif defined(__WXPM__)
#include "wx/os2/dataobj2.h"
#endif
// wxURLDataObject is simply wxTextDataObject with a different name
class WXDLLEXPORT wxURLDataObject : public wxTextDataObject
{
public:
wxString GetURL() const { return GetText(); }
void SetURL(const wxString& url) { SetText(url); }
};
#endif // __WXMSW__/!__WXMSW__
#endif // _WX_DATAOBJ_H_BASE_