include/wx/dataobj.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/dataobj.h
   3 // Purpose:     common data object classes
   4 // Author:      Vadim Zeitlin, Robert Roebling
   5 // Modified by:
   6 // Created:     26.05.99
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) wxWindows Team
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_DATAOBJ_H_BASE_
  13 #define _WX_DATAOBJ_H_BASE_
  14
  15 #if defined(__GNUG__) && !defined(__APPLE__)
  16     #pragma interface "dataobjbase.h"
  17 #endif
  18
  19 // ----------------------------------------------------------------------------
  20 // headers
  21 // ----------------------------------------------------------------------------
  22 #include "wx/defs.h"
  23
  24 #if wxUSE_DATAOBJ
  25
  26 #include "wx/string.h"
  27 #include "wx/bitmap.h"
  28 #include "wx/list.h"
  29 #include "wx/arrstr.h"
  30
  31 // ============================================================================
  32 /*
  33    Generic data transfer related classes. The class hierarchy is as follows:
  34
  35                                 - wxDataObject-
  36                                /               \
  37                               /                 \
  38             wxDataObjectSimple                  wxDataObjectComposite
  39            /           |      \
  40           /            |       \
  41    wxTextDataObject    |     wxBitmapDataObject
  42                        |
  43                wxCustomDataObject
  44
  45 */
  46 // ============================================================================
  47
  48 // ----------------------------------------------------------------------------
  49 // wxDataFormat class is declared in platform-specific headers: it represents
  50 // a format for data which may be either one of the standard ones (text,
  51 // bitmap, ...) or a custom one which is then identified by a unique string.
  52 // ----------------------------------------------------------------------------
  53
  54 /* the class interface looks like this (pseudo code):
  55
  56 class wxDataFormat
  57 {
  58 public:
  59     typedef <integral type> NativeFormat;
  60
  61     wxDataFormat(NativeFormat format = wxDF_INVALID);
  62     wxDataFormat(const wxChar *format);
  63
  64     wxDataFormat& operator=(NativeFormat format);
  65     wxDataFormat& operator=(const wxDataFormat& format);
  66
  67     bool operator==(NativeFormat format) const;
  68     bool operator!=(NativeFormat format) const;
  69
  70     void SetType(NativeFormat format);
  71     NativeFormat GetType() const;
  72
  73     wxString GetId() const;
  74     void SetId(const wxChar *format);
  75 };
  76
  77 */
  78
  79 #if defined(__WXMSW__)
  80     #include "wx/msw/ole/dataform.h"
  81 #elif defined(__WXMOTIF__)
  82     #include "wx/motif/dataform.h"
  83 #elif defined(__WXGTK__)
  84     #include "wx/gtk/dataform.h"
  85 #elif defined(__WXX11__)
  86     #include "wx/x11/dataform.h"
  87 #elif defined(__WXMAC__)
  88     #include "wx/mac/dataform.h"
  89 #elif defined(__WXPM__)
  90     #include "wx/os2/dataform.h"
  91 #endif
  92
  93 // the value for default argument to some functions (corresponds to
  94 // wxDF_INVALID)
  95 extern WXDLLEXPORT const wxDataFormat& wxFormatInvalid;
  96
  97 // ----------------------------------------------------------------------------
  98 // wxDataObject represents a piece of data which knows which formats it
  99 // supports and knows how to render itself in each of them - GetDataHere(),
 100 // and how to restore data from the buffer (SetData()).
 101 //
 102 // Although this class may be used directly (i.e. custom classes may be
 103 // derived from it), in many cases it might be simpler to use either
 104 // wxDataObjectSimple or wxDataObjectComposite classes.
 105 //
 106 // A data object may be "read only", i.e. support only GetData() functions or
 107 // "read-write", i.e. support both GetData() and SetData() (in principle, it
 108 // might be "write only" too, but this is rare). Moreover, it doesn't have to
 109 // support the same formats in Get() and Set() directions: for example, a data
 110 // object containing JPEG image might accept BMPs in GetData() because JPEG
 111 // image may be easily transformed into BMP but not in SetData(). Accordingly,
 112 // all methods dealing with formats take an additional "direction" argument
 113 // which is either SET or GET and which tells the function if the format needs
 114 // to be supported by SetData() or GetDataHere().
 115 // ----------------------------------------------------------------------------
 116
 117 class WXDLLEXPORT wxDataObjectBase
 118 {
 119 public:
 120     enum Direction
 121     {
 122         Get  = 0x01,    // format is supported by GetDataHere()
 123         Set  = 0x02,    // format is supported by SetData()
 124         Both = 0x03     // format is supported by both (unused currently)
 125     };
 126
 127     // this class is polymorphic, hence it needs a virtual dtor
 128     virtual ~wxDataObjectBase();
 129
 130     // get the best suited format for rendering our data
 131     virtual wxDataFormat GetPreferredFormat(Direction dir = Get) const = 0;
 132
 133     // get the number of formats we support
 134     virtual size_t GetFormatCount(Direction dir = Get) const = 0;
 135
 136     // return all formats in the provided array (of size GetFormatCount())
 137     virtual void GetAllFormats(wxDataFormat *formats,
 138                                Direction dir = Get) const = 0;
 139
 140     // get the (total) size of data for the given format
 141     virtual size_t GetDataSize(const wxDataFormat& format) const = 0;
 142
 143     // copy raw data (in the specified format) to the provided buffer, return
 144     // TRUE if data copied successfully, FALSE otherwise
 145     virtual bool GetDataHere(const wxDataFormat& format, void *buf) const = 0;
 146
 147     // get data from the buffer of specified length (in the given format),
 148     // return TRUE if the data was read successfully, FALSE otherwise
 149     virtual bool SetData(const wxDataFormat& WXUNUSED(format),
 150                          size_t WXUNUSED(len), const void * WXUNUSED(buf))
 151     {
 152         return FALSE;
 153     }
 154
 155     // returns TRUE if this format is supported
 156     bool IsSupported(const wxDataFormat& format, Direction dir = Get) const;
 157 };
 158
 159 // ----------------------------------------------------------------------------
 160 // include the platform-specific declarations of wxDataObject
 161 // ----------------------------------------------------------------------------
 162
 163 #if defined(__WXMSW__)
 164     #include "wx/msw/ole/dataobj.h"
 165 #elif defined(__WXMOTIF__)
 166     #include "wx/motif/dataobj.h"
 167 #elif defined(__WXX11__)
 168     #include "wx/x11/dataobj.h"
 169 #elif defined(__WXGTK__)
 170     #include "wx/gtk/dataobj.h"
 171 #elif defined(__WXMAC__)
 172     #include "wx/mac/dataobj.h"
 173 #elif defined(__WXPM__)
 174     #include "wx/os2/dataobj.h"
 175 #endif
 176
 177 // ----------------------------------------------------------------------------
 178 // wxDataObjectSimple is a wxDataObject which only supports one format (in
 179 // both Get and Set directions, but you may return FALSE from GetDataHere() or
 180 // SetData() if one of them is not supported). This is the simplest possible
 181 // wxDataObject implementation.
 182 //
 183 // This is still an "abstract base class" (although it doesn't have any pure
 184 // virtual functions), to use it you should derive from it and implement
 185 // GetDataSize(), GetDataHere() and SetData() functions because the base class
 186 // versions don't do anything - they just return "not implemented".
 187 //
 188 // This class should be used when you provide data in only one format (no
 189 // conversion to/from other formats), either a standard or a custom one.
 190 // Otherwise, you should use wxDataObjectComposite or wxDataObject directly.
 191 // ----------------------------------------------------------------------------
 192
 193 class WXDLLEXPORT wxDataObjectSimple : public wxDataObject
 194 {
 195 public:
 196     // ctor takes the format we support, but it can also be set later with
 197     // SetFormat()
 198     wxDataObjectSimple(const wxDataFormat& format = wxFormatInvalid)
 199         : m_format(format)
 200         {
 201         }
 202
 203     // get/set the format we support
 204     const wxDataFormat& GetFormat() const { return m_format; }
 205     void SetFormat(const wxDataFormat& format) { m_format = format; }
 206
 207     // virtual functions to override in derived class (the base class versions
 208     // just return "not implemented")
 209     // -----------------------------------------------------------------------
 210
 211     // get the size of our data
 212     virtual size_t GetDataSize() const
 213         { return 0; }
 214
 215     // copy our data to the buffer
 216     virtual bool GetDataHere(void *WXUNUSED(buf)) const
 217         { return FALSE; }
 218
 219     // copy data from buffer to our data
 220     virtual bool SetData(size_t WXUNUSED(len), const void *WXUNUSED(buf))
 221         { return FALSE; }
 222
 223     // implement base class pure virtuals
 224     // ----------------------------------
 225     virtual wxDataFormat GetPreferredFormat(wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
 226         { return m_format; }
 227     virtual size_t GetFormatCount(wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
 228         { return 1; }
 229     virtual void GetAllFormats(wxDataFormat *formats,
 230                                wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
 231         { *formats = m_format; }
 232     virtual size_t GetDataSize(const wxDataFormat& WXUNUSED(format)) const
 233         { return GetDataSize(); }
 234     virtual bool GetDataHere(const wxDataFormat& WXUNUSED(format),
 235                              void *buf) const
 236         { return GetDataHere(buf); }
 237     virtual bool SetData(const wxDataFormat& WXUNUSED(format),
 238                          size_t len, const void *buf)
 239         { return SetData(len, buf); }
 240
 241 private:
 242     // the one and only format we support
 243     wxDataFormat m_format;
 244 };
 245
 246 // ----------------------------------------------------------------------------
 247 // wxDataObjectComposite is the simplest way to implement wxDataObject
 248 // supporting multiple formats. It contains several wxDataObjectSimple and
 249 // supports all formats supported by any of them.
 250 //
 251 // This class shouldn't be (normally) derived from, but may be used directly.
 252 // If you need more flexibility than what it provides, you should probably use
 253 // wxDataObject directly.
 254 // ----------------------------------------------------------------------------
 255
 256 WX_DECLARE_EXPORTED_LIST(wxDataObjectSimple, wxSimpleDataObjectList);
 257
 258 class WXDLLEXPORT wxDataObjectComposite : public wxDataObject
 259 {
 260 public:
 261     // ctor
 262     wxDataObjectComposite();
 263     virtual ~wxDataObjectComposite();
 264
 265     // add data object (it will be deleted by wxDataObjectComposite, hence it
 266     // must be allocated on the heap) whose format will become the preferred
 267     // one if preferred == TRUE
 268     void Add(wxDataObjectSimple *dataObject, bool preferred = FALSE);
 269
 270     // implement base class pure virtuals
 271     // ----------------------------------
 272     virtual wxDataFormat GetPreferredFormat(wxDataObjectBase::Direction dir = Get) const;
 273     virtual size_t GetFormatCount(wxDataObjectBase::Direction dir = Get) const;
 274     virtual void GetAllFormats(wxDataFormat *formats, wxDataObjectBase::Direction dir = Get) const;
 275     virtual size_t GetDataSize(const wxDataFormat& format) const;
 276     virtual bool GetDataHere(const wxDataFormat& format, void *buf) const;
 277     virtual bool SetData(const wxDataFormat& format, size_t len, const void *buf);
 278
 279 protected:
 280     // returns the pointer to the object which supports this format or NULL
 281     wxDataObjectSimple *GetObject(const wxDataFormat& format) const;
 282 #if defined(__WXMSW__)
 283     virtual const void* GetSizeFromBuffer( const void* buffer, size_t* size,
 284                                            const wxDataFormat& format );
 285     virtual void* SetSizeInBuffer( void* buffer, size_t size,
 286                                    const wxDataFormat& format );
 287     virtual size_t GetBufferOffset( const wxDataFormat& format );
 288 #endif
 289
 290 private:
 291     // the list of all (simple) data objects whose formats we support
 292     wxSimpleDataObjectList m_dataObjects;
 293
 294     // the index of the preferred one (0 initially, so by default the first
 295     // one is the preferred)
 296     size_t m_preferred;
 297 };
 298
 299 // ============================================================================
 300 // Standard implementations of wxDataObjectSimple which can be used directly
 301 // (i.e. without having to derive from them) for standard data type transfers.
 302 //
 303 // Note that although all of them can work with provided data, you can also
 304 // override their virtual GetXXX() functions to only provide data on demand.
 305 // ============================================================================
 306
 307 // ----------------------------------------------------------------------------
 308 // wxTextDataObject contains text data
 309 // ----------------------------------------------------------------------------
 310
 311 class WXDLLEXPORT wxTextDataObject : public wxDataObjectSimple
 312 {
 313 public:
 314     // ctor: you can specify the text here or in SetText(), or override
 315     // GetText()
 316     wxTextDataObject(const wxString& text = wxEmptyString)
 317         : wxDataObjectSimple(wxUSE_UNICODE?wxDF_UNICODETEXT:wxDF_TEXT),
 318           m_text(text)
 319         {
 320         }
 321
 322     // virtual functions which you may override if you want to provide text on
 323     // demand only - otherwise, the trivial default versions will be used
 324     virtual size_t GetTextLength() const { return m_text.Len() + 1; }
 325     virtual wxString GetText() const { return m_text; }
 326     virtual void SetText(const wxString& text) { m_text = text; }
 327
 328     // implement base class pure virtuals
 329     // ----------------------------------
 330     virtual size_t GetDataSize() const;
 331     virtual bool GetDataHere(void *buf) const;
 332     virtual bool SetData(size_t len, const void *buf);
 333
 334 private:
 335     wxString m_text;
 336
 337     // virtual function hiding supression
 338     size_t GetDataSize(const wxDataFormat& format) const
 339         { return(wxDataObjectSimple::GetDataSize(format)); }
 340     bool GetDataHere(const wxDataFormat& format, void *pBuf) const
 341         { return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
 342     bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf)
 343         { return(wxDataObjectSimple::SetData(format, nLen, pBuf)); }
 344 };
 345
 346 // ----------------------------------------------------------------------------
 347 // wxBitmapDataObject contains a bitmap
 348 // ----------------------------------------------------------------------------
 349
 350 class WXDLLEXPORT wxBitmapDataObjectBase : public wxDataObjectSimple
 351 {
 352 public:
 353     // ctor: you can specify the bitmap here or in SetBitmap(), or override
 354     // GetBitmap()
 355     wxBitmapDataObjectBase(const wxBitmap& bitmap = wxNullBitmap)
 356         : wxDataObjectSimple(wxDF_BITMAP), m_bitmap(bitmap)
 357         {
 358         }
 359
 360     // virtual functions which you may override if you want to provide data on
 361     // demand only - otherwise, the trivial default versions will be used
 362     virtual wxBitmap GetBitmap() const { return m_bitmap; }
 363     virtual void SetBitmap(const wxBitmap& bitmap) { m_bitmap = bitmap; }
 364
 365 protected:
 366     wxBitmap m_bitmap;
 367 };
 368
 369 // ----------------------------------------------------------------------------
 370 // wxFileDataObject contains a list of filenames
 371 //
 372 // NB: notice that this is a "write only" object, it can only be filled with
 373 //     data from drag and drop operation.
 374 // ----------------------------------------------------------------------------
 375
 376 class WXDLLEXPORT wxFileDataObjectBase : public wxDataObjectSimple
 377 {
 378 public:
 379     // ctor: use AddFile() later to fill the array
 380     wxFileDataObjectBase() : wxDataObjectSimple(wxDF_FILENAME) { }
 381
 382     // get a reference to our array
 383     const wxArrayString& GetFilenames() const { return m_filenames; }
 384
 385     // the Get() functions do nothing for us
 386     virtual size_t GetDataSize() const { return 0; }
 387     virtual bool GetDataHere(void *WXUNUSED(buf)) const { return FALSE; }
 388
 389 protected:
 390     wxArrayString m_filenames;
 391
 392 private:
 393     // Virtual function hiding supression
 394     size_t GetDataSize(const wxDataFormat& format) const
 395         { return(wxDataObjectSimple::GetDataSize(format)); }
 396     bool GetDataHere(const wxDataFormat& format, void* pBuf) const
 397         { return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
 398 };
 399
 400 // ----------------------------------------------------------------------------
 401 // wxCustomDataObject contains arbitrary untyped user data.
 402 //
 403 // It is understood that this data can be copied bitwise.
 404 // ----------------------------------------------------------------------------
 405
 406 class WXDLLEXPORT wxCustomDataObject : public wxDataObjectSimple
 407 {
 408 public:
 409     // if you don't specify the format in the ctor, you can still use
 410     // SetFormat() later
 411     wxCustomDataObject(const wxDataFormat& format = wxFormatInvalid);
 412
 413     // the dtor calls Free()
 414     virtual ~wxCustomDataObject();
 415
 416     // you can call SetData() to set m_data: it will make a copy of the data
 417     // you pass - or you can use TakeData() which won't copy anything, but
 418     // will take ownership of data (i.e. will call Free() on it later)
 419     void TakeData(size_t size, void *data);
 420
 421     // this function is called to allocate "size" bytes of memory from
 422     // SetData(). The default version uses operator new[].
 423     virtual void *Alloc(size_t size);
 424
 425     // this function is called when the data is freed, you may override it to
 426     // anything you want (or may be nothing at all). The default version calls
 427     // operator delete[] on m_data
 428     virtual void Free();
 429
 430     // get data: you may override these functions if you wish to provide data
 431     // only when it's requested
 432     virtual size_t GetSize() const { return m_size; }
 433     virtual void *GetData() const { return m_data; }
 434
 435     // implement base class pure virtuals
 436     // ----------------------------------
 437     virtual size_t GetDataSize() const;
 438     virtual bool GetDataHere(void *buf) const;
 439     virtual bool SetData(size_t size, const void *buf);
 440
 441 private:
 442     size_t m_size;
 443     void  *m_data;
 444
 445     // virtual function hiding supression
 446     size_t GetDataSize(const wxDataFormat& format) const
 447         { return(wxDataObjectSimple::GetDataSize(format)); }
 448     bool GetDataHere(const wxDataFormat& format, void* pBuf) const
 449         { return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
 450     bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf)
 451         { return(wxDataObjectSimple::SetData(format, nLen, pBuf)); }
 452
 453     DECLARE_NO_COPY_CLASS(wxCustomDataObject)
 454 };
 455
 456 // ----------------------------------------------------------------------------
 457 // include platform-specific declarations of wxXXXBase classes
 458 // ----------------------------------------------------------------------------
 459
 460 #if defined(__WXMSW__)
 461     #include "wx/msw/ole/dataobj2.h"
 462
 463     // wxURLDataObject defined in msw/ole/dataobj2.h
 464 #else // !__WXMSW__
 465     #if defined(__WXGTK__)
 466         #include "wx/gtk/dataobj2.h"
 467     #elif defined(__WXX11__)
 468         #include "wx/x11/dataobj2.h"
 469     #elif defined(__WXMOTIF__)
 470         #include "wx/motif/dataobj2.h"
 471     #elif defined(__WXMAC__)
 472         #include "wx/mac/dataobj2.h"
 473     #elif defined(__WXPM__)
 474         #include "wx/os2/dataobj2.h"
 475     #endif
 476
 477     // wxURLDataObject is simply wxTextDataObject with a different name
 478     class WXDLLEXPORT wxURLDataObject : public wxTextDataObject
 479     {
 480     public:
 481         wxString GetURL() const { return GetText(); }
 482         void SetURL(const wxString& url) { SetText(url); }
 483     };
 484 #endif // __WXMSW__/!__WXMSW__
 485
 486 #endif // wxUSE_DATAOBJ
 487
 488 #endif // _WX_DATAOBJ_H_BASE_