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) wxWidgets Team
   9 // Licence:     wxWindows licence
  10 ///////////////////////////////////////////////////////////////////////////////
  11
  12 #ifndef _WX_DATAOBJ_H_BASE_
  13 #define _WX_DATAOBJ_H_BASE_
  14
  15 // ----------------------------------------------------------------------------
  16 // headers
  17 // ----------------------------------------------------------------------------
  18 #include "wx/defs.h"
  19
  20 #if wxUSE_DATAOBJ
  21
  22 #include "wx/string.h"
  23 #include "wx/bitmap.h"
  24 #include "wx/list.h"
  25 #include "wx/arrstr.h"
  26
  27 // ============================================================================
  28 /*
  29    Generic data transfer related classes. The class hierarchy is as follows:
  30
  31                                 - wxDataObject-
  32                                /               \
  33                               /                 \
  34             wxDataObjectSimple                  wxDataObjectComposite
  35            /           |      \
  36           /            |       \
  37    wxTextDataObject    |     wxBitmapDataObject
  38                        |
  39                wxCustomDataObject
  40
  41 */
  42 // ============================================================================
  43
  44 // ----------------------------------------------------------------------------
  45 // wxDataFormat class is declared in platform-specific headers: it represents
  46 // a format for data which may be either one of the standard ones (text,
  47 // bitmap, ...) or a custom one which is then identified by a unique string.
  48 // ----------------------------------------------------------------------------
  49
  50 /* the class interface looks like this (pseudo code):
  51
  52 class wxDataFormat
  53 {
  54 public:
  55     typedef <integral type> NativeFormat;
  56
  57     wxDataFormat(NativeFormat format = wxDF_INVALID);
  58     wxDataFormat(const wxChar *format);
  59
  60     wxDataFormat& operator=(NativeFormat format);
  61     wxDataFormat& operator=(const wxDataFormat& format);
  62
  63     bool operator==(NativeFormat format) const;
  64     bool operator!=(NativeFormat format) const;
  65
  66     void SetType(NativeFormat format);
  67     NativeFormat GetType() const;
  68
  69     wxString GetId() const;
  70     void SetId(const wxChar *format);
  71 };
  72
  73 */
  74
  75 #if defined(__WXMSW__)
  76     #include "wx/msw/ole/dataform.h"
  77 #elif defined(__WXMOTIF__)
  78     #include "wx/motif/dataform.h"
  79 #elif defined(__WXGTK20__)
  80     #include "wx/gtk/dataform.h"
  81 #elif defined(__WXGTK__)
  82     #include "wx/gtk1/dataform.h"
  83 #elif defined(__WXX11__)
  84     #include "wx/x11/dataform.h"
  85 #elif defined(__WXMAC__)
  86     #include "wx/mac/dataform.h"
  87 #elif defined(__WXCOCOA__)
  88     #include "wx/cocoa/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(__WXCOCOA__)
 174     #include "wx/cocoa/dataobj.h"
 175 #elif defined(__WXPM__)
 176     #include "wx/os2/dataobj.h"
 177 #endif
 178
 179 // ----------------------------------------------------------------------------
 180 // wxDataObjectSimple is a wxDataObject which only supports one format (in
 181 // both Get and Set directions, but you may return false from GetDataHere() or
 182 // SetData() if one of them is not supported). This is the simplest possible
 183 // wxDataObject implementation.
 184 //
 185 // This is still an "abstract base class" (although it doesn't have any pure
 186 // virtual functions), to use it you should derive from it and implement
 187 // GetDataSize(), GetDataHere() and SetData() functions because the base class
 188 // versions don't do anything - they just return "not implemented".
 189 //
 190 // This class should be used when you provide data in only one format (no
 191 // conversion to/from other formats), either a standard or a custom one.
 192 // Otherwise, you should use wxDataObjectComposite or wxDataObject directly.
 193 // ----------------------------------------------------------------------------
 194
 195 class WXDLLEXPORT wxDataObjectSimple : public wxDataObject
 196 {
 197 public:
 198     // ctor takes the format we support, but it can also be set later with
 199     // SetFormat()
 200     wxDataObjectSimple(const wxDataFormat& format = wxFormatInvalid)
 201         : m_format(format)
 202         {
 203         }
 204
 205     // get/set the format we support
 206     const wxDataFormat& GetFormat() const { return m_format; }
 207     void SetFormat(const wxDataFormat& format) { m_format = format; }
 208
 209     // virtual functions to override in derived class (the base class versions
 210     // just return "not implemented")
 211     // -----------------------------------------------------------------------
 212
 213     // get the size of our data
 214     virtual size_t GetDataSize() const
 215         { return 0; }
 216
 217     // copy our data to the buffer
 218     virtual bool GetDataHere(void *WXUNUSED(buf)) const
 219         { return false; }
 220
 221     // copy data from buffer to our data
 222     virtual bool SetData(size_t WXUNUSED(len), const void *WXUNUSED(buf))
 223         { return false; }
 224
 225     // implement base class pure virtuals
 226     // ----------------------------------
 227     virtual wxDataFormat GetPreferredFormat(wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
 228         { return m_format; }
 229     virtual size_t GetFormatCount(wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
 230         { return 1; }
 231     virtual void GetAllFormats(wxDataFormat *formats,
 232                                wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
 233         { *formats = m_format; }
 234     virtual size_t GetDataSize(const wxDataFormat& WXUNUSED(format)) const
 235         { return GetDataSize(); }
 236     virtual bool GetDataHere(const wxDataFormat& WXUNUSED(format),
 237                              void *buf) const
 238         { return GetDataHere(buf); }
 239     virtual bool SetData(const wxDataFormat& WXUNUSED(format),
 240                          size_t len, const void *buf)
 241         { return SetData(len, buf); }
 242
 243 private:
 244     // the one and only format we support
 245     wxDataFormat m_format;
 246
 247     DECLARE_NO_COPY_CLASS(wxDataObjectSimple)
 248 };
 249
 250 // ----------------------------------------------------------------------------
 251 // wxDataObjectComposite is the simplest way to implement wxDataObject
 252 // supporting multiple formats. It contains several wxDataObjectSimple and
 253 // supports all formats supported by any of them.
 254 //
 255 // This class shouldn't be (normally) derived from, but may be used directly.
 256 // If you need more flexibility than what it provides, you should probably use
 257 // wxDataObject directly.
 258 // ----------------------------------------------------------------------------
 259
 260 WX_DECLARE_EXPORTED_LIST(wxDataObjectSimple, wxSimpleDataObjectList);
 261
 262 class WXDLLEXPORT wxDataObjectComposite : public wxDataObject
 263 {
 264 public:
 265     // ctor
 266     wxDataObjectComposite();
 267     virtual ~wxDataObjectComposite();
 268
 269     // add data object (it will be deleted by wxDataObjectComposite, hence it
 270     // must be allocated on the heap) whose format will become the preferred
 271     // one if preferred == true
 272     void Add(wxDataObjectSimple *dataObject, bool preferred = false);
 273
 274     // implement base class pure virtuals
 275     // ----------------------------------
 276     virtual wxDataFormat GetPreferredFormat(wxDataObjectBase::Direction dir = Get) const;
 277     virtual size_t GetFormatCount(wxDataObjectBase::Direction dir = Get) const;
 278     virtual void GetAllFormats(wxDataFormat *formats, wxDataObjectBase::Direction dir = Get) const;
 279     virtual size_t GetDataSize(const wxDataFormat& format) const;
 280     virtual bool GetDataHere(const wxDataFormat& format, void *buf) const;
 281     virtual bool SetData(const wxDataFormat& format, size_t len, const void *buf);
 282
 283 protected:
 284     // returns the pointer to the object which supports this format or NULL
 285     wxDataObjectSimple *GetObject(const wxDataFormat& format) const;
 286 #if defined(__WXMSW__)
 287     virtual const void* GetSizeFromBuffer( const void* buffer, size_t* size,
 288                                            const wxDataFormat& format );
 289     virtual void* SetSizeInBuffer( void* buffer, size_t size,
 290                                    const wxDataFormat& format );
 291     virtual size_t GetBufferOffset( const wxDataFormat& format );
 292 #endif
 293
 294 private:
 295     // the list of all (simple) data objects whose formats we support
 296     wxSimpleDataObjectList m_dataObjects;
 297
 298     // the index of the preferred one (0 initially, so by default the first
 299     // one is the preferred)
 300     size_t m_preferred;
 301
 302     DECLARE_NO_COPY_CLASS(wxDataObjectComposite)
 303 };
 304
 305 // ============================================================================
 306 // Standard implementations of wxDataObjectSimple which can be used directly
 307 // (i.e. without having to derive from them) for standard data type transfers.
 308 //
 309 // Note that although all of them can work with provided data, you can also
 310 // override their virtual GetXXX() functions to only provide data on demand.
 311 // ============================================================================
 312
 313 // ----------------------------------------------------------------------------
 314 // wxTextDataObject contains text data
 315 // ----------------------------------------------------------------------------
 316
 317 class WXDLLEXPORT wxTextDataObject : public wxDataObjectSimple
 318 {
 319 public:
 320     // ctor: you can specify the text here or in SetText(), or override
 321     // GetText()
 322     wxTextDataObject(const wxString& text = wxEmptyString)
 323         : wxDataObjectSimple(
 324 #if wxUSE_UNICODE
 325                              wxDF_UNICODETEXT
 326 #else
 327                              wxDF_TEXT
 328 #endif
 329                             ),
 330           m_text(text)
 331         {
 332         }
 333
 334     // virtual functions which you may override if you want to provide text on
 335     // demand only - otherwise, the trivial default versions will be used
 336     virtual size_t GetTextLength() const { return m_text.Len() + 1; }
 337     virtual wxString GetText() const { return m_text; }
 338     virtual void SetText(const wxString& text) { m_text = text; }
 339
 340     // implement base class pure virtuals
 341     // ----------------------------------
 342
 343     // some platforms have 2 and not 1 format for text data
 344 #if wxUSE_UNICODE && (defined(__WXGTK20__) || defined(__WXMAC__))
 345     virtual size_t GetFormatCount(Direction WXUNUSED(dir) = Get) const { return 2; }
 346     virtual void GetAllFormats(wxDataFormat *formats,
 347                                wxDataObjectBase::Direction WXUNUSED(dir) = Get) const;
 348
 349     virtual size_t GetDataSize() const { return GetDataSize(GetPreferredFormat()); }
 350     virtual bool GetDataHere(void *buf) const { return GetDataHere(GetPreferredFormat(), buf); }
 351     virtual bool SetData(size_t len, const void *buf) { return SetData(GetPreferredFormat(), len, buf); }
 352
 353     size_t GetDataSize(const wxDataFormat& format) const;
 354     bool GetDataHere(const wxDataFormat& format, void *pBuf) const;
 355     bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf);
 356 #else
 357     virtual size_t GetDataSize() const;
 358     virtual bool GetDataHere(void *buf) const;
 359     virtual bool SetData(size_t len, const void *buf);
 360
 361     size_t GetDataSize(const wxDataFormat& format) const
 362         { return(wxDataObjectSimple::GetDataSize(format)); }
 363     bool GetDataHere(const wxDataFormat& format, void *pBuf) const
 364         { return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
 365     bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf)
 366         { return(wxDataObjectSimple::SetData(format, nLen, pBuf)); }
 367 #endif
 368
 369 private:
 370     wxString m_text;
 371
 372     DECLARE_NO_COPY_CLASS(wxTextDataObject)
 373 };
 374
 375 // ----------------------------------------------------------------------------
 376 // wxBitmapDataObject contains a bitmap
 377 // ----------------------------------------------------------------------------
 378
 379 class WXDLLEXPORT wxBitmapDataObjectBase : public wxDataObjectSimple
 380 {
 381 public:
 382     // ctor: you can specify the bitmap here or in SetBitmap(), or override
 383     // GetBitmap()
 384     wxBitmapDataObjectBase(const wxBitmap& bitmap = wxNullBitmap)
 385         : wxDataObjectSimple(wxDF_BITMAP), m_bitmap(bitmap)
 386         {
 387         }
 388
 389     // virtual functions which you may override if you want to provide data on
 390     // demand only - otherwise, the trivial default versions will be used
 391     virtual wxBitmap GetBitmap() const { return m_bitmap; }
 392     virtual void SetBitmap(const wxBitmap& bitmap) { m_bitmap = bitmap; }
 393
 394 protected:
 395     wxBitmap m_bitmap;
 396
 397     DECLARE_NO_COPY_CLASS(wxBitmapDataObjectBase)
 398 };
 399
 400 // ----------------------------------------------------------------------------
 401 // wxFileDataObject contains a list of filenames
 402 //
 403 // NB: notice that this is a "write only" object, it can only be filled with
 404 //     data from drag and drop operation.
 405 // ----------------------------------------------------------------------------
 406
 407 class WXDLLEXPORT wxFileDataObjectBase : public wxDataObjectSimple
 408 {
 409 public:
 410     // ctor: use AddFile() later to fill the array
 411     wxFileDataObjectBase() : wxDataObjectSimple(wxDF_FILENAME) { }
 412
 413     // get a reference to our array
 414     const wxArrayString& GetFilenames() const { return m_filenames; }
 415
 416     // the Get() functions do nothing for us
 417     virtual size_t GetDataSize() const { return 0; }
 418     virtual bool GetDataHere(void *WXUNUSED(buf)) const { return false; }
 419
 420 protected:
 421     wxArrayString m_filenames;
 422
 423 private:
 424     // Virtual function hiding supression
 425     size_t GetDataSize(const wxDataFormat& format) const
 426         { return(wxDataObjectSimple::GetDataSize(format)); }
 427     bool GetDataHere(const wxDataFormat& format, void* pBuf) const
 428         { return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
 429
 430     DECLARE_NO_COPY_CLASS(wxFileDataObjectBase)
 431 };
 432
 433 // ----------------------------------------------------------------------------
 434 // wxCustomDataObject contains arbitrary untyped user data.
 435 //
 436 // It is understood that this data can be copied bitwise.
 437 // ----------------------------------------------------------------------------
 438
 439 class WXDLLEXPORT wxCustomDataObject : public wxDataObjectSimple
 440 {
 441 public:
 442     // if you don't specify the format in the ctor, you can still use
 443     // SetFormat() later
 444     wxCustomDataObject(const wxDataFormat& format = wxFormatInvalid);
 445
 446     // the dtor calls Free()
 447     virtual ~wxCustomDataObject();
 448
 449     // you can call SetData() to set m_data: it will make a copy of the data
 450     // you pass - or you can use TakeData() which won't copy anything, but
 451     // will take ownership of data (i.e. will call Free() on it later)
 452     void TakeData(size_t size, void *data);
 453
 454     // this function is called to allocate "size" bytes of memory from
 455     // SetData(). The default version uses operator new[].
 456     virtual void *Alloc(size_t size);
 457
 458     // this function is called when the data is freed, you may override it to
 459     // anything you want (or may be nothing at all). The default version calls
 460     // operator delete[] on m_data
 461     virtual void Free();
 462
 463     // get data: you may override these functions if you wish to provide data
 464     // only when it's requested
 465     virtual size_t GetSize() const { return m_size; }
 466     virtual void *GetData() const { return m_data; }
 467
 468     // implement base class pure virtuals
 469     // ----------------------------------
 470     virtual size_t GetDataSize() const;
 471     virtual bool GetDataHere(void *buf) const;
 472     virtual bool SetData(size_t size, const void *buf);
 473
 474 private:
 475     size_t m_size;
 476     void  *m_data;
 477
 478     // virtual function hiding supression
 479     size_t GetDataSize(const wxDataFormat& format) const
 480         { return(wxDataObjectSimple::GetDataSize(format)); }
 481     bool GetDataHere(const wxDataFormat& format, void* pBuf) const
 482         { return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
 483     bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf)
 484         { return(wxDataObjectSimple::SetData(format, nLen, pBuf)); }
 485
 486     DECLARE_NO_COPY_CLASS(wxCustomDataObject)
 487 };
 488
 489 // ----------------------------------------------------------------------------
 490 // include platform-specific declarations of wxXXXBase classes
 491 // ----------------------------------------------------------------------------
 492
 493 #if defined(__WXMSW__)
 494     #include "wx/msw/ole/dataobj2.h"
 495
 496     // wxURLDataObject defined in msw/ole/dataobj2.h
 497 #else // !__WXMSW__
 498     #if defined(__WXGTK__)
 499         #include "wx/gtk/dataobj2.h"
 500     #elif defined(__WXX11__)
 501         #include "wx/x11/dataobj2.h"
 502     #elif defined(__WXMOTIF__)
 503         #include "wx/motif/dataobj2.h"
 504     #elif defined(__WXMAC__)
 505         #include "wx/mac/dataobj2.h"
 506     #elif defined(__WXCOCOA__)
 507         #include "wx/cocoa/dataobj2.h"
 508     #elif defined(__WXPM__)
 509         #include "wx/os2/dataobj2.h"
 510     #endif
 511
 512     // wxURLDataObject is simply wxTextDataObject with a different name
 513     class WXDLLEXPORT wxURLDataObject : public wxTextDataObject
 514     {
 515     public:
 516         wxString GetURL() const { return GetText(); }
 517         void SetURL(const wxString& url) { SetText(url); }
 518     };
 519 #endif // __WXMSW__/!__WXMSW__
 520
 521 #endif // wxUSE_DATAOBJ
 522
 523 #endif // _WX_DATAOBJ_H_BASE_