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 wxString& 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 wxString& 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/osx/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 WXDLLIMPEXP_CORE 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 WXDLLIMPEXP_CORE 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(__WXGTK20__)
 170     #include "wx/gtk/dataobj.h"
 171 #elif defined(__WXGTK__)
 172     #include "wx/gtk1/dataobj.h"
 173 #elif defined(__WXMAC__)
 174     #include "wx/osx/dataobj.h"
 175 #elif defined(__WXCOCOA__)
 176     #include "wx/cocoa/dataobj.h"
 177 #elif defined(__WXPM__)
 178     #include "wx/os2/dataobj.h"
 179 #endif
 180
 181 // ----------------------------------------------------------------------------
 182 // wxDataObjectSimple is a wxDataObject which only supports one format (in
 183 // both Get and Set directions, but you may return false from GetDataHere() or
 184 // SetData() if one of them is not supported). This is the simplest possible
 185 // wxDataObject implementation.
 186 //
 187 // This is still an "abstract base class" (although it doesn't have any pure
 188 // virtual functions), to use it you should derive from it and implement
 189 // GetDataSize(), GetDataHere() and SetData() functions because the base class
 190 // versions don't do anything - they just return "not implemented".
 191 //
 192 // This class should be used when you provide data in only one format (no
 193 // conversion to/from other formats), either a standard or a custom one.
 194 // Otherwise, you should use wxDataObjectComposite or wxDataObject directly.
 195 // ----------------------------------------------------------------------------
 196
 197 class WXDLLIMPEXP_CORE wxDataObjectSimple : public wxDataObject
 198 {
 199 public:
 200     // ctor takes the format we support, but it can also be set later with
 201     // SetFormat()
 202     wxDataObjectSimple(const wxDataFormat& format = wxFormatInvalid)
 203         : m_format(format)
 204         {
 205         }
 206
 207     // get/set the format we support
 208     const wxDataFormat& GetFormat() const { return m_format; }
 209     void SetFormat(const wxDataFormat& format) { m_format = format; }
 210
 211     // virtual functions to override in derived class (the base class versions
 212     // just return "not implemented")
 213     // -----------------------------------------------------------------------
 214
 215     // get the size of our data
 216     virtual size_t GetDataSize() const
 217         { return 0; }
 218
 219     // copy our data to the buffer
 220     virtual bool GetDataHere(void *WXUNUSED(buf)) const
 221         { return false; }
 222
 223     // copy data from buffer to our data
 224     virtual bool SetData(size_t WXUNUSED(len), const void *WXUNUSED(buf))
 225         { return false; }
 226
 227     // implement base class pure virtuals
 228     // ----------------------------------
 229     virtual wxDataFormat GetPreferredFormat(wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
 230         { return m_format; }
 231     virtual size_t GetFormatCount(wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
 232         { return 1; }
 233     virtual void GetAllFormats(wxDataFormat *formats,
 234                                wxDataObjectBase::Direction WXUNUSED(dir) = Get) const
 235         { *formats = m_format; }
 236     virtual size_t GetDataSize(const wxDataFormat& WXUNUSED(format)) const
 237         { return GetDataSize(); }
 238     virtual bool GetDataHere(const wxDataFormat& WXUNUSED(format),
 239                              void *buf) const
 240         { return GetDataHere(buf); }
 241     virtual bool SetData(const wxDataFormat& WXUNUSED(format),
 242                          size_t len, const void *buf)
 243         { return SetData(len, buf); }
 244
 245 private:
 246     // the one and only format we support
 247     wxDataFormat m_format;
 248
 249     wxDECLARE_NO_COPY_CLASS(wxDataObjectSimple);
 250 };
 251
 252 // ----------------------------------------------------------------------------
 253 // wxDataObjectComposite is the simplest way to implement wxDataObject
 254 // supporting multiple formats. It contains several wxDataObjectSimple and
 255 // supports all formats supported by any of them.
 256 //
 257 // This class shouldn't be (normally) derived from, but may be used directly.
 258 // If you need more flexibility than what it provides, you should probably use
 259 // wxDataObject directly.
 260 // ----------------------------------------------------------------------------
 261
 262 WX_DECLARE_EXPORTED_LIST(wxDataObjectSimple, wxSimpleDataObjectList);
 263
 264 class WXDLLIMPEXP_CORE wxDataObjectComposite : public wxDataObject
 265 {
 266 public:
 267     // ctor
 268     wxDataObjectComposite();
 269     virtual ~wxDataObjectComposite();
 270
 271     // add data object (it will be deleted by wxDataObjectComposite, hence it
 272     // must be allocated on the heap) whose format will become the preferred
 273     // one if preferred == true
 274     void Add(wxDataObjectSimple *dataObject, bool preferred = false);
 275
 276     // Report the format passed to the SetData method.  This should be the
 277     // format of the data object within the composite that received data from
 278     // the clipboard or the DnD operation.  You can use this method to find
 279     // out what kind of data object was received.
 280     wxDataFormat GetReceivedFormat() const;
 281
 282     // Returns the pointer to the object which supports this format or NULL.
 283     // The returned pointer is owned by wxDataObjectComposite and must
 284     // therefore not be destroyed by the caller.
 285     wxDataObjectSimple *GetObject(const wxDataFormat& format,
 286                                   wxDataObjectBase::Direction dir = Get) const;
 287
 288     // implement base class pure virtuals
 289     // ----------------------------------
 290     virtual wxDataFormat GetPreferredFormat(wxDataObjectBase::Direction dir = Get) const;
 291     virtual size_t GetFormatCount(wxDataObjectBase::Direction dir = Get) const;
 292     virtual void GetAllFormats(wxDataFormat *formats, wxDataObjectBase::Direction dir = Get) const;
 293     virtual size_t GetDataSize(const wxDataFormat& format) const;
 294     virtual bool GetDataHere(const wxDataFormat& format, void *buf) const;
 295     virtual bool SetData(const wxDataFormat& format, size_t len, const void *buf);
 296 #if defined(__WXMSW__)
 297     virtual const void* GetSizeFromBuffer( const void* buffer, size_t* size,
 298                                            const wxDataFormat& format );
 299     virtual void* SetSizeInBuffer( void* buffer, size_t size,
 300                                    const wxDataFormat& format );
 301     virtual size_t GetBufferOffset( const wxDataFormat& format );
 302 #endif
 303
 304 private:
 305     // the list of all (simple) data objects whose formats we support
 306     wxSimpleDataObjectList m_dataObjects;
 307
 308     // the index of the preferred one (0 initially, so by default the first
 309     // one is the preferred)
 310     size_t m_preferred;
 311
 312     wxDataFormat m_receivedFormat;
 313
 314     wxDECLARE_NO_COPY_CLASS(wxDataObjectComposite);
 315 };
 316
 317 // ============================================================================
 318 // Standard implementations of wxDataObjectSimple which can be used directly
 319 // (i.e. without having to derive from them) for standard data type transfers.
 320 //
 321 // Note that although all of them can work with provided data, you can also
 322 // override their virtual GetXXX() functions to only provide data on demand.
 323 // ============================================================================
 324
 325 // ----------------------------------------------------------------------------
 326 // wxTextDataObject contains text data
 327 // ----------------------------------------------------------------------------
 328
 329 #if wxUSE_UNICODE
 330     #if defined(__WXGTK20__)
 331         #define wxNEEDS_UTF8_FOR_TEXT_DATAOBJ
 332     #elif defined(__WXMAC__)
 333         #define wxNEEDS_UTF16_FOR_TEXT_DATAOBJ
 334     #endif
 335 #endif // wxUSE_UNICODE
 336
 337 class WXDLLIMPEXP_CORE wxTextDataObject : public wxDataObjectSimple
 338 {
 339 public:
 340     // ctor: you can specify the text here or in SetText(), or override
 341     // GetText()
 342     wxTextDataObject(const wxString& text = wxEmptyString)
 343         : wxDataObjectSimple(
 344 #if wxUSE_UNICODE
 345                              wxDF_UNICODETEXT
 346 #else
 347                              wxDF_TEXT
 348 #endif
 349                             ),
 350           m_text(text)
 351         {
 352         }
 353
 354     // virtual functions which you may override if you want to provide text on
 355     // demand only - otherwise, the trivial default versions will be used
 356     virtual size_t GetTextLength() const { return m_text.Len() + 1; }
 357     virtual wxString GetText() const { return m_text; }
 358     virtual void SetText(const wxString& text) { m_text = text; }
 359
 360     // implement base class pure virtuals
 361     // ----------------------------------
 362
 363     // some platforms have 2 and not 1 format for text data
 364 #if defined(wxNEEDS_UTF8_FOR_TEXT_DATAOBJ) || defined(wxNEEDS_UTF16_FOR_TEXT_DATAOBJ)
 365     virtual size_t GetFormatCount(Direction WXUNUSED(dir) = Get) const { return 2; }
 366     virtual void GetAllFormats(wxDataFormat *formats,
 367                                wxDataObjectBase::Direction WXUNUSED(dir) = Get) const;
 368
 369     virtual size_t GetDataSize() const { return GetDataSize(GetPreferredFormat()); }
 370     virtual bool GetDataHere(void *buf) const { return GetDataHere(GetPreferredFormat(), buf); }
 371     virtual bool SetData(size_t len, const void *buf) { return SetData(GetPreferredFormat(), len, buf); }
 372
 373     size_t GetDataSize(const wxDataFormat& format) const;
 374     bool GetDataHere(const wxDataFormat& format, void *pBuf) const;
 375     bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf);
 376 #else // !wxNEEDS_UTF{8,16}_FOR_TEXT_DATAOBJ
 377     virtual size_t GetDataSize() const;
 378     virtual bool GetDataHere(void *buf) const;
 379     virtual bool SetData(size_t len, const void *buf);
 380     // Must provide overloads to avoid hiding them (and warnings about it)
 381     virtual size_t GetDataSize(const wxDataFormat&) const
 382     {
 383         return GetDataSize();
 384     }
 385     virtual bool GetDataHere(const wxDataFormat&, void *buf) const
 386     {
 387         return GetDataHere(buf);
 388     }
 389     virtual bool SetData(const wxDataFormat&, size_t len, const void *buf)
 390     {
 391         return SetData(len, buf);
 392     }
 393 #endif // different wxTextDataObject implementations
 394
 395 private:
 396     wxString m_text;
 397
 398     wxDECLARE_NO_COPY_CLASS(wxTextDataObject);
 399 };
 400
 401 // ----------------------------------------------------------------------------
 402 // wxBitmapDataObject contains a bitmap
 403 // ----------------------------------------------------------------------------
 404
 405 class WXDLLIMPEXP_CORE wxBitmapDataObjectBase : public wxDataObjectSimple
 406 {
 407 public:
 408     // ctor: you can specify the bitmap here or in SetBitmap(), or override
 409     // GetBitmap()
 410     wxBitmapDataObjectBase(const wxBitmap& bitmap = wxNullBitmap)
 411         : wxDataObjectSimple(wxDF_BITMAP), m_bitmap(bitmap)
 412         {
 413         }
 414
 415     // virtual functions which you may override if you want to provide data on
 416     // demand only - otherwise, the trivial default versions will be used
 417     virtual wxBitmap GetBitmap() const { return m_bitmap; }
 418     virtual void SetBitmap(const wxBitmap& bitmap) { m_bitmap = bitmap; }
 419
 420 protected:
 421     wxBitmap m_bitmap;
 422
 423     wxDECLARE_NO_COPY_CLASS(wxBitmapDataObjectBase);
 424 };
 425
 426 // ----------------------------------------------------------------------------
 427 // wxFileDataObject contains a list of filenames
 428 //
 429 // NB: notice that this is a "write only" object, it can only be filled with
 430 //     data from drag and drop operation.
 431 // ----------------------------------------------------------------------------
 432
 433 class WXDLLIMPEXP_CORE wxFileDataObjectBase : public wxDataObjectSimple
 434 {
 435 public:
 436     // ctor: use AddFile() later to fill the array
 437     wxFileDataObjectBase() : wxDataObjectSimple(wxDF_FILENAME) { }
 438
 439     // get a reference to our array
 440     const wxArrayString& GetFilenames() const { return m_filenames; }
 441
 442 protected:
 443     wxArrayString m_filenames;
 444
 445     wxDECLARE_NO_COPY_CLASS(wxFileDataObjectBase);
 446 };
 447
 448 // ----------------------------------------------------------------------------
 449 // wxCustomDataObject contains arbitrary untyped user data.
 450 //
 451 // It is understood that this data can be copied bitwise.
 452 // ----------------------------------------------------------------------------
 453
 454 class WXDLLIMPEXP_CORE wxCustomDataObject : public wxDataObjectSimple
 455 {
 456 public:
 457     // if you don't specify the format in the ctor, you can still use
 458     // SetFormat() later
 459     wxCustomDataObject(const wxDataFormat& format = wxFormatInvalid);
 460
 461     // the dtor calls Free()
 462     virtual ~wxCustomDataObject();
 463
 464     // you can call SetData() to set m_data: it will make a copy of the data
 465     // you pass - or you can use TakeData() which won't copy anything, but
 466     // will take ownership of data (i.e. will call Free() on it later)
 467     void TakeData(size_t size, void *data);
 468
 469     // this function is called to allocate "size" bytes of memory from
 470     // SetData(). The default version uses operator new[].
 471     virtual void *Alloc(size_t size);
 472
 473     // this function is called when the data is freed, you may override it to
 474     // anything you want (or may be nothing at all). The default version calls
 475     // operator delete[] on m_data
 476     virtual void Free();
 477
 478     // get data: you may override these functions if you wish to provide data
 479     // only when it's requested
 480     virtual size_t GetSize() const { return m_size; }
 481     virtual void *GetData() const { return m_data; }
 482
 483     // implement base class pure virtuals
 484     // ----------------------------------
 485     virtual size_t GetDataSize() const;
 486     virtual bool GetDataHere(void *buf) const;
 487     virtual bool SetData(size_t size, const void *buf);
 488     // Must provide overloads to avoid hiding them (and warnings about it)
 489     virtual size_t GetDataSize(const wxDataFormat&) const
 490     {
 491         return GetDataSize();
 492     }
 493     virtual bool GetDataHere(const wxDataFormat&, void *buf) const
 494     {
 495         return GetDataHere(buf);
 496     }
 497     virtual bool SetData(const wxDataFormat&, size_t len, const void *buf)
 498     {
 499         return SetData(len, buf);
 500     }
 501
 502 private:
 503     size_t m_size;
 504     void  *m_data;
 505
 506     wxDECLARE_NO_COPY_CLASS(wxCustomDataObject);
 507 };
 508
 509 // ----------------------------------------------------------------------------
 510 // include platform-specific declarations of wxXXXBase classes
 511 // ----------------------------------------------------------------------------
 512
 513 #if defined(__WXMSW__)
 514     #include "wx/msw/ole/dataobj2.h"
 515     // wxURLDataObject defined in msw/ole/dataobj2.h
 516 #elif defined(__WXGTK20__)
 517     #include "wx/gtk/dataobj2.h"
 518     // wxURLDataObject defined in msw/ole/dataobj2.h
 519
 520 #else
 521     #if defined(__WXGTK__)
 522         #include "wx/gtk1/dataobj2.h"
 523     #elif defined(__WXX11__)
 524         #include "wx/x11/dataobj2.h"
 525     #elif defined(__WXMOTIF__)
 526         #include "wx/motif/dataobj2.h"
 527     #elif defined(__WXMAC__)
 528         #include "wx/osx/dataobj2.h"
 529     #elif defined(__WXCOCOA__)
 530         #include "wx/cocoa/dataobj2.h"
 531     #elif defined(__WXPM__)
 532         #include "wx/os2/dataobj2.h"
 533     #endif
 534
 535     // wxURLDataObject is simply wxTextDataObject with a different name
 536     class WXDLLIMPEXP_CORE wxURLDataObject : public wxTextDataObject
 537     {
 538     public:
 539         wxURLDataObject(const wxString& url = wxEmptyString)
 540             : wxTextDataObject(url)
 541         {
 542         }
 543
 544         wxString GetURL() const { return GetText(); }
 545         void SetURL(const wxString& url) { SetText(url); }
 546     };
 547 #endif
 548
 549 #endif // wxUSE_DATAOBJ
 550
 551 #endif // _WX_DATAOBJ_H_BASE_