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 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  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(__WXCOCOA__)
  90     #include "wx/cocoa/dataform.h"
  91 #elif defined(__WXPM__)
  92     #include "wx/os2/dataform.h"
  93 #endif
  94
  95 // the value for default argument to some functions (corresponds to
  96 // wxDF_INVALID)
  97 extern WXDLLEXPORT const wxDataFormat& wxFormatInvalid;
  98
  99 // ----------------------------------------------------------------------------
 100 // wxDataObject represents a piece of data which knows which formats it
 101 // supports and knows how to render itself in each of them - GetDataHere(),
 102 // and how to restore data from the buffer (SetData()).
 103 //
 104 // Although this class may be used directly (i.e. custom classes may be
 105 // derived from it), in many cases it might be simpler to use either
 106 // wxDataObjectSimple or wxDataObjectComposite classes.
 107 //
 108 // A data object may be "read only", i.e. support only GetData() functions or
 109 // "read-write", i.e. support both GetData() and SetData() (in principle, it
 110 // might be "write only" too, but this is rare). Moreover, it doesn't have to
 111 // support the same formats in Get() and Set() directions: for example, a data
 112 // object containing JPEG image might accept BMPs in GetData() because JPEG
 113 // image may be easily transformed into BMP but not in SetData(). Accordingly,
 114 // all methods dealing with formats take an additional "direction" argument
 115 // which is either SET or GET and which tells the function if the format needs
 116 // to be supported by SetData() or GetDataHere().
 117 // ----------------------------------------------------------------------------
 118
 119 class WXDLLEXPORT wxDataObjectBase
 120 {
 121 public:
 122     enum Direction
 123     {
 124         Get  = 0x01,    // format is supported by GetDataHere()
 125         Set  = 0x02,    // format is supported by SetData()
 126         Both = 0x03     // format is supported by both (unused currently)
 127     };
 128
 129     // this class is polymorphic, hence it needs a virtual dtor
 130     virtual ~wxDataObjectBase();
 131
 132     // get the best suited format for rendering our data
 133     virtual wxDataFormat GetPreferredFormat(Direction dir = Get) const = 0;
 134
 135     // get the number of formats we support
 136     virtual size_t GetFormatCount(Direction dir = Get) const = 0;
 137
 138     // return all formats in the provided array (of size GetFormatCount())
 139     virtual void GetAllFormats(wxDataFormat *formats,
 140                                Direction dir = Get) const = 0;
 141
 142     // get the (total) size of data for the given format
 143     virtual size_t GetDataSize(const wxDataFormat& format) const = 0;
 144
 145     // copy raw data (in the specified format) to the provided buffer, return
 146     // true if data copied successfully, false otherwise
 147     virtual bool GetDataHere(const wxDataFormat& format, void *buf) const = 0;
 148
 149     // get data from the buffer of specified length (in the given format),
 150     // return true if the data was read successfully, false otherwise
 151     virtual bool SetData(const wxDataFormat& WXUNUSED(format),
 152                          size_t WXUNUSED(len), const void * WXUNUSED(buf))
 153     {
 154         return false;
 155     }
 156
 157     // returns true if this format is supported
 158     bool IsSupported(const wxDataFormat& format, Direction dir = Get) const;
 159 };
 160
 161 // ----------------------------------------------------------------------------
 162 // include the platform-specific declarations of wxDataObject
 163 // ----------------------------------------------------------------------------
 164
 165 #if defined(__WXMSW__)
 166     #include "wx/msw/ole/dataobj.h"
 167 #elif defined(__WXMOTIF__)
 168     #include "wx/motif/dataobj.h"
 169 #elif defined(__WXX11__)
 170     #include "wx/x11/dataobj.h"
 171 #elif defined(__WXGTK__)
 172     #include "wx/gtk/dataobj.h"
 173 #elif defined(__WXMAC__)
 174     #include "wx/mac/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 WXDLLEXPORT 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     DECLARE_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 WXDLLEXPORT 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     // implement base class pure virtuals
 277     // ----------------------------------
 278     virtual wxDataFormat GetPreferredFormat(wxDataObjectBase::Direction dir = Get) const;
 279     virtual size_t GetFormatCount(wxDataObjectBase::Direction dir = Get) const;
 280     virtual void GetAllFormats(wxDataFormat *formats, wxDataObjectBase::Direction dir = Get) const;
 281     virtual size_t GetDataSize(const wxDataFormat& format) const;
 282     virtual bool GetDataHere(const wxDataFormat& format, void *buf) const;
 283     virtual bool SetData(const wxDataFormat& format, size_t len, const void *buf);
 284
 285 protected:
 286     // returns the pointer to the object which supports this format or NULL
 287     wxDataObjectSimple *GetObject(const wxDataFormat& format) const;
 288 #if defined(__WXMSW__)
 289     virtual const void* GetSizeFromBuffer( const void* buffer, size_t* size,
 290                                            const wxDataFormat& format );
 291     virtual void* SetSizeInBuffer( void* buffer, size_t size,
 292                                    const wxDataFormat& format );
 293     virtual size_t GetBufferOffset( const wxDataFormat& format );
 294 #endif
 295
 296 private:
 297     // the list of all (simple) data objects whose formats we support
 298     wxSimpleDataObjectList m_dataObjects;
 299
 300     // the index of the preferred one (0 initially, so by default the first
 301     // one is the preferred)
 302     size_t m_preferred;
 303
 304     DECLARE_NO_COPY_CLASS(wxDataObjectComposite)
 305 };
 306
 307 // ============================================================================
 308 // Standard implementations of wxDataObjectSimple which can be used directly
 309 // (i.e. without having to derive from them) for standard data type transfers.
 310 //
 311 // Note that although all of them can work with provided data, you can also
 312 // override their virtual GetXXX() functions to only provide data on demand.
 313 // ============================================================================
 314
 315 // ----------------------------------------------------------------------------
 316 // wxTextDataObject contains text data
 317 // ----------------------------------------------------------------------------
 318
 319 class WXDLLEXPORT wxTextDataObject : public wxDataObjectSimple
 320 {
 321 public:
 322     // ctor: you can specify the text here or in SetText(), or override
 323     // GetText()
 324     wxTextDataObject(const wxString& text = wxEmptyString)
 325         : wxDataObjectSimple(wxUSE_UNICODE?wxDF_UNICODETEXT:wxDF_TEXT),
 326           m_text(text)
 327         {
 328         }
 329
 330     // virtual functions which you may override if you want to provide text on
 331     // demand only - otherwise, the trivial default versions will be used
 332     virtual size_t GetTextLength() const { return m_text.Len() + 1; }
 333     virtual wxString GetText() const { return m_text; }
 334     virtual void SetText(const wxString& text) { m_text = text; }
 335
 336     // implement base class pure virtuals
 337     // ----------------------------------
 338
 339 #if wxUSE_UNICODE && defined(__WXGTK20__)
 340     virtual size_t GetFormatCount(Direction WXUNUSED(dir) = Get) const { return 2; }
 341     virtual void GetAllFormats(wxDataFormat *formats,
 342                                wxDataObjectBase::Direction WXUNUSED(dir) = Get) const;
 343
 344     virtual size_t GetDataSize() const { return GetDataSize(GetPreferredFormat()); }
 345     virtual bool GetDataHere(void *buf) const { return GetDataHere(GetPreferredFormat(), buf); }
 346     virtual bool SetData(size_t len, const void *buf) { return SetData(GetPreferredFormat(), len, buf); }
 347
 348     size_t GetDataSize(const wxDataFormat& format) const;
 349     bool GetDataHere(const wxDataFormat& format, void *pBuf) const;
 350     bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf);
 351 #elif wxUSE_UNICODE && defined(__WXMAC__)
 352     virtual size_t GetFormatCount(Direction WXUNUSED(dir) = Get) const { return 2; }
 353     virtual void GetAllFormats(wxDataFormat *formats,
 354                                wxDataObjectBase::Direction WXUNUSED(dir) = Get) const;
 355
 356     virtual size_t GetDataSize() const { return GetDataSize(GetPreferredFormat()); }
 357     virtual bool GetDataHere(void *buf) const { return GetDataHere(GetPreferredFormat(), buf); }
 358     virtual bool SetData(size_t len, const void *buf) { return SetData(GetPreferredFormat(), len, buf); }
 359
 360     size_t GetDataSize(const wxDataFormat& format) const;
 361     bool GetDataHere(const wxDataFormat& format, void *pBuf) const;
 362     bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf);
 363 #else
 364     virtual size_t GetDataSize() const;
 365     virtual bool GetDataHere(void *buf) const;
 366     virtual bool SetData(size_t len, const void *buf);
 367
 368     size_t GetDataSize(const wxDataFormat& format) const
 369         { return(wxDataObjectSimple::GetDataSize(format)); }
 370     bool GetDataHere(const wxDataFormat& format, void *pBuf) const
 371         { return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
 372     bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf)
 373         { return(wxDataObjectSimple::SetData(format, nLen, pBuf)); }
 374 #endif
 375
 376 private:
 377     wxString m_text;
 378
 379     DECLARE_NO_COPY_CLASS(wxTextDataObject)
 380 };
 381
 382 // ----------------------------------------------------------------------------
 383 // wxBitmapDataObject contains a bitmap
 384 // ----------------------------------------------------------------------------
 385
 386 class WXDLLEXPORT wxBitmapDataObjectBase : public wxDataObjectSimple
 387 {
 388 public:
 389     // ctor: you can specify the bitmap here or in SetBitmap(), or override
 390     // GetBitmap()
 391     wxBitmapDataObjectBase(const wxBitmap& bitmap = wxNullBitmap)
 392         : wxDataObjectSimple(wxDF_BITMAP), m_bitmap(bitmap)
 393         {
 394         }
 395
 396     // virtual functions which you may override if you want to provide data on
 397     // demand only - otherwise, the trivial default versions will be used
 398     virtual wxBitmap GetBitmap() const { return m_bitmap; }
 399     virtual void SetBitmap(const wxBitmap& bitmap) { m_bitmap = bitmap; }
 400
 401 protected:
 402     wxBitmap m_bitmap;
 403
 404     DECLARE_NO_COPY_CLASS(wxBitmapDataObjectBase)
 405 };
 406
 407 // ----------------------------------------------------------------------------
 408 // wxFileDataObject contains a list of filenames
 409 //
 410 // NB: notice that this is a "write only" object, it can only be filled with
 411 //     data from drag and drop operation.
 412 // ----------------------------------------------------------------------------
 413
 414 class WXDLLEXPORT wxFileDataObjectBase : public wxDataObjectSimple
 415 {
 416 public:
 417     // ctor: use AddFile() later to fill the array
 418     wxFileDataObjectBase() : wxDataObjectSimple(wxDF_FILENAME) { }
 419
 420     // get a reference to our array
 421     const wxArrayString& GetFilenames() const { return m_filenames; }
 422
 423     // the Get() functions do nothing for us
 424     virtual size_t GetDataSize() const { return 0; }
 425     virtual bool GetDataHere(void *WXUNUSED(buf)) const { return false; }
 426
 427 protected:
 428     wxArrayString m_filenames;
 429
 430 private:
 431     // Virtual function hiding supression
 432     size_t GetDataSize(const wxDataFormat& format) const
 433         { return(wxDataObjectSimple::GetDataSize(format)); }
 434     bool GetDataHere(const wxDataFormat& format, void* pBuf) const
 435         { return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
 436
 437     DECLARE_NO_COPY_CLASS(wxFileDataObjectBase)
 438 };
 439
 440 // ----------------------------------------------------------------------------
 441 // wxCustomDataObject contains arbitrary untyped user data.
 442 //
 443 // It is understood that this data can be copied bitwise.
 444 // ----------------------------------------------------------------------------
 445
 446 class WXDLLEXPORT wxCustomDataObject : public wxDataObjectSimple
 447 {
 448 public:
 449     // if you don't specify the format in the ctor, you can still use
 450     // SetFormat() later
 451     wxCustomDataObject(const wxDataFormat& format = wxFormatInvalid);
 452
 453     // the dtor calls Free()
 454     virtual ~wxCustomDataObject();
 455
 456     // you can call SetData() to set m_data: it will make a copy of the data
 457     // you pass - or you can use TakeData() which won't copy anything, but
 458     // will take ownership of data (i.e. will call Free() on it later)
 459     void TakeData(size_t size, void *data);
 460
 461     // this function is called to allocate "size" bytes of memory from
 462     // SetData(). The default version uses operator new[].
 463     virtual void *Alloc(size_t size);
 464
 465     // this function is called when the data is freed, you may override it to
 466     // anything you want (or may be nothing at all). The default version calls
 467     // operator delete[] on m_data
 468     virtual void Free();
 469
 470     // get data: you may override these functions if you wish to provide data
 471     // only when it's requested
 472     virtual size_t GetSize() const { return m_size; }
 473     virtual void *GetData() const { return m_data; }
 474
 475     // implement base class pure virtuals
 476     // ----------------------------------
 477     virtual size_t GetDataSize() const;
 478     virtual bool GetDataHere(void *buf) const;
 479     virtual bool SetData(size_t size, const void *buf);
 480
 481 private:
 482     size_t m_size;
 483     void  *m_data;
 484
 485     // virtual function hiding supression
 486     size_t GetDataSize(const wxDataFormat& format) const
 487         { return(wxDataObjectSimple::GetDataSize(format)); }
 488     bool GetDataHere(const wxDataFormat& format, void* pBuf) const
 489         { return(wxDataObjectSimple::GetDataHere(format, pBuf)); }
 490     bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf)
 491         { return(wxDataObjectSimple::SetData(format, nLen, pBuf)); }
 492
 493     DECLARE_NO_COPY_CLASS(wxCustomDataObject)
 494 };
 495
 496 // ----------------------------------------------------------------------------
 497 // include platform-specific declarations of wxXXXBase classes
 498 // ----------------------------------------------------------------------------
 499
 500 #if defined(__WXMSW__)
 501     #include "wx/msw/ole/dataobj2.h"
 502
 503     // wxURLDataObject defined in msw/ole/dataobj2.h
 504 #else // !__WXMSW__
 505     #if defined(__WXGTK__)
 506         #include "wx/gtk/dataobj2.h"
 507     #elif defined(__WXX11__)
 508         #include "wx/x11/dataobj2.h"
 509     #elif defined(__WXMOTIF__)
 510         #include "wx/motif/dataobj2.h"
 511     #elif defined(__WXMAC__)
 512         #include "wx/mac/dataobj2.h"
 513     #elif defined(__WXCOCOA__)
 514         #include "wx/cocoa/dataobj2.h"
 515     #elif defined(__WXPM__)
 516         #include "wx/os2/dataobj2.h"
 517     #endif
 518
 519     // wxURLDataObject is simply wxTextDataObject with a different name
 520     class WXDLLEXPORT wxURLDataObject : public wxTextDataObject
 521     {
 522     public:
 523         wxString GetURL() const { return GetText(); }
 524         void SetURL(const wxString& url) { SetText(url); }
 525     };
 526 #endif // __WXMSW__/!__WXMSW__
 527
 528 #endif // wxUSE_DATAOBJ
 529
 530 #endif // _WX_DATAOBJ_H_BASE_