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(__WXGTK20__)
 170     #include "wx/gtk/dataobj.h"
 171 #elif defined(__WXGTK__)
 172     #include "wx/gtk1/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 #if defined(__WXMSW__)
 285     virtual const void* GetSizeFromBuffer( const void* buffer, size_t* size,
 286                                            const wxDataFormat& format );
 287     virtual void* SetSizeInBuffer( void* buffer, size_t size,
 288                                    const wxDataFormat& format );
 289     virtual size_t GetBufferOffset( const wxDataFormat& format );
 290 #endif
 291
 292 protected:
 293     // returns the pointer to the object which supports this format or NULL
 294     wxDataObjectSimple *GetObject(const wxDataFormat& format) const;
 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(
 326 #if wxUSE_UNICODE
 327                              wxDF_UNICODETEXT
 328 #else
 329                              wxDF_TEXT
 330 #endif
 331                             ),
 332           m_text(text)
 333         {
 334         }
 335
 336     // virtual functions which you may override if you want to provide text on
 337     // demand only - otherwise, the trivial default versions will be used
 338     virtual size_t GetTextLength() const { return m_text.Len() + 1; }
 339     virtual wxString GetText() const { return m_text; }
 340     virtual void SetText(const wxString& text) { m_text = text; }
 341
 342     // implement base class pure virtuals
 343     // ----------------------------------
 344
 345     // some platforms have 2 and not 1 format for text data
 346 #if wxUSE_UNICODE && (defined(__WXGTK20__) || defined(__WXMAC__))
 347     virtual size_t GetFormatCount(Direction WXUNUSED(dir) = Get) const { return 2; }
 348     virtual void GetAllFormats(wxDataFormat *formats,
 349                                wxDataObjectBase::Direction WXUNUSED(dir) = Get) const;
 350
 351     virtual size_t GetDataSize() const { return GetDataSize(GetPreferredFormat()); }
 352     virtual bool GetDataHere(void *buf) const { return GetDataHere(GetPreferredFormat(), buf); }
 353     virtual bool SetData(size_t len, const void *buf) { return SetData(GetPreferredFormat(), len, buf); }
 354
 355     size_t GetDataSize(const wxDataFormat& format) const;
 356     bool GetDataHere(const wxDataFormat& format, void *pBuf) const;
 357     bool SetData(const wxDataFormat& format, size_t nLen, const void* pBuf);
 358 #else
 359     virtual size_t GetDataSize() const;
 360     virtual bool GetDataHere(void *buf) const;
 361     virtual bool SetData(size_t len, const void *buf);
 362     // Must provide overloads to avoid hiding them (and warnings about it)
 363     virtual size_t GetDataSize(const wxDataFormat&) const
 364     {
 365         return GetDataSize();
 366     }
 367     virtual bool GetDataHere(const wxDataFormat&, void *buf) const
 368     {
 369         return GetDataHere(buf);
 370     }
 371     virtual bool SetData(const wxDataFormat&, size_t len, const void *buf)
 372     {
 373         return SetData(len, buf);
 374     }
 375 #endif
 376
 377 private:
 378     wxString m_text;
 379
 380     DECLARE_NO_COPY_CLASS(wxTextDataObject)
 381 };
 382
 383 // ----------------------------------------------------------------------------
 384 // wxBitmapDataObject contains a bitmap
 385 // ----------------------------------------------------------------------------
 386
 387 class WXDLLEXPORT wxBitmapDataObjectBase : public wxDataObjectSimple
 388 {
 389 public:
 390     // ctor: you can specify the bitmap here or in SetBitmap(), or override
 391     // GetBitmap()
 392     wxBitmapDataObjectBase(const wxBitmap& bitmap = wxNullBitmap)
 393         : wxDataObjectSimple(wxDF_BITMAP), m_bitmap(bitmap)
 394         {
 395         }
 396
 397     // virtual functions which you may override if you want to provide data on
 398     // demand only - otherwise, the trivial default versions will be used
 399     virtual wxBitmap GetBitmap() const { return m_bitmap; }
 400     virtual void SetBitmap(const wxBitmap& bitmap) { m_bitmap = bitmap; }
 401
 402 protected:
 403     wxBitmap m_bitmap;
 404
 405     DECLARE_NO_COPY_CLASS(wxBitmapDataObjectBase)
 406 };
 407
 408 // ----------------------------------------------------------------------------
 409 // wxFileDataObject contains a list of filenames
 410 //
 411 // NB: notice that this is a "write only" object, it can only be filled with
 412 //     data from drag and drop operation.
 413 // ----------------------------------------------------------------------------
 414
 415 class WXDLLEXPORT wxFileDataObjectBase : public wxDataObjectSimple
 416 {
 417 public:
 418     // ctor: use AddFile() later to fill the array
 419     wxFileDataObjectBase() : wxDataObjectSimple(wxDF_FILENAME) { }
 420
 421     // get a reference to our array
 422     const wxArrayString& GetFilenames() const { return m_filenames; }
 423
 424 protected:
 425     wxArrayString m_filenames;
 426
 427     DECLARE_NO_COPY_CLASS(wxFileDataObjectBase)
 428 };
 429
 430 // ----------------------------------------------------------------------------
 431 // wxCustomDataObject contains arbitrary untyped user data.
 432 //
 433 // It is understood that this data can be copied bitwise.
 434 // ----------------------------------------------------------------------------
 435
 436 class WXDLLEXPORT wxCustomDataObject : public wxDataObjectSimple
 437 {
 438 public:
 439     // if you don't specify the format in the ctor, you can still use
 440     // SetFormat() later
 441     wxCustomDataObject(const wxDataFormat& format = wxFormatInvalid);
 442
 443     // the dtor calls Free()
 444     virtual ~wxCustomDataObject();
 445
 446     // you can call SetData() to set m_data: it will make a copy of the data
 447     // you pass - or you can use TakeData() which won't copy anything, but
 448     // will take ownership of data (i.e. will call Free() on it later)
 449     void TakeData(size_t size, void *data);
 450
 451     // this function is called to allocate "size" bytes of memory from
 452     // SetData(). The default version uses operator new[].
 453     virtual void *Alloc(size_t size);
 454
 455     // this function is called when the data is freed, you may override it to
 456     // anything you want (or may be nothing at all). The default version calls
 457     // operator delete[] on m_data
 458     virtual void Free();
 459
 460     // get data: you may override these functions if you wish to provide data
 461     // only when it's requested
 462     virtual size_t GetSize() const { return m_size; }
 463     virtual void *GetData() const { return m_data; }
 464
 465     // implement base class pure virtuals
 466     // ----------------------------------
 467     virtual size_t GetDataSize() const;
 468     virtual bool GetDataHere(void *buf) const;
 469     virtual bool SetData(size_t size, const void *buf);
 470     // Must provide overloads to avoid hiding them (and warnings about it)
 471     virtual size_t GetDataSize(const wxDataFormat&) const
 472     {
 473         return GetDataSize();
 474     }
 475     virtual bool GetDataHere(const wxDataFormat&, void *buf) const
 476     {
 477         return GetDataHere(buf);
 478     }
 479     virtual bool SetData(const wxDataFormat&, size_t len, const void *buf)
 480     {
 481         return SetData(len, buf);
 482     }
 483
 484 private:
 485     size_t m_size;
 486     void  *m_data;
 487
 488     DECLARE_NO_COPY_CLASS(wxCustomDataObject)
 489 };
 490
 491 // ----------------------------------------------------------------------------
 492 // include platform-specific declarations of wxXXXBase classes
 493 // ----------------------------------------------------------------------------
 494
 495 #if defined(__WXMSW__)
 496     #include "wx/msw/ole/dataobj2.h"
 497
 498     // wxURLDataObject defined in msw/ole/dataobj2.h
 499 #else // !__WXMSW__
 500     #if defined(__WXGTK20__)
 501         #include "wx/gtk/dataobj2.h"
 502     #elif defined(__WXGTK__)
 503         #include "wx/gtk1/dataobj2.h"
 504     #elif defined(__WXX11__)
 505         #include "wx/x11/dataobj2.h"
 506     #elif defined(__WXMOTIF__)
 507         #include "wx/motif/dataobj2.h"
 508     #elif defined(__WXMAC__)
 509         #include "wx/mac/dataobj2.h"
 510     #elif defined(__WXCOCOA__)
 511         #include "wx/cocoa/dataobj2.h"
 512     #elif defined(__WXPM__)
 513         #include "wx/os2/dataobj2.h"
 514     #endif
 515
 516     // wxURLDataObject is simply wxTextDataObject with a different name
 517     class WXDLLEXPORT wxURLDataObject : public wxTextDataObject
 518     {
 519     public:
 520         wxString GetURL() const { return GetText(); }
 521         void SetURL(const wxString& url) { SetText(url); }
 522     };
 523 #endif // __WXMSW__/!__WXMSW__
 524
 525 #endif // wxUSE_DATAOBJ
 526
 527 #endif // _WX_DATAOBJ_H_BASE_