src/msw/dde.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        msw/dde.cpp
   3 // Purpose:     DDE classes
   4 // Author:      Julian Smart
   5 // Modified by:
   6 // Created:     01/02/97
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Julian Smart
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 // ============================================================================
  13 // declarations
  14 // ============================================================================
  15
  16 // ----------------------------------------------------------------------------
  17 // headers
  18 // ----------------------------------------------------------------------------
  19
  20 #ifdef __GNUG__
  21     #pragma implementation "dde.h"
  22 #endif
  23
  24 // For compilers that support precompilation, includes "wx.h".
  25 #include "wx/wxprec.h"
  26
  27 #ifdef __BORLANDC__
  28     #pragma hdrstop
  29 #endif
  30
  31 #if wxUSE_IPC
  32
  33 #ifndef WX_PRECOMP
  34     #include "wx/utils.h"
  35     #include "wx/app.h"
  36 #endif
  37
  38 #include "wx/module.h"
  39 #include "wx/dde.h"
  40 #include "wx/intl.h"
  41
  42
  43 #include "wx/msw/private.h"
  44
  45 #include <string.h>
  46 #include <windows.h>
  47 #include <ddeml.h>
  48
  49 #ifdef __GNUWIN32_OLD__
  50     #include "wx/msw/gnuwin32/extra.h"
  51 #endif
  52
  53 // some compilers headers don't define this one (mingw32)
  54 #ifndef DMLERR_NO_ERROR
  55     #define DMLERR_NO_ERROR (0)
  56
  57     // this one is also missing from some mingw32 headers, but there is no way
  58     // to test for it (I know of) - the test for DMLERR_NO_ERROR works for me,
  59     // but is surely not the right thing to do
  60     extern "C"
  61     HDDEDATA STDCALL DdeClientTransaction(LPBYTE pData,
  62                                           DWORD cbData,
  63                                           HCONV hConv,
  64                                           HSZ hszItem,
  65                                           UINT wFmt,
  66                                           UINT wType,
  67                                           DWORD dwTimeout,
  68                                           LPDWORD pdwResult);
  69 #endif // no DMLERR_NO_ERROR
  70
  71 // ----------------------------------------------------------------------------
  72 // macros and constants
  73 // ----------------------------------------------------------------------------
  74
  75 #ifdef __WIN32__
  76     #define _EXPORT
  77 #else
  78     #define _EXPORT _export
  79 #endif
  80
  81 #if wxUSE_UNICODE
  82     #define DDE_CP      CP_WINUNICODE
  83 #else
  84     #define DDE_CP      CP_WINANSI
  85 #endif
  86
  87 #define GetHConv()       ((HCONV)m_hConv)
  88
  89 // default timeout for DDE operations (5sec)
  90 #define DDE_TIMEOUT     5000
  91
  92 // ----------------------------------------------------------------------------
  93 // private functions
  94 // ----------------------------------------------------------------------------
  95
  96 static wxDDEConnection *DDEFindConnection(HCONV hConv);
  97 static void DDEDeleteConnection(HCONV hConv);
  98 static wxDDEServer *DDEFindServer(const wxString& s);
  99
 100 extern "C" HDDEDATA EXPENTRY _EXPORT _DDECallback(WORD wType,
 101                                                   WORD wFmt,
 102                                                   HCONV hConv,
 103                                                   HSZ hsz1,
 104                                                   HSZ hsz2,
 105                                                   HDDEDATA hData,
 106                                                   DWORD lData1,
 107                                                   DWORD lData2);
 108
 109 // Add topic name to atom table before using in conversations
 110 static HSZ DDEAddAtom(const wxString& string);
 111 static HSZ DDEGetAtom(const wxString& string);
 112
 113 // string handles
 114 static HSZ DDEAtomFromString(const wxString& s);
 115 static wxString DDEStringFromAtom(HSZ hsz);
 116
 117 // error handling
 118 static wxString DDEGetErrorMsg(UINT error);
 119 static void DDELogError(const wxString& s, UINT error = DMLERR_NO_ERROR);
 120
 121 // ----------------------------------------------------------------------------
 122 // global variables
 123 // ----------------------------------------------------------------------------
 124
 125 static DWORD DDEIdInst = 0L;
 126 static wxDDEConnection *DDECurrentlyConnecting = NULL;
 127 static wxList wxAtomTable(wxKEY_STRING);
 128
 129 #include "wx/listimpl.cpp"
 130
 131 WX_DEFINE_LIST(wxDDEClientList);
 132 WX_DEFINE_LIST(wxDDEServerList);
 133 WX_DEFINE_LIST(wxDDEConnectionList);
 134
 135 static wxDDEClientList wxDDEClientObjects;
 136 static wxDDEServerList wxDDEServerObjects;
 137
 138 static bool DDEInitialized = false;
 139
 140 // ----------------------------------------------------------------------------
 141 // private classes
 142 // ----------------------------------------------------------------------------
 143
 144 // A module to allow DDE cleanup without calling these functions
 145 // from app.cpp or from the user's application.
 146
 147 class wxDDEModule : public wxModule
 148 {
 149 public:
 150     wxDDEModule() {}
 151     bool OnInit() { return true; }
 152     void OnExit() { wxDDECleanUp(); }
 153
 154 private:
 155     DECLARE_DYNAMIC_CLASS(wxDDEModule)
 156 };
 157
 158 // ----------------------------------------------------------------------------
 159 // wxWin macros
 160 // ----------------------------------------------------------------------------
 161
 162 IMPLEMENT_DYNAMIC_CLASS(wxDDEServer, wxServerBase)
 163 IMPLEMENT_DYNAMIC_CLASS(wxDDEClient, wxClientBase)
 164 IMPLEMENT_CLASS(wxDDEConnection, wxConnectionBase)
 165 IMPLEMENT_DYNAMIC_CLASS(wxDDEModule, wxModule)
 166
 167 // ============================================================================
 168 // implementation
 169 // ============================================================================
 170
 171 // ----------------------------------------------------------------------------
 172 // initialization and cleanup
 173 // ----------------------------------------------------------------------------
 174
 175 extern void wxDDEInitialize()
 176 {
 177     if ( !DDEInitialized )
 178     {
 179         // Should insert filter flags
 180         PFNCALLBACK callback = (PFNCALLBACK)
 181             MakeProcInstance((FARPROC)_DDECallback, wxGetInstance());
 182         UINT rc = DdeInitialize(&DDEIdInst, callback, APPCLASS_STANDARD, 0L);
 183         if ( rc != DMLERR_NO_ERROR )
 184         {
 185             DDELogError(_T("Failed to initialize DDE"), rc);
 186         }
 187         else
 188         {
 189             DDEInitialized = true;
 190         }
 191     }
 192 }
 193
 194 void wxDDECleanUp()
 195 {
 196     wxDDEClientObjects.DeleteContents(true);
 197     wxDDEClientObjects.Clear();
 198     wxDDEClientObjects.DeleteContents(false);
 199
 200     wxDDEServerObjects.DeleteContents(true);
 201     wxDDEServerObjects.Clear();
 202     wxDDEServerObjects.DeleteContents(false);
 203
 204     wxAtomTable.Clear();
 205
 206     if ( DDEIdInst != 0 )
 207     {
 208         DdeUninitialize(DDEIdInst);
 209         DDEIdInst = 0;
 210     }
 211 }
 212
 213 // ----------------------------------------------------------------------------
 214 // functions working with the global connection list(s)
 215 // ----------------------------------------------------------------------------
 216
 217 // Global find connection
 218 static wxDDEConnection *DDEFindConnection(HCONV hConv)
 219 {
 220     wxDDEServerList::Node *serverNode = wxDDEServerObjects.GetFirst();
 221     wxDDEConnection *found = NULL;
 222     while (serverNode && !found)
 223     {
 224         wxDDEServer *object = serverNode->GetData();
 225         found = object->FindConnection((WXHCONV) hConv);
 226         serverNode = serverNode->GetNext();
 227     }
 228
 229     if (found)
 230     {
 231         return found;
 232     }
 233
 234     wxDDEClientList::Node *clientNode = wxDDEClientObjects.GetFirst();
 235     while (clientNode && !found)
 236     {
 237         wxDDEClient *object = clientNode->GetData();
 238         found = object->FindConnection((WXHCONV) hConv);
 239         clientNode = clientNode->GetNext();
 240     }
 241     return found;
 242 }
 243
 244 // Global delete connection
 245 static void DDEDeleteConnection(HCONV hConv)
 246 {
 247     wxDDEServerList::Node *serverNode = wxDDEServerObjects.GetFirst();
 248     bool found = false;
 249     while (serverNode && !found)
 250     {
 251         wxDDEServer *object = serverNode->GetData();
 252         found = object->DeleteConnection((WXHCONV) hConv);
 253         serverNode = serverNode->GetNext();
 254     }
 255     if (found)
 256     {
 257         return;
 258     }
 259
 260     wxDDEClientList::Node *clientNode = wxDDEClientObjects.GetFirst();
 261     while (clientNode && !found)
 262     {
 263         wxDDEClient *object = clientNode->GetData();
 264         found = object->DeleteConnection((WXHCONV) hConv);
 265         clientNode = clientNode->GetNext();
 266     }
 267 }
 268
 269 // Find a server from a service name
 270 static wxDDEServer *DDEFindServer(const wxString& s)
 271 {
 272     wxDDEServerList::Node *node = wxDDEServerObjects.GetFirst();
 273     wxDDEServer *found = NULL;
 274     while (node && !found)
 275     {
 276         wxDDEServer *object = node->GetData();
 277
 278         if (object->GetServiceName() == s)
 279         {
 280             found = object;
 281         }
 282         else
 283         {
 284             node = node->GetNext();
 285         }
 286     }
 287
 288     return found;
 289 }
 290
 291 // ----------------------------------------------------------------------------
 292 // wxDDEServer
 293 // ----------------------------------------------------------------------------
 294
 295 wxDDEServer::wxDDEServer()
 296 {
 297     wxDDEInitialize();
 298
 299     wxDDEServerObjects.Append(this);
 300 }
 301
 302 bool wxDDEServer::Create(const wxString& server)
 303 {
 304     m_serviceName = server;
 305
 306     if ( !DdeNameService(DDEIdInst, DDEAtomFromString(server), (HSZ)NULL, DNS_REGISTER) )
 307     {
 308         DDELogError(wxString::Format(_("Failed to register DDE server '%s'"),
 309                                      server.c_str()));
 310
 311         return false;
 312     }
 313
 314     return true;
 315 }
 316
 317 wxDDEServer::~wxDDEServer()
 318 {
 319     if ( !!m_serviceName )
 320     {
 321         if ( !DdeNameService(DDEIdInst, DDEAtomFromString(m_serviceName),
 322                              (HSZ)NULL, DNS_UNREGISTER) )
 323         {
 324             DDELogError(wxString::Format(_("Failed to unregister DDE server '%s'"),
 325                                          m_serviceName.c_str()));
 326         }
 327     }
 328
 329     wxDDEServerObjects.DeleteObject(this);
 330
 331     wxDDEConnectionList::Node *node = m_connections.GetFirst();
 332     while (node)
 333     {
 334         wxDDEConnection *connection = node->GetData();
 335         wxDDEConnectionList::Node *next = node->GetNext();
 336         connection->SetConnected(false);
 337         connection->OnDisconnect(); // May delete the node implicitly
 338         node = next;
 339     }
 340
 341     // If any left after this, delete them
 342     node = m_connections.GetFirst();
 343     while (node)
 344     {
 345         wxDDEConnection *connection = node->GetData();
 346         wxDDEConnectionList::Node *next = node->GetNext();
 347         delete connection;
 348         node = next;
 349     }
 350 }
 351
 352 wxConnectionBase *wxDDEServer::OnAcceptConnection(const wxString& /* topic */)
 353 {
 354     return new wxDDEConnection;
 355 }
 356
 357 wxDDEConnection *wxDDEServer::FindConnection(WXHCONV conv)
 358 {
 359     wxDDEConnectionList::Node *node = m_connections.GetFirst();
 360     wxDDEConnection *found = NULL;
 361     while (node && !found)
 362     {
 363         wxDDEConnection *connection = node->GetData();
 364         if (connection->m_hConv == conv)
 365             found = connection;
 366         else node = node->GetNext();
 367     }
 368     return found;
 369 }
 370
 371 // Only delete the entry in the map, not the actual connection
 372 bool wxDDEServer::DeleteConnection(WXHCONV conv)
 373 {
 374     wxDDEConnectionList::Node *node = m_connections.GetFirst();
 375     bool found = false;
 376     while (node && !found)
 377     {
 378         wxDDEConnection *connection = node->GetData();
 379         if (connection->m_hConv == conv)
 380         {
 381             found = true;
 382             delete node;
 383         }
 384         else
 385         {
 386             node = node->GetNext();
 387         }
 388     }
 389     return found;
 390 }
 391
 392 // ----------------------------------------------------------------------------
 393 // wxDDEClient
 394 // ----------------------------------------------------------------------------
 395
 396 wxDDEClient::wxDDEClient()
 397 {
 398     wxDDEInitialize();
 399
 400     wxDDEClientObjects.Append(this);
 401 }
 402
 403 wxDDEClient::~wxDDEClient()
 404 {
 405     wxDDEClientObjects.DeleteObject(this);
 406     wxDDEConnectionList::Node *node = m_connections.GetFirst();
 407     while (node)
 408     {
 409         wxDDEConnection *connection = node->GetData();
 410         delete connection;  // Deletes the node implicitly (see ~wxDDEConnection)
 411         node = m_connections.GetFirst();
 412     }
 413 }
 414
 415 bool wxDDEClient::ValidHost(const wxString& /* host */)
 416 {
 417     return true;
 418 }
 419
 420 wxConnectionBase *wxDDEClient::MakeConnection(const wxString& WXUNUSED(host),
 421                                               const wxString& server,
 422                                               const wxString& topic)
 423 {
 424     HCONV hConv = DdeConnect(DDEIdInst, DDEAtomFromString(server), DDEAtomFromString(topic),
 425                              (PCONVCONTEXT)NULL);
 426     if ( !hConv )
 427     {
 428         DDELogError(wxString::Format(_("Failed to create connection to server '%s' on topic '%s'"),
 429                                      server.c_str(), topic.c_str()));
 430     }
 431     else
 432     {
 433         wxDDEConnection *connection = (wxDDEConnection*) OnMakeConnection();
 434         if (connection)
 435         {
 436             connection->m_hConv = (WXHCONV) hConv;
 437             connection->m_topicName = topic;
 438             connection->m_client = this;
 439             m_connections.Append(connection);
 440             return connection;
 441         }
 442     }
 443
 444     return (wxConnectionBase*) NULL;
 445 }
 446
 447 wxConnectionBase *wxDDEClient::OnMakeConnection()
 448 {
 449     return new wxDDEConnection;
 450 }
 451
 452 wxDDEConnection *wxDDEClient::FindConnection(WXHCONV conv)
 453 {
 454     wxDDEConnectionList::Node *node = m_connections.GetFirst();
 455     wxDDEConnection *found = NULL;
 456     while (node && !found)
 457     {
 458         wxDDEConnection *connection = node->GetData();
 459         if (connection->m_hConv == conv)
 460             found = connection;
 461         else node = node->GetNext();
 462     }
 463     return found;
 464 }
 465
 466 // Only delete the entry in the map, not the actual connection
 467 bool wxDDEClient::DeleteConnection(WXHCONV conv)
 468 {
 469     wxDDEConnectionList::Node *node = m_connections.GetFirst();
 470     bool found = false;
 471     while (node && !found)
 472     {
 473         wxDDEConnection *connection = node->GetData();
 474         if (connection->m_hConv == conv)
 475         {
 476             found = true;
 477             delete node;
 478         }
 479         else node = node->GetNext();
 480     }
 481     return found;
 482 }
 483
 484 // ----------------------------------------------------------------------------
 485 // wxDDEConnection
 486 // ----------------------------------------------------------------------------
 487
 488 wxDDEConnection::wxDDEConnection(wxChar *buffer, int size)
 489      : wxConnectionBase(buffer, size)
 490 {
 491     m_client = NULL;
 492     m_server = NULL;
 493
 494     m_hConv = 0;
 495     m_sendingData = NULL;
 496 }
 497
 498 wxDDEConnection::wxDDEConnection()
 499      : wxConnectionBase()
 500 {
 501     m_hConv = 0;
 502     m_sendingData = NULL;
 503     m_server = NULL;
 504     m_client = NULL;
 505 }
 506
 507 wxDDEConnection::~wxDDEConnection()
 508 {
 509     Disconnect();
 510     if (m_server)
 511         m_server->GetConnections().DeleteObject(this);
 512     else
 513         m_client->GetConnections().DeleteObject(this);
 514 }
 515
 516 // Calls that CLIENT can make
 517 bool wxDDEConnection::Disconnect()
 518 {
 519     if ( !GetConnected() )
 520         return true;
 521
 522     DDEDeleteConnection(GetHConv());
 523
 524     bool ok = DdeDisconnect(GetHConv()) != 0;
 525     if ( !ok )
 526     {
 527         DDELogError(_T("Failed to disconnect from DDE server gracefully"));
 528     }
 529
 530     SetConnected( false );  // so we don't try and disconnect again
 531
 532     return ok;
 533 }
 534
 535 bool wxDDEConnection::Execute(const wxChar *data, int size, wxIPCFormat format)
 536 {
 537     DWORD result;
 538     if (size < 0)
 539     {
 540         size = wxStrlen(data) + 1;
 541     }
 542
 543     bool ok = DdeClientTransaction((LPBYTE)data, size,
 544                                     GetHConv(),
 545                                     NULL,
 546                                     format,
 547                                     XTYP_EXECUTE,
 548                                     DDE_TIMEOUT,
 549                                     &result) != 0;
 550
 551     if ( !ok )
 552     {
 553         DDELogError(_T("DDE execute request failed"));
 554     }
 555
 556     return ok;
 557 }
 558
 559 wxChar *wxDDEConnection::Request(const wxString& item, int *size, wxIPCFormat format)
 560 {
 561     DWORD result;
 562
 563     HSZ atom = DDEGetAtom(item);
 564
 565     HDDEDATA returned_data = DdeClientTransaction(NULL, 0,
 566                                                   GetHConv(),
 567                                                   atom, format,
 568                                                   XTYP_REQUEST,
 569                                                   DDE_TIMEOUT,
 570                                                   &result);
 571     if ( !returned_data )
 572     {
 573         DDELogError(_T("DDE data request failed"));
 574
 575         return NULL;
 576     }
 577
 578     DWORD len = DdeGetData(returned_data, NULL, 0, 0);
 579
 580     wxChar *data = GetBufferAtLeast( len );
 581     wxASSERT_MSG(data != NULL,
 582                  _T("Buffer too small in wxDDEConnection::Request") );
 583     DdeGetData(returned_data, (LPBYTE)data, len, 0);
 584
 585     DdeFreeDataHandle(returned_data);
 586
 587     if (size)
 588         *size = (int)len;
 589
 590     return data;
 591 }
 592
 593 bool wxDDEConnection::Poke(const wxString& item, wxChar *data, int size, wxIPCFormat format)
 594 {
 595     DWORD result;
 596     if (size < 0)
 597     {
 598         size = wxStrlen(data) + 1;
 599     }
 600
 601     HSZ item_atom = DDEGetAtom(item);
 602     bool ok = DdeClientTransaction((LPBYTE)data, size,
 603                                    GetHConv(),
 604                                    item_atom, format,
 605                                    XTYP_POKE,
 606                                    DDE_TIMEOUT,
 607                                    &result) != 0;
 608     if ( !ok )
 609     {
 610         DDELogError(_("DDE poke request failed"));
 611     }
 612
 613     return ok;
 614 }
 615
 616 bool wxDDEConnection::StartAdvise(const wxString& item)
 617 {
 618     DWORD result;
 619     HSZ atom = DDEGetAtom(item);
 620
 621     bool ok = DdeClientTransaction(NULL, 0,
 622                                    GetHConv(),
 623                                    atom, CF_TEXT,
 624                                    XTYP_ADVSTART,
 625                                    DDE_TIMEOUT,
 626                                    &result) != 0;
 627     if ( !ok )
 628     {
 629         DDELogError(_("Failed to establish an advise loop with DDE server"));
 630     }
 631
 632     return ok;
 633 }
 634
 635 bool wxDDEConnection::StopAdvise(const wxString& item)
 636 {
 637     DWORD result;
 638     HSZ atom = DDEGetAtom(item);
 639
 640     bool ok = DdeClientTransaction(NULL, 0,
 641                                    GetHConv(),
 642                                    atom, CF_TEXT,
 643                                    XTYP_ADVSTOP,
 644                                    DDE_TIMEOUT,
 645                                    &result) != 0;
 646     if ( !ok )
 647     {
 648         DDELogError(_("Failed to terminate the advise loop with DDE server"));
 649     }
 650
 651     return ok;
 652 }
 653
 654 // Calls that SERVER can make
 655 bool wxDDEConnection::Advise(const wxString& item,
 656                              wxChar *data,
 657                              int size,
 658                              wxIPCFormat format)
 659 {
 660     if (size < 0)
 661     {
 662         size = wxStrlen(data) + 1;
 663     }
 664
 665     HSZ item_atom = DDEGetAtom(item);
 666     HSZ topic_atom = DDEGetAtom(m_topicName);
 667     m_sendingData = data;  // mrf: potential for scope problems here?
 668     m_dataSize = size;
 669     m_dataType = format;
 670
 671     bool ok = DdePostAdvise(DDEIdInst, topic_atom, item_atom) != 0;
 672     if ( !ok )
 673     {
 674         DDELogError(_("Failed to send DDE advise notification"));
 675     }
 676
 677     return ok;
 678 }
 679
 680 bool wxDDEConnection::OnDisconnect()
 681 {
 682     delete this;
 683     return true;
 684 }
 685
 686 // ----------------------------------------------------------------------------
 687 // _DDECallback
 688 // ----------------------------------------------------------------------------
 689
 690 #define DDERETURN HDDEDATA
 691
 692 HDDEDATA EXPENTRY _EXPORT
 693 _DDECallback(WORD wType,
 694              WORD wFmt,
 695              HCONV hConv,
 696              HSZ hsz1,
 697              HSZ hsz2,
 698              HDDEDATA hData,
 699              DWORD WXUNUSED(lData1),
 700              DWORD WXUNUSED(lData2))
 701 {
 702     switch (wType)
 703     {
 704         case XTYP_CONNECT:
 705             {
 706                 wxString topic = DDEStringFromAtom(hsz1),
 707                          srv = DDEStringFromAtom(hsz2);
 708                 wxDDEServer *server = DDEFindServer(srv);
 709                 if (server)
 710                 {
 711                     wxDDEConnection *connection =
 712                         (wxDDEConnection*) server->OnAcceptConnection(topic);
 713                     if (connection)
 714                     {
 715                         connection->m_server = server;
 716                         server->GetConnections().Append(connection);
 717                         connection->m_hConv = 0;
 718                         connection->m_topicName = topic;
 719                         DDECurrentlyConnecting = connection;
 720                         return (DDERETURN)(DWORD)true;
 721                     }
 722                 }
 723                 break;
 724             }
 725
 726         case XTYP_CONNECT_CONFIRM:
 727             {
 728                 if (DDECurrentlyConnecting)
 729                 {
 730                     DDECurrentlyConnecting->m_hConv = (WXHCONV) hConv;
 731                     DDECurrentlyConnecting = NULL;
 732                     return (DDERETURN)(DWORD)true;
 733                 }
 734                 break;
 735             }
 736
 737         case XTYP_DISCONNECT:
 738             {
 739                 wxDDEConnection *connection = DDEFindConnection(hConv);
 740                 if (connection)
 741                 {
 742                     connection->SetConnected( false );
 743                     if (connection->OnDisconnect())
 744                     {
 745                         DDEDeleteConnection(hConv);  // Delete mapping: hConv => connection
 746                         return (DDERETURN)(DWORD)true;
 747                     }
 748                 }
 749                 break;
 750             }
 751
 752         case XTYP_EXECUTE:
 753             {
 754                 wxDDEConnection *connection = DDEFindConnection(hConv);
 755
 756                 if (connection)
 757                 {
 758                     DWORD len = DdeGetData(hData, NULL, 0, 0);
 759
 760                     wxChar *data = connection->GetBufferAtLeast( len );
 761                     wxASSERT_MSG(data != NULL,
 762                                  _T("Buffer too small in _DDECallback (XTYP_EXECUTE)") );
 763
 764                     DdeGetData(hData, (LPBYTE)data, len, 0);
 765
 766                     DdeFreeDataHandle(hData);
 767
 768                     if ( connection->OnExecute(connection->m_topicName,
 769                                                data,
 770                                                (int)len,
 771                                                (wxIPCFormat) wFmt) )
 772                     {
 773                         return (DDERETURN)(DWORD)DDE_FACK;
 774                     }
 775                 }
 776
 777                 return (DDERETURN)DDE_FNOTPROCESSED;
 778             }
 779
 780         case XTYP_REQUEST:
 781             {
 782                 wxDDEConnection *connection = DDEFindConnection(hConv);
 783
 784                 if (connection)
 785                 {
 786                     wxString item_name = DDEStringFromAtom(hsz2);
 787
 788                     int user_size = -1;
 789                     wxChar *data = connection->OnRequest(connection->m_topicName,
 790                                                        item_name,
 791                                                        &user_size,
 792                                                        (wxIPCFormat) wFmt);
 793                     if (data)
 794                     {
 795                         if (user_size < 0)
 796                             user_size = wxStrlen((wxChar*)data) + 1;
 797
 798                         HDDEDATA handle = DdeCreateDataHandle(DDEIdInst,
 799                                                               (LPBYTE)data,
 800                                                               user_size,
 801                                                               0,
 802                                                               hsz2,
 803                                                               wFmt,
 804                                                               0);
 805                         return (DDERETURN)handle;
 806                     }
 807                 }
 808                 break;
 809             }
 810
 811         case XTYP_POKE:
 812             {
 813                 wxDDEConnection *connection = DDEFindConnection(hConv);
 814
 815                 if (connection)
 816                 {
 817                     wxString item_name = DDEStringFromAtom(hsz2);
 818
 819                     DWORD len = DdeGetData(hData, NULL, 0, 0);
 820
 821                     wxChar *data = connection->GetBufferAtLeast( len );
 822                     wxASSERT_MSG(data != NULL,
 823                                  _T("Buffer too small in _DDECallback (XTYP_EXECUTE)") );
 824
 825                     DdeGetData(hData, (LPBYTE)data, len, 0);
 826
 827                     DdeFreeDataHandle(hData);
 828
 829                     connection->OnPoke(connection->m_topicName,
 830                                        item_name,
 831                                        data,
 832                                        (int)len,
 833                                        (wxIPCFormat) wFmt);
 834
 835                     return (DDERETURN)DDE_FACK;
 836                 }
 837                 else
 838                 {
 839                     return (DDERETURN)DDE_FNOTPROCESSED;
 840                 }
 841             }
 842
 843         case XTYP_ADVSTART:
 844             {
 845                 wxDDEConnection *connection = DDEFindConnection(hConv);
 846
 847                 if (connection)
 848                 {
 849                     wxString item_name = DDEStringFromAtom(hsz2);
 850
 851                     return (DDERETURN)connection->
 852                                 OnStartAdvise(connection->m_topicName, item_name);
 853                 }
 854
 855                 break;
 856             }
 857
 858         case XTYP_ADVSTOP:
 859             {
 860                 wxDDEConnection *connection = DDEFindConnection(hConv);
 861
 862                 if (connection)
 863                 {
 864                     wxString item_name = DDEStringFromAtom(hsz2);
 865
 866                     return (DDERETURN)connection->
 867                         OnStopAdvise(connection->m_topicName, item_name);
 868                 }
 869
 870                 break;
 871             }
 872
 873         case XTYP_ADVREQ:
 874             {
 875                 wxDDEConnection *connection = DDEFindConnection(hConv);
 876
 877                 if (connection && connection->m_sendingData)
 878                 {
 879                     HDDEDATA data = DdeCreateDataHandle
 880                                     (
 881                                         DDEIdInst,
 882                                         (LPBYTE)connection->m_sendingData,
 883                                         connection->m_dataSize,
 884                                         0,
 885                                         hsz2,
 886                                         connection->m_dataType,
 887                                         0
 888                                     );
 889
 890                     connection->m_sendingData = NULL;
 891
 892                     return (DDERETURN)data;
 893                 }
 894
 895                 break;
 896             }
 897
 898         case XTYP_ADVDATA:
 899             {
 900                 wxDDEConnection *connection = DDEFindConnection(hConv);
 901
 902                 if (connection)
 903                 {
 904                     wxString item_name = DDEStringFromAtom(hsz2);
 905
 906                     DWORD len = DdeGetData(hData, NULL, 0, 0);
 907
 908                     wxChar *data = connection->GetBufferAtLeast( len );
 909                     wxASSERT_MSG(data != NULL,
 910                                  _T("Buffer too small in _DDECallback (XTYP_ADVDATA)") );
 911
 912                     DdeGetData(hData, (LPBYTE)data, len, 0);
 913
 914                     DdeFreeDataHandle(hData);
 915                     if ( connection->OnAdvise(connection->m_topicName,
 916                                               item_name,
 917                                               data,
 918                                               (int)len,
 919                                               (wxIPCFormat) wFmt) )
 920                     {
 921                         return (DDERETURN)(DWORD)DDE_FACK;
 922                     }
 923                 }
 924
 925                 return (DDERETURN)DDE_FNOTPROCESSED;
 926             }
 927     }
 928
 929     return (DDERETURN)0;
 930 }
 931
 932 // ----------------------------------------------------------------------------
 933 // DDE strings and atoms
 934 // ----------------------------------------------------------------------------
 935
 936 // Atom table stuff
 937 static HSZ DDEAddAtom(const wxString& string)
 938 {
 939     HSZ atom = DDEAtomFromString(string);
 940     wxAtomTable.Append(string, (wxObject *)atom);
 941     return atom;
 942 }
 943
 944 static HSZ DDEGetAtom(const wxString& string)
 945 {
 946     wxNode *node = wxAtomTable.Find(string);
 947     if (node)
 948         return (HSZ)node->GetData();
 949     else
 950     {
 951         DDEAddAtom(string);
 952         return (HSZ)(wxAtomTable.Find(string)->GetData());
 953     }
 954 }
 955
 956 // atom <-> strings
 957 static HSZ DDEAtomFromString(const wxString& s)
 958 {
 959     wxASSERT_MSG( DDEIdInst, _T("DDE not initialized") );
 960
 961     HSZ hsz = DdeCreateStringHandle(DDEIdInst, (wxChar*) s.c_str(), DDE_CP);
 962     if ( !hsz )
 963     {
 964         DDELogError(_("Failed to create DDE string"));
 965     }
 966
 967     return hsz;
 968 }
 969
 970 static wxString DDEStringFromAtom(HSZ hsz)
 971 {
 972     // all DDE strings are normally limited to 255 bytes
 973     static const size_t len = 256;
 974
 975     wxString s;
 976     (void)DdeQueryString(DDEIdInst, hsz, s.GetWriteBuf(len), len, DDE_CP);
 977     s.UngetWriteBuf();
 978
 979     return s;
 980 }
 981
 982 // ----------------------------------------------------------------------------
 983 // error handling
 984 // ----------------------------------------------------------------------------
 985
 986 static void DDELogError(const wxString& s, UINT error)
 987 {
 988     if ( !error )
 989     {
 990         error = DdeGetLastError(DDEIdInst);
 991     }
 992
 993     wxLogError(s + _T(": ") + DDEGetErrorMsg(error));
 994 }
 995
 996 static wxString DDEGetErrorMsg(UINT error)
 997 {
 998     wxString err;
 999     switch ( error )
1000     {
1001         case DMLERR_NO_ERROR:
1002             err = _("no DDE error.");
1003             break;
1004
1005         case DMLERR_ADVACKTIMEOUT:
1006             err = _("a request for a synchronous advise transaction has timed out.");
1007             break;
1008         case DMLERR_BUSY:
1009             err = _("the response to the transaction caused the DDE_FBUSY bit to be set.");
1010             break;
1011         case DMLERR_DATAACKTIMEOUT:
1012             err = _("a request for a synchronous data transaction has timed out.");
1013             break;
1014         case DMLERR_DLL_NOT_INITIALIZED:
1015             err = _("a DDEML function was called without first calling the DdeInitialize function,\nor an invalid instance identifier\nwas passed to a DDEML function.");
1016             break;
1017         case DMLERR_DLL_USAGE:
1018             err = _("an application initialized as APPCLASS_MONITOR has\nattempted to perform a DDE transaction,\nor an application initialized as APPCMD_CLIENTONLY has \nattempted to perform server transactions.");
1019             break;
1020         case DMLERR_EXECACKTIMEOUT:
1021             err = _("a request for a synchronous execute transaction has timed out.");
1022             break;
1023         case DMLERR_INVALIDPARAMETER:
1024             err = _("a parameter failed to be validated by the DDEML.");
1025             break;
1026         case DMLERR_LOW_MEMORY:
1027             err = _("a DDEML application has created a prolonged race condition.");
1028             break;
1029         case DMLERR_MEMORY_ERROR:
1030             err = _("a memory allocation failed.");
1031             break;
1032         case DMLERR_NO_CONV_ESTABLISHED:
1033             err = _("a client's attempt to establish a conversation has failed.");
1034             break;
1035         case DMLERR_NOTPROCESSED:
1036             err = _("a transaction failed.");
1037             break;
1038         case DMLERR_POKEACKTIMEOUT:
1039             err = _("a request for a synchronous poke transaction has timed out.");
1040             break;
1041         case DMLERR_POSTMSG_FAILED:
1042             err = _("an internal call to the PostMessage function has failed. ");
1043             break;
1044         case DMLERR_REENTRANCY:
1045             err = _("reentrancy problem.");
1046             break;
1047         case DMLERR_SERVER_DIED:
1048             err = _("a server-side transaction was attempted on a conversation\nthat was terminated by the client, or the server\nterminated before completing a transaction.");
1049             break;
1050         case DMLERR_SYS_ERROR:
1051             err = _("an internal error has occurred in the DDEML.");
1052             break;
1053         case DMLERR_UNADVACKTIMEOUT:
1054             err = _("a request to end an advise transaction has timed out.");
1055             break;
1056         case DMLERR_UNFOUND_QUEUE_ID:
1057             err = _("an invalid transaction identifier was passed to a DDEML function.\nOnce the application has returned from an XTYP_XACT_COMPLETE callback,\nthe transaction identifier for that callback is no longer valid.");
1058             break;
1059         default:
1060             err.Printf(_("Unknown DDE error %08x"), error);
1061     }
1062
1063     return err;
1064 }
1065
1066 #endif
1067   // wxUSE_IPC