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 #if defined(__GNUG__) && !defined(NO_GCC_PRAGMA)
  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 #include "wx/hashmap.h"
  42
  43 #include "wx/msw/private.h"
  44
  45 #include <string.h>
  46 #include <ddeml.h>
  47
  48 #ifdef __GNUWIN32_OLD__
  49     #include "wx/msw/gnuwin32/extra.h"
  50 #endif
  51
  52 // ----------------------------------------------------------------------------
  53 // macros and constants
  54 // ----------------------------------------------------------------------------
  55
  56 #ifdef __WIN32__
  57     #define _EXPORT
  58 #else
  59     #define _EXPORT _export
  60 #endif
  61
  62 #if wxUSE_UNICODE
  63     #define DDE_CP      CP_WINUNICODE
  64 #else
  65     #define DDE_CP      CP_WINANSI
  66 #endif
  67
  68 #define GetHConv()       ((HCONV)m_hConv)
  69
  70 // default timeout for DDE operations (5sec)
  71 #define DDE_TIMEOUT     5000
  72
  73 // ----------------------------------------------------------------------------
  74 // private functions
  75 // ----------------------------------------------------------------------------
  76
  77 static wxDDEConnection *DDEFindConnection(HCONV hConv);
  78 static void DDEDeleteConnection(HCONV hConv);
  79 static wxDDEServer *DDEFindServer(const wxString& s);
  80
  81 extern "C" HDDEDATA EXPENTRY _EXPORT _DDECallback(WORD wType,
  82                                                   WORD wFmt,
  83                                                   HCONV hConv,
  84                                                   HSZ hsz1,
  85                                                   HSZ hsz2,
  86                                                   HDDEDATA hData,
  87                                                   DWORD lData1,
  88                                                   DWORD lData2);
  89
  90 // Add topic name to atom table before using in conversations
  91 static HSZ DDEAddAtom(const wxString& string);
  92 static HSZ DDEGetAtom(const wxString& string);
  93
  94 // string handles
  95 static HSZ DDEAtomFromString(const wxString& s);
  96 static wxString DDEStringFromAtom(HSZ hsz);
  97 static void DDEFreeString(HSZ hsz);
  98
  99 // error handling
 100 static wxString DDEGetErrorMsg(UINT error);
 101 static void DDELogError(const wxString& s, UINT error = DMLERR_NO_ERROR);
 102
 103 // ----------------------------------------------------------------------------
 104 // global variables
 105 // ----------------------------------------------------------------------------
 106
 107 WX_DECLARE_STRING_HASH_MAP( HSZ, wxAtomMap );
 108
 109 static DWORD DDEIdInst = 0L;
 110 static wxDDEConnection *DDECurrentlyConnecting = NULL;
 111 static wxAtomMap wxAtomTable;
 112
 113 #include "wx/listimpl.cpp"
 114
 115 WX_DEFINE_LIST(wxDDEClientList);
 116 WX_DEFINE_LIST(wxDDEServerList);
 117 WX_DEFINE_LIST(wxDDEConnectionList);
 118
 119 static wxDDEClientList wxDDEClientObjects;
 120 static wxDDEServerList wxDDEServerObjects;
 121
 122 static bool DDEInitialized = false;
 123
 124 // ----------------------------------------------------------------------------
 125 // private classes
 126 // ----------------------------------------------------------------------------
 127
 128 // A module to allow DDE cleanup without calling these functions
 129 // from app.cpp or from the user's application.
 130
 131 class wxDDEModule : public wxModule
 132 {
 133 public:
 134     wxDDEModule() {}
 135     bool OnInit() { return true; }
 136     void OnExit() { wxDDECleanUp(); }
 137
 138 private:
 139     DECLARE_DYNAMIC_CLASS(wxDDEModule)
 140 };
 141
 142 // ----------------------------------------------------------------------------
 143 // wxWin macros
 144 // ----------------------------------------------------------------------------
 145
 146 IMPLEMENT_DYNAMIC_CLASS(wxDDEServer, wxServerBase)
 147 IMPLEMENT_DYNAMIC_CLASS(wxDDEClient, wxClientBase)
 148 IMPLEMENT_CLASS(wxDDEConnection, wxConnectionBase)
 149 IMPLEMENT_DYNAMIC_CLASS(wxDDEModule, wxModule)
 150
 151 // ============================================================================
 152 // implementation
 153 // ============================================================================
 154
 155 // ----------------------------------------------------------------------------
 156 // initialization and cleanup
 157 // ----------------------------------------------------------------------------
 158
 159 extern void wxDDEInitialize()
 160 {
 161     if ( !DDEInitialized )
 162     {
 163         // Should insert filter flags
 164         PFNCALLBACK callback = (PFNCALLBACK)
 165             MakeProcInstance((FARPROC)_DDECallback, wxGetInstance());
 166         UINT rc = DdeInitialize(&DDEIdInst, callback, APPCLASS_STANDARD, 0L);
 167         if ( rc != DMLERR_NO_ERROR )
 168         {
 169             DDELogError(_T("Failed to initialize DDE"), rc);
 170         }
 171         else
 172         {
 173             DDEInitialized = true;
 174         }
 175     }
 176 }
 177
 178 void wxDDECleanUp()
 179 {
 180     // deleting them later won't work as DDE won't be initialized any more
 181     wxASSERT_MSG( wxDDEServerObjects.empty() &&
 182                     wxDDEClientObjects.empty(),
 183                     _T("all DDE objects should be deleted by now") );
 184
 185     wxAtomTable.clear();
 186
 187     if ( DDEIdInst != 0 )
 188     {
 189         DdeUninitialize(DDEIdInst);
 190         DDEIdInst = 0;
 191     }
 192 }
 193
 194 // ----------------------------------------------------------------------------
 195 // functions working with the global connection list(s)
 196 // ----------------------------------------------------------------------------
 197
 198 // Global find connection
 199 static wxDDEConnection *DDEFindConnection(HCONV hConv)
 200 {
 201     wxDDEServerList::compatibility_iterator serverNode = wxDDEServerObjects.GetFirst();
 202     wxDDEConnection *found = NULL;
 203     while (serverNode && !found)
 204     {
 205         wxDDEServer *object = serverNode->GetData();
 206         found = object->FindConnection((WXHCONV) hConv);
 207         serverNode = serverNode->GetNext();
 208     }
 209
 210     if (found)
 211     {
 212         return found;
 213     }
 214
 215     wxDDEClientList::compatibility_iterator clientNode = wxDDEClientObjects.GetFirst();
 216     while (clientNode && !found)
 217     {
 218         wxDDEClient *object = clientNode->GetData();
 219         found = object->FindConnection((WXHCONV) hConv);
 220         clientNode = clientNode->GetNext();
 221     }
 222     return found;
 223 }
 224
 225 // Global delete connection
 226 static void DDEDeleteConnection(HCONV hConv)
 227 {
 228     wxDDEServerList::compatibility_iterator serverNode = wxDDEServerObjects.GetFirst();
 229     bool found = false;
 230     while (serverNode && !found)
 231     {
 232         wxDDEServer *object = serverNode->GetData();
 233         found = object->DeleteConnection((WXHCONV) hConv);
 234         serverNode = serverNode->GetNext();
 235     }
 236     if (found)
 237     {
 238         return;
 239     }
 240
 241     wxDDEClientList::compatibility_iterator clientNode = wxDDEClientObjects.GetFirst();
 242     while (clientNode && !found)
 243     {
 244         wxDDEClient *object = clientNode->GetData();
 245         found = object->DeleteConnection((WXHCONV) hConv);
 246         clientNode = clientNode->GetNext();
 247     }
 248 }
 249
 250 // Find a server from a service name
 251 static wxDDEServer *DDEFindServer(const wxString& s)
 252 {
 253     wxDDEServerList::compatibility_iterator node = wxDDEServerObjects.GetFirst();
 254     wxDDEServer *found = NULL;
 255     while (node && !found)
 256     {
 257         wxDDEServer *object = node->GetData();
 258
 259         if (object->GetServiceName() == s)
 260         {
 261             found = object;
 262         }
 263         else
 264         {
 265             node = node->GetNext();
 266         }
 267     }
 268
 269     return found;
 270 }
 271
 272 // ----------------------------------------------------------------------------
 273 // wxDDEServer
 274 // ----------------------------------------------------------------------------
 275
 276 wxDDEServer::wxDDEServer()
 277 {
 278     wxDDEInitialize();
 279
 280     wxDDEServerObjects.Append(this);
 281 }
 282
 283 bool wxDDEServer::Create(const wxString& server)
 284 {
 285     m_serviceName = server;
 286
 287     HSZ hsz = DDEAtomFromString(server);
 288
 289     if ( !hsz )
 290     {
 291         return false;
 292     }
 293
 294
 295     bool success = (DdeNameService(DDEIdInst, hsz, (HSZ) NULL, DNS_REGISTER)
 296         != NULL);
 297
 298     if (!success)
 299     {
 300         DDELogError(wxString::Format(_("Failed to register DDE server '%s'"),
 301             server.c_str()));
 302     }
 303
 304     DDEFreeString(hsz);
 305
 306     return success;
 307 }
 308
 309 wxDDEServer::~wxDDEServer()
 310 {
 311     if ( !!m_serviceName )
 312     {
 313         HSZ hsz = DDEAtomFromString(m_serviceName);
 314
 315         if (hsz)
 316         {
 317             if ( !DdeNameService(DDEIdInst, hsz,
 318                 (HSZ) NULL, DNS_UNREGISTER) )
 319             {
 320                 DDELogError(wxString::Format(
 321                     _("Failed to unregister DDE server '%s'"),
 322                     m_serviceName.c_str()));
 323             }
 324
 325             DDEFreeString(hsz);
 326         }
 327     }
 328
 329     wxDDEServerObjects.DeleteObject(this);
 330
 331     wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
 332     while (node)
 333     {
 334         wxDDEConnection *connection = node->GetData();
 335         wxDDEConnectionList::compatibility_iterator 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::compatibility_iterator 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::compatibility_iterator 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::compatibility_iterator node = m_connections.GetFirst();
 375     while (node)
 376     {
 377         wxDDEConnection *connection = node->GetData();
 378         if (connection->m_hConv == conv)
 379         {
 380             m_connections.Erase(node);
 381             return true;
 382         }
 383         else
 384         {
 385             node = node->GetNext();
 386         }
 387     }
 388     return false;
 389 }
 390
 391 // ----------------------------------------------------------------------------
 392 // wxDDEClient
 393 // ----------------------------------------------------------------------------
 394
 395 wxDDEClient::wxDDEClient()
 396 {
 397     wxDDEInitialize();
 398
 399     wxDDEClientObjects.Append(this);
 400 }
 401
 402 wxDDEClient::~wxDDEClient()
 403 {
 404     wxDDEClientObjects.DeleteObject(this);
 405     wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
 406     while (node)
 407     {
 408         wxDDEConnection *connection = node->GetData();
 409         delete connection;  // Deletes the node implicitly (see ~wxDDEConnection)
 410         node = m_connections.GetFirst();
 411     }
 412 }
 413
 414 bool wxDDEClient::ValidHost(const wxString& /* host */)
 415 {
 416     return true;
 417 }
 418
 419 wxConnectionBase *wxDDEClient::MakeConnection(const wxString& WXUNUSED(host),
 420                                               const wxString& server,
 421                                               const wxString& topic)
 422 {
 423     HSZ hszServer = DDEAtomFromString(server);
 424
 425     if ( !hszServer )
 426     {
 427         return (wxConnectionBase*) NULL;
 428     }
 429
 430
 431     HSZ hszTopic = DDEAtomFromString(topic);
 432
 433     if ( !hszTopic )
 434     {
 435         DDEFreeString(hszServer);
 436         return (wxConnectionBase*) NULL;
 437     }
 438
 439
 440     HCONV hConv = ::DdeConnect(DDEIdInst, hszServer, hszTopic,
 441         (PCONVCONTEXT) NULL);
 442
 443     DDEFreeString(hszServer);
 444     DDEFreeString(hszTopic);
 445
 446
 447     if ( !hConv )
 448     {
 449         DDELogError( wxString::Format(
 450             _("Failed to create connection to server '%s' on topic '%s'"),
 451             server.c_str(), topic.c_str()) );
 452     }
 453     else
 454     {
 455         wxDDEConnection *connection = (wxDDEConnection*) OnMakeConnection();
 456         if (connection)
 457         {
 458             connection->m_hConv = (WXHCONV) hConv;
 459             connection->m_topicName = topic;
 460             connection->m_client = this;
 461             m_connections.Append(connection);
 462             return connection;
 463         }
 464     }
 465
 466     return (wxConnectionBase*) NULL;
 467 }
 468
 469 wxConnectionBase *wxDDEClient::OnMakeConnection()
 470 {
 471     return new wxDDEConnection;
 472 }
 473
 474 wxDDEConnection *wxDDEClient::FindConnection(WXHCONV conv)
 475 {
 476     wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
 477     wxDDEConnection *found = NULL;
 478     while (node && !found)
 479     {
 480         wxDDEConnection *connection = node->GetData();
 481         if (connection->m_hConv == conv)
 482             found = connection;
 483         else node = node->GetNext();
 484     }
 485     return found;
 486 }
 487
 488 // Only delete the entry in the map, not the actual connection
 489 bool wxDDEClient::DeleteConnection(WXHCONV conv)
 490 {
 491     wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
 492     while (node)
 493     {
 494         wxDDEConnection *connection = node->GetData();
 495         if (connection->m_hConv == conv)
 496         {
 497             m_connections.Erase(node);
 498             return true;
 499         }
 500         else node = node->GetNext();
 501     }
 502     return false;
 503 }
 504
 505 // ----------------------------------------------------------------------------
 506 // wxDDEConnection
 507 // ----------------------------------------------------------------------------
 508
 509 wxDDEConnection::wxDDEConnection(wxChar *buffer, int size)
 510      : wxConnectionBase(buffer, size)
 511 {
 512     m_client = NULL;
 513     m_server = NULL;
 514
 515     m_hConv = 0;
 516     m_sendingData = NULL;
 517 }
 518
 519 wxDDEConnection::wxDDEConnection()
 520      : wxConnectionBase()
 521 {
 522     m_hConv = 0;
 523     m_sendingData = NULL;
 524     m_server = NULL;
 525     m_client = NULL;
 526 }
 527
 528 wxDDEConnection::~wxDDEConnection()
 529 {
 530     Disconnect();
 531     if (m_server)
 532         m_server->GetConnections().DeleteObject(this);
 533     else
 534         m_client->GetConnections().DeleteObject(this);
 535 }
 536
 537 // Calls that CLIENT can make
 538 bool wxDDEConnection::Disconnect()
 539 {
 540     if ( !GetConnected() )
 541         return true;
 542
 543     DDEDeleteConnection(GetHConv());
 544
 545     bool ok = DdeDisconnect(GetHConv()) != 0;
 546     if ( !ok )
 547     {
 548         DDELogError(_T("Failed to disconnect from DDE server gracefully"));
 549     }
 550
 551     SetConnected( false );  // so we don't try and disconnect again
 552
 553     return ok;
 554 }
 555
 556 bool wxDDEConnection::Execute(const wxChar *data, int size, wxIPCFormat format)
 557 {
 558     DWORD result;
 559     if (size < 0)
 560     {
 561         size = wxStrlen(data) + 1;
 562     }
 563
 564     bool ok = DdeClientTransaction((LPBYTE)data,
 565                                     size * sizeof(wxChar),
 566                                     GetHConv(),
 567                                     NULL,
 568                                     format,
 569                                     XTYP_EXECUTE,
 570                                     DDE_TIMEOUT,
 571                                     &result) != 0;
 572
 573     if ( !ok )
 574     {
 575         DDELogError(_T("DDE execute request failed"));
 576     }
 577
 578     return ok;
 579 }
 580
 581 wxChar *wxDDEConnection::Request(const wxString& item, int *size, wxIPCFormat format)
 582 {
 583     DWORD result;
 584
 585     HSZ atom = DDEGetAtom(item);
 586
 587     HDDEDATA returned_data = DdeClientTransaction(NULL, 0,
 588                                                   GetHConv(),
 589                                                   atom, format,
 590                                                   XTYP_REQUEST,
 591                                                   DDE_TIMEOUT,
 592                                                   &result);
 593     if ( !returned_data )
 594     {
 595         DDELogError(_T("DDE data request failed"));
 596
 597         return NULL;
 598     }
 599
 600     DWORD len = DdeGetData(returned_data, NULL, 0, 0);
 601
 602     wxChar *data = GetBufferAtLeast( len/sizeof(wxChar) );
 603     wxASSERT_MSG(data != NULL,
 604                  _T("Buffer too small in wxDDEConnection::Request") );
 605     (void) DdeGetData(returned_data, (LPBYTE)data, len, 0);
 606
 607     (void) DdeFreeDataHandle(returned_data);
 608
 609     if (size)
 610         *size = (int)len/sizeof(wxChar);
 611
 612     return data;
 613 }
 614
 615 bool wxDDEConnection::Poke(const wxString& item, wxChar *data, int size, wxIPCFormat format)
 616 {
 617     DWORD result;
 618     if (size < 0)
 619     {
 620         size = wxStrlen(data) + 1;
 621     }
 622
 623     HSZ item_atom = DDEGetAtom(item);
 624     bool ok = DdeClientTransaction((LPBYTE)data,
 625                                    size * sizeof(wxChar),
 626                                    GetHConv(),
 627                                    item_atom, format,
 628                                    XTYP_POKE,
 629                                    DDE_TIMEOUT,
 630                                    &result) != 0;
 631     if ( !ok )
 632     {
 633         DDELogError(_("DDE poke request failed"));
 634     }
 635
 636     return ok;
 637 }
 638
 639 bool wxDDEConnection::StartAdvise(const wxString& item)
 640 {
 641     DWORD result;
 642     HSZ atom = DDEGetAtom(item);
 643
 644     bool ok = DdeClientTransaction(NULL, 0,
 645                                    GetHConv(),
 646                                    atom, CF_TEXT,
 647                                    XTYP_ADVSTART,
 648                                    DDE_TIMEOUT,
 649                                    &result) != 0;
 650     if ( !ok )
 651     {
 652         DDELogError(_("Failed to establish an advise loop with DDE server"));
 653     }
 654
 655     return ok;
 656 }
 657
 658 bool wxDDEConnection::StopAdvise(const wxString& item)
 659 {
 660     DWORD result;
 661     HSZ atom = DDEGetAtom(item);
 662
 663     bool ok = DdeClientTransaction(NULL, 0,
 664                                    GetHConv(),
 665                                    atom, CF_TEXT,
 666                                    XTYP_ADVSTOP,
 667                                    DDE_TIMEOUT,
 668                                    &result) != 0;
 669     if ( !ok )
 670     {
 671         DDELogError(_("Failed to terminate the advise loop with DDE server"));
 672     }
 673
 674     return ok;
 675 }
 676
 677 // Calls that SERVER can make
 678 bool wxDDEConnection::Advise(const wxString& item,
 679                              wxChar *data,
 680                              int size,
 681                              wxIPCFormat format)
 682 {
 683     if (size < 0)
 684     {
 685         size = wxStrlen(data) + 1;
 686     }
 687
 688     HSZ item_atom = DDEGetAtom(item);
 689     HSZ topic_atom = DDEGetAtom(m_topicName);
 690     m_sendingData = data;  // mrf: potential for scope problems here?
 691     m_dataSize = size;
 692     m_dataType = format;
 693
 694     bool ok = DdePostAdvise(DDEIdInst, topic_atom, item_atom) != 0;
 695     if ( !ok )
 696     {
 697         DDELogError(_("Failed to send DDE advise notification"));
 698     }
 699
 700     return ok;
 701 }
 702
 703 bool wxDDEConnection::OnDisconnect()
 704 {
 705     delete this;
 706     return true;
 707 }
 708
 709 // ----------------------------------------------------------------------------
 710 // _DDECallback
 711 // ----------------------------------------------------------------------------
 712
 713 #define DDERETURN HDDEDATA
 714
 715 HDDEDATA EXPENTRY _EXPORT
 716 _DDECallback(WORD wType,
 717              WORD wFmt,
 718              HCONV hConv,
 719              HSZ hsz1,
 720              HSZ hsz2,
 721              HDDEDATA hData,
 722              DWORD WXUNUSED(lData1),
 723              DWORD WXUNUSED(lData2))
 724 {
 725     switch (wType)
 726     {
 727         case XTYP_CONNECT:
 728             {
 729                 wxString topic = DDEStringFromAtom(hsz1),
 730                          srv = DDEStringFromAtom(hsz2);
 731                 wxDDEServer *server = DDEFindServer(srv);
 732                 if (server)
 733                 {
 734                     wxDDEConnection *connection =
 735                         (wxDDEConnection*) server->OnAcceptConnection(topic);
 736                     if (connection)
 737                     {
 738                         connection->m_server = server;
 739                         server->GetConnections().Append(connection);
 740                         connection->m_hConv = 0;
 741                         connection->m_topicName = topic;
 742                         DDECurrentlyConnecting = connection;
 743                         return (DDERETURN)(DWORD)true;
 744                     }
 745                 }
 746                 break;
 747             }
 748
 749         case XTYP_CONNECT_CONFIRM:
 750             {
 751                 if (DDECurrentlyConnecting)
 752                 {
 753                     DDECurrentlyConnecting->m_hConv = (WXHCONV) hConv;
 754                     DDECurrentlyConnecting = NULL;
 755                     return (DDERETURN)(DWORD)true;
 756                 }
 757                 break;
 758             }
 759
 760         case XTYP_DISCONNECT:
 761             {
 762                 wxDDEConnection *connection = DDEFindConnection(hConv);
 763                 if (connection)
 764                 {
 765                     connection->SetConnected( false );
 766                     if (connection->OnDisconnect())
 767                     {
 768                         DDEDeleteConnection(hConv);  // Delete mapping: hConv => connection
 769                         return (DDERETURN)(DWORD)true;
 770                     }
 771                 }
 772                 break;
 773             }
 774
 775         case XTYP_EXECUTE:
 776             {
 777                 wxDDEConnection *connection = DDEFindConnection(hConv);
 778
 779                 if (connection)
 780                 {
 781                     DWORD len = DdeGetData(hData, NULL, 0, 0);
 782
 783                     wxChar *data = connection->GetBufferAtLeast( len/sizeof(wxChar) );
 784                     wxASSERT_MSG(data != NULL,
 785                                  _T("Buffer too small in _DDECallback (XTYP_EXECUTE)") );
 786
 787                     DdeGetData(hData, (LPBYTE)data, len, 0);
 788
 789                     DdeFreeDataHandle(hData);
 790
 791                     if ( connection->OnExecute(connection->m_topicName,
 792                                                data,
 793                                                (int)len/sizeof(wxChar),
 794                                                (wxIPCFormat) wFmt) )
 795                     {
 796                         return (DDERETURN)(DWORD)DDE_FACK;
 797                     }
 798                 }
 799
 800                 return (DDERETURN)DDE_FNOTPROCESSED;
 801             }
 802
 803         case XTYP_REQUEST:
 804             {
 805                 wxDDEConnection *connection = DDEFindConnection(hConv);
 806
 807                 if (connection)
 808                 {
 809                     wxString item_name = DDEStringFromAtom(hsz2);
 810
 811                     int user_size = -1;
 812                     wxChar *data = connection->OnRequest(connection->m_topicName,
 813                                                        item_name,
 814                                                        &user_size,
 815                                                        (wxIPCFormat) wFmt);
 816                     if (data)
 817                     {
 818                         if (user_size < 0)
 819                             user_size = wxStrlen((wxChar*)data) + 1;
 820
 821                         HDDEDATA handle = DdeCreateDataHandle(DDEIdInst,
 822                                                               (LPBYTE)data,
 823                                                               user_size*sizeof(wxChar),
 824                                                               0,
 825                                                               hsz2,
 826                                                               wFmt,
 827                                                               0);
 828                         return (DDERETURN)handle;
 829                     }
 830                 }
 831                 break;
 832             }
 833
 834         case XTYP_POKE:
 835             {
 836                 wxDDEConnection *connection = DDEFindConnection(hConv);
 837
 838                 if (connection)
 839                 {
 840                     wxString item_name = DDEStringFromAtom(hsz2);
 841
 842                     DWORD len = DdeGetData(hData, NULL, 0, 0);
 843
 844                     wxChar *data = connection->GetBufferAtLeast( len/sizeof(wxChar) );
 845                     wxASSERT_MSG(data != NULL,
 846                                  _T("Buffer too small in _DDECallback (XTYP_EXECUTE)") );
 847
 848                     DdeGetData(hData, (LPBYTE)data, len, 0);
 849
 850                     DdeFreeDataHandle(hData);
 851
 852                     connection->OnPoke(connection->m_topicName,
 853                                        item_name,
 854                                        data,
 855                                        (int)len/sizeof(wxChar),
 856                                        (wxIPCFormat) wFmt);
 857
 858                     return (DDERETURN)DDE_FACK;
 859                 }
 860                 else
 861                 {
 862                     return (DDERETURN)DDE_FNOTPROCESSED;
 863                 }
 864             }
 865
 866         case XTYP_ADVSTART:
 867             {
 868                 wxDDEConnection *connection = DDEFindConnection(hConv);
 869
 870                 if (connection)
 871                 {
 872                     wxString item_name = DDEStringFromAtom(hsz2);
 873
 874                     return (DDERETURN)connection->
 875                                 OnStartAdvise(connection->m_topicName, item_name);
 876                 }
 877
 878                 break;
 879             }
 880
 881         case XTYP_ADVSTOP:
 882             {
 883                 wxDDEConnection *connection = DDEFindConnection(hConv);
 884
 885                 if (connection)
 886                 {
 887                     wxString item_name = DDEStringFromAtom(hsz2);
 888
 889                     return (DDERETURN)connection->
 890                         OnStopAdvise(connection->m_topicName, item_name);
 891                 }
 892
 893                 break;
 894             }
 895
 896         case XTYP_ADVREQ:
 897             {
 898                 wxDDEConnection *connection = DDEFindConnection(hConv);
 899
 900                 if (connection && connection->m_sendingData)
 901                 {
 902                     HDDEDATA data = DdeCreateDataHandle
 903                                     (
 904                                         DDEIdInst,
 905                                         (LPBYTE)connection->m_sendingData,
 906                                         connection->m_dataSize*sizeof(wxChar),
 907                                         0,
 908                                         hsz2,
 909                                         connection->m_dataType,
 910                                         0
 911                                     );
 912
 913                     connection->m_sendingData = NULL;
 914
 915                     return (DDERETURN)data;
 916                 }
 917
 918                 break;
 919             }
 920
 921         case XTYP_ADVDATA:
 922             {
 923                 wxDDEConnection *connection = DDEFindConnection(hConv);
 924
 925                 if (connection)
 926                 {
 927                     wxString item_name = DDEStringFromAtom(hsz2);
 928
 929                     DWORD len = DdeGetData(hData, NULL, 0, 0);
 930
 931                     wxChar *data = connection->GetBufferAtLeast( len/sizeof(wxChar) );
 932                     wxASSERT_MSG(data != NULL,
 933                                  _T("Buffer too small in _DDECallback (XTYP_ADVDATA)") );
 934
 935                     DdeGetData(hData, (LPBYTE)data, len, 0);
 936
 937                     DdeFreeDataHandle(hData);
 938                     if ( connection->OnAdvise(connection->m_topicName,
 939                                               item_name,
 940                                               data,
 941                                               (int)len/sizeof(wxChar),
 942                                               (wxIPCFormat) wFmt) )
 943                     {
 944                         return (DDERETURN)(DWORD)DDE_FACK;
 945                     }
 946                 }
 947
 948                 return (DDERETURN)DDE_FNOTPROCESSED;
 949             }
 950     }
 951
 952     return (DDERETURN)0;
 953 }
 954
 955 // ----------------------------------------------------------------------------
 956 // DDE strings and atoms
 957 // ----------------------------------------------------------------------------
 958
 959 // Atom table stuff
 960 static HSZ DDEAddAtom(const wxString& str)
 961 {
 962     HSZ atom = DDEAtomFromString(str);
 963     wxAtomTable[str] = atom;
 964     return atom;
 965 }
 966
 967 static HSZ DDEGetAtom(const wxString& str)
 968 {
 969     wxAtomMap::iterator it = wxAtomTable.find(str);
 970
 971     if (it != wxAtomTable.end())
 972         return it->second;
 973
 974     return DDEAddAtom(str);
 975 }
 976
 977 /* atom <-> strings
 978 The returned handle has to be freed by the caller (using
 979 (static) DDEFreeString).
 980 */
 981 static HSZ DDEAtomFromString(const wxString& s)
 982 {
 983     wxASSERT_MSG( DDEIdInst, _T("DDE not initialized") );
 984
 985     HSZ hsz = DdeCreateStringHandle(DDEIdInst, (wxChar*) s.c_str(), DDE_CP);
 986     if ( !hsz )
 987     {
 988         DDELogError(_("Failed to create DDE string"));
 989     }
 990
 991     return hsz;
 992 }
 993
 994 static wxString DDEStringFromAtom(HSZ hsz)
 995 {
 996     // all DDE strings are normally limited to 255 bytes
 997     static const size_t len = 256;
 998
 999     wxString s;
1000     (void)DdeQueryString(DDEIdInst, hsz, wxStringBuffer(s, len), len, DDE_CP);
1001
1002     return s;
1003 }
1004
1005 static void DDEFreeString(HSZ hsz)
1006 {
1007     // DS: Failure to free a string handle might indicate there's
1008     // some other severe error.
1009     bool ok = (::DdeFreeStringHandle(DDEIdInst, hsz) != 0);
1010     wxASSERT_MSG( ok, wxT("Failed to free DDE string handle") );
1011     wxUnusedVar(ok);
1012 }
1013
1014 // ----------------------------------------------------------------------------
1015 // error handling
1016 // ----------------------------------------------------------------------------
1017
1018 static void DDELogError(const wxString& s, UINT error)
1019 {
1020     if ( !error )
1021     {
1022         error = DdeGetLastError(DDEIdInst);
1023     }
1024
1025     wxLogError(s + _T(": ") + DDEGetErrorMsg(error));
1026 }
1027
1028 static wxString DDEGetErrorMsg(UINT error)
1029 {
1030     wxString err;
1031     switch ( error )
1032     {
1033         case DMLERR_NO_ERROR:
1034             err = _("no DDE error.");
1035             break;
1036
1037         case DMLERR_ADVACKTIMEOUT:
1038             err = _("a request for a synchronous advise transaction has timed out.");
1039             break;
1040         case DMLERR_BUSY:
1041             err = _("the response to the transaction caused the DDE_FBUSY bit to be set.");
1042             break;
1043         case DMLERR_DATAACKTIMEOUT:
1044             err = _("a request for a synchronous data transaction has timed out.");
1045             break;
1046         case DMLERR_DLL_NOT_INITIALIZED:
1047             err = _("a DDEML function was called without first calling the DdeInitialize function,\nor an invalid instance identifier\nwas passed to a DDEML function.");
1048             break;
1049         case DMLERR_DLL_USAGE:
1050             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.");
1051             break;
1052         case DMLERR_EXECACKTIMEOUT:
1053             err = _("a request for a synchronous execute transaction has timed out.");
1054             break;
1055         case DMLERR_INVALIDPARAMETER:
1056             err = _("a parameter failed to be validated by the DDEML.");
1057             break;
1058         case DMLERR_LOW_MEMORY:
1059             err = _("a DDEML application has created a prolonged race condition.");
1060             break;
1061         case DMLERR_MEMORY_ERROR:
1062             err = _("a memory allocation failed.");
1063             break;
1064         case DMLERR_NO_CONV_ESTABLISHED:
1065             err = _("a client's attempt to establish a conversation has failed.");
1066             break;
1067         case DMLERR_NOTPROCESSED:
1068             err = _("a transaction failed.");
1069             break;
1070         case DMLERR_POKEACKTIMEOUT:
1071             err = _("a request for a synchronous poke transaction has timed out.");
1072             break;
1073         case DMLERR_POSTMSG_FAILED:
1074             err = _("an internal call to the PostMessage function has failed. ");
1075             break;
1076         case DMLERR_REENTRANCY:
1077             err = _("reentrancy problem.");
1078             break;
1079         case DMLERR_SERVER_DIED:
1080             err = _("a server-side transaction was attempted on a conversation\nthat was terminated by the client, or the server\nterminated before completing a transaction.");
1081             break;
1082         case DMLERR_SYS_ERROR:
1083             err = _("an internal error has occurred in the DDEML.");
1084             break;
1085         case DMLERR_UNADVACKTIMEOUT:
1086             err = _("a request to end an advise transaction has timed out.");
1087             break;
1088         case DMLERR_UNFOUND_QUEUE_ID:
1089             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.");
1090             break;
1091         default:
1092             err.Printf(_("Unknown DDE error %08x"), error);
1093     }
1094
1095     return err;
1096 }
1097
1098 #endif
1099   // wxUSE_IPC