src/msw/dde.cpp

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        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 and Markus Holzem
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 #ifdef __GNUG__
  13 #pragma implementation "dde.h"
  14 #endif
  15
  16 // For compilers that support precompilation, includes "wx.h".
  17 #include "wx/wxprec.h"
  18
  19 #ifdef __BORLANDC__
  20 #pragma hdrstop
  21 #endif
  22
  23 #ifndef WX_PRECOMP
  24 #include "wx/defs.h"
  25 #endif
  26
  27 #if wxUSE_IPC
  28
  29 #ifndef WX_PRECOMP
  30 #include "wx/utils.h"
  31 #include "wx/app.h"
  32 #endif
  33
  34 #include "wx/module.h"
  35 #include "wx/dde.h"
  36
  37 #include "wx/msw/private.h"
  38 #include <windows.h>
  39 #include <ddeml.h>
  40
  41 #ifndef __TWIN32__
  42 #if !wxUSE_NORLANDER_HEADERS
  43 #ifdef __GNUWIN32__
  44 #include "wx/msw/gnuwin32/extra.h"
  45 #endif
  46 #endif
  47 #endif
  48
  49 #include <string.h>
  50
  51 #ifdef __WIN32__
  52 #define _EXPORT /**/
  53 #else
  54 #define _EXPORT _export
  55 #endif
  56
  57 #if !USE_SHARED_LIBRARY
  58 IMPLEMENT_DYNAMIC_CLASS(wxDDEServer, wxServerBase)
  59 IMPLEMENT_DYNAMIC_CLASS(wxDDEClient, wxClientBase)
  60 IMPLEMENT_CLASS(wxDDEConnection, wxConnectionBase)
  61 #endif
  62
  63 static wxDDEConnection *DDEFindConnection(HCONV hConv);
  64 static void DDEDeleteConnection(HCONV hConv);
  65 static wxDDEServer *DDEFindServer(const wxString& s);
  66
  67 extern "C" HDDEDATA EXPENTRY _EXPORT _DDECallback(
  68 WORD wType,
  69 WORD wFmt,
  70 HCONV hConv,
  71 HSZ hsz1,
  72 HSZ hsz2,
  73 HDDEDATA hData,
  74 DWORD lData1,
  75 DWORD lData2);
  76
  77 // Add topic name to atom table before using in conversations
  78 static HSZ DDEAddAtom(const wxString& string);
  79 static HSZ DDEGetAtom(const wxString& string);
  80 static void DDEPrintError(void);
  81
  82 static DWORD DDEIdInst = 0L;
  83 static wxDDEConnection *DDECurrentlyConnecting = NULL;
  84
  85 static wxList wxAtomTable(wxKEY_STRING);
  86 static wxList wxDDEClientObjects;
  87 static wxList wxDDEServerObjects;
  88
  89 char *DDEDefaultIPCBuffer = NULL;
  90 int DDEDefaultIPCBufferSize = 0;
  91
  92 /*
  93  * Initialization
  94  *
  95  */
  96
  97 static bool DDEInitialized = FALSE;
  98
  99 void wxDDEInitialize()
 100 {
 101   if (DDEInitialized)
 102     return;
 103   DDEInitialized = TRUE;
 104
 105   // Should insert filter flags
 106   DdeInitialize(&DDEIdInst, (PFNCALLBACK)MakeProcInstance(
 107                (FARPROC)_DDECallback, wxGetInstance()),
 108                APPCLASS_STANDARD,
 109                0L);
 110 }
 111
 112 /*
 113  * CleanUp
 114  */
 115
 116 void wxDDECleanUp()
 117 {
 118   if (DDEIdInst != 0)
 119   {
 120     DdeUninitialize(DDEIdInst);
 121     DDEIdInst = 0;
 122   }
 123   if (DDEDefaultIPCBuffer)
 124     delete [] DDEDefaultIPCBuffer ;
 125 }
 126
 127 // A module to allow DDE initialization/cleanup
 128 // without calling these functions from app.cpp or from
 129 // the user's application.
 130
 131 class wxDDEModule: public wxModule
 132 {
 133 DECLARE_DYNAMIC_CLASS(wxDDEModule)
 134 public:
 135     wxDDEModule() {}
 136     bool OnInit() { wxDDEInitialize(); return TRUE; };
 137     void OnExit() { wxDDECleanUp(); };
 138 };
 139
 140 IMPLEMENT_DYNAMIC_CLASS(wxDDEModule, wxModule)
 141
 142 // Global find connection
 143 static wxDDEConnection *DDEFindConnection(HCONV hConv)
 144 {
 145   wxNode *node = wxDDEServerObjects.First();
 146   wxDDEConnection *found = NULL;
 147   while (node && !found)
 148   {
 149     wxDDEServer *object = (wxDDEServer *)node->Data();
 150     found = object->FindConnection((WXHCONV) hConv);
 151     node = node->Next();
 152   }
 153   if (found)
 154         return found;
 155
 156   node = wxDDEClientObjects.First();
 157   while (node && !found)
 158   {
 159     wxDDEClient *object = (wxDDEClient *)node->Data();
 160     found = object->FindConnection((WXHCONV) hConv);
 161     node = node->Next();
 162   }
 163   return found;
 164 }
 165
 166 // Global delete connection
 167 static void DDEDeleteConnection(HCONV hConv)
 168 {
 169   wxNode *node = wxDDEServerObjects.First();
 170   bool found = FALSE;
 171   while (node && !found)
 172   {
 173     wxDDEServer *object = (wxDDEServer *)node->Data();
 174     found = object->DeleteConnection((WXHCONV) hConv);
 175     node = node->Next();
 176   }
 177   if (found)
 178         return;
 179
 180   node = wxDDEServerObjects.First();
 181   while (node && !found)
 182   {
 183     wxDDEClient *object = (wxDDEClient *)node->Data();
 184     found = object->DeleteConnection((WXHCONV) hConv);
 185     node = node->Next();
 186   }
 187 }
 188
 189 // Find a server from a service name
 190 static wxDDEServer *DDEFindServer(const wxString& s)
 191 {
 192   wxNode *node = wxDDEServerObjects.First();
 193   wxDDEServer *found = NULL;
 194   while (node && !found)
 195   {
 196     wxDDEServer *object = (wxDDEServer *)node->Data();
 197
 198     if (object->GetServiceName() == s)
 199       found = object;
 200     else node = node->Next();
 201   }
 202   return found;
 203 }
 204
 205 /*
 206  * Server
 207  *
 208  */
 209
 210 wxDDEServer::wxDDEServer(void)
 211 {
 212   m_serviceName = "";
 213   wxDDEServerObjects.Append(this);
 214 }
 215
 216 bool wxDDEServer::Create(const wxString& server_name)
 217 {
 218   m_serviceName = server_name;
 219   HSZ serviceName = DdeCreateStringHandle(DDEIdInst, WXSTRINGCAST server_name, CP_WINANSI);
 220
 221   if (DdeNameService(DDEIdInst, serviceName, (HSZ) NULL, DNS_REGISTER) == 0)
 222   {
 223     DDEPrintError();
 224     return FALSE;
 225   }
 226   return TRUE;
 227 }
 228
 229 wxDDEServer::~wxDDEServer(void)
 230 {
 231   if (m_serviceName != T(""))
 232   {
 233     HSZ serviceName = DdeCreateStringHandle(DDEIdInst, WXSTRINGCAST m_serviceName, CP_WINANSI);
 234     if (DdeNameService(DDEIdInst, serviceName, NULL, DNS_UNREGISTER) == 0)
 235     {
 236       DDEPrintError();
 237     }
 238   }
 239   wxDDEServerObjects.DeleteObject(this);
 240
 241   wxNode *node = m_connections.First();
 242   while (node)
 243   {
 244     wxDDEConnection *connection = (wxDDEConnection *)node->Data();
 245     wxNode *next = node->Next();
 246     connection->OnDisconnect(); // May delete the node implicitly
 247     node = next;
 248   }
 249
 250   // If any left after this, delete them
 251   node = m_connections.First();
 252   while (node)
 253   {
 254     wxDDEConnection *connection = (wxDDEConnection *)node->Data();
 255     wxNode *next = node->Next();
 256     delete connection;
 257     node = next;
 258   }
 259 }
 260
 261 wxConnectionBase *wxDDEServer::OnAcceptConnection(const wxString& /* topic */)
 262 {
 263         return new wxDDEConnection;
 264 }
 265
 266 wxDDEConnection *wxDDEServer::FindConnection(WXHCONV conv)
 267 {
 268   wxNode *node = m_connections.First();
 269   wxDDEConnection *found = NULL;
 270   while (node && !found)
 271   {
 272     wxDDEConnection *connection = (wxDDEConnection *)node->Data();
 273     if (connection->m_hConv == conv)
 274       found = connection;
 275     else node = node->Next();
 276   }
 277   return found;
 278 }
 279
 280 // Only delete the entry in the map, not the actual connection
 281 bool wxDDEServer::DeleteConnection(WXHCONV conv)
 282 {
 283   wxNode *node = m_connections.First();
 284   bool found = FALSE;
 285   while (node && !found)
 286   {
 287     wxDDEConnection *connection = (wxDDEConnection *)node->Data();
 288     if (connection->m_hConv == conv)
 289     {
 290       found = TRUE;
 291       delete node;
 292     }
 293     else node = node->Next();
 294   }
 295   return found;
 296 }
 297
 298
 299 /*
 300  * Client
 301  *
 302  */
 303
 304
 305 wxDDEClient::wxDDEClient(void)
 306 {
 307   wxDDEClientObjects.Append(this);
 308 }
 309
 310 wxDDEClient::~wxDDEClient(void)
 311 {
 312   wxDDEClientObjects.DeleteObject(this);
 313   wxNode *node = m_connections.First();
 314   while (node)
 315   {
 316     wxDDEConnection *connection = (wxDDEConnection *)node->Data();
 317     delete connection;  // Deletes the node implicitly (see ~wxDDEConnection)
 318     node = m_connections.First();
 319   }
 320 }
 321
 322 bool wxDDEClient::ValidHost(const wxString& /* host */)
 323 {
 324   return TRUE;
 325 }
 326
 327 wxConnectionBase *wxDDEClient::MakeConnection(const wxString& /* host */, const wxString& server_name, const wxString& topic)
 328 {
 329   HSZ serviceName = DdeCreateStringHandle(DDEIdInst, WXSTRINGCAST server_name, CP_WINANSI);
 330   HSZ topic_atom = DdeCreateStringHandle(DDEIdInst, WXSTRINGCAST topic, CP_WINANSI);
 331
 332   HCONV hConv = DdeConnect(DDEIdInst, serviceName, topic_atom, (PCONVCONTEXT)NULL);
 333   if (hConv == (HCONV) NULL)
 334     return (wxConnectionBase*) NULL;
 335   else
 336   {
 337     wxDDEConnection *connection = (wxDDEConnection*) OnMakeConnection();
 338     if (connection)
 339     {
 340       connection->m_hConv = (WXHCONV) hConv;
 341       connection->m_topicName = topic;
 342           connection->m_client = this;
 343       m_connections.Append(connection);
 344       return connection;
 345     }
 346     else return (wxConnectionBase*) NULL;
 347   }
 348 }
 349
 350 wxConnectionBase *wxDDEClient::OnMakeConnection(void)
 351 {
 352         return new wxDDEConnection;
 353 }
 354
 355 wxDDEConnection *wxDDEClient::FindConnection(WXHCONV conv)
 356 {
 357   wxNode *node = m_connections.First();
 358   wxDDEConnection *found = NULL;
 359   while (node && !found)
 360   {
 361     wxDDEConnection *connection = (wxDDEConnection *)node->Data();
 362     if (connection->m_hConv == conv)
 363       found = connection;
 364     else node = node->Next();
 365   }
 366   return found;
 367 }
 368
 369 // Only delete the entry in the map, not the actual connection
 370 bool wxDDEClient::DeleteConnection(WXHCONV conv)
 371 {
 372   wxNode *node = m_connections.First();
 373   bool found = FALSE;
 374   while (node && !found)
 375   {
 376     wxDDEConnection *connection = (wxDDEConnection *)node->Data();
 377     if (connection->m_hConv == conv)
 378     {
 379       found = TRUE;
 380       delete node;
 381     }
 382     else node = node->Next();
 383   }
 384   return found;
 385 }
 386
 387 /*
 388  * Connection
 389  */
 390
 391 wxDDEConnection::wxDDEConnection(char *buffer, int size)
 392 {
 393   if (buffer == NULL)
 394   {
 395     if (DDEDefaultIPCBuffer == NULL)
 396       DDEDefaultIPCBuffer = new char[DDEDefaultIPCBufferSize];
 397     m_bufPtr = DDEDefaultIPCBuffer;
 398     m_bufSize = DDEDefaultIPCBufferSize;
 399   }
 400   else
 401   {
 402     m_bufPtr = buffer;
 403     m_bufSize = size;
 404   }
 405
 406   m_topicName = "";
 407
 408   m_client = NULL;
 409   m_server = NULL;
 410
 411   m_hConv = 0;
 412   m_sendingData = NULL;
 413 }
 414
 415 wxDDEConnection::wxDDEConnection(void)
 416 {
 417   m_hConv = 0;
 418   m_sendingData = NULL;
 419   m_server = NULL;
 420   m_client = NULL;
 421   if (DDEDefaultIPCBuffer == NULL)
 422     DDEDefaultIPCBuffer = new char[DDEDefaultIPCBufferSize];
 423
 424   m_bufPtr = DDEDefaultIPCBuffer;
 425   m_bufSize = DDEDefaultIPCBufferSize;
 426   m_topicName = "";
 427 }
 428
 429 wxDDEConnection::~wxDDEConnection(void)
 430 {
 431         if (m_server)
 432                 m_server->GetConnections().DeleteObject(this);
 433         else
 434             m_client->GetConnections().DeleteObject(this);
 435 }
 436
 437 // Calls that CLIENT can make
 438 bool wxDDEConnection::Disconnect(void)
 439 {
 440   DDEDeleteConnection((HCONV) m_hConv);
 441   return (DdeDisconnect((HCONV) m_hConv) != 0);
 442 }
 443
 444 bool wxDDEConnection::Execute(const wxChar *data, int size, wxIPCFormat format)
 445 {
 446   DWORD result;
 447   if (size < 0)
 448     size = wxStrlen(data);
 449
 450   size ++;
 451
 452   return (DdeClientTransaction((LPBYTE)data, size, (HCONV) m_hConv,
 453     NULL, format, XTYP_EXECUTE, 5000, &result) ? TRUE : FALSE);
 454 }
 455
 456 char *wxDDEConnection::Request(const wxString& item, int *size, wxIPCFormat format)
 457 {
 458   DWORD result;
 459   HSZ atom = DDEGetAtom(item);
 460
 461   HDDEDATA returned_data = DdeClientTransaction(NULL, 0, (HCONV) m_hConv,
 462     atom, format, XTYP_REQUEST, 5000, &result);
 463
 464   DWORD len = DdeGetData(returned_data, (LPBYTE)(m_bufPtr), m_bufSize, 0);
 465
 466   DdeFreeDataHandle(returned_data);
 467
 468   if (size) *size = (int)len;
 469   if (len > 0)
 470   {
 471     return m_bufPtr;
 472   }
 473   else return NULL;
 474 }
 475
 476 bool wxDDEConnection::Poke(const wxString& item, wxChar *data, int size, wxIPCFormat format)
 477 {
 478   DWORD result;
 479   if (size < 0)
 480     size = wxStrlen(data);
 481
 482   size ++;
 483
 484   HSZ item_atom = DDEGetAtom(item);
 485   return (DdeClientTransaction((LPBYTE)data, size, (HCONV) m_hConv,
 486     item_atom, format, XTYP_POKE, 5000, &result) ? TRUE : FALSE);
 487 }
 488
 489 bool wxDDEConnection::StartAdvise(const wxString& item)
 490 {
 491   DWORD result;
 492   HSZ atom = DDEGetAtom(item);
 493
 494   return (DdeClientTransaction(NULL, 0, (HCONV) m_hConv,
 495     atom, CF_TEXT, XTYP_ADVSTART, 5000, &result) ? TRUE : FALSE);
 496 }
 497
 498 bool wxDDEConnection::StopAdvise(const wxString& item)
 499 {
 500   DWORD result;
 501   HSZ atom = DDEGetAtom(item);
 502
 503   return (DdeClientTransaction(NULL, 0, (HCONV) m_hConv,
 504     atom, CF_TEXT, XTYP_ADVSTOP, 5000, &result) ? TRUE : FALSE);
 505 }
 506
 507 // Calls that SERVER can make
 508 bool wxDDEConnection::Advise(const wxString& item, wxChar *data, int size, wxIPCFormat format)
 509 {
 510   if (size < 0)
 511     size = wxStrlen(data);
 512
 513   size ++;
 514
 515   HSZ item_atom = DDEGetAtom(item);
 516   HSZ topic_atom = DDEGetAtom(m_topicName);
 517   m_sendingData = data;
 518   m_dataSize = size;
 519   m_dataType = format;
 520   return (DdePostAdvise(DDEIdInst, topic_atom, item_atom) != 0);
 521 }
 522
 523 bool wxDDEConnection::OnDisconnect(void)
 524 {
 525         delete this;
 526         return TRUE;
 527 }
 528
 529
 530 #define DDERETURN HDDEDATA
 531
 532 HDDEDATA EXPENTRY _EXPORT _DDECallback(
 533 WORD wType,
 534 WORD wFmt,
 535 HCONV hConv,
 536 HSZ hsz1,
 537 HSZ hsz2,
 538 HDDEDATA hData,
 539 DWORD /* lData1 */,
 540 DWORD /* lData2 */)
 541 {
 542   switch (wType)
 543   {
 544     case XTYP_CONNECT:
 545     {
 546       wxChar topic_buf[100];
 547       wxChar server_buf[100];
 548       DdeQueryString(DDEIdInst, hsz1, (LPTSTR)topic_buf, WXSIZEOF(topic_buf),
 549                      CP_WINANSI);
 550       DdeQueryString(DDEIdInst, hsz2, (LPTSTR)server_buf, WXSIZEOF(topic_buf),
 551                      CP_WINANSI);
 552       wxDDEServer *server = DDEFindServer(server_buf);
 553       if (server)
 554       {
 555         wxDDEConnection *connection =
 556           (wxDDEConnection*) server->OnAcceptConnection(wxString(topic_buf));
 557         if (connection)
 558         {
 559           connection->m_server = server;
 560           server->GetConnections().Append(connection);
 561           connection->m_hConv = 0;
 562           connection->m_topicName = topic_buf;
 563           DDECurrentlyConnecting = connection;
 564           return (DDERETURN)(DWORD)TRUE;
 565         }
 566       }
 567       else return (DDERETURN)0;
 568       break;
 569     }
 570
 571     case XTYP_CONNECT_CONFIRM:
 572     {
 573       if (DDECurrentlyConnecting)
 574       {
 575         DDECurrentlyConnecting->m_hConv = (WXHCONV) hConv;
 576         DDECurrentlyConnecting = NULL;
 577         return (DDERETURN)(DWORD)TRUE;
 578       }
 579       else return 0;
 580       break;
 581     }
 582
 583     case XTYP_DISCONNECT:
 584     {
 585       wxDDEConnection *connection = DDEFindConnection(hConv);
 586       if (connection && connection->OnDisconnect())
 587       {
 588         DDEDeleteConnection(hConv);  // Delete mapping: hConv => connection
 589         return (DDERETURN)(DWORD)TRUE;
 590       }
 591       else return (DDERETURN)0;
 592       break;
 593     }
 594
 595     case XTYP_EXECUTE:
 596     {
 597       wxDDEConnection *connection = DDEFindConnection(hConv);
 598
 599       if (connection)
 600       {
 601         DWORD len = DdeGetData(hData, (LPBYTE)(connection->m_bufPtr), connection->m_bufSize, 0);
 602         DdeFreeDataHandle(hData);
 603         if (connection->OnExecute(connection->m_topicName, connection->m_bufPtr, (int)len, (wxIPCFormat) wFmt))
 604           return (DDERETURN)(DWORD)DDE_FACK;
 605         else
 606           return (DDERETURN)DDE_FNOTPROCESSED;
 607       } else return (DDERETURN)DDE_FNOTPROCESSED;
 608       break;
 609     }
 610
 611     case XTYP_REQUEST:
 612     {
 613       wxDDEConnection *connection = DDEFindConnection(hConv);
 614
 615       if (connection)
 616       {
 617         wxChar item_name[200];
 618         DdeQueryString(DDEIdInst, hsz2, (LPTSTR)item_name, WXSIZEOF(item_name),
 619                      CP_WINANSI);
 620
 621         int user_size = -1;
 622         char *data = connection->OnRequest(connection->m_topicName, wxString(item_name), &user_size, (wxIPCFormat) wFmt);
 623         if (data)
 624         {
 625           if (user_size < 0) user_size = strlen(data);
 626
 627           HDDEDATA handle = DdeCreateDataHandle(DDEIdInst,
 628                  (LPBYTE)data, user_size + 1, 0, hsz2, wFmt, 0);
 629           return (DDERETURN)handle;
 630         } else return (DDERETURN)0;
 631       } else return (DDERETURN)0;
 632       break;
 633     }
 634
 635     case XTYP_POKE:
 636     {
 637       wxDDEConnection *connection = DDEFindConnection(hConv);
 638
 639       if (connection)
 640       {
 641         wxChar item_name[200];
 642         DdeQueryString(DDEIdInst, hsz2, (LPTSTR)item_name, WXSIZEOF(item_name),
 643                      CP_WINANSI);
 644         DWORD len = DdeGetData(hData, (LPBYTE)(connection->m_bufPtr), connection->m_bufSize, 0);
 645         DdeFreeDataHandle(hData);
 646         connection->OnPoke(connection->m_topicName, wxString(item_name), connection->m_bufPtr, (int)len, (wxIPCFormat) wFmt);
 647         return (DDERETURN)(DWORD)DDE_FACK;
 648       } else return (DDERETURN)DDE_FNOTPROCESSED;
 649       break;
 650     }
 651
 652     case XTYP_ADVSTART:
 653     {
 654       wxDDEConnection *connection = DDEFindConnection(hConv);
 655
 656       if (connection)
 657       {
 658         wxChar item_name[200];
 659         DdeQueryString(DDEIdInst, hsz2, (LPTSTR)item_name, WXSIZEOF(item_name),
 660                      CP_WINANSI);
 661
 662         return (DDERETURN)(DWORD)connection->OnStartAdvise(connection->m_topicName, wxString(item_name));
 663       } else return (DDERETURN)0;
 664       break;
 665     }
 666
 667     case XTYP_ADVSTOP:
 668     {
 669       wxDDEConnection *connection = DDEFindConnection(hConv);
 670
 671       if (connection)
 672       {
 673         wxChar item_name[200];
 674         DdeQueryString(DDEIdInst, hsz2, (LPTSTR)item_name, WXSIZEOF(item_name),
 675                      CP_WINANSI);
 676         return (DDERETURN)(DWORD)connection->OnStopAdvise(connection->m_topicName, wxString(item_name));
 677       } else return (DDERETURN)0;
 678       break;
 679     }
 680
 681     case XTYP_ADVREQ:
 682     {
 683       wxDDEConnection *connection = DDEFindConnection(hConv);
 684
 685       if (connection && connection->m_sendingData)
 686       {
 687         HDDEDATA data = DdeCreateDataHandle(DDEIdInst,
 688                           (LPBYTE)connection->m_sendingData,
 689                           connection->m_dataSize, 0, hsz2, connection->m_dataType, 0);
 690         connection->m_sendingData = NULL;
 691         return (DDERETURN)data;
 692       } else return (DDERETURN)NULL;
 693       break;
 694     }
 695
 696     case XTYP_ADVDATA:
 697     {
 698       wxDDEConnection *connection = DDEFindConnection(hConv);
 699
 700       if (connection)
 701       {
 702         wxChar item_name[200];
 703         DdeQueryString(DDEIdInst, hsz2, (LPTSTR)item_name, WXSIZEOF(item_name),
 704                      CP_WINANSI);
 705
 706         DWORD len = DdeGetData(hData, (LPBYTE)(connection->m_bufPtr), connection->m_bufSize, 0);
 707         DdeFreeDataHandle(hData);
 708         if (connection->OnAdvise(connection->m_topicName, wxString(item_name), connection->m_bufPtr, (int)len, (wxIPCFormat) wFmt))
 709           return (DDERETURN)(DWORD)DDE_FACK;
 710         else
 711           return (DDERETURN)DDE_FNOTPROCESSED;
 712       } else return (DDERETURN)DDE_FNOTPROCESSED;
 713       break;
 714     }
 715   }
 716   return 0;
 717 }
 718
 719 // Atom table stuff
 720 static HSZ DDEAddAtom(const wxString& string)
 721 {
 722   HSZ atom = DdeCreateStringHandle(DDEIdInst, WXSTRINGCAST string, CP_WINANSI);
 723   wxAtomTable.Append(string, (wxObject *)atom);
 724   return atom;
 725 }
 726
 727 static HSZ DDEGetAtom(const wxString& string)
 728 {
 729   wxNode *node = wxAtomTable.Find(string);
 730   if (node)
 731     return (HSZ)node->Data();
 732   else
 733   {
 734     DDEAddAtom(string);
 735     return (HSZ)(wxAtomTable.Find(string)->Data());
 736   }
 737 }
 738
 739 void DDEPrintError(void)
 740 {
 741   wxChar *err = NULL;
 742   switch (DdeGetLastError(DDEIdInst))
 743   {
 744     case DMLERR_ADVACKTIMEOUT:
 745       err = T("A request for a synchronous advise transaction has timed out.");
 746       break;
 747     case DMLERR_BUSY:
 748       err = T("The response to the transaction caused the DDE_FBUSY bit to be set.");
 749       break;
 750     case DMLERR_DATAACKTIMEOUT:
 751       err = T("A request for a synchronous data transaction has timed out.");
 752       break;
 753     case DMLERR_DLL_NOT_INITIALIZED:
 754       err = T("A DDEML function was called without first calling the DdeInitialize function,\n\ror an invalid instance identifier\n\rwas passed to a DDEML function.");
 755       break;
 756     case DMLERR_DLL_USAGE:
 757       err = T("An application initialized as APPCLASS_MONITOR has\n\rattempted to perform a DDE transaction,\n\ror an application initialized as APPCMD_CLIENTONLY has \n\rattempted to perform server transactions.");
 758       break;
 759     case DMLERR_EXECACKTIMEOUT:
 760       err = T("A request for a synchronous execute transaction has timed out.");
 761       break;
 762     case DMLERR_INVALIDPARAMETER:
 763       err = T("A parameter failed to be validated by the DDEML.");
 764       break;
 765     case DMLERR_LOW_MEMORY:
 766       err = T("A DDEML application has created a prolonged race condition.");
 767       break;
 768     case DMLERR_MEMORY_ERROR:
 769       err = T("A memory allocation failed.");
 770       break;
 771     case DMLERR_NO_CONV_ESTABLISHED:
 772       err = T("A client's attempt to establish a conversation has failed.");
 773       break;
 774     case DMLERR_NOTPROCESSED:
 775       err = T("A transaction failed.");
 776       break;
 777     case DMLERR_POKEACKTIMEOUT:
 778       err = T("A request for a synchronous poke transaction has timed out.");
 779       break;
 780     case DMLERR_POSTMSG_FAILED:
 781       err = T("An internal call to the PostMessage function has failed. ");
 782       break;
 783     case DMLERR_REENTRANCY:
 784       err = T("Reentrancy problem.");
 785       break;
 786     case DMLERR_SERVER_DIED:
 787       err = T("A server-side transaction was attempted on a conversation\n\rthat was terminated by the client, or the server\n\rterminated before completing a transaction.");
 788       break;
 789     case DMLERR_SYS_ERROR:
 790       err = T("An internal error has occurred in the DDEML.");
 791       break;
 792     case DMLERR_UNADVACKTIMEOUT:
 793       err = T("A request to end an advise transaction has timed out.");
 794       break;
 795     case DMLERR_UNFOUND_QUEUE_ID:
 796       err = T("An invalid transaction identifier was passed to a DDEML function.\n\rOnce the application has returned from an XTYP_XACT_COMPLETE callback,\n\rthe transaction identifier for that callback is no longer valid.");
 797       break;
 798     default:
 799       err = T("Unrecognised error type.");
 800       break;
 801   }
 802   MessageBox((HWND) NULL, (LPCTSTR)err, T("DDE Error"), MB_OK | MB_ICONINFORMATION);
 803 }
 804
 805 #endif
 806   // wxUSE_IPC