]> git.saurik.com Git - wxWidgets.git/blobdiff - src/msw/dde.cpp
fix crash which happened if you called SetAttr(NULL) followed by SetAttr(attr) (...
[wxWidgets.git] / src / msw / dde.cpp
index 063a74b067c7240f9e395a807caa5e1d484dd955..550a8fc1cdd316045c2922d9b0ad6188d0f21498 100644 (file)
@@ -1,11 +1,11 @@
 /////////////////////////////////////////////////////////////////////////////
-// Name:        msw/dde.cpp
+// Name:        src/msw/dde.cpp
 // Purpose:     DDE classes
 // Author:      Julian Smart
 // Modified by:
 // Created:     01/02/97
 // RCS-ID:      $Id$
-// Copyright:   (c) Julian Smart and Markus Holzem
+// Copyright:   (c) Julian Smart
 // Licence:     wxWindows licence
 /////////////////////////////////////////////////////////////////////////////
 
 // headers
 // ----------------------------------------------------------------------------
 
-#ifdef __GNUG__
-    #pragma implementation "dde.h"
-#endif
-
 // For compilers that support precompilation, includes "wx.h".
 #include "wx/wxprec.h"
 
 #ifndef WX_PRECOMP
     #include "wx/utils.h"
     #include "wx/app.h"
+    #include "wx/hashmap.h"
+    #include "wx/module.h"
 #endif
 
-#include "wx/module.h"
 #include "wx/dde.h"
 #include "wx/intl.h"
-
+#include "wx/buffer.h"
+#include "wx/strconv.h"
 
 #include "wx/msw/private.h"
 
 #include <string.h>
-#include <windows.h>
 #include <ddeml.h>
 
-#ifdef __WXWINE__
-#define PCONVCONTEXT CONVCONTEXT*
-#endif
-
-#if defined(__TWIN32__) || defined(__GNUWIN32_OLD__)
-    #include "wx/msw/gnuwin32/extra.h"
-#endif
-
-// some compilers headers don't define this one (mingw32)
-#ifndef DMLERR_NO_ERROR
-    #define DMLERR_NO_ERROR (0)
-
-    // this one is also missing from some mingw32 headers, but there is no way
-    // to test for it (I know of) - the test for DMLERR_NO_ERROR works for me,
-    // but is surely not the right thing to do
-    extern "C"
-    HDDEDATA STDCALL DdeClientTransaction(LPBYTE pData,
-                                          DWORD cbData,
-                                          HCONV hConv,
-                                          HSZ hszItem,
-                                          UINT wFmt,
-                                          UINT wType,
-                                          DWORD dwTimeout,
-                                          LPDWORD pdwResult);
-#endif // no DMLERR_NO_ERROR
-
 // ----------------------------------------------------------------------------
 // macros and constants
 // ----------------------------------------------------------------------------
@@ -117,6 +88,7 @@ static HSZ DDEGetAtom(const wxString& string);
 // string handles
 static HSZ DDEAtomFromString(const wxString& s);
 static wxString DDEStringFromAtom(HSZ hsz);
+static void DDEFreeString(HSZ hsz);
 
 // error handling
 static wxString DDEGetErrorMsg(UINT error);
@@ -126,16 +98,22 @@ static void DDELogError(const wxString& s, UINT error = DMLERR_NO_ERROR);
 // global variables
 // ----------------------------------------------------------------------------
 
+WX_DECLARE_STRING_HASH_MAP( HSZ, wxAtomMap );
+
 static DWORD DDEIdInst = 0L;
 static wxDDEConnection *DDECurrentlyConnecting = NULL;
+static wxAtomMap wxAtomTable;
+
+#include "wx/listimpl.cpp"
 
-static wxList wxAtomTable(wxKEY_STRING);
-static wxList wxDDEClientObjects;
-static wxList wxDDEServerObjects;
+WX_DEFINE_LIST(wxDDEClientList)
+WX_DEFINE_LIST(wxDDEServerList)
+WX_DEFINE_LIST(wxDDEConnectionList)
 
-char *DDEDefaultIPCBuffer = NULL;
-int DDEDefaultIPCBufferSize = 0;
-static bool DDEInitialized = FALSE;
+static wxDDEClientList wxDDEClientObjects;
+static wxDDEServerList wxDDEServerObjects;
+
+static bool DDEInitialized = false;
 
 // ----------------------------------------------------------------------------
 // private classes
@@ -148,7 +126,7 @@ class wxDDEModule : public wxModule
 {
 public:
     wxDDEModule() {}
-    bool OnInit() { return TRUE; }
+    bool OnInit() { return true; }
     void OnExit() { wxDDECleanUp(); }
 
 private:
@@ -186,20 +164,25 @@ extern void wxDDEInitialize()
         }
         else
         {
-            DDEInitialized = TRUE;
+            DDEInitialized = true;
         }
     }
 }
 
 void wxDDECleanUp()
 {
+    // deleting them later won't work as DDE won't be initialized any more
+    wxASSERT_MSG( wxDDEServerObjects.empty() &&
+                    wxDDEClientObjects.empty(),
+                    _T("all DDE objects should be deleted by now") );
+
+    wxAtomTable.clear();
+
     if ( DDEIdInst != 0 )
     {
         DdeUninitialize(DDEIdInst);
         DDEIdInst = 0;
     }
-
-    delete [] DDEDefaultIPCBuffer;
 }
 
 // ----------------------------------------------------------------------------
@@ -209,64 +192,75 @@ void wxDDECleanUp()
 // Global find connection
 static wxDDEConnection *DDEFindConnection(HCONV hConv)
 {
-  wxNode *node = wxDDEServerObjects.First();
-  wxDDEConnection *found = NULL;
-  while (node && !found)
-  {
-    wxDDEServer *object = (wxDDEServer *)node->Data();
-    found = object->FindConnection((WXHCONV) hConv);
-    node = node->Next();
-  }
-  if (found)
-      return found;
-
-  node = wxDDEClientObjects.First();
-  while (node && !found)
-  {
-    wxDDEClient *object = (wxDDEClient *)node->Data();
-    found = object->FindConnection((WXHCONV) hConv);
-    node = node->Next();
-  }
-  return found;
+    wxDDEServerList::compatibility_iterator serverNode = wxDDEServerObjects.GetFirst();
+    wxDDEConnection *found = NULL;
+    while (serverNode && !found)
+    {
+        wxDDEServer *object = serverNode->GetData();
+        found = object->FindConnection((WXHCONV) hConv);
+        serverNode = serverNode->GetNext();
+    }
+
+    if (found)
+    {
+        return found;
+    }
+
+    wxDDEClientList::compatibility_iterator clientNode = wxDDEClientObjects.GetFirst();
+    while (clientNode && !found)
+    {
+        wxDDEClient *object = clientNode->GetData();
+        found = object->FindConnection((WXHCONV) hConv);
+        clientNode = clientNode->GetNext();
+    }
+    return found;
 }
 
 // Global delete connection
 static void DDEDeleteConnection(HCONV hConv)
 {
-  wxNode *node = wxDDEServerObjects.First();
-  bool found = FALSE;
-  while (node && !found)
-  {
-    wxDDEServer *object = (wxDDEServer *)node->Data();
-    found = object->DeleteConnection((WXHCONV) hConv);
-    node = node->Next();
-  }
-  if (found)
-    return;
-
-  node = wxDDEClientObjects.First();
-  while (node && !found)
-  {
-    wxDDEClient *object = (wxDDEClient *)node->Data();
-    found = object->DeleteConnection((WXHCONV) hConv);
-    node = node->Next();
-  }
+    wxDDEServerList::compatibility_iterator serverNode = wxDDEServerObjects.GetFirst();
+    bool found = false;
+    while (serverNode && !found)
+    {
+        wxDDEServer *object = serverNode->GetData();
+        found = object->DeleteConnection((WXHCONV) hConv);
+        serverNode = serverNode->GetNext();
+    }
+    if (found)
+    {
+        return;
+    }
+
+    wxDDEClientList::compatibility_iterator clientNode = wxDDEClientObjects.GetFirst();
+    while (clientNode && !found)
+    {
+        wxDDEClient *object = clientNode->GetData();
+        found = object->DeleteConnection((WXHCONV) hConv);
+        clientNode = clientNode->GetNext();
+    }
 }
 
 // Find a server from a service name
 static wxDDEServer *DDEFindServer(const wxString& s)
 {
-  wxNode *node = wxDDEServerObjects.First();
-  wxDDEServer *found = NULL;
-  while (node && !found)
-  {
-    wxDDEServer *object = (wxDDEServer *)node->Data();
-
-    if (object->GetServiceName() == s)
-      found = object;
-    else node = node->Next();
-  }
-  return found;
+    wxDDEServerList::compatibility_iterator node = wxDDEServerObjects.GetFirst();
+    wxDDEServer *found = NULL;
+    while (node && !found)
+    {
+        wxDDEServer *object = node->GetData();
+
+        if (object->GetServiceName() == s)
+        {
+            found = object;
+        }
+        else
+        {
+            node = node->GetNext();
+        }
+    }
+
+    return found;
 }
 
 // ----------------------------------------------------------------------------
@@ -284,46 +278,66 @@ bool wxDDEServer::Create(const wxString& server)
 {
     m_serviceName = server;
 
-    if ( !DdeNameService(DDEIdInst, DDEAtomFromString(server), (HSZ)NULL, DNS_REGISTER) )
+    HSZ hsz = DDEAtomFromString(server);
+
+    if ( !hsz )
     {
-        DDELogError(wxString::Format(_("Failed to register DDE server '%s'"),
-                                     server.c_str()));
+        return false;
+    }
+
 
-        return FALSE;
+    bool success = (DdeNameService(DDEIdInst, hsz, (HSZ) NULL, DNS_REGISTER)
+        != NULL);
+
+    if (!success)
+    {
+        DDELogError(wxString::Format(_("Failed to register DDE server '%s'"),
+            server.c_str()));
     }
 
-    return TRUE;
+    DDEFreeString(hsz);
+
+    return success;
 }
 
 wxDDEServer::~wxDDEServer()
 {
-    if ( !!m_serviceName )
+    if ( !m_serviceName.empty() )
     {
-        if ( !DdeNameService(DDEIdInst, DDEAtomFromString(m_serviceName),
-                             (HSZ)NULL, DNS_UNREGISTER) )
+        HSZ hsz = DDEAtomFromString(m_serviceName);
+
+        if (hsz)
         {
-            DDELogError(wxString::Format(_("Failed to unregister DDE server '%s'"),
-                                         m_serviceName.c_str()));
+            if ( !DdeNameService(DDEIdInst, hsz,
+                (HSZ) NULL, DNS_UNREGISTER) )
+            {
+                DDELogError(wxString::Format(
+                    _("Failed to unregister DDE server '%s'"),
+                    m_serviceName.c_str()));
+            }
+
+            DDEFreeString(hsz);
         }
     }
 
     wxDDEServerObjects.DeleteObject(this);
 
-    wxNode *node = m_connections.First();
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
     while (node)
     {
-        wxDDEConnection *connection = (wxDDEConnection *)node->Data();
-        wxNode *next = node->Next();
+        wxDDEConnection *connection = node->GetData();
+        wxDDEConnectionList::compatibility_iterator next = node->GetNext();
+        connection->SetConnected(false);
         connection->OnDisconnect(); // May delete the node implicitly
         node = next;
     }
 
     // If any left after this, delete them
-    node = m_connections.First();
+    node = m_connections.GetFirst();
     while (node)
     {
-        wxDDEConnection *connection = (wxDDEConnection *)node->Data();
-        wxNode *next = node->Next();
+        wxDDEConnection *connection = node->GetData();
+        wxDDEConnectionList::compatibility_iterator next = node->GetNext();
         delete connection;
         node = next;
     }
@@ -336,14 +350,14 @@ wxConnectionBase *wxDDEServer::OnAcceptConnection(const wxString& /* topic */)
 
 wxDDEConnection *wxDDEServer::FindConnection(WXHCONV conv)
 {
-    wxNode *node = m_connections.First();
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
     wxDDEConnection *found = NULL;
     while (node && !found)
     {
-        wxDDEConnection *connection = (wxDDEConnection *)node->Data();
+        wxDDEConnection *connection = node->GetData();
         if (connection->m_hConv == conv)
             found = connection;
-        else node = node->Next();
+        else node = node->GetNext();
     }
     return found;
 }
@@ -351,19 +365,21 @@ wxDDEConnection *wxDDEServer::FindConnection(WXHCONV conv)
 // Only delete the entry in the map, not the actual connection
 bool wxDDEServer::DeleteConnection(WXHCONV conv)
 {
-    wxNode *node = m_connections.First();
-    bool found = FALSE;
-    while (node && !found)
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
+    while (node)
     {
-        wxDDEConnection *connection = (wxDDEConnection *)node->Data();
+        wxDDEConnection *connection = node->GetData();
         if (connection->m_hConv == conv)
         {
-            found = TRUE;
-            delete node;
+            m_connections.Erase(node);
+            return true;
+        }
+        else
+        {
+            node = node->GetNext();
         }
-        else node = node->Next();
     }
-    return found;
+    return false;
 }
 
 // ----------------------------------------------------------------------------
@@ -380,30 +396,53 @@ wxDDEClient::wxDDEClient()
 wxDDEClient::~wxDDEClient()
 {
     wxDDEClientObjects.DeleteObject(this);
-    wxNode *node = m_connections.First();
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
     while (node)
     {
-        wxDDEConnection *connection = (wxDDEConnection *)node->Data();
+        wxDDEConnection *connection = node->GetData();
         delete connection;  // Deletes the node implicitly (see ~wxDDEConnection)
-        node = m_connections.First();
+        node = m_connections.GetFirst();
     }
 }
 
 bool wxDDEClient::ValidHost(const wxString& /* host */)
 {
-    return TRUE;
+    return true;
 }
 
 wxConnectionBase *wxDDEClient::MakeConnection(const wxString& WXUNUSED(host),
                                               const wxString& server,
                                               const wxString& topic)
 {
-    HCONV hConv = DdeConnect(DDEIdInst, DDEAtomFromString(server), DDEAtomFromString(topic),
-                             (PCONVCONTEXT)NULL);
+    HSZ hszServer = DDEAtomFromString(server);
+
+    if ( !hszServer )
+    {
+        return (wxConnectionBase*) NULL;
+    }
+
+
+    HSZ hszTopic = DDEAtomFromString(topic);
+
+    if ( !hszTopic )
+    {
+        DDEFreeString(hszServer);
+        return (wxConnectionBase*) NULL;
+    }
+
+
+    HCONV hConv = ::DdeConnect(DDEIdInst, hszServer, hszTopic,
+        (PCONVCONTEXT) NULL);
+
+    DDEFreeString(hszServer);
+    DDEFreeString(hszTopic);
+
+
     if ( !hConv )
     {
-        DDELogError(wxString::Format(_("Failed to create connection to server '%s' on topic '%s'"),
-                                     server.c_str(), topic.c_str()));
+        DDELogError( wxString::Format(
+            _("Failed to create connection to server '%s' on topic '%s'"),
+            server.c_str(), topic.c_str()) );
     }
     else
     {
@@ -428,14 +467,14 @@ wxConnectionBase *wxDDEClient::OnMakeConnection()
 
 wxDDEConnection *wxDDEClient::FindConnection(WXHCONV conv)
 {
-    wxNode *node = m_connections.First();
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
     wxDDEConnection *found = NULL;
     while (node && !found)
     {
-        wxDDEConnection *connection = (wxDDEConnection *)node->Data();
+        wxDDEConnection *connection = node->GetData();
         if (connection->m_hConv == conv)
             found = connection;
-        else node = node->Next();
+        else node = node->GetNext();
     }
     return found;
 }
@@ -443,40 +482,27 @@ wxDDEConnection *wxDDEClient::FindConnection(WXHCONV conv)
 // Only delete the entry in the map, not the actual connection
 bool wxDDEClient::DeleteConnection(WXHCONV conv)
 {
-    wxNode *node = m_connections.First();
-    bool found = FALSE;
-    while (node && !found)
+    wxDDEConnectionList::compatibility_iterator node = m_connections.GetFirst();
+    while (node)
     {
-        wxDDEConnection *connection = (wxDDEConnection *)node->Data();
+        wxDDEConnection *connection = node->GetData();
         if (connection->m_hConv == conv)
         {
-            found = TRUE;
-            delete node;
+            m_connections.Erase(node);
+            return true;
         }
-        else node = node->Next();
+        else node = node->GetNext();
     }
-    return found;
+    return false;
 }
 
 // ----------------------------------------------------------------------------
 // wxDDEConnection
 // ----------------------------------------------------------------------------
 
-wxDDEConnection::wxDDEConnection(char *buffer, int size)
+wxDDEConnection::wxDDEConnection(void *buffer, size_t size)
+     : wxConnectionBase(buffer, size)
 {
-    if (buffer == NULL)
-    {
-        if (DDEDefaultIPCBuffer == NULL)
-            DDEDefaultIPCBuffer = new char[DDEDefaultIPCBufferSize];
-        m_bufPtr = DDEDefaultIPCBuffer;
-        m_bufSize = DDEDefaultIPCBufferSize;
-    }
-    else
-    {
-        m_bufPtr = buffer;
-        m_bufSize = size;
-    }
-
     m_client = NULL;
     m_server = NULL;
 
@@ -485,20 +511,17 @@ wxDDEConnection::wxDDEConnection(char *buffer, int size)
 }
 
 wxDDEConnection::wxDDEConnection()
+     : wxConnectionBase()
 {
     m_hConv = 0;
     m_sendingData = NULL;
     m_server = NULL;
     m_client = NULL;
-    if (DDEDefaultIPCBuffer == NULL)
-        DDEDefaultIPCBuffer = new char[DDEDefaultIPCBufferSize];
-
-    m_bufPtr = DDEDefaultIPCBuffer;
-    m_bufSize = DDEDefaultIPCBufferSize;
 }
 
 wxDDEConnection::~wxDDEConnection()
 {
+    Disconnect();
     if (m_server)
         m_server->GetConnections().DeleteObject(this);
     else
@@ -508,6 +531,9 @@ wxDDEConnection::~wxDDEConnection()
 // Calls that CLIENT can make
 bool wxDDEConnection::Disconnect()
 {
+    if ( !GetConnected() )
+        return true;
+
     DDEDeleteConnection(GetHConv());
 
     bool ok = DdeDisconnect(GetHConv()) != 0;
@@ -516,24 +542,110 @@ bool wxDDEConnection::Disconnect()
         DDELogError(_T("Failed to disconnect from DDE server gracefully"));
     }
 
+    SetConnected( false );  // so we don't try and disconnect again
+
     return ok;
 }
 
-bool wxDDEConnection::Execute(const wxChar *data, int size, wxIPCFormat format)
+bool
+wxDDEConnection::DoExecute(const void *data, size_t size, wxIPCFormat format)
 {
-    DWORD result;
-    if (size < 0)
+    wxCHECK_MSG( format == wxIPC_TEXT ||
+                 format == wxIPC_UTF8TEXT ||
+                 format == wxIPC_UNICODETEXT,
+                 false,
+                 _T("wxDDEServer::Execute() supports only text data") );
+
+    wxMemoryBuffer buffer;
+    LPBYTE realData = NULL;
+    size_t realSize = 0;
+    wxMBConv *conv = NULL;
+
+    // Windows only supports either ANSI or UTF-16 format depending on the
+    // build, so we need to convert the data if it doesn't use it already
+#if wxUSE_UNICODE
+    if ( format == wxIPC_TEXT )
     {
-        size = wxStrlen(data) + 1;
+        conv = &wxConvLibc;
+    }
+    else if ( format == wxIPC_UTF8TEXT )
+    {
+        conv = &wxConvUTF8;
+    }
+    else // no conversion necessary for wxIPC_UNICODETEXT
+    {
+        realData = (LPBYTE)data;
+        realSize = size;
     }
 
-    bool ok = DdeClientTransaction((LPBYTE)data, size,
-                                    GetHConv(),
-                                    NULL,
-                                    format,
-                                    XTYP_EXECUTE,
-                                    DDE_TIMEOUT,
-                                    &result) != 0;
+    if ( conv )
+    {
+        const char * const text = (const char *)data;
+        const size_t len = size/sizeof(char);
+
+        realSize = conv->ToWChar(NULL, 0, text, len);
+        if ( realSize == wxCONV_FAILED )
+            return false;
+
+        realData = (LPBYTE)buffer.GetWriteBuf(realSize*sizeof(wchar_t));
+        if ( !realData )
+            return false;
+
+        realSize = conv->ToWChar((wchar_t *)realData, realSize, text, len);
+        if ( realSize == wxCONV_FAILED )
+            return false;
+    }
+#else // !wxUSE_UNICODE
+    if ( format == wxIPC_UNICODETEXT )
+    {
+        conv = &wxConvLibc;
+    }
+    else if ( format == wxIPC_UTF8TEXT )
+    {
+        // we could implement this in theory but it's not obvious how to pass
+        // the format information and, basically, why bother -- just use
+        // Unicode build
+        wxFAIL_MSG( _T("UTF-8 text not supported in ANSI build") );
+
+        return false;
+    }
+    else // don't convert wxIPC_TEXT
+    {
+        realData = (LPBYTE)data;
+        realSize = size;
+    }
+
+    if ( conv )
+    {
+        const wchar_t * const wtext = (const wchar_t *)data;
+        const size_t len = size/sizeof(wchar_t);
+
+        realSize = conv->FromWChar(NULL, 0, wtext, len);
+        if ( realSize == wxCONV_FAILED )
+            return false;
+
+        realData = (LPBYTE)buffer.GetWriteBuf(realSize*sizeof(char));
+        if ( !realData )
+            return false;
+
+        realSize = conv->FromWChar((char*)realData, realSize, wtext, len);
+        if ( realSize == wxCONV_FAILED )
+            return false;
+    }
+#endif // wxUSE_UNICODE/!wxUSE_UNICODE
+
+    DWORD result;
+    bool ok = DdeClientTransaction(realData,
+                                   realSize*sizeof(wxChar),
+                                   GetHConv(),
+                                   NULL,
+                                   // MSDN: if the transaction specified by
+                                   // the wType parameter does not pass data
+                                   // or is XTYP_EXECUTE, wFmt should be zero.
+                                   0,
+                                   XTYP_EXECUTE,
+                                   DDE_TIMEOUT,
+                                   &result) != 0;
 
     if ( !ok )
     {
@@ -543,9 +655,10 @@ bool wxDDEConnection::Execute(const wxChar *data, int size, wxIPCFormat format)
     return ok;
 }
 
-char *wxDDEConnection::Request(const wxString& item, int *size, wxIPCFormat format)
+const void *wxDDEConnection::Request(const wxString& item, size_t *size, wxIPCFormat format)
 {
     DWORD result;
+
     HSZ atom = DDEGetAtom(item);
 
     HDDEDATA returned_data = DdeClientTransaction(NULL, 0,
@@ -561,26 +674,28 @@ char *wxDDEConnection::Request(const wxString& item, int *size, wxIPCFormat form
         return NULL;
     }
 
-    DWORD len = DdeGetData(returned_data, (LPBYTE)m_bufPtr, m_bufSize, 0);
+    DWORD len = DdeGetData(returned_data, NULL, 0, 0);
 
-    DdeFreeDataHandle(returned_data);
+    void *data = GetBufferAtLeast(len);
+    wxASSERT_MSG(data != NULL,
+                 _T("Buffer too small in wxDDEConnection::Request") );
+    (void) DdeGetData(returned_data, (LPBYTE)data, len, 0);
+
+    (void) DdeFreeDataHandle(returned_data);
 
     if (size)
-        *size = (int)len;
+        *size = (size_t)len;
 
-    return m_bufPtr;
+    return data;
 }
 
-bool wxDDEConnection::Poke(const wxString& item, wxChar *data, int size, wxIPCFormat format)
+bool wxDDEConnection::DoPoke(const wxString& item, const void *data, size_t size, wxIPCFormat format)
 {
     DWORD result;
-    if (size < 0)
-    {
-        size = wxStrlen(data) + 1;
-    }
 
     HSZ item_atom = DDEGetAtom(item);
-    bool ok = DdeClientTransaction((LPBYTE)data, size,
+    bool ok = DdeClientTransaction((LPBYTE)data,
+                                   size,
                                    GetHConv(),
                                    item_atom, format,
                                    XTYP_POKE,
@@ -633,21 +748,17 @@ bool wxDDEConnection::StopAdvise(const wxString& item)
 }
 
 // Calls that SERVER can make
-bool wxDDEConnection::Advise(const wxString& item,
-                             wxChar *data,
-                             int size,
-                             wxIPCFormat format)
+bool wxDDEConnection::DoAdvise(const wxString& item,
+                               const void *data,
+                               size_t size,
+                               wxIPCFormat format)
 {
-    if (size < 0)
-    {
-        size = wxStrlen(data) + 1;
-    }
-
     HSZ item_atom = DDEGetAtom(item);
     HSZ topic_atom = DDEGetAtom(m_topicName);
-    m_sendingData = data;
+    m_sendingData = data;  // mrf: potential for scope problems here?
     m_dataSize = size;
-    m_dataType = format;
+    // wxIPC_PRIVATE does not succeed, so use text instead
+    m_dataType = format == wxIPC_PRIVATE ? wxIPC_TEXT : format;
 
     bool ok = DdePostAdvise(DDEIdInst, topic_atom, item_atom) != 0;
     if ( !ok )
@@ -658,12 +769,6 @@ bool wxDDEConnection::Advise(const wxString& item,
     return ok;
 }
 
-bool wxDDEConnection::OnDisconnect()
-{
-    delete this;
-    return TRUE;
-}
-
 // ----------------------------------------------------------------------------
 // _DDECallback
 // ----------------------------------------------------------------------------
@@ -698,7 +803,7 @@ _DDECallback(WORD wType,
                         connection->m_hConv = 0;
                         connection->m_topicName = topic;
                         DDECurrentlyConnecting = connection;
-                        return (DDERETURN)(DWORD)TRUE;
+                        return (DDERETURN)(DWORD)true;
                     }
                 }
                 break;
@@ -710,7 +815,7 @@ _DDECallback(WORD wType,
                 {
                     DDECurrentlyConnecting->m_hConv = (WXHCONV) hConv;
                     DDECurrentlyConnecting = NULL;
-                    return (DDERETURN)(DWORD)TRUE;
+                    return (DDERETURN)(DWORD)true;
                 }
                 break;
             }
@@ -718,10 +823,14 @@ _DDECallback(WORD wType,
         case XTYP_DISCONNECT:
             {
                 wxDDEConnection *connection = DDEFindConnection(hConv);
-                if (connection && connection->OnDisconnect())
+                if (connection)
                 {
-                    DDEDeleteConnection(hConv);  // Delete mapping: hConv => connection
-                    return (DDERETURN)(DWORD)TRUE;
+                    connection->SetConnected( false );
+                    if (connection->OnDisconnect())
+                    {
+                        DDEDeleteConnection(hConv);  // Delete mapping: hConv => connection
+                        return (DDERETURN)(DWORD)true;
+                    }
                 }
                 break;
             }
@@ -732,15 +841,29 @@ _DDECallback(WORD wType,
 
                 if (connection)
                 {
-                    DWORD len = DdeGetData(hData,
-                                           (LPBYTE)connection->m_bufPtr,
-                                           connection->m_bufSize,
-                                           0);
+                    DWORD len = DdeGetData(hData, NULL, 0, 0);
+
+                    void *data = connection->GetBufferAtLeast(len);
+                    wxASSERT_MSG(data != NULL,
+                                 _T("Buffer too small in _DDECallback (XTYP_EXECUTE)") );
+
+                    DdeGetData(hData, (LPBYTE)data, len, 0);
+
                     DdeFreeDataHandle(hData);
+
+                    // XTYP_EXECUTE can be used for text only and the text is
+                    // always in ANSI format for ANSI build and Unicode format
+                    // in Unicode build
+                    #if wxUSE_UNICODE
+                        wFmt = wxIPC_UNICODETEXT;
+                    #else
+                        wFmt = wxIPC_TEXT;
+                    #endif
+
                     if ( connection->OnExecute(connection->m_topicName,
-                                               connection->m_bufPtr,
+                                               data,
                                                (int)len,
-                                               (wxIPCFormat) wFmt) )
+                                               (wxIPCFormat)wFmt) )
                     {
                         return (DDERETURN)(DWORD)DDE_FACK;
                     }
@@ -757,15 +880,26 @@ _DDECallback(WORD wType,
                 {
                     wxString item_name = DDEStringFromAtom(hsz2);
 
-                    int user_size = -1;
-                    char *data = connection->OnRequest(connection->m_topicName,
-                                                       item_name,
-                                                       &user_size,
-                                                       (wxIPCFormat) wFmt);
+                    size_t user_size = wxNO_LEN;
+                    const void *data = connection->OnRequest(connection->m_topicName,
+                                                             item_name,
+                                                             &user_size,
+                                                             (wxIPCFormat)wFmt);
                     if (data)
                     {
-                        if (user_size < 0)
-                            user_size = wxStrlen((wxChar*)data) + 1;
+                      if (user_size == wxNO_LEN)
+                        switch (wFmt)
+                        {
+                          case wxIPC_TEXT:
+                          case wxIPC_UTF8TEXT:
+                            user_size = strlen((const char*)data) + 1;  // includes final NUL
+                            break;
+                          case wxIPC_UNICODETEXT:
+                            user_size = (wcslen((const wchar_t*)data) + 1) * sizeof(wchar_t);  // includes final NUL
+                            break;
+                          default:
+                            user_size = 0;
+                        }
 
                         HDDEDATA handle = DdeCreateDataHandle(DDEIdInst,
                                                               (LPBYTE)data,
@@ -788,15 +922,19 @@ _DDECallback(WORD wType,
                 {
                     wxString item_name = DDEStringFromAtom(hsz2);
 
-                    DWORD len = DdeGetData(hData,
-                                           (LPBYTE)connection->m_bufPtr,
-                                           connection->m_bufSize,
-                                           0);
+                    DWORD len = DdeGetData(hData, NULL, 0, 0);
+
+                    void *data = connection->GetBufferAtLeast(len);
+                    wxASSERT_MSG(data != NULL,
+                                 _T("Buffer too small in _DDECallback (XTYP_POKE)") );
+
+                    DdeGetData(hData, (LPBYTE)data, len, 0);
+
                     DdeFreeDataHandle(hData);
 
                     connection->OnPoke(connection->m_topicName,
                                        item_name,
-                                       (wxChar*)connection->m_bufPtr,
+                                       data,
                                        (int)len,
                                        (wxIPCFormat) wFmt);
 
@@ -871,14 +1009,18 @@ _DDECallback(WORD wType,
                 {
                     wxString item_name = DDEStringFromAtom(hsz2);
 
-                    DWORD len = DdeGetData(hData,
-                                           (LPBYTE)connection->m_bufPtr,
-                                           connection->m_bufSize,
-                                           0);
+                    DWORD len = DdeGetData(hData, NULL, 0, 0);
+
+                    void *data = connection->GetBufferAtLeast(len);
+                    wxASSERT_MSG(data != NULL,
+                                 _T("Buffer too small in _DDECallback (XTYP_ADVDATA)") );
+
+                    DdeGetData(hData, (LPBYTE)data, len, 0);
+
                     DdeFreeDataHandle(hData);
                     if ( connection->OnAdvise(connection->m_topicName,
                                               item_name,
-                                              connection->m_bufPtr,
+                                              data,
                                               (int)len,
                                               (wxIPCFormat) wFmt) )
                     {
@@ -898,31 +1040,32 @@ _DDECallback(WORD wType,
 // ----------------------------------------------------------------------------
 
 // Atom table stuff
-static HSZ DDEAddAtom(const wxString& string)
+static HSZ DDEAddAtom(const wxString& str)
 {
-    HSZ atom = DDEAtomFromString(string);
-    wxAtomTable.Append(string, (wxObject *)atom);
+    HSZ atom = DDEAtomFromString(str);
+    wxAtomTable[str] = atom;
     return atom;
 }
 
-static HSZ DDEGetAtom(const wxString& string)
+static HSZ DDEGetAtom(const wxString& str)
 {
-    wxNode *node = wxAtomTable.Find(string);
-    if (node)
-        return (HSZ)node->Data();
-    else
-    {
-        DDEAddAtom(string);
-        return (HSZ)(wxAtomTable.Find(string)->Data());
-    }
+    wxAtomMap::iterator it = wxAtomTable.find(str);
+
+    if (it != wxAtomTable.end())
+        return it->second;
+
+    return DDEAddAtom(str);
 }
 
-// atom <-> strings
+/* atom <-> strings
+The returned handle has to be freed by the caller (using
+(static) DDEFreeString).
+*/
 static HSZ DDEAtomFromString(const wxString& s)
 {
     wxASSERT_MSG( DDEIdInst, _T("DDE not initialized") );
 
-    HSZ hsz = DdeCreateStringHandle(DDEIdInst, (wxChar*) s.c_str(), DDE_CP);
+    HSZ hsz = DdeCreateStringHandle(DDEIdInst, (wxChar*)s.wx_str(), DDE_CP);
     if ( !hsz )
     {
         DDELogError(_("Failed to create DDE string"));
@@ -937,12 +1080,20 @@ static wxString DDEStringFromAtom(HSZ hsz)
     static const size_t len = 256;
 
     wxString s;
-    (void)DdeQueryString(DDEIdInst, hsz, s.GetWriteBuf(len), len, DDE_CP);
-    s.UngetWriteBuf();
+    (void)DdeQueryString(DDEIdInst, hsz, wxStringBuffer(s, len), len, DDE_CP);
 
     return s;
 }
 
+static void DDEFreeString(HSZ hsz)
+{
+    // DS: Failure to free a string handle might indicate there's
+    // some other severe error.
+    bool ok = (::DdeFreeStringHandle(DDEIdInst, hsz) != 0);
+    wxASSERT_MSG( ok, wxT("Failed to free DDE string handle") );
+    wxUnusedVar(ok);
+}
+
 // ----------------------------------------------------------------------------
 // error handling
 // ----------------------------------------------------------------------------