docs/latex/wx/ddeconn.tex

   1 \section{\class{wxDDEConnection}}\label{wxddeconnection}
   2
   3 A wxDDEConnection object represents the connection between a client and a
   4 server. It can be created by making a connection using a\rtfsp
   5 \helpref{wxDDEClient}{wxddeclient} object, or by the acceptance of a connection by a\rtfsp
   6 \helpref{wxDDEServer}{wxddeserver} object. The bulk of a DDE (Dynamic Data Exchange)
   7 conversation is controlled by
   8 calling members in a {\bf wxDDEConnection} object or by overriding its
   9 members.
  10
  11 An application should normally derive a new connection class from
  12 wxDDEConnection, in order to override the communication event handlers
  13 to do something interesting.
  14
  15 This DDE-based implementation is available on Windows only,
  16 but a platform-independent, socket-based version
  17 of this API is available using \helpref{wxTCPConnection}{wxtcpconnection}.
  18
  19 \wxheading{Derived from}
  20
  21 wxConnectionBase\\
  22 \helpref{wxObject}{wxobject}
  23
  24 \wxheading{Include files}
  25
  26 <wx/dde.h>
  27
  28 \wxheading{Types}
  29
  30 \index{wxIPCFormat}wxIPCFormat is defined as follows:
  31
  32 \begin{verbatim}
  33 enum wxIPCFormat
  34 {
  35   wxIPC_INVALID =          0,
  36   wxIPC_TEXT =             1,  /* CF_TEXT */
  37   wxIPC_BITMAP =           2,  /* CF_BITMAP */
  38   wxIPC_METAFILE =         3,  /* CF_METAFILEPICT */
  39   wxIPC_SYLK =             4,
  40   wxIPC_DIF =              5,
  41   wxIPC_TIFF =             6,
  42   wxIPC_OEMTEXT =          7,  /* CF_OEMTEXT */
  43   wxIPC_DIB =              8,  /* CF_DIB */
  44   wxIPC_PALETTE =          9,
  45   wxIPC_PENDATA =          10,
  46   wxIPC_RIFF =             11,
  47   wxIPC_WAVE =             12,
  48   wxIPC_UNICODETEXT =      13,
  49   wxIPC_ENHMETAFILE =      14,
  50   wxIPC_FILENAME =         15, /* CF_HDROP */
  51   wxIPC_LOCALE =           16,
  52   wxIPC_PRIVATE =          20
  53 };
  54 \end{verbatim}
  55
  56 \wxheading{See also}
  57
  58 \helpref{wxDDEClient}{wxddeclient}, \helpref{wxDDEServer}{wxddeserver}, \helpref{Interprocess communications overview}{ipcoverview}
  59
  60 \latexignore{\rtfignore{\wxheading{Members}}}
  61
  62 \membersection{wxDDEConnection::wxDDEConnection}
  63
  64 \func{}{wxDDEConnection}{\void}
  65
  66 \func{}{wxDDEConnection}{\param{char* }{buffer}, \param{int}{ size}}
  67
  68 Constructs a connection object. If no user-defined connection object is
  69 to be derived from wxDDEConnection, then the constructor should not be
  70 called directly, since the default connection object will be provided on
  71 requesting (or accepting) a connection. However, if the user defines his
  72 or her own derived connection object, the \helpref{wxDDEServer::OnAcceptConnection}{wxddeserveronacceptconnection}\rtfsp
  73 and/or \helpref{wxDDEClient::OnMakeConnection}{wxddeclientonmakeconnection} members should be replaced by
  74 functions which construct the new connection object. If the arguments of
  75 the wxDDEConnection constructor are void, then a default buffer is
  76 associated with the connection. Otherwise, the programmer must provide a
  77 a buffer and size of the buffer for the connection object to use in
  78 transactions.
  79
  80 \membersection{wxDDEConnection::Advise}
  81
  82 \func{bool}{Advise}{\param{const wxString\& }{item}, \param{char* }{data}, \param{int}{ size = -1}, \param{wxIPCFormat}{ format = wxCF\_TEXT}}
  83
  84 Called by the server application to advise the client of a change in
  85 the data associated with the given item. Causes the client
  86 connection's \helpref{wxDDEConnection::OnAdvise}{wxddeconnectiononadvise}
  87 member to be called. Returns true if successful.
  88
  89 \membersection{wxDDEConnection::Execute}
  90
  91 \func{bool}{Execute}{\param{char* }{data}, \param{int}{ size = -1}, \param{wxIPCFormat}{ format = wxCF\_TEXT}}
  92
  93 Called by the client application to execute a command on the server. Can
  94 also be used to transfer arbitrary data to the server (similar
  95 to \helpref{wxDDEConnection::Poke}{wxddeconnectionpoke} in that respect). Causes the
  96 server connection's \helpref{wxDDEConnection::OnExecute}{wxddeconnectiononexecute} member to be
  97 called. Returns true if successful.
  98
  99 \membersection{wxDDEConnection::Disconnect}
 100
 101 \func{bool}{Disconnect}{\void}
 102
 103 Called by the client or server application to disconnect from the other
 104 program; it causes the \helpref{wxDDEConnection::OnDisconnect}{wxddeconnectionondisconnect} message
 105 to be sent to the corresponding connection object in the other
 106 program. The default behaviour of {\bf OnDisconnect} is to delete the
 107 connection, but the calling application must explicitly delete its
 108 side of the connection having called {\bf Disconnect}. Returns true if
 109 successful.
 110
 111 \membersection{wxDDEConnection::OnAdvise}\label{wxddeconnectiononadvise}
 112
 113 \func{virtual bool}{OnAdvise}{\param{const wxString\& }{topic}, \param{const wxString\& }{item}, \param{char* }{data}, \param{int}{ size}, \param{wxIPCFormat}{ format}}
 114
 115 Message sent to the client application when the server notifies it of a
 116 change in the data associated with the given item.
 117
 118 \membersection{wxDDEConnection::OnDisconnect}\label{wxddeconnectionondisconnect}
 119
 120 \func{virtual bool}{OnDisconnect}{\void}
 121
 122 Message sent to the client or server application when the other
 123 application notifies it to delete the connection. Default behaviour is
 124 to delete the connection object.
 125
 126 \membersection{wxDDEConnection::OnExecute}\label{wxddeconnectiononexecute}
 127
 128 \func{virtual bool}{OnExecute}{\param{const wxString\& }{topic}, \param{char* }{data}, \param{int}{ size}, \param{wxIPCFormat}{ format}}
 129
 130 Message sent to the server application when the client notifies it to
 131 execute the given data. Note that there is no item associated with
 132 this message.
 133
 134 \membersection{wxDDEConnection::OnPoke}\label{wxddeconnectiononpoke}
 135
 136 \func{virtual bool}{OnPoke}{\param{const wxString\& }{topic}, \param{const wxString\& }{item}, \param{char* }{data}, \param{int}{ size}, \param{wxIPCFormat}{ format}}
 137
 138 Message sent to the server application when the client notifies it to
 139 accept the given data.
 140
 141 \membersection{wxDDEConnection::OnRequest}\label{wxddeconnectiononrequest}
 142
 143 \func{virtual char*}{OnRequest}{\param{const wxString\& }{topic}, \param{const wxString\& }{item}, \param{int *}{size}, \param{wxIPCFormat}{ format}}
 144
 145 Message sent to the server application when the client
 146 calls \helpref{wxDDEConnection::Request}{wxddeconnectionrequest}. The server
 147 should respond by returning a character string from {\bf OnRequest},
 148 or NULL to indicate no data.
 149
 150 \membersection{wxDDEConnection::OnStartAdvise}\label{wxddeconnectiononstartadvise}
 151
 152 \func{virtual bool}{OnStartAdvise}{\param{const wxString\& }{topic}, \param{const wxString\& }{item}}
 153
 154 Message sent to the server application by the client, when the client
 155 wishes to start an `advise loop' for the given topic and item. The
 156 server can refuse to participate by returning false.
 157
 158 \membersection{wxDDEConnection::OnStopAdvise}\label{wxddeconnectiononstopadvise}
 159
 160 \func{virtual bool}{OnStopAdvise}{\param{const wxString\& }{topic}, \param{const wxString\& }{item}}
 161
 162 Message sent to the server application by the client, when the client
 163 wishes to stop an `advise loop' for the given topic and item. The
 164 server can refuse to stop the advise loop by returning false, although
 165 this doesn't have much meaning in practice.
 166
 167 \membersection{wxDDEConnection::Poke}\label{wxddeconnectionpoke}
 168
 169 \func{bool}{Poke}{\param{const wxString\& }{item}, \param{char* }{data}, \param{int}{ size = -1}, \param{wxIPCFormat}{ format = wxCF\_TEXT}}
 170
 171 Called by the client application to poke data into the server. Can be
 172 used to transfer arbitrary data to the server. Causes the server
 173 connection's \helpref{wxDDEConnection::OnPoke}{wxddeconnectiononpoke} member
 174 to be called. Returns true if successful.
 175
 176 \membersection{wxDDEConnection::Request}\label{wxddeconnectionrequest}
 177
 178 \func{char*}{Request}{\param{const wxString\& }{item}, \param{int *}{size}, \param{wxIPCFormat}{ format = wxIPC\_TEXT}}
 179
 180 Called by the client application to request data from the server. Causes
 181 the server connection's \helpref{wxDDEConnection::OnRequest}{wxddeconnectiononrequest} member to be called. Returns a
 182 character string (actually a pointer to the connection's buffer) if
 183 successful, NULL otherwise.
 184
 185 \membersection{wxDDEConnection::StartAdvise}\label{wxddeconnectionstartadvise}
 186
 187 \func{bool}{StartAdvise}{\param{const wxString\& }{item}}
 188
 189 Called by the client application to ask if an advise loop can be started
 190 with the server. Causes the server connection's \helpref{wxDDEConnection::OnStartAdvise}{wxddeconnectiononstartadvise}\rtfsp
 191 member to be called. Returns true if the server okays it, false
 192 otherwise.
 193
 194 \membersection{wxDDEConnection::StopAdvise}\label{wxddeconnectionstopadvise}
 195
 196 \func{bool}{StopAdvise}{\param{const wxString\& }{item}}
 197
 198 Called by the client application to ask if an advise loop can be
 199 stopped. Causes the server connection's \helpref{wxDDEConnection::OnStopAdvise}{wxddeconnectiononstopadvise} member
 200 to be called. Returns true if the server okays it, false otherwise.
 201