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libtdevnc/client_examples/backchannel.c

100 lines
2.2 KiB

/* A simple example of an RFB client */
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <errno.h>
#include <rfb/rfbclient.h>
static void HandleRect(rfbClient* client, int x, int y, int w, int h) {
}
/*
* The client part of the back channel extension example.
*
*/
#define rfbBackChannel 155
typedef struct backChannelMsg {
uint8_t type;
uint8_t pad1;
uint16_t pad2;
uint32_t size;
} backChannelMsg;
static void sendMessage(rfbClient* client, char* text)
{
backChannelMsg msg;
uint32_t length = strlen(text)+1;
msg.type = rfbBackChannel;
msg.size = rfbClientSwap32IfLE(length);
if(!WriteToRFBServer(client, (char*)&msg, sizeof(msg)) ||
!WriteToRFBServer(client, text, length)) {
rfbClientLog("enableBackChannel: write error (%d: %s)", errno, strerror(errno));
}
}
static rfbBool handleBackChannelMessage(rfbClient* client,
rfbServerToClientMsg* message)
{
backChannelMsg msg;
char* text;
if(message->type != rfbBackChannel)
return FALSE;
rfbClientSetClientData(client, sendMessage, sendMessage);
if(!ReadFromRFBServer(client, ((char*)&msg)+1, sizeof(msg)-1))
return TRUE;
msg.size = rfbClientSwap32IfLE(msg.size);
text = malloc(msg.size);
if(!ReadFromRFBServer(client, text, msg.size)) {
free(text);
return TRUE;
}
rfbClientLog("got back channel message: %s\n", text);
free(text);
return TRUE;
}
static int backChannelEncodings[] = { rfbBackChannel, 0 };
static rfbClientProtocolExtension backChannel = {
backChannelEncodings, /* encodings */
NULL, /* handleEncoding */
handleBackChannelMessage, /* handleMessage */
NULL /* next extension */
};
int
main(int argc, char **argv)
{
rfbClient* client = rfbGetClient(8,3,4);
client->GotFrameBufferUpdate = HandleRect;
rfbClientRegisterExtension(&backChannel);
if (!rfbInitClient(client,&argc,argv))
return 1;
while (1) {
/* After each idle second, send a message */
if(WaitForMessage(client,1000000)>0)
HandleRFBServerMessage(client);
else if(rfbClientGetClientData(client, sendMessage))
sendMessage(client, "Dear Server,\n"
"thank you for understanding "
"back channel messages!");
}
rfbClientCleanup(client);
return 0;
}