/////////////////////////////////////////////////////////////////////////////////////////////// 
// Win32 Communications Library for COM and USB 
// Developed for the JRCX Project 
// for the ÒThinking Outside the (Desktop) BoxÓ MindStorms/NSF Project 
// Author        : Drew Jacobs 
// Institution: Villanova University 
// Last Revision : 07/22/03 
// Permission is granted to distribute or modify this software for academic use 
// as long as this original authorship notice is retained in the source code. 
//////////////////////////////////////////////////////////////////////////////////////////////// 
 
#include <stdio.h> 
#include <windows.h> 
 
#include "jni.h" 
#include "Communicator.h" 
 
#define WIN32_LEAN_AND_MEAN 
#define DEBUG 1 
 
////////////////////////////////////////////////////////////// 
 
HANDLE hPortFile; 
bool bOpen = false; 
 
////////////////////////////////////////////////////////////// 
 
JNIEXPORT jboolean JNICALL Java_Communicator_openPort (JNIEnv *env, jobject obj, jstring port) 
{ 
 if (bOpen)  
 { 
  if (DEBUG) printf("WARNING: Port Already Open"); 
  return true; 
 } 
 
 const char *str = env->GetStringUTFChars(port, 0); 
  
 hPortFile = CreateFile(str, GENERIC_READ | GENERIC_WRITE, 0, 0, OPEN_EXISTING, 
FILE_ATTRIBUTE_NORMAL, 0); 
 if (hPortFile == INVALID_HANDLE_VALUE) 
  return false; 
 
  
 PurgeComm(hPortFile, PURGE_TXCLEAR | PURGE_RXCLEAR); 
 bOpen=true; 
 return true; 
} 
 
////////////////////////////////////////////////////////////// 
 
JNIEXPORT jboolean JNICALL Java_Communicator_setCommProperties (JNIEnv *ev, jobject obj, jint baud) 
{ 
 DCB dcb; 
 
    dcb.DCBlength = sizeof(DCB);                // sizeof(DCB)  
 
    if(!GetCommState(hPortFile, &dcb))  
  return false; 
 
    dcb.BaudRate = CBR_2400; 
    dcb.fBinary = TRUE; 
    dcb.fOutxCtsFlow = FALSE; 
    dcb.fOutxDsrFlow = FALSE; 
    dcb.fDtrControl = DTR_CONTROL_DISABLE;      // DTR flow control type  
    dcb.fDsrSensitivity = FALSE;                // DSR sensitivity  
    //dcb.fTXContinueOnXoff = 0;                // XOFF continues Tx  
    dcb.fOutX = FALSE;                          // XON/XOFF out flow control  
    dcb.fInX = FALSE;                           // XON/XOFF in flow control  
    //dcb.fErrorChar = 0;                       // enable error replacement  
    dcb.fNull = FALSE;                          // enable null stripping  
    dcb.fRtsControl = RTS_CONTROL_DISABLE;      // RTS flow control  
    dcb.fAbortOnError = FALSE;                  // abort reads/writes on error  
    //dcb.XonLim = 100; 
    //dcb.XoffLim = 100; 
    dcb.ByteSize = 8;                           // number of bits/byte, 4-8  
    dcb.Parity = ODDPARITY;            // 0-4=no,odd,even,mark,space  
    dcb.StopBits = ONESTOPBIT;           // 0,1,2 = 1, 1.5, 2  
    //dcb.XonChar = 1; 
    //dcb.XoffChar = 2; 
    //dcb.ErrorChar = 0; 
    //dcb.EofChar = 0; 
    //dcb.EvtChar = 0; 
 
 dcb.fParity = TRUE; 
 
    return SetCommState(hPortFile, &dcb); 
} 
 
////////////////////////////////////////////////////////////// 
 
JNIEXPORT jboolean JNICALL Java_Communicator_write (JNIEnv *env, jobject obj, jbyteArray 
sendPacket) 
{ 
 DWORD numBytes; 
 DWORD numWritten; 
 jbyte* packet; 
 
 numBytes = env->GetArrayLength(sendPacket); 
  
 packet = env->GetByteArrayElements(sendPacket, 0); 
 
 WriteFile(hPortFile, packet, numBytes, &numWritten, (struct _OVERLAPPED *)NULL); 
 
 env->ReleaseByteArrayElements(sendPacket, packet, 0); 
   
 FlushFileBuffers(hPortFile); 
 
 if (numWritten != numBytes) 
  return false; 
 
 return true; 
} 
 
////////////////////////////////////////////////////////////// 
 
JNIEXPORT jbyte JNICALL Java_Communicator_read (JNIEnv *env, jobject obj) 
{ 
 jbyte* ji = new jbyte[1]; 
 DWORD numRead; 
 
 if (!ReadFile(hPortFile, ji, 1, &numRead, (struct _OVERLAPPED *)NULL)) 
 { 
  DWORD Error = GetLastError(); 
  DWORD Errors; 
  COMSTAT cstat; 
  ClearCommError(hPortFile, &Errors, &cstat); 
 
  jclass jc = env->FindClass("jRCX/RCXException"); 
  if (jc==0) 
      return 0; 
  env->ThrowNew(jc, "ReadFile Generated an Error while attempting to Read"); 
  ji[0]=0; 
 } 
 
 if (numRead == 0) 
 { 
  jclass jc = env->FindClass("jRCX/RCXException"); 
  if (jc==0) 
      return 0; 
                   env->ThrowNew(jc, "ReadFile failed to read any bytes"); 
  ji[0]=0; 
 } 
  
 return ji[0]; 
} 
 
////////////////////////////////////////////////////////////// 
 
JNIEXPORT jboolean JNICALL Java_Communicator_setTimeout (JNIEnv *env, jobject obj, jint timeout) 
{ 
 COMMTIMEOUTS timeouts; 
 
 timeouts.ReadIntervalTimeout = 20; 
 timeouts.ReadTotalTimeoutMultiplier = 1; 
 timeouts.WriteTotalTimeoutMultiplier = 0;  
 timeouts.WriteTotalTimeoutConstant = 0; 
 timeouts.ReadTotalTimeoutConstant = timeout; 
 
 if(!SetCommTimeouts(hPortFile, &timeouts)) { return false; } 
 return true; 
} 
 
////////////////////////////////////////////////////////////// 
  
JNIEXPORT jboolean JNICALL Java_Communicator_closePort (JNIEnv *env, jobject obj) 
{ 
 if (!bOpen)  
 { 
  if (DEBUG) printf("WARNING: Port Already Closed"); 
  return true; 
 } 
 CloseHandle(hPortFile); 
 bOpen = false; 
 return true; 
}