Add support for set/clear BREAK/RTS/DTR signals in Windows.

src/main/c/Windows/SerialPort_Windows.c

@@ -629,4 +629,52 @@ JNIEXPORT jint JNICALL Java_com_fazecast_jSerialComm_SerialPort_writeBytes(JNIEn
 	return (result == TRUE) ? numBytesWritten : -1;
 }
 
+JNIEXPORT void JNICALL Java_com_fazecast_jSerialComm_SerialPort_setBreak(JNIEnv *env, jobject obj, jlong serialPortFD)
+{
+	HANDLE serialPortHandle = (HANDLE)serialPortFD;
+	if (serialPortHandle == INVALID_HANDLE_VALUE)
+		return;
+	SetCommBreak(serialPortHandle);
+}
+
+JNIEXPORT void JNICALL Java_com_fazecast_jSerialComm_SerialPort_clearBreak(JNIEnv *env, jobject obj, jlong serialPortFD)
+{
+	HANDLE serialPortHandle = (HANDLE)serialPortFD;
+	if (serialPortHandle == INVALID_HANDLE_VALUE)
+		return;
+	ClearCommBreak(serialPortHandle);
+}
+
+JNIEXPORT void JNICALL Java_com_fazecast_jSerialComm_SerialPort_setRTS(JNIEnv *env, jobject obj, jlong serialPortFD)
+{
+	HANDLE serialPortHandle = (HANDLE)serialPortFD;
+	if (serialPortHandle == INVALID_HANDLE_VALUE)
+		return;
+	EscapeCommFunction(serialPortHandle, SETRTS);
+}
+
+JNIEXPORT void JNICALL Java_com_fazecast_jSerialComm_SerialPort_clearRTS(JNIEnv *env, jobject obj, jlong serialPortFD)
+{
+	HANDLE serialPortHandle = (HANDLE)serialPortFD;
+	if (serialPortHandle == INVALID_HANDLE_VALUE)
+		return;
+	EscapeCommFunction(serialPortHandle, CLRRTS);
+}
+
+JNIEXPORT void JNICALL Java_com_fazecast_jSerialComm_SerialPort_setDTR(JNIEnv *env, jobject obj, jlong serialPortFD)
+{
+	HANDLE serialPortHandle = (HANDLE)serialPortFD;
+	if (serialPortHandle == INVALID_HANDLE_VALUE)
+		return;
+	EscapeCommFunction(serialPortHandle, SETDTR);
+}
+
+JNIEXPORT void JNICALL Java_com_fazecast_jSerialComm_SerialPort_clearDTR(JNIEnv *env, jobject obj, jlong serialPortFD)
+{
+	HANDLE serialPortHandle = (HANDLE)serialPortFD;
+	if (serialPortHandle == INVALID_HANDLE_VALUE)
+		return;
+	EscapeCommFunction(serialPortHandle, CLRDTR);
+}
+
 #endif

src/main/java/com/fazecast/jSerialComm/SerialPort.java

@@ -175,13 +175,13 @@ public final class SerialPort
 				FileOutputStream destinationFileContents = new FileOutputStream(tempNativeLibrary);
 				byte transferBuffer[] = new byte[4096];
 				int numBytesRead;
-	
+
 				while ((numBytesRead = fileContents.read(transferBuffer)) > 0)
 					destinationFileContents.write(transferBuffer, 0, numBytesRead);
-	
+
 				fileContents.close();
 				destinationFileContents.close();
-				
+
 				// Load native library
 				System.load(tempFileName);
 				initializeLibrary();
@@ -189,7 +189,7 @@ public final class SerialPort
 		}
 		catch (Exception e) { e.printStackTrace(); }
 	}
-	
+
 	// Static symbolic link testing function
 	private static boolean isSymbolicLink(File file) throws IOException
 	{
@@ -227,7 +227,7 @@ public final class SerialPort
 			// Resolve home directory ~
 			if (portDescriptor.startsWith("~" + File.separator))
 				portDescriptor = System.getProperty("user.home") + portDescriptor.substring(1);
-			
+
 			// See what kind of descriptor was passed in
 			if (isWindows)
 				portDescriptor = "\\\\.\\" + portDescriptor.substring(portDescriptor.lastIndexOf('\\')+1);
@@ -448,6 +448,12 @@ public final class SerialPort
 	private final native int bytesAwaitingWrite(long portHandle);		// Returns number of bytes still waiting to be written
 	private final native int readBytes(long portHandle, byte[] buffer, long bytesToRead);	// Reads bytes from serial port
 	private final native int writeBytes(long portHandle, byte[] buffer, long bytesToWrite);	// Write bytes to serial port
+	private final native void setBreak(long portHandle);
+	private final native void clearBreak(long portHandle);
+	private final native void setRTS(long portHandle);
+	private final native void clearRTS(long portHandle);
+	private final native void setDTR(long portHandle);
+	private final native void clearDTR(long portHandle);
 
 	/**
 	 * Returns the number of bytes available without blocking if {@link #readBytes} were to be called immediately
@@ -496,6 +502,15 @@ public final class SerialPort
 	 */
 	public final int writeBytes(byte[] buffer, long bytesToWrite) { return writeBytes(portHandle, buffer, bytesToWrite); }
 
+	public final void setBreak()   { setBreak(portHandle); }
+	public final void clearBreak() { clearBreak(portHandle); }
+
+	public final void setRTS()   { setRTS(portHandle); }
+	public final void clearRTS() { clearRTS(portHandle); }
+
+	public final void setDTR()   { setDTR(portHandle); }
+	public final void clearDTR() { clearDTR(portHandle); }
+
 	// Default Constructor
 	private SerialPort() {}