NDEF NFC library

Diff: NDefNfcTag.h

Revision:

8:473f6e0b03df

Child:

9:689c1f56f359

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/NDefNfcTag.h	Tue Dec 22 15:34:06 2015 +0000
@@ -0,0 +1,172 @@
+/**
+ ******************************************************************************
+ * @file    Type4NfcTag.h
+ * @author  ST / Central Labs
+ * @version V1.0.0
+ * @date    1 Nov 2015
+ * @brief   Generic interface that a device must implement for use the NDefLib
+ ******************************************************************************
+ * @attention
+ *
+ * <h2><center>&copy; COPYRIGHT(c) 2015 STMicroelectronics</center></h2>
+ *
+ * Redistribution and use in source and binary forms, with or without modification,
+ * are permitted provided that the following conditions are met:
+ *   1. Redistributions of source code must retain the above copyright notice,
+ *      this list of conditions and the following disclaimer.
+ *   2. Redistributions in binary form must reproduce the above copyright notice,
+ *      this list of conditions and the following disclaimer in the documentation
+ *      and/or other materials provided with the distribution.
+ *   3. Neither the name of STMicroelectronics nor the names of its contributors
+ *      may be used to endorse or promote products derived from this software
+ *      without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ ******************************************************************************
+ */
+#ifndef NDefNFCTAG_H_
+#define NDefNFCTAG_H_
+
+#include "NDefLib/Message.h"
+
+namespace NDefLib {
+
+/**
+ * Abstract class used for write/read NDef message in an nfc tag
+ */
+class NDefNfcTag {
+public:
+
+	NDefNfcTag():mSessionIsOpen(false){}
+
+	/**
+	 * open the communication with the nfc tag
+	 * \par when override this method call this implementation as last action for set the session opened
+	 * @param force force to open a communication
+	 * @return true if success
+	 */
+	virtual bool openSession(bool force = false){
+		mSessionIsOpen=true;
+		return true;
+	}
+
+	/**
+	 * close the communication with the nfc tag
+	 * \par when override this method call this implementation as last action for set the session closed
+	 * @return true if success
+	 */
+	virtual bool closeSession(){
+		mSessionIsOpen=false;
+		return true;
+	}
+
+	/**
+	 * write a message in the nfc tag, this call will delete the previous message
+	 * @param msg message to write
+	 * @return true if success
+	 */
+	bool write(const Message &msg) {
+		if(!mSessionIsOpen)
+			return false;
+
+		const uint16_t length = msg.getByteLength();
+		uint8_t *buffer = new uint8_t[length];
+		if(buffer==NULL) //impossible allocate the buffer for write the message
+			return false;
+		msg.write(buffer);
+		bool retValue = writeByte(buffer, length);
+		delete[] buffer;
+		return retValue;
+	}
+
+	/**
+	 * read a message from the tag
+	 * @param[in,out] msg message object where we will add the record read by the
+	 * tag
+	 * @return true if success
+	 */
+	bool read(Message *msg) {
+		if(!mSessionIsOpen)
+			return false;
+
+		uint16_t length = getMessageLength();
+		if (length == 0)
+			return false;
+		//else
+		uint8_t *buffer = new uint8_t[length];
+		if(buffer==NULL)
+			return false;
+
+		//read all the message content
+		bool retValue = readByte(2, length, buffer);
+		if (retValue) {
+			Message::parseMessage(buffer, length, msg);
+		}
+		delete[] buffer;
+		return retValue;
+	}
+
+	virtual ~NDefNfcTag() {}
+
+	/**
+	 * true if we have a communication open with the nfc tag
+	 * @return
+	 */
+	bool isSessionOpen(){
+		return mSessionIsOpen;
+	}
+
+
+protected:
+
+	/**
+	 * write a sequence of byte in the NDEF file
+	 * @param buffer buffer to write
+	 * @param length number of byte to write
+	 * @param offset offset where start to write
+	 * @return true if success
+	 */
+	virtual bool writeByte(const uint8_t *buffer, uint16_t length, uint16_t offset=0)=0;
+
+	/**
+	 * read a sequence of byte from the NDEF file
+	 * @param byteOffset offset were start read
+	 * @param byteLength number of byte to read
+	 * @param buffer buffer where store the data read
+	 * @return true if success
+	 */
+	virtual bool readByte(const uint16_t byteOffset, const uint16_t byteLength,
+			uint8_t *buffer)=0;
+
+private:
+	/**
+	 * variable to set when we open/close a communication channel with the tag
+	 */
+	bool mSessionIsOpen;
+
+	/**
+	 * read the NDEF message length
+	 * @return NDEF message length
+	 */
+	uint16_t getMessageLength() {
+		uint8_t lenghtByte[2];
+		if (readByte(0, 2, lenghtByte))
+			return (((uint16_t) lenghtByte[0]) << 8 | lenghtByte[1]);
+		return 0;
+	} //getMessageLength
+
+};
+
+} /* namespace NDefLib */
+
+#endif /* NDefNFCTAG_H_ */