thoughts on message queuee message

new interface. What if there are MQ messages with different sizes?
-> generic interface

furthermore, maybe command message should be refactored to operate
on a mq message instead of implementing it

ipc/CommandMessage.h

@@ -28,7 +28,8 @@ public:
 	static const Command_t REPLY_REJECTED = MAKE_COMMAND_ID( 0xD1 );
 
 	/**
-	 * This is the size of a message as it is seen by the MessageQueue
+	 * This is the size of a message as it is seen by the MessageQueue.
+	 * 14 of the 24 available MessageQueueMessage bytes are used.
 	 */
 	static const size_t COMMAND_MESSAGE_SIZE = HEADER_SIZE
 			+ sizeof(Command_t) + 2 * sizeof(uint32_t);

ipc/MessageQueueMessage.h

@@ -1,6 +1,7 @@
 #ifndef MESSAGEQUEUEMESSAGE_H_
 #define MESSAGEQUEUEMESSAGE_H_
 
+#include <framework/ipc/MessageQueueMessageIF.h>
 #include <framework/ipc/MessageQueueSenderIF.h>
 #include <stddef.h>
 
@@ -23,7 +24,7 @@
  *	receive messages from other tasks.
  *	@ingroup message_queue
  */
-class MessageQueueMessage {
+class MessageQueueMessage: public MessageQueueMessageIF {
 public:
 	/**
 	 * @brief	The class is initialized empty with this constructor.
@@ -43,6 +44,7 @@ public:
 	 * 				MAX_MESSAGE_SIZE and larger than MIN_MESSAGE_SIZE.
 	 */
 	MessageQueueMessage(uint8_t* data, size_t size);
+
 	/**
 	 * @brief	The size information of each message is stored in this attribute.
 	 * @details

ipc/MessageQueueMessageIF.h

@@ -0,0 +1,44 @@
+#ifndef FRAMEWORK_IPC_MESSAGEQUEUEMESSAGEIF_H_
+#define FRAMEWORK_IPC_MESSAGEQUEUEMESSAGEIF_H_
+#include <framework/ipc/MessageQueueSenderIF.h>
+#include <cstddef>
+
+class MessageQueueMessageIF {
+public:
+	virtual ~MessageQueueMessageIF() {};
+
+	/**
+	 * @brief	With this method, the whole content and the message
+	 * 			size is set to zero.
+	 */
+	virtual void clear() = 0;
+	/**
+	 * @brief	This is a debug method that prints the content
+	 * 			(till messageSize) to the debug output.
+	 */
+	virtual void print() = 0;
+	virtual const uint8_t* getBuffer() const = 0;
+	/**
+	 * @brief	This method is used to get the complete data of the message.
+	 */
+	virtual uint8_t* getBuffer() = 0;
+	/**
+	 * @brief	This method is used to set the sender's message queue id
+	 * 			information prior to sending the message.
+	 * @param setId	The message queue id that identifies the sending message queue.
+	 */
+	virtual void setSender(MessageQueueId_t setId) = 0;
+	/**
+	 * @brief	This helper function is used by the MessageQueue class to
+	 * 			check the size of an incoming message.
+	 * @details
+	 * The method must be overwritten by child classes if size checks shall
+	 * be more strict.
+	 * @return	The default implementation returns HEADER_SIZE.
+	 */
+	virtual size_t getMinimumMessageSize() = 0;
+};
+
+
+
+#endif /* FRAMEWORK_IPC_MESSAGEQUEUEMESSAGEIF_H_ */