NetworkNode.h

///
/// NetworkNode.h 
///
/// Handle incoming network messages.
///
 
#ifndef NO_NETWORK
 
#ifndef __NETWORK_NODE_H__
#define __NETWORK_NODE_H__
 
// Engine includes.
#include "EventKeyboard.h"
#include "EventMouse.h"
#include "EventNetwork.h"
#include "Object.h"
 
namespace df {
 
// Network message types.
enum class MessageType {
  UNDEFINED_MESSAGE=-1,
  SYNC_OBJECT,    // Create or update object, as appropriate.
  DELETE_OBJECT,  // Delete object.
  GAME_OVER,      // Indicate game over.
  KEYBOARD_INPUT, // Keyboard event.
  MOUSE_INPUT,    // Mouse event.
  CUSTOM_MESSAGE, // Game code defined.
};
 
// HEADER:
// 0) Total size is an int (total number of bytes in message).
// 1) Message type is an int (an enum).
 
// SYNC_OBJECT:
// 2) Object id as int.
// 3) String length as int.
// 4) Object type as string.
// 5) Serialized Object data (string of bytes).
 
// DELETE_OBJECT:
// 2) Object id as int.
 
// SET_GAME_OVER:
// (nothing)
 
// KEYBOARD:
// 2) Keyboard action as int (a EventKeyboardAction enum).
// 3) Key as int (a Keyboard::Key enum).
 
// MOUSE:
// 2) Mouse action as int (a EventMouseAction enum).
// 3) Mouse button as int (a Mouse::Button enum).
// 4) Mouse-x as float.
// 5) Mouse-y as float.
 
// CUSTOM:
// 2) Bytes as blob.
 
class NetworkNode : public Object {
 
 protected:
  char *m_p_buff;   // Data buffer for network communication.
  int m_buff_size;  // Number of bytes allocated.
  
 public:
  NetworkNode();
  ~NetworkNode();
 
  /// Handle network and step events.
  /// Step events: call genDataEvents().
  /// Network events: if type DATA, call handleData().
  /// Return 1 if handled, else 0 if ignored.
  virtual int eventHandler(const Event *p_e) override;
 
  /// Handle and generate events based on type.
  /// GAME_OVER: generate game over network event.
  /// DELETE: markForDelete() and generate delete network event.
  /// SYNC: create if needed, then deserialize and generate sync network event.
  /// KEYBOARD: generate send keyboard network event.
  /// MOUSE: generate send mouse network event.
  /// CUSTOM: generate custom network event.
  /// Return 1 if handled, else 0 if ignored.
  virtual int handleData(const EventNetwork *p_e);
 
  ////////////////////////////////////////////////////////////
  /// Send message (supporting various message types).
 
  /// Send message from Server to Client.
  /// SET_GAME_OVER
  /// Return 1 if something sent, 0 if nothing sent, -1 if error.
  int sendMessage(MessageType msg_type, int sock=-1);
 
  /// Send message from Server to Client.
  /// SYNC_OBJECT or DELETE_OBJECT
  /// Synchronize attr, passed to serialize() (default is sync all).
  /// Return 1 if something sent, 0 if nothing sent, -1 if error.
  int sendMessage(MessageType msg_type, Object *p_obj,
                  unsigned int attr=0, int sock=-1);
 
  /// Send message from Client to Server.
  /// KEYBOARD_INPUT
  /// Return 1 if something sent, 0 if nothing sent, -1 if error.
  int sendMessage(MessageType msg_type, EventKeyboardAction action,
                  Keyboard::Key key, int sock=-1);
 
  /// Send message from Client to Server.
  /// MOUSE_INPUT
  /// Return 1 if something sent, 0 if nothing sent, -1 if error.
  int sendMessage(MessageType msg_type, EventMouseAction action,
                  Mouse::Button button, Vector mouse_position,
                  int sock=-1);
 
  /// Send message from either Client to Server or Server to Client.
  /// CUSTOM_MESSAGE
  /// Return 1 if something sent, 0 if nothing sent, -1 if error.
  int sendMessage(MessageType msg_type, int num_bytes, const void *bytes, 
                  int sock=-1);
 
  ////////////////////////////////////////////////////////////
 
  /// Called each step to generate data events, when appropriate.  If
  /// complete network message, (first int is message size, in bytes)
  /// generate EventNetwork (DATA).  Return 1 if generated event, 0 if
  /// no message complete message, -1 if error.
  int genDataEvents(int sock=0) const;
 
  ////////////////////////////////////////////////////////////
 
  /// Create (new) Object of given type.
  /// Return pointer to Object (NULL if creation failed).
  virtual Object *createObject(std::string object_type);
  
 private:
 
  /// Increase size of network message buffer (if needed).
  /// Return 0 if ok, else -1 if error.
  int sizeBuffer(int msg_size);
 
  /// Prepare message buffer and header.
  /// Return 0 if ok, else -1 if error.
  int prepMessageHeader(MessageType msg_type, int msg_size);
};
 
} // end of namespace df
 
#endif // __NETWORK_NODE_H__
 
#endif // NO_NETWORK