/**
 * command.h
 * Implemented by Blueprint Technologies, Inc.
 */

#ifndef _command_h
#define _command_h

/**
 * Declares an interface for executing an operation.
 */

class Command
{

public:
	virtual void execute() = 0;

};

/**
 * Knows how to perform the operations associated with
 * carrying out a request. Any class may serve as a Receiver.
 */

class Receiver
{

public:
	virtual void action()
	{
	};

};

/**
 * Defines a binding between a Receiver object and an
 * action. Implements 'execute' by invoking the corresponding
 * operation on Receiver.
 */

class ConcreteCommand: public Command
{

private:
	Receiver* receiver;

public:
	ConcreteCommand(): Command(), receiver(0)
	{
	};

	virtual void execute()
	{
		receiver -> action();
	};

	Receiver* getReceiver()
	{
		return receiver;
	};

	void setReceiver( Receiver* receiver )
	{
		this -> receiver = receiver;
	};

};

/**
 * Asks the command to carry out the request.
 */

class Invoker
{

private:
	Command* command;

public:
	Invoker(): command(0) {};

	void invoke()
	{
		if( command )
		{
			command -> execute();
		}
	};

	Command* getCommand()
	{
		return command;
	};

	void setCommand( Command* command )
	{
		this -> command = command;
	}
};

#endif