// inherit12.cpp  		By: Aiman Hanna -  ©1993-2002 Aiman Hanna

// This program illustrates why virtual functions are needed.
// Actually the program shows how we would implement our code if 
// we were not capable of using virtual functions.
// Notice the increase of the amount of the code, as a result.

#include "inherit12.h"

// Definition of Vehicle's member functions

Vehicle::Vehicle( void )
{
 cout << " \n Vehicle...Executing the default constructor of the Vehicle class." << "\n";
	color = green;	     
	numcyl = 4;
	name = "VEC";		    
}




Vehicle::Vehicle( avl_colors clr, int cyl, char* nm )
{      
 cout << "\n Vehicle...Executing the parameterized constructor of the Vehicle class."  << "\n";
	color = clr;
	numcyl = cyl;	     
	name = nm;    
} 




void Vehicle::ShowInfo( void )
{
	// Is the following information enough?
	cout << " Vehicle....Here is all the known information: " << "\n";	
	cout << " The vehicle color is: " << GetColor( ) << ",\n";
	cout << " and the number of cylinders is: " << GetNumCyl( )  << "\n\n\n";
}




int Vehicle::GetNumCyl( void )
{
 return numcyl;

}


char* Vehicle::GetColor( void )
{
 switch ( color )
 {
  case red:    return "red";  
  case black:  return "black";
  case white:  return "white";
  case green:  return "green";
 }
return "unknown";
}


char* Vehicle::GetName( void )
{
 return name;
}




// Define Bus's member functions

Bus::Bus( avl_colors aclr, int cyl, yes_no bar, char* nm ) : 
			Vehicle( aclr, cyl, nm )
{
 cout << " Bus...Executing the constructor of the bus class. " << "\n";

 barexist = bar;

}


void Bus::ShowInfo( void )
{
 // Bus had to redefine this function to include its specific information
 cout << " Bus...Here is all the needed information: " << "\n";
 cout << " The bus color is: " << GetColor( ) << ",\n";
 cout << " the number of cylinders is: " << GetNumCyl( )  << ",\n";
 if ( HasBar( ) == yes )
 	cout << " and the bus has a bar. " << "\n\n\n";
 else
	cout << " and the bus does not have a bar. " << "\n\n\n";

}


yes_no Bus::HasBar ( void )
{
 return barexist;
}





// Define Van's mamber functions

Van::Van( avl_colors aclr, int cyl, yes_no tur, char* nm ) : 
			       Bus( aclr, cyl, no, nm )   // always no bar
{
 cout << " Van...Executing the constructor of the Van class. " << "\n\n\n";
 turbo = tur;

}




void Van::ShowInfo( void )
{
 // Van had to redefine this function to include its specific information
 cout << " Van...Here is all the needed information: " << "\n";
 cout << " The van color is: " << GetColor( ) << ",\n";
 cout << " the number of cylinders is: " << GetNumCyl( )  << ",\n";
 if ( IsTurbo( ) == yes )
 	cout << " and the van is turbo " << "\n\n\n";
 else
	cout << " and the van is not turbo. " << "\n\n\n";

}



yes_no Van::IsTurbo( void )
{
return turbo;
}




int main( void )
{

Vehicle *Vec_arr[6];

Bus     bs1( white, 12, yes );
Van     vn1( black, 8, yes );
Van     vn2( white, 6, no );
Bus     bs2( green, 12, no );
Bus     bs3( black, 8, yes );
Bus     bs4( red, 8, no );


Vec_arr[0] = &bs1;
Vec_arr[1] = &vn1; 
Vec_arr[2] = &vn2;
Vec_arr[3] = &bs2;
Vec_arr[4] = &bs3;
Vec_arr[5] = &bs4;			
			
// It becomes the programmer's responsibility to determine 
// the derived class type addressed by the Vehicle pointer.
// Notice the need of the knowledge of type representation. Burden 
// of type resolution is on the programmer's code. 
			
for ( int counter = 0; counter < 6; counter++ )
{   	
		// Note that strcmp() returns zero if strings are the same
	if ( !strcmp( Vec_arr[ counter ] -> GetName( ), "BUS" ) )		
		((Bus* )Vec_arr[ counter  ]) ->ShowInfo( );
	else if ( !strcmp( Vec_arr[ counter ] -> GetName( ), "VAN" ) )
		((Van*)Vec_arr[ counter ]) ->ShowInfo( );
 
/* This will need to be repeated for all other derived classes....
//  	.
//	.
//	.
//	. .........etc.
*/

}

return 0;
}





// The result of running the program is as follow:
/*
 Vehicle...Executing the parameterized constructor of the Vehicle class.
 Bus...Executing the constructor of the bus class. 

 Vehicle...Executing the parameterized constructor of the Vehicle class.
 Bus...Executing the constructor of the bus class. 
 Van...Executing the constructor of the Van class. 



 Vehicle...Executing the parameterized constructor of the Vehicle class.
 Bus...Executing the constructor of the bus class. 
 Van...Executing the constructor of the Van class. 



 Vehicle...Executing the parameterized constructor of the Vehicle class.
 Bus...Executing the constructor of the bus class. 

 Vehicle...Executing the parameterized constructor of the Vehicle class.
 Bus...Executing the constructor of the bus class. 

 Vehicle...Executing the parameterized constructor of the Vehicle class.
 Bus...Executing the constructor of the bus class. 
 Bus...Here is all the needed information: 
 The bus color is: white,
 the number of cylinders is: 12,
 and the bus has a bar. 


 Van...Here is all the needed information: 
 The van color is: black,
 the number of cylinders is: 8,
 and the van is turbo 


 Van...Here is all the needed information: 
 The van color is: white,
 the number of cylinders is: 6,
 and the van is not turbo. 


 Bus...Here is all the needed information: 
 The bus color is: green,
 the number of cylinders is: 12,
 and the bus does not have a bar. 


 Bus...Here is all the needed information: 
 The bus color is: black,
 the number of cylinders is: 8,
 and the bus has a bar. 


 Bus...Here is all the needed information: 
 The bus color is: red,
 the number of cylinders is: 8,
 and the bus does not have a bar. 

*/