public class calculatorCalculations
{
	
	private double totalNum = 0d;
	private double regA = 0d, regB = 0d; //Temporary registers for percentage or double operations
	private boolean blank = true; //If no values have been previously stored
	
	public void calculatorCalculations ()
	{
	}
	
	public double getTotalNum ()
	{
		return totalNum;
	}
	
	public String toString ()
	{
		return Double.toString(totalNum);
	}
	
	public boolean isBlank ()
	{
		return blank;
	}
	
	public void reset ()
	{
		
		totalNum = regA = regB = 0d;
		blank = true;
				
	}
	
	public void performPercentCalculation (char operation) //After a percent has been used, pressing equals button calls this
	{
		
		totalNum = regA;
		totalNum = performCalculation((regA / 100) * regB, operation);
		
	}
		
	
	public void performNormalCalculation (double secondNum, char operation) //Standard operations
	{		
		totalNum = performCalculation(secondNum, operation);		
	}
	
	public void performSpecialCalculation (double currentNumber, char operation)
	{
		
		if (blank)
		{
			
			totalNum = currentNumber;
			totalNum = performCalculation(0, operation);

		}
		else
		{
			
			regA = totalNum;			
			totalNum = currentNumber;
			totalNum = regA + performCalculation(0, operation);
			
		}			
		
	}
	
	private double performCalculation (double secondNum, char operation)
	{
		
		blank = false;
		
		switch (operation)
		{
			
			case '+':	return totalNum + secondNum;
			case '-':	return totalNum - secondNum;
			case '*':	return totalNum * secondNum;
			case '/':	return division(secondNum);
			case '^':	return square();
			case 'v':	return squareRoot();
			case '%':	return percentage(secondNum);
			default	:	return totalNum;
						
		}
		
	}		
	
	private double division (double secondNum)
	{
		
		if (totalNum == 0D || secondNum == 0D) //Prevents dividing by zero
		{
			return 0D;
		}
		
		return totalNum / secondNum;
		
	}
	
	private double square ()
	{
		return totalNum * totalNum;
	}
	
	private double squareRoot ()
	{
		return Math.sqrt(totalNum);
	}
	
	private double percentage (double secondNum)
	{
		
		regA = totalNum;
		regB = secondNum;
		return (totalNum / 100) * secondNum;
		
	}	
	
}