calculator.java

使用java实现的计算器程序.拥有简单的计算功能,如开方,平方等.

///////    Calculator.java    ///////

public class Calculator
{  
   public Calculator(CalcEng e, CalcFace f)
   {   eng = e; 
       cf = f;
       f.setCalc(this);
   }
   protected Calculator() {}
   
   public void on() throws java.io.IOException
   {
	   output();
	   cf.input();
   }

   public void enterNumber(String number, char op)
   {   eng.setOperand( Double.parseDouble(number) );
       enterOp(op);
   }

   public void enterOp( char op )
   {
	   eng.operate( op );
	   treatStatus(eng.status());
       output();
   }
//former protected method   
   protected void treatStatus(String e)
   {   if ( eng.isError() )         // error
	   {
	   cf.showStatus(e);
	   cf.errorInput("AaCc"); 
       }
       else
          cf.showStatus(e);
   }
//former protected method
   protected void output()
   {
	   double number = eng.getOutput();
	   cf.showNumber(""+number);
   }
//former protected members
   protected CalcEng eng = null;
   protected CalcFace cf = null;
}