package com.devious.calculator;
import java.util.Observable;
public class CalcModel extends Observable
{
public static final int OP_NONE = 0;
public static final int OP_ADD = 1;
public static final int OP_SUB = 2;
public static final int OP_MUL = 3;
public static final int OP_DIV = 4;
private int pendingOp = 0;
private int previousValue = 0;
private int currentValue = 0;
public String getValue()
{
return Integer.toString(currentValue);
}
public void addDigit(String s)
{
char c = s.charAt(0);
String val = getValue() + c;
setDisplay(Integer.parseInt(val));
}
public void addDigit(char c)
{
String val = getValue() + c;
setDisplay(Integer.parseInt(val));
}
public void setOperation(int op)
{
if (pendingOp != OP_NONE)
calculate();
previousValue = currentValue;
this.pendingOp = op;
currentValue = 0;
}
public void setDisplay(int value)
{
currentValue = value;
setChanged();
notifyObservers();
}
public void clear()
{
this.pendingOp = OP_NONE;
previousValue = 0;
setDisplay(0);
}
public void calculate()
{
switch (pendingOp)
{
case OP_ADD:
setDisplay(previousValue + currentValue);
break;
case OP_SUB:
setDisplay(previousValue - currentValue);
break;
case OP_MUL:
setDisplay(previousValue * currentValue);
break;
case OP_DIV:
setDisplay(previousValue / currentValue);
break;
}
pendingOp = OP_NONE;
previousValue = 0;
}
}
Аналогично создадим файл:
