calculator.java

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			case '6':		case '7':		case '8':
			case '9':
				m_display += c;
				break;

			//	Decimal		===============================
			case '.':
			case ',':
				m_display += m_decimal;
				break;

			//	Commands	===============================
			case '/':		case '*':
			case '-':       case '+':
			case '%':
				if (m_display.length() > 1)
				{
					char last = m_display.charAt(m_display.length()-1);
					if (OPERANDS.indexOf(last) == -1)
						m_display += c;
					else
						m_display = m_display.substring(0, m_display.length()-1) + c;
				}
				m_display = m_format.format(evaluate());
				if (c != '%')
					m_display += c;
				break;

			//	Clear last char
			case 'C':
				if (m_display.length() > 0)
					m_display = m_display.substring(0, m_display.length()-1);
				break;

			//	Clear all
			case 'A':
				m_display = "";
				break;

			//	Currency convert toggle
			case '$':
				m_display = m_format.format(evaluate());
				toggleCurrency();
				break;

			//	fini
			case '=':
				m_display = m_format.format(evaluate());
				m_abort = false;
				dispose();
				break;

			//	Error		===============================
			default:
				ADialog.beep();
				break;
		}	//	switch

		if (m_display.equals(""))
			m_display = "0";

		//	Eliminate leading zeroes
		if (m_display.length() > 1 && m_display.startsWith("0"))
			if (m_display.charAt(1) != ',' && m_display.charAt(1) != '.')
				m_display = m_display.substring(1);

		//	Display it
		display.setText(m_display);
	}	//	handleInput

	/**
	 *	Evaluate.
	 *	- evaluate info in display and set number
	 * 	@return result
	 */
	private BigDecimal evaluate()
	{
		//	nothing or zero
		if (m_display == null || m_display.equals("") || m_display.equals("0"))
		{
			m_number = new BigDecimal(0.0);
			return m_number;
		}

		StringTokenizer st = new StringTokenizer(m_display, OPERANDS, true);

		//	first token
		String token = st.nextToken();
		//	do we have a negative number ?
		if (token.equals("-"))
		{
			if (st.hasMoreTokens())
				token += st.nextToken();
			else
			{
				m_number = new BigDecimal(0.0);
				return m_number;
			}
		}

		//	First Number
		Number firstNumber;
		try
		{
			firstNumber = m_format.parse(token);
		}
		catch (ParseException pe1)
		{
			log.log(Level.SEVERE, "Calculator.evaluate - token: " + token, pe1);
			m_number = new BigDecimal(0.0);
			return  m_number;
		}
		BigDecimal firstNo =  new BigDecimal(firstNumber.toString());

		//	intermediate result
		m_number = firstNo;

		//	only one number
		if (!st.hasMoreTokens())
			return m_number;

		//	now we should get an operand
		token = st.nextToken();
		if (OPERANDS.indexOf(token) == -1)
		{
			log.log(Level.SEVERE, "Calculator.evaluate - Unknown token: " + token);
			return m_number;
		}
		//	get operand
		char op = token.charAt(0);

		//	no second number
		if (!st.hasMoreTokens())
			return m_number;

		token = st.nextToken();
		Number secondNumber;
		try
		{
			secondNumber = m_format.parse(token);
		}
		catch (ParseException pe2)
		{
			log.log(Level.SEVERE, "Calculator.evaluate - token: " + token, pe2);
			m_number = new BigDecimal(0.0);
			return m_number;
		}
		BigDecimal secondNo = new BigDecimal(secondNumber.toString());

		//	Check the next operant
		char op2 = 0;
		if (st.hasMoreTokens())
		{
			token = st.nextToken();
			if (OPERANDS.indexOf(token) == -1)
			{
				log.log(Level.SEVERE, "Calculator.evaluate - Unknown token: " + token);
				return m_number;
			}
			//	get operand
			op2 = token.charAt(0);
		}

		//	Percent operation
		if (op2 == '%')
			secondNo = firstNo.multiply(secondNo)
				.divide(new BigDecimal(100.0), m_format.getMaximumFractionDigits(), BigDecimal.ROUND_HALF_UP);

		switch (op)
		{
			case '/':
				m_number = firstNo
					.divide(secondNo, m_format.getMaximumFractionDigits(), BigDecimal.ROUND_HALF_UP);
				break;
			case '*':
				m_number = firstNo.multiply(secondNo);
				break;
			case '-':
				m_number = firstNo.subtract(secondNo);
				break;
			case '+':
				m_number = firstNo.add(secondNo);
				break;
			default:
				break;
		}
		return m_number.setScale(m_format.getMaximumFractionDigits(), BigDecimal.ROUND_HALF_UP);
	}	//	evaluate


	/**
	 *	Display or don't display Currency
	 */
	private void toggleCurrency()
	{
		if (currencyPanel.isVisible())
			currencyPanel.setVisible(false);
		else
		{
			if (!m_currencyOK)
				loadCurrency();
			currencyPanel.setVisible(true);
		}
		pack();
	}	//	toggleCurrency

	/**
	 *	Load Currency
	 */
	private void loadCurrency()
	{
		//	Get Default
		int C_Currency_ID = Env.getContextAsInt(Env.getCtx(), m_WindowNo, "C_Currency_ID");
		if (C_Currency_ID == 0)
			C_Currency_ID = Env.getContextAsInt(Env.getCtx(), "$C_Currency_ID");

		String sql = "SELECT C_Currency_ID, ISO_Code FROM C_Currency "
			+ "WHERE IsActive='Y' ORDER BY 2";
		KeyNamePair defaultValue = null;
		try
		{
			Statement stmt = DB.createStatement();
			ResultSet rs = stmt.executeQuery(sql);
			while (rs.next())
			{
				int id = rs.getInt("C_Currency_ID");
				String s = rs.getString("ISO_Code");
				KeyNamePair p = new KeyNamePair(id, s);
				curFrom.addItem(p);
				curTo.addItem(p);
				//	Default
				if (id == C_Currency_ID)
					defaultValue = p;
			}
			rs.close();
			stmt.close();
		}
		catch (SQLException e)
		{
			log.log(Level.SEVERE, "Calculator.loadCurrency", e);
		}

		//	Set Defaults
		if (defaultValue != null)
		{
			curFrom.setSelectedItem(defaultValue);
			curTo.setSelectedItem(defaultValue);
		}
		//	Set Listener
		curTo.addActionListener(this);
		m_currencyOK = true;
	}	//	loadCurrency


	/**
	 *	Return Number
	 * 	@return result
	 */
	public BigDecimal getNumber()
	{
		if (m_abort)
			return null;

		return m_number;
	}   //	getNumber

	/*************************************************************************/

	/**
	 *  KeyPressed Listener
	 * 	@param e event
	 */
	public void keyPressed(KeyEvent e)
	{
		//  sequence:	pressed - typed(no KeyCode) - released

		char input = e.getKeyChar();
		int code = e.getKeyCode();

		e.consume();		//	does not work on JTextField

		if (code == KeyEvent.VK_DELETE)
			input = 'A';
		else if (code == KeyEvent.VK_BACK_SPACE)
			input = 'C';
		else if (code == KeyEvent.VK_ENTER)
			input = '=';
		//	abort
		else if (code == KeyEvent.VK_CANCEL || code == KeyEvent.VK_ESCAPE)
		{
			m_abort = true;
			dispose();
			return;
		}
		handleInput(input);
	}

	/**
	 *  KeyTyped Listener (nop)
	 * 	@param e event
	 */
	public void keyTyped(KeyEvent e) {}
	/**
	 *  KeyReleased Listener (nop)
	 * 	@param e event
	 */
	public void keyReleased(KeyEvent e) {}

}	//	Calculator