package com.c2kernel.gui.tabs.outcome.form.field;

import java.awt.Toolkit;
import java.math.BigInteger;

import javax.swing.JTextField;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
import javax.swing.text.JTextComponent;
import javax.swing.text.PlainDocument;

/**************************************************************************
 *
 * $Revision: 1.4 $
 * $Date: 2005/08/16 13:59:56 $
 *
 * Copyright (C) 2003 CERN - European Organization for Nuclear Research
 * All rights reserved.
 **************************************************************************/
public class IntegerEditField extends StringEditField {
    
    public IntegerEditField() {
        super();
        field.setToolTipText("This field must contains a whole number e.g. 3");
    }

    public String getText() {
        return field.getText();
    }

    public void setText(String text) {
        field.setText(text);
    }

    public String getDefaultValue() {
        return "0";
    }
    
    public JTextComponent makeTextField() {
        return new IntegerTextField();
    }
    
    private class IntegerTextField extends JTextField {

        public IntegerTextField() {
            super();
            setHorizontalAlignment(RIGHT);
        }
        protected Document createDefaultModel() {
            return new IntegerDocument();
        }
    }
    
    private class IntegerDocument extends PlainDocument {

        BigInteger currentVal = new BigInteger("0");

        public void insertString(int offs, String str, AttributeSet a) throws BadLocationException {

            if (str == null || str.equals("")) {
                return;
            }

            String proposedResult = null;

            if (getLength() == 0) {
                proposedResult = str;
            } else {
                StringBuffer currentBuffer = new StringBuffer( this.getText(0, getLength()) );
                currentBuffer.insert(offs, str);
                proposedResult = currentBuffer.toString();
            }
     
            try {
                currentVal = parse(proposedResult);
                super.insertString(offs, str, a);
            } catch (Exception e) {
                Toolkit.getDefaultToolkit().beep();
            }
      
        }

        public void remove(int offs, int len) throws BadLocationException {

            String currentText = this.getText(0, getLength());
            String beforeOffset = currentText.substring(0, offs);
            String afterOffset = currentText.substring(len + offs, currentText.length());
            String proposedResult = beforeOffset + afterOffset;
            if (proposedResult.length() == 0) { // empty is ok
                super.remove(offs, len);
                return;
            }

            try {
                currentVal = parse(proposedResult);
                super.remove(offs, len);
            } catch (Exception e) { 
                Toolkit.getDefaultToolkit().beep();
            }

        }   

        public BigInteger parse(String proposedResult) throws NumberFormatException {

            BigInteger value = new BigInteger("0");
            if ( proposedResult.length() != 0) {
                value =  new BigInteger(proposedResult);      
            }
            return value;
        }
    }
}