/*
    *  File: DoubleField.java 
    *  Copyright (c) 2004-2007  Peter Kliem (Peter.Kliem@jaret.de)
    *  A commercial license is available, see http://www.jaret.de.
    *
    * All rights reserved. This program and the accompanying materials
    * are made available under the terms of the Common Public License v1.0
    * which accompanies this distribution, and is available at
    * http://www.eclipse.org/legal/cpl-v10.html
   */
  package de.jaret.util.ui;
  
  import java.text.DecimalFormat;
  import java.text.NumberFormat;
  import java.text.ParseException;
  
  import org.eclipse.swt.SWT;
  import org.eclipse.swt.events.KeyEvent;
  import org.eclipse.swt.events.KeyListener;
  import org.eclipse.swt.events.VerifyEvent;
  import org.eclipse.swt.events.VerifyListener;
  import org.eclipse.swt.widgets.Text;
  
  /**
   * Helper wrapping a Text to allow only editing of double values.
   * 
   * @author Peter Kliem
   * @version $Id: DoubleField.java 242 2007-02-11 21:05:07Z olk $
   */
  public class DoubleField implements VerifyListener, KeyListener {
      protected int _digits = 1;
      protected double _min = -Double.MAX_VALUE;
      protected double _max = Double.MAX_VALUE;
      protected Text _text;
      protected NumberFormat _numberFormat;
      protected double _increment = 1.0;
  
      public DoubleField(int digits, double min, double max) {
          _digits = digits;
          _min = min;
          _max = max;
          updateNumberFormat();
      }
  
      public DoubleField() {
          this(1, -Double.MAX_VALUE, Double.MAX_VALUE);
      }
  
      public double getValue() throws ParseException {
          double value = ((Number) _numberFormat.parse(_text.getText())).doubleValue();
          return value;
      }
  
      public void setValue(double value) {
          if (_text != null) {
              _text.setText(_numberFormat.format(value));
          }
      }
  
      private void updateNumberFormat() {
          if (_numberFormat == null) {
              _numberFormat = DecimalFormat.getInstance();
          }
          _numberFormat.setMaximumFractionDigits(_digits);
          _numberFormat.setGroupingUsed(false);
      }
  
      /**
       * @return the digits
       */
      public int getDigits() {
          return _digits;
      }
  
      /**
       * @param digits the digits to set
       */
      public void setDigits(int digits) {
          _digits = digits;
          updateNumberFormat();
      }
  
      /**
       * @return the max
       */
      public double getMax() {
          return _max;
      }
  
      /**
       * @param max the max to set
       */
      public void setMax(double max) {
          _max = max;
      }
  
      /**
       * @return the min
       */
     public double getMin() {
         return _min;
     }
 
     /**
      * @param min the min to set
      */
     public void setMin(double min) {
         _min = min;
     }
 
     /**
      * @return the text
      */
     public Text getText() {
         return _text;
     }
 
     /**
      * @param text the text to set
      */
     public void setText(Text text) {
         if (_text != null) {
             _text.removeVerifyListener(this);
             _text.removeKeyListener(this);
         }
         _text = text;
         if (_text != null) {
             _text.addVerifyListener(this);
             _text.addKeyListener(this);
         }
     }
 
     public void verifyText(VerifyEvent e) {
         if (e.text.length() > 1) {
             try {
                 _numberFormat.parse(e.text);
                 return;
             } catch (Exception ex) {
                 // ignore, text will no t be inserted
             }
         }
         // System.out.println("characteer "+(int)e.character);
         if (Character.isDigit(e.character) || e.character < 32 || e.character == 127) {
             return;
         }
         if (e.character == '.' || e.character == ',') {
             if (_text.getText().indexOf('.') == -1 && _text.getText().indexOf(',') == -1) {
                 return;
             }
         }
         if (e.character == '-') {
             if (_text.getText().indexOf('-') == -1 && _text.getCaretPosition() == 0) {
                 return;
             }
         }
         e.doit = false;
     }
 
     /**
      * @return the increment
      */
     public double getIncrement() {
         return _increment;
     }
 
     /**
      * @param increment the increment to set
      */
     public void setIncrement(double increment) {
         _increment = increment;
     }
 
     public void keyPressed(KeyEvent e) {
         if (e.keyCode == SWT.ARROW_DOWN) {
             try {
                 double value = getValue();
                 value -= _increment;
                 if (value < _min) {
                     value = _min;
                 }
                 setValue(value);
             } catch (ParseException ex) {
                 // ignore
             }
             e.doit = false;
         } else if (e.keyCode == SWT.ARROW_UP) {
             try {
                 double value = getValue();
                 value += _increment;
                 if (value > _max) {
                     value = _max;
                 }
                 setValue(value);
             } catch (ParseException ex) {
                 // ignore
             }
             e.doit = false;
         }
     }
 
     public void keyReleased(KeyEvent e) {
     }
 
 }