NumericTextField.java

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
*	Tiny Look and Feel                                                         *
*                                                                              *
*  (C) Copyright 2003 - 2007 Hans Bickel                                       *
*                                                                              *
*   For licensing information and credits, please refer to the                 *
*   comment in file de.muntjak.tinylookandfeel.TinyLookAndFeel                 *
*                                                                              *
* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

package de.muntjak.tinylookandfeel.controlpanel;

import java.util.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.text.*;

/**
 * NumericTextField
 * 
 * @version 1.0
 * @author Hans Bickel
 */
public class NumericTextField extends JTextField {

	private Vector listeners;
	private ActionEvent actionEvent;
	private int min, max, columns;
	private boolean resistUpdate;
	
  	public NumericTextField(int columns, int value, int min, int max) {
    	super(columns);
    	
    	this.columns = columns;
    	this.min = min;
		this.max = max;
		setHorizontalAlignment(JTextField.RIGHT);
		
		setText("" + value);
    	addKeyListener(new ArrowKeyAction(this, min, max));
    	actionEvent = new ActionEvent(this, Event.ACTION_EVENT, "");
  	}
  	
  	public int getValue() {
  		if(getText().length() == 0) return 0;
  		
  		return Integer.parseInt(getText());
  	}
  	
  	public void setValue(int newValue) {
  		if(resistUpdate) return;
  		
  		setText(String.valueOf(newValue));
  	}
  	
  	public void addActionListener(ActionListener l) {
  		if(listeners == null) {
  			listeners = new Vector();
  		}
  		
  		if(listeners.contains(l)) return;
  		
  		listeners.add(l);
  	}
  	
  	public void removeActionListener(ActionListener l) {
  		if(listeners == null) return;
  		
  		if(!listeners.contains(l)) return;
  		
  		listeners.remove(l);
  	}
  	
  	public void notifyActionListeners() {
  		if(listeners == null) return;
  		
  		resistUpdate = true;
  		
  		Iterator ii = listeners.iterator();
  		while(ii.hasNext()) {
  			((ActionListener)ii.next()).actionPerformed(actionEvent);
  		}
  		
  		resistUpdate = false;
  	}

  	protected Document createDefaultModel() {
    	return new NumericDocument();
  	}

  	protected class NumericDocument extends PlainDocument {
  		
  		NumericDocument() {
  			addDocumentListener(new KeyInputListener());
  		}
  		
    	public void insertString(
        	int offs,
        	String str,
        	AttributeSet a) throws BadLocationException
        {
      		if(str == null || str.length() == 0) return;      		
      		if(getLength() + str.length() > columns) return;

      		if(!checkInput(str)) {
      			Toolkit.getDefaultToolkit().beep();
      			return;
      		}
      		
      		String text = getText(0, getLength());
      		
      		if(offs == 0) {
      			text = str + text;
      		}
      		else if(offs >= text.length()) {
      			text += str;
      		}
      		else {
      			text = text.substring(0, offs) + str + text.substring(offs);
      		}
      		
      		int val = Integer.parseInt(text);
      		boolean correct = false;
      		
      		if(val < min) {
      			val = min;
      			correct = true;
      		} 
      		else if(val > max) {
      			val = max;
      			correct = true;
      		}
      		
      		if(correct) {
      			remove(0, getLength());
      			super.insertString(0, String.valueOf(val), a);
      		}
      		else {
      			super.insertString(offs, str, a);
      		}
    	}
    	
    	private boolean checkInput(String s) {
    		for(int i = 0; i < s.length(); i++) {
    			if(!Character.isDigit(s.charAt(i))) {
    				return false;
    			}
    		}
    		
    		return true;
    	}
  	}
  	
  	class ArrowKeyAction extends KeyAdapter implements ActionListener {
		
		private JTextField theField;
		private javax.swing.Timer keyTimer;
		private int step;
		
		ArrowKeyAction(JTextField field, int min, int max) {
			theField = field;
			keyTimer = new javax.swing.Timer(20, this);
		}
		
		public void keyPressed(KeyEvent e) {
			if(e.getKeyCode() == 38) {	// up => decrease
				step = 1;
				if(e.getModifiers() == KeyEvent.SHIFT_MASK) {
					step = 10;
				}
				
				changeVal();
				keyTimer.setInitialDelay(300);
				keyTimer.start();
			}
			else if(e.getKeyCode() == 40) {	// up => increase
				step = -1;
				if(e.getModifiers() == KeyEvent.SHIFT_MASK) {
					step = -10;
				}
				
				changeVal();
				keyTimer.setInitialDelay(300);
				keyTimer.start();
			}
		}
		
		public void keyReleased(KeyEvent e) {
			keyTimer.stop();
		}
		
		// the keyTimer action
		public void actionPerformed(ActionEvent e) {
			changeVal();
		}
		
		private void changeVal() {
			int val = Integer.parseInt(theField.getText()) + step;
			
			if(val > max) val = max;
			else if(val < min) val = min;

			// this should trigger insertUpdate()
			theField.setText("" + val);
		}
	}
	
	class KeyInputListener implements DocumentListener {
		public void changedUpdate(DocumentEvent e) {
		}
		
		public void insertUpdate(DocumentEvent e) {
			notifyActionListeners();
		}

		public void removeUpdate(DocumentEvent e) {
			notifyActionListeners();
		}
	}
}