/* TextField.java -- A one line text entry field
   Copyright (C) 1999 Free Software Foundation, Inc.

This file is part of the non-peer AWT libraries of GNU Classpath.

This library is free software; you can redistribute it and/or modify
it under the terms of the GNU Library General Public License as published 
by the Free Software Foundation, either version 2 of the License, or
(at your option) any later verion.

This library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Library General Public License for more details.

You should have received a copy of the GNU Library General Public License
along with this library; if not, write to the Free Software Foundation
Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307 USA. */


package java.awt;

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.peer.TextFieldPeer;
import java.awt.peer.TextComponentPeer;
import java.awt.peer.ComponentPeer;

/**
  * This class implements a single line text entry field widget
  *
  * @author Aaron M. Renn (arenn@urbanophile.com)
  */
public class TextField extends TextComponent implements java.io.Serializable
{

/*
 * Static Variables
 */

// Serialization constant
private static final long serialVersionUID = -2966288784432217853L;

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

/*
 * Instance Variables
 */

/**
  * @serial The number of columns in the text entry field.
  */
private int columns;

/**
  * @serial The character that is echoed when doing protected input
  */
private char echoChar;

// List of registered ActionListener's for this object.
private ActionListener action_listeners;

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

/*
 * Constructors
 */

/*
 * Initializes a new instance of <code>TextField</code> that is empty
 * and has one column.
 */
public
TextField()
{
  this("", 1);
}

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

/**
  * Initializes a new instance of <code>TextField</code> containing
  * the specified text.  The number of columns will be equal to the
  * length of the text string.
  *
  * @param text The text to display in the field.
  */
public
TextField(String text)
{
  this(text, text.length());
}

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

/**
  * Initializes a new instance of <code>TextField</code> that is empty
  * and has the specified number of columns.
  *
  * @param columns The number of columns in the text field.
  */
public
TextField(int columns)
{
  this("", columns);
}

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

/**
  * Initializes a new instance of <code>TextField</code> with the
  * specified text and number of columns.
  *
  * @param text The text to display in the field.
  * @param columns The number of columns in the field.
  */
public
TextField(String text, int columns)
{
  super(text);
  this.columns = columns;
}

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

/*
 * Instance Methods
 */

/**
  * Returns the number of columns in the field.
  *
  * @return The number of columns in the field.
  */
public int
getColumns()
{
  return(columns);
}

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

/**
  * Sets the number of columns in this field to the specified value.
  *
  * @param columns The new number of columns in the field.
  *
  * @exception IllegalArgumentException If columns is less than zero.
  */
public synchronized void
setColumns(int columns)
{
  if (columns < 0)
    throw new IllegalArgumentException("Value is less than zero: " +
                                       columns);

  this.columns = columns;
  // FIXME: How to we communicate this to our peer?
}

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

/**
  * Returns the character that is echoed to the screen when a text 
  * field is protected (such as when a password is being entered).
  *
  * @return The echo character for this text field.
  */
public char
getEchoChar()
{
  return(echoChar);
}

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

/**
  * Sets the character that is echoed when protected input such as
  * a password is displayed.
  *
  * @param echoChar The new echo character.
  */
public void
setEchoChar(char echoChar)
{
  this.echoChar = echoChar;

  TextFieldPeer tfp = (TextFieldPeer)getPeer();
  if (tfp != null)
    tfp.setEchoChar(echoChar);
}

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

/**
  * Sets the character that is echoed when protected input such as
  * a password is displayed.
  *
  * @param echoChar The new echo character.
  *
  * @deprecated This method is deprecated in favor of 
  * <code>setEchoChar()</code>
  */
public void
setEchoCharacter(char echoChar)
{
  setEchoChar(echoChar);
}

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

/**
  * Tests whether or not this text field has an echo character set
  * so that characters the user type are not echoed to the screen.
  *
  * @return <code>true</code> if an echo character is set,
  * <code>false</code> otherwise.
  */
public boolean
echoCharIsSet()
{
  if (echoChar == '\u0000')
    return(false);
  else
    return(true);
}

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

/**
  * Returns the minimum size for this text field.
  *
  * @return The minimum size for this text field.
  */
public Dimension
getMinimumSize()
{
  return(getMinimumSize(getColumns()));
}

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

/**
  * Returns the minimum size of a text field with the specified number
  * of columns.
  *
  * @param columns The number of columns to get the minimum size for.
  */
public Dimension
getMinimumSize(int columns)
{
  TextFieldPeer tfp = (TextFieldPeer)getPeer();
  if (tfp == null)
    return(null); // FIXME: What do we do if there is no peer?

  return(tfp.getMinimumSize(columns));
}

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

/**
  * Returns the minimum size for this text field.
  *
  * @return The minimum size for this text field.
  *
  * @deprecated This method is depcreated in favor of
  * <code>getMinimumSize()</code>.
  */
public Dimension
minimumSize()
{
  return(getMinimumSize(getColumns()));
}

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

/**
  * Returns the minimum size of a text field with the specified number
  * of columns.
  *
  * @param columns The number of columns to get the minimum size for.
  *
  * @deprecated This method is deprecated in favor of 
  * <code>getMinimumSize(int)</code>.
  */
public Dimension
minimumSize(int columns)
{
  return(getMinimumSize(columns));
}

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

/**
  * Returns the preferred size for this text field.
  *
  * @return The preferred size for this text field.
  */
public Dimension
getPreferredSize()
{
  return(getPreferredSize(getColumns()));
}

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

/**
  * Returns the preferred size of a text field with the specified number
  * of columns.
  *
  * @param columns The number of columns to get the preferred size for.
  */
public Dimension
getPreferredSize(int columns)
{
  TextFieldPeer tfp = (TextFieldPeer)getPeer();
  if (tfp == null)
    return(null); // FIXME: What do we do if there is no peer?

  return(tfp.getPreferredSize(columns));
}

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

/**
  * Returns the preferred size for this text field.
  *
  * @return The preferred size for this text field.
  *
  * @deprecated This method is deprecated in favor of 
  * <code>getPreferredSize()</code>.
  */
public Dimension
preferredSize()
{
  return(getPreferredSize(getColumns()));
}

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

/**
  * Returns the preferred size of a text field with the specified number
  * of columns.
  *
  * @param columns The number of columns to get the preferred size for.
  *
  * @deprecated This method is deprecated in favor of 
  * <code>getPreferredSize(int)</code>.
  */
public Dimension
preferredSize(int columns)
{
  return(getPreferredSize(columns));
}

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

/**
  * Notifies this object that it should create its native peer.
  */
public void
addNotify()
{
  if (getPeer() != null)
    return;

  setPeer((ComponentPeer)getToolkit().createTextField(this));
}

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

/**
  * Addes a new listener to the list of action listeners for this
  * object.
  *
  * @param listener The listener to add to the list.
  */
public synchronized void
addActionListener(ActionListener listener)
{
  action_listeners = AWTEventMulticaster.add(action_listeners, listener);

  enableEvents(AWTEvent.ACTION_EVENT_MASK);
}

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

/**
  * Removes the specified listener from the list of action listeners
  * for this object.
  *
  * @param listener The listener to remove from the list.
  */
public synchronized void
removeActionListener(ActionListener listener)
{
  action_listeners = AWTEventMulticaster.remove(action_listeners, listener);
}

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

/**
  * Processes the specified event.  If the event is an instance of
  * <code>ActionEvent</code> then <code>processActionEvent()</code> is
  * called to process it, otherwise the event is sent to the
  * superclass.
  *
  * @param event The event to process.
  */
protected void
processEvent(AWTEvent event)
{
  if (event instanceof ActionEvent)
    processActionEvent((ActionEvent)event);
  else
    super.processEvent(event);
}

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

/**
  * Processes an action event by calling any registered listeners.
  * Note to subclasses: This method is not called unless action events
  * are enabled on this object.  This will be true if any listeners
  * are registered, or if action events were specifically enabled
  * using <code>enableEvents()</code>.
  * 
  * @param event The event to process.
  */
protected void
processActionEvent(ActionEvent event)
{
  if (action_listeners != null)
    action_listeners.actionPerformed(event);
}

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

/**
  * Returns a debug string for this object.
  *
  * @return A debug string for this object.
  */
protected String
paramString()
{
  return(getClass().getName() + "(columns=" + getColumns() + ",echoChar=" +
         getEchoChar());
}

} // class TextField