//******************************************************************************
//
// File: LongTextField.java
// Package: edu.rit.swing
// Unit: Class edu.rit.swing.LongTextField
//
// This Java source file is copyright (C) 2011 by Alan Kaminsky. All rights
// reserved. For further information, contact the author, Alan Kaminsky, at
// ark@cs.rit.edu.
//
// This Java source file is part of the Parallel Java Library ("PJ"). PJ is free
// software; you can redistribute it and/or modify it under the terms of the GNU
// General Public License as published by the Free Software Foundation; either
// version 3 of the License, or (at your option) any later version.
//
// PJ 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 General Public License for more details.
//
// A copy of the GNU General Public License is provided in the file gpl.txt. You
// may also obtain a copy of the GNU General Public License on the World Wide
// Web at http://www.gnu.org/licenses/gpl.html.
//
//******************************************************************************
package edu.rit.swing;
import java.awt.Toolkit;
import javax.swing.JTextField;
/**
* Class LongTextField provides a JTextField for entering a long value. The
* LongTextField can be incorporated into a window or dialog.
*
* @author Alan Kaminsky
* @version 07-Mar-2011
*/
public class LongTextField
extends JTextField
{
// Exported constructors.
/**
* Construct a new long text field with the given number of columns. The
* value is initially 0.
*
* @param columns Number of columns.
*/
public LongTextField
(int columns)
{
super (columns);
value (0);
}
/**
* Construct a new long text field with the given value and number of
* columns.
*
* @param value Initial value.
* @param columns Number of columns.
*/
public LongTextField
(long value,
int columns)
{
super (columns);
value (value);
}
// Exported operations.
/**
* Determine if this long text field contains a syntactically valid long
* integer in the given range. If it does, true is returned. If it does not,
* a beep is sounded, the input focus is set to this long text field, all
* the text is selected, and false is returned.
*
* @param lb Lower bound.
* @param ub Upper bound.
*
* @return True if this long text field contains a syntactically valid
* long integer in the given range, false otherwise.
*/
public boolean isOkay
(long lb,
long ub)
{
// Check validity.
boolean valid = false;
try
{
long value = Long.parseLong (getText());
valid = lb <= value && value <= ub;
}
catch (NumberFormatException exc)
{
}
// Take action if invalid.
if (! valid)
{
requestFocusInWindow();
setSelectionStart (0);
setSelectionEnd (Integer.MAX_VALUE);
Toolkit.getDefaultToolkit().beep();
}
return valid;
}
/**
* Get this long text field's value. If this long text field does not
* contain a syntactically valid long integer, 0 is returned.
*
* @return Value.
*/
public long value()
{
try
{
return Long.parseLong (getText());
}
catch (NumberFormatException exc)
{
return 0;
}
}
/**
* Set this long text field's value.
*
* @param value Value.
*/
public void value
(long value)
{
setText (""+value);
}
}
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