jspinfield.java

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/*
 *  02/02/2002 - 20:54:54
 *
 *  JSpinField.java  - A spin field similar to JSpinner in JDJ 1.4
 *  Copyright (C) 2002 Kai Toedter
 *  [e-mail]
 *  www.toedter.com
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public License
 *  as published by the Free Software Foundation; either version 2
 *  of the License, or (at your option) any later version.
 *
 *  This program 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 Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */
package com.toedter.components;

import java.awt.Adjustable;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.AdjustmentEvent;
import java.awt.event.AdjustmentListener;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollBar;
import javax.swing.JTextField;
import javax.swing.event.CaretEvent;
import javax.swing.event.CaretListener;

/**
 *  JSpinField is a numeric field with 2 spin buttons to increase or decrease
 *  the value.
 *
 *@author     Kai Toedter
 *@version    1.1.4 07/16/02
 */
public class JSpinField extends JPanel implements CaretListener,
		AdjustmentListener, ActionListener {
	private static final long serialVersionUID = 3257009856274576438L;
	/**
	 *  Default JSpinField constructor.
	 */
	public JSpinField() {
		super();
		min = 0;
		max = 100;
		value = 0;
		darkGreen = new Color(0, 150, 0);

		setLayout(new BorderLayout());
		textField = new JTextField(Integer.toString(value));
		textField.addCaretListener(this);
		textField.addActionListener(this);
        textField.setHorizontalAlignment( JTextField.RIGHT );
		add(textField, BorderLayout.CENTER);
		
		scrollBar = new JScrollBar(Adjustable.VERTICAL, 0, 0, 0, 100);
		scrollBar.setPreferredSize(
				new Dimension(scrollBar.getPreferredSize().width,
				textField.getPreferredSize().height));
		scrollBar.setMinimum(min);
		scrollBar.setMaximum(max);
		scrollBar.setValue(max + min - value);
		scrollBar.setVisibleAmount(0);

		scrollBar.addAdjustmentListener(this);
		add(scrollBar, BorderLayout.EAST);
	}


	/**
	 *  Sets the value attribute of the JSpinField object
	 *
	 *@param  newValue         The new value value
	 *@param  updateTextField  The new value value
	 *@param  updateScrollbar  The new value value
	 */
	protected void setValue(int newValue, boolean updateTextField,
			boolean updateScrollbar) {
		int oldValue = value;

		if (newValue < min) {
			value = min;
		} else if (newValue > max) {
			value = max;
		} else {
			value = newValue;
		}

		if (updateTextField) {
			textField.setText(Integer.toString(value));
			textField.setForeground(Color.black);
		}

		if (updateScrollbar) {
			scrollBar.setValue(max + min - value);
		}

		firePropertyChange("value", oldValue, value);
	}


	/**
	 *  Sets the value. This is a bound property.
	 *
	 *@param  newValue  the new value
	 *@see              #getValue
	 */
	public void setValue(int newValue) {
		setValue(newValue, true, true);
	}


	/**
	 *  Returns the value.
	 *
	 *@return    The value value
	 */
	public int getValue() {
		return value;
	}


	/**
	 *  Sets the minimum value.
	 *
	 *@param  newMinimum  the new minimum value
	 *@see                #getMinimum
	 */
	public void setMinimum(int newMinimum) {
		min = newMinimum;
		scrollBar.setMinimum(min);
	}


	/**
	 *  Returns the minimum value.
	 *
	 *@return    The minimum value
	 */
	public int getMinimum() {
		return min;
	}


	/**
	 *  Sets the maximum value and adjusts the preferred width.
	 *
	 *@param  newMaximum  the new maximum value
	 *@see                #getMaximum
	 */
	public void setMaximum(int newMaximum) {
		max = newMaximum;
		scrollBar.setMaximum(max);
		
		textField.setPreferredSize(
				new Dimension(new JTextField(Integer.toString(newMaximum)).getPreferredSize().width,
				textField.getPreferredSize().height));
	}


	/**
	 *  Sets the horizontal alignment of the displayed value.
	 */
	public void setHorizontalAlignment(int alignment) {
		textField.setHorizontalAlignment(alignment);
	}


	/**
	 *  Returns the maximum value.
	 *
	 *@return    The maximum value
	 */
	public int getMaximum() {
		return max;
	}


	/**
	 *  Sets the font property.
	 *
	 *@param  font  the new font
	 */
	public void setFont(Font font) {
		if (textField != null) {
			textField.setFont(font);
		}
	}


	/**
	 *  Sets the foreground color.
	 *
	 *@param  fg  the new foreground
	 */
	public void setForeground(Color fg) {
		if (textField != null) {
			textField.setForeground(fg);
		}
	}


	/**
	 *  After any user input, the value of the textfield is proofed. Depending on
	 *  being an integer, the value is colored green or red.
	 *
	 *@param  e  Description of the Parameter
	 */
	public void caretUpdate(CaretEvent e) {
		try {
			int testValue = Integer.valueOf(textField.getText()).intValue();

			if ((testValue >= min) && (testValue <= max)) {
				textField.setForeground(darkGreen);
				setValue(testValue, false, false);
			} else {
				textField.setForeground(Color.red);
			}
		} catch (Exception ex) {
			if (ex instanceof NumberFormatException) {
				textField.setForeground(Color.red);
			}
			// Ignore all other exceptions, e.g. illegal state exception
		}
		textField.repaint();
	}


	/**
	 *  The 2 buttons are implemented with a JScrollBar.
	 *
	 *@param  e  Description of the Parameter
	 */
	public void adjustmentValueChanged(AdjustmentEvent e) {
		setValue(max + min - e.getValue(), true, false);
	}


	/**
	 *  After any user input, the value of the textfield is proofed. Depending on
	 *  being an integer, the value is colored green or red. If the textfield is
	 *  green, the enter key is accepted and the new value is set.
	 *
	 *@param  e  Description of the Parameter
	 */
	public void actionPerformed(ActionEvent e) {
		if (textField.getForeground().equals(darkGreen)) {
			setValue(Integer.valueOf(textField.getText()).intValue());
		}
	}


	/**
	 *  Enable or disable the JSpinField.
	 *
	 *@param  enabled  The new enabled value
	 */
	public void setEnabled(boolean enabled) {
		super.setEnabled(enabled);
		textField.setEnabled(enabled);
		scrollBar.setEnabled(enabled);
	}


	/**
	 *  Creates a JFrame with a JSpinField inside and can be used for testing.
	 *
	 *@param  s  The command line arguments
	 */
	public static void main(String[] s) {
		JFrame frame = new JFrame("JSpinField");
		frame.getContentPane().add(new JSpinField());
		frame.pack();
		frame.setVisible(true);
	}


	/**
	 *  the text (number) field
	 */
	protected JTextField textField;
	/**
	 *  the scrollbar for the spin buttons
	 */
	protected JScrollBar scrollBar;
	private Color darkGreen;
	private int min;
	private int max;
	private int value;
}