/*

 * Copyright (c) 2008, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

package javax.swing.colorchooser;

import java.awt.event.FocusEvent;

import java.awt.event.FocusListener;

import java.text.ParseException;

import static java.util.Locale.ENGLISH;

import javax.swing.JFormattedTextField;

import javax.swing.JFormattedTextField.AbstractFormatter;

import javax.swing.SwingConstants;

import javax.swing.SwingUtilities;

import javax.swing.text.AttributeSet;

import javax.swing.text.BadLocationException;

import javax.swing.text.DefaultFormatterFactory;

import javax.swing.text.DocumentFilter;

final class ValueFormatter extends AbstractFormatter implements FocusListener, Runnable {

    static void init(int length, boolean hex, JFormattedTextField text) {

        ValueFormatter formatter = new ValueFormatter(length, hex);

        text.setColumns(length);

        text.setFormatterFactory(new DefaultFormatterFactory(formatter));

        text.setHorizontalAlignment(SwingConstants.RIGHT);

        text.setMinimumSize(text.getPreferredSize());

        text.addFocusListener(formatter);

    }

    private final DocumentFilter filter = new DocumentFilter() {

        @Override

        public void remove(FilterBypass fb, int offset, int length) throws BadLocationException {

            if (isValid(fb.getDocument().getLength() - length)) {

                fb.remove(offset, length);

            }

        }

        @Override

        public void replace(FilterBypass fb, int offset, int length, String text, AttributeSet set) throws BadLocationException {

            if (isValid(fb.getDocument().getLength() + text.length() - length) && isValid(text)) {

                fb.replace(offset, length, text.toUpperCase(ENGLISH), set);

            }

        }

        @Override

        public void insertString(FilterBypass fb, int offset, String text, AttributeSet set) throws BadLocationException {

            if (isValid(fb.getDocument().getLength() + text.length()) && isValid(text)) {

                fb.insertString(offset, text.toUpperCase(ENGLISH), set);

            }

        }

    };

    private final int length;

    private final int radix;

    private JFormattedTextField text;

    ValueFormatter(int length, boolean hex) {

        this.length = length;

        this.radix = hex ? 16 : 10;

    }

    @Override

    public Object stringToValue(String text) throws ParseException {

        try {

            return Integer.valueOf(text, this.radix);

        }

        catch (NumberFormatException nfe) {

            ParseException pe = new ParseException("illegal format", 0);

            pe.initCause(nfe);

            throw pe;

        }

    }

    @Override

    public String valueToString(Object object) throws ParseException {

        if (object instanceof Integer) {

            if (this.radix == 10) {

                return object.toString();

            }

            int value = (Integer) object;

            int index = this.length;

            char[] array = new char[index];

            while (0 < index--) {

                array[index] = Character.forDigit(value & 0x0F, this.radix);

                value >>= 4;

            }

            return new String(array).toUpperCase(ENGLISH);

        }

        throw new ParseException("illegal object", 0);

    }

    @Override

    protected DocumentFilter getDocumentFilter() {

        return this.filter;

    }

    public void focusGained(FocusEvent event) {

        Object source = event.getSource();

        if (source instanceof JFormattedTextField) {

            this.text = (JFormattedTextField) source;

            SwingUtilities.invokeLater(this);

        }

    }

    public void focusLost(FocusEvent event) {

    }

    public void run() {

        if (this.text != null) {

            this.text.selectAll();

        }

    }

    private boolean isValid(int length) {

        return (0 <= length) && (length <= this.length);

    }

    private boolean isValid(String text) {

        int length = text.length();

        for (int i = 0; i < length; i++) {

            char ch = text.charAt(i);

            if (Character.digit(ch, this.radix) < 0) {

                return false;

            }

        }

        return true;

    }

}