/*

 * Copyright 2000-2003 Sun Microsystems, Inc.  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.  Sun designates this

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

 * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

package javax.swing.text;

import java.lang.reflect.*;

import java.text.*;

import java.util.*;

import javax.swing.text.*;

/**

 * <code>NumberFormatter</code> subclasses <code>InternationalFormatter</code>

 * adding special behavior for numbers. Among the specializations are

 * (these are only used if the <code>NumberFormatter</code> does not display

 * invalid nubers, eg <code>setAllowsInvalid(false)</code>):

 * <ul>

 *   <li>Pressing +/- (- is determined from the

 *       <code>DecimalFormatSymbols</code> associated with the

 *       <code>DecimalFormat</code>) in any field but the exponent

 *       field will attempt to change the sign of the number to

 *       positive/negative.

 *   <li>Pressing +/- (- is determined from the

 *       <code>DecimalFormatSymbols</code> associated with the

 *       <code>DecimalFormat</code>) in the exponent field will

 *       attemp to change the sign of the exponent to positive/negative.

 * </ul>

 * <p>

 * If you are displaying scientific numbers, you may wish to turn on

 * overwrite mode, <code>setOverwriteMode(true)</code>. For example:

 * <pre>

 * DecimalFormat decimalFormat = new DecimalFormat("0.000E0");

 * NumberFormatter textFormatter = new NumberFormatter(decimalFormat);

 * textFormatter.setOverwriteMode(true);

 * textFormatter.setAllowsInvalid(false);

 * </pre>

 * <p>

 * If you are going to allow the user to enter decimal

 * values, you should either force the DecimalFormat to contain at least

 * one decimal (<code>#.0###</code>), or allow the value to be invalid

 * <code>setAllowsInvalid(true)</code>. Otherwise users may not be able to

 * input decimal values.

 * <p>

 * <code>NumberFormatter</code> provides slightly different behavior to

 * <code>stringToValue</code> than that of its superclass. If you have

 * specified a Class for values, {@link #setValueClass}, that is one of

 * of <code>Integer</code>, <code>Long</code>, <code>Float</code>,

 * <code>Double</code>, <code>Byte</code> or <code>Short</code> and

 * the Format's <code>parseObject</code> returns an instance of

 * <code>Number</code>, the corresponding instance of the value class

 * will be created using the constructor appropriate for the primitive

 * type the value class represents. For example:

 * <code>setValueClass(Integer.class)</code> will cause the resulting

 * value to be created via

 * <code>new Integer(((Number)formatter.parseObject(string)).intValue())</code>.

 * This is typically useful if you

 * wish to set a min/max value as the various <code>Number</code>

 * implementations are generally not comparable to each other. This is also

 * useful if for some reason you need a specific <code>Number</code>

 * implementation for your values.

 * <p>

 * <strong>Warning:</strong>

 * Serialized objects of this class will not be compatible with

 * future Swing releases. The current serialization support is

 * appropriate for short term storage or RMI between applications running

 * the same version of Swing.  As of 1.4, support for long term storage

 * of all JavaBeans<sup><font size="-2">TM</font></sup>

 * has been added to the <code>java.beans</code> package.

 * Please see {@link java.beans.XMLEncoder}.

 *

 * @since 1.4

 */

public class NumberFormatter extends InternationalFormatter {

    /** The special characters from the Format instance. */

    private String specialChars;

    /**

     * Creates a <code>NumberFormatter</code> with the a default

     * <code>NumberFormat</code> instance obtained from

     * <code>NumberFormat.getNumberInstance()</code>.

     */

    public NumberFormatter() {

        this(NumberFormat.getNumberInstance());

    }

    /**

     * Creates a NumberFormatter with the specified Format instance.

     *

     * @param format Format used to dictate legal values

     */

    public NumberFormatter(NumberFormat format) {

        super(format);

        setFormat(format);

        setAllowsInvalid(true);

        setCommitsOnValidEdit(false);

        setOverwriteMode(false);

    }

    /**

     * Sets the format that dictates the legal values that can be edited

     * and displayed.

     * <p>

     * If you have used the nullary constructor the value of this property

     * will be determined for the current locale by way of the

     * <code>NumberFormat.getNumberInstance()</code> method.

     *

     * @param format NumberFormat instance used to dictate legal values

     */

    public void setFormat(Format format) {

        super.setFormat(format);

        DecimalFormatSymbols dfs = getDecimalFormatSymbols();

        if (dfs != null) {

            StringBuffer sb = new StringBuffer();

            sb.append(dfs.getCurrencySymbol());

            sb.append(dfs.getDecimalSeparator());

            sb.append(dfs.getGroupingSeparator());

            sb.append(dfs.getInfinity());

            sb.append(dfs.getInternationalCurrencySymbol());

            sb.append(dfs.getMinusSign());

            sb.append(dfs.getMonetaryDecimalSeparator());

            sb.append(dfs.getNaN());

            sb.append(dfs.getPercent());

            sb.append('+');

            specialChars = sb.toString();

        }

        else {

            specialChars = "";

        }

    }

    /**

     * Invokes <code>parseObject</code> on <code>f</code>, returning

     * its value.

     */

    Object stringToValue(String text, Format f) throws ParseException {

        if (f == null) {

            return text;

        }

        Object value = f.parseObject(text);

        return convertValueToValueClass(value, getValueClass());

    }

    /**

     * Converts the passed in value to the passed in class. This only

     * works if <code>valueClass</code> is one of <code>Integer</code>,

     * <code>Long</code>, <code>Float</code>, <code>Double</code>,

     * <code>Byte</code> or <code>Short</code> and <code>value</code>

     * is an instanceof <code>Number</code>.

     */

    private Object convertValueToValueClass(Object value, Class valueClass) {

        if (valueClass != null && (value instanceof Number)) {

            if (valueClass == Integer.class) {

                return new Integer(((Number)value).intValue());

            }

            else if (valueClass == Long.class) {

                return new Long(((Number)value).longValue());

            }

            else if (valueClass == Float.class) {

                return new Float(((Number)value).floatValue());

            }

            else if (valueClass == Double.class) {

                return new Double(((Number)value).doubleValue());

            }

            else if (valueClass == Byte.class) {

                return new Byte(((Number)value).byteValue());

            }

            else if (valueClass == Short.class) {

                return new Short(((Number)value).shortValue());

            }

        }

        return value;

    }

    /**

     * Returns the character that is used to toggle to positive values.

     */

    private char getPositiveSign() {

        return '+';

    }

    /**

     * Returns the character that is used to toggle to negative values.

     */

    private char getMinusSign() {

        DecimalFormatSymbols dfs = getDecimalFormatSymbols();

        if (dfs != null) {

            return dfs.getMinusSign();

        }

        return '-';

    }

    /**

     * Returns the character that is used to toggle to negative values.

     */

    private char getDecimalSeparator() {

        DecimalFormatSymbols dfs = getDecimalFormatSymbols();

        if (dfs != null) {

            return dfs.getDecimalSeparator();

        }

        return '.';

    }

    /**

     * Returns the DecimalFormatSymbols from the Format instance.

     */

    private DecimalFormatSymbols getDecimalFormatSymbols() {

        Format f = getFormat();

        if (f instanceof DecimalFormat) {

            return ((DecimalFormat)f).getDecimalFormatSymbols();

        }

        return null;

    }

    /**

     */

    private boolean isValidInsertionCharacter(char aChar) {

        return (Character.isDigit(aChar) || specialChars.indexOf(aChar) != -1);

    }

    /**

     * Subclassed to return false if <code>text</code> contains in an invalid

     * character to insert, that is, it is not a digit

     * (<code>Character.isDigit()</code>) and

     * not one of the characters defined by the DecimalFormatSymbols.

     */

    boolean isLegalInsertText(String text) {

        if (getAllowsInvalid()) {

            return true;

        }

        for (int counter = text.length() - 1; counter >= 0; counter--) {

            char aChar = text.charAt(counter);

            if (!Character.isDigit(aChar) &&

                           specialChars.indexOf(aChar) == -1){

                return false;

            }

        }

        return true;

    }

    /**

     * Subclassed to treat the decimal separator, grouping separator,

     * exponent symbol, percent, permille, currency and sign as literals.

     */

    boolean isLiteral(Map attrs) {

        if (!super.isLiteral(attrs)) {

            if (attrs == null) {

                return false;

            }

            int size = attrs.size();

            if (attrs.get(NumberFormat.Field.GROUPING_SEPARATOR) != null) {

                size--;

                if (attrs.get(NumberFormat.Field.INTEGER) != null) {

                    size--;

                }

            }

            if (attrs.get(NumberFormat.Field.EXPONENT_SYMBOL) != null) {

                size--;

            }

            if (attrs.get(NumberFormat.Field.PERCENT) != null) {

                size--;

            }

            if (attrs.get(NumberFormat.Field.PERMILLE) != null) {

                size--;

            }

            if (attrs.get(NumberFormat.Field.CURRENCY) != null) {

                size--;

            }

            if (attrs.get(NumberFormat.Field.SIGN) != null) {

                size--;

            }

            if (size == 0) {

                return true;

            }

            return false;

        }

        return true;

    }

    /**

     * Subclassed to make the decimal separator navigatable, as well

     * as making the character between the integer field and the next

     * field navigatable.

     */

    boolean isNavigatable(int index) {

        if (!super.isNavigatable(index)) {

            // Don't skip the decimal, it causes wierd behavior

            if (getBufferedChar(index) == getDecimalSeparator()) {

                return true;

            }

            return false;

        }

        return true;

    }

    /**

     * Returns the first <code>NumberFormat.Field</code> starting

     * <code>index</code> incrementing by <code>direction</code>.

     */

    private NumberFormat.Field getFieldFrom(int index, int direction) {

        if (isValidMask()) {

            int max = getFormattedTextField().getDocument().getLength();

            AttributedCharacterIterator iterator = getIterator();

            if (index >= max) {

                index += direction;

            }

            while (index >= 0 && index < max) {

                iterator.setIndex(index);

                Map attrs = iterator.getAttributes();

                if (attrs != null && attrs.size() > 0) {

                    Iterator keys = attrs.keySet().iterator();

                    while (keys.hasNext()) {

                        Object key = keys.next();

                        if (key instanceof NumberFormat.Field) {

                            return (NumberFormat.Field)key;

                        }

                    }

                }

                index += direction;

            }

        }

        return null;

    }

    /**

     * Overriden to toggle the value if the positive/minus sign

     * is inserted.

     */

    void replace(DocumentFilter.FilterBypass fb, int offset, int length,

                String string, AttributeSet attr) throws BadLocationException {

        if (!getAllowsInvalid() && length == 0 && string != null &&

            string.length() == 1 &&

            toggleSignIfNecessary(fb, offset, string.charAt(0))) {

            return;

        }

        super.replace(fb, offset, length, string, attr);

    }

    /**

     * Will change the sign of the integer or exponent field if

     * <code>aChar</code> is the positive or minus sign. Returns

     * true if a sign change was attempted.

     */

    private boolean toggleSignIfNecessary(DocumentFilter.FilterBypass fb,

                                              int offset, char aChar) throws

                              BadLocationException {

        if (aChar == getMinusSign() || aChar == getPositiveSign()) {

            NumberFormat.Field field = getFieldFrom(offset, -1);

            Object newValue;

            try {

                if (field == null ||

                    (field != NumberFormat.Field.EXPONENT &&

                     field != NumberFormat.Field.EXPONENT_SYMBOL &&

                     field != NumberFormat.Field.EXPONENT_SIGN)) {

                    newValue = toggleSign((aChar == getPositiveSign()));

                }

                else {

                    // exponent

                    newValue = toggleExponentSign(offset, aChar);

                }

                if (newValue != null && isValidValue(newValue, false)) {

                    int lc = getLiteralCountTo(offset);

                    String string = valueToString(newValue);

                    fb.remove(0, fb.getDocument().getLength());

                    fb.insertString(0, string, null);

                    updateValue(newValue);

                    repositionCursor(getLiteralCountTo(offset) -

                                     lc + offset, 1);

                    return true;

                }

            } catch (ParseException pe) {

                invalidEdit();

            }

        }

        return false;

    }

    /**

     * Returns true if the range offset to length identifies the only

     * integer field.

     */

    private boolean isOnlyIntegerField(int offset, int length) {

        if (isValidMask()) {

            int start = getAttributeStart(NumberFormat.Field.INTEGER);

            if (start != -1) {

                AttributedCharacterIterator iterator = getIterator();

                iterator.setIndex(start);

                if (offset > start || iterator.getRunLimit(

                    NumberFormat.Field.INTEGER) > (offset + length)) {

                    return false;

                }

                return true;

            }

        }

        return false;

    }

    /**

     * Invoked to toggle the sign. For this to work the value class

     * must have a single arg constructor that takes a String.

     */

    private Object toggleSign(boolean positive) throws ParseException {

        Object value = stringToValue(getFormattedTextField().getText());

        if (value != null) {

            // toString isn't localized, so that using +/- should work

            // correctly.

            String string = value.toString();

            if (string != null && string.length() > 0) {

                if (positive) {

                    if (string.charAt(0) == '-') {

                        string = string.substring(1);

                    }

                }

                else {

                    if (string.charAt(0) == '+') {

                        string = string.substring(1);

                    }

                    if (string.length() > 0 && string.charAt(0) != '-') {

                        string = "-" + string;

                    }

                }

                if (string != null) {

                    Class valueClass = getValueClass();

                    if (valueClass == null) {

                        valueClass = value.getClass();

                    }

                    try {

                        Constructor cons = valueClass.getConstructor(

                                              new Class[] { String.class });

                        if (cons != null) {

                            return cons.newInstance(new Object[]{string});

                        }

                    } catch (Throwable ex) { }

                }

            }

        }

        return null;

    }

    /**

     * Invoked to toggle the sign of the exponent (for scientific

     * numbers).

     */

    private Object toggleExponentSign(int offset, char aChar) throws

                             BadLocationException, ParseException {

        String string = getFormattedTextField().getText();

        int replaceLength = 0;

        int loc = getAttributeStart(NumberFormat.Field.EXPONENT_SIGN);

        if (loc >= 0) {

            replaceLength = 1;

            offset = loc;

        }

        if (aChar == getPositiveSign()) {

            string = getReplaceString(offset, replaceLength, null);

        }

        else {

            string = getReplaceString(offset, replaceLength,

                                      new String(new char[] { aChar }));

        }

        return stringToValue(string);

    }

}