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	/*
	* Copyright (c) 1996, 2013, 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
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	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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	/*
	* (C) Copyright Taligent, Inc. 1996, 1997 - All Rights Reserved
	* (C) Copyright IBM Corp. 1996 - 1998 - All Rights Reserved
	*
	* The original version of this source code and documentation is copyrighted
	* and owned by Taligent, Inc., a wholly-owned subsidiary of IBM. These
	* materials are provided under terms of a License Agreement between Taligent
	* and Sun. This technology is protected by multiple US and International
	* patents. This notice and attribution to Taligent may not be removed.
	* Taligent is a registered trademark of Taligent, Inc.
	*
	*/

	package java.text;

	import java.io.Serializable;

	/**
	* <code>Format</code> is an abstract base class for formatting locale-sensitive
	* information such as dates, messages, and numbers.
	*
	* <p>
	* <code>Format</code> defines the programming interface for formatting
	* locale-sensitive objects into <code>String</code>s (the
	* <code>format</code> method) and for parsing <code>String</code>s back
	* into objects (the <code>parseObject</code> method).
	*
	* <p>
	* Generally, a format's <code>parseObject</code> method must be able to parse
	* any string formatted by its <code>format</code> method. However, there may
	* be exceptional cases where this is not possible. For example, a
	* <code>format</code> method might create two adjacent integer numbers with
	* no separator in between, and in this case the <code>parseObject</code> could
	* not tell which digits belong to which number.
	*
	* <h3>Subclassing</h3>
	*
	* <p>
	* The Java Platform provides three specialized subclasses of <code>Format</code>--
	* <code>DateFormat</code>, <code>MessageFormat</code>, and
	* <code>NumberFormat</code>--for formatting dates, messages, and numbers,
	* respectively.
	* <p>
	* Concrete subclasses must implement three methods:
	* <ol>
	* <li> <code>format(Object obj, StringBuffer toAppendTo, FieldPosition pos)</code>
	* <li> <code>formatToCharacterIterator(Object obj)</code>
	* <li> <code>parseObject(String source, ParsePosition pos)</code>
	* </ol>
	* These general methods allow polymorphic parsing and formatting of objects
	* and are used, for example, by <code>MessageFormat</code>.
	* Subclasses often also provide additional <code>format</code> methods for
	* specific input types as well as <code>parse</code> methods for specific
	* result types. Any <code>parse</code> method that does not take a
	* <code>ParsePosition</code> argument should throw <code>ParseException</code>
	* when no text in the required format is at the beginning of the input text.
	*
	* <p>
	* Most subclasses will also implement the following factory methods:
	* <ol>
	* <li>
	* <code>getInstance</code> for getting a useful format object appropriate
	* for the current locale
	* <li>
	* <code>getInstance(Locale)</code> for getting a useful format
	* object appropriate for the specified locale
	* </ol>
	* In addition, some subclasses may also implement other
	* <code>getXxxxInstance</code> methods for more specialized control. For
	* example, the <code>NumberFormat</code> class provides
	* <code>getPercentInstance</code> and <code>getCurrencyInstance</code>
	* methods for getting specialized number formatters.
	*
	* <p>
	* Subclasses of <code>Format</code> that allow programmers to create objects
	* for locales (with <code>getInstance(Locale)</code> for example)
	* must also implement the following class method:
	* <blockquote>
	* <pre>
	* public static Locale[] getAvailableLocales()
	* </pre>
	* </blockquote>
	*
	* <p>
	* And finally subclasses may define a set of constants to identify the various
	* fields in the formatted output. These constants are used to create a FieldPosition
	* object which identifies what information is contained in the field and its
	* position in the formatted result. These constants should be named
	* <code><em>item</em>_FIELD</code> where <code><em>item</em></code> identifies
	* the field. For examples of these constants, see <code>ERA_FIELD</code> and its
	* friends in {@link DateFormat}.
	*
	* <h4><a name="synchronization">Synchronization</a></h4>
	*
	* <p>
	* Formats are generally not synchronized.
	* It is recommended to create separate format instances for each thread.
	* If multiple threads access a format concurrently, it must be synchronized
	* externally.
	*
	* @see java.text.ParsePosition
	* @see java.text.FieldPosition
	* @see java.text.NumberFormat
	* @see java.text.DateFormat
	* @see java.text.MessageFormat
	* @author Mark Davis
	*/
	public abstract class Format implements Serializable, Cloneable {

	private static final long serialVersionUID = -299282585814624189L;

	/**
	* Sole constructor. (For invocation by subclass constructors, typically
	* implicit.)
	*/
	protected Format() {
	}

	/**
	* Formats an object to produce a string. This is equivalent to
	* <blockquote>
	* {@link #format(Object, StringBuffer, FieldPosition) format}<code>(obj,
	* new StringBuffer(), new FieldPosition(0)).toString();</code>
	* </blockquote>
	*
	* @param obj The object to format
	* @return Formatted string.
	* @exception IllegalArgumentException if the Format cannot format the given
	* object
	*/
	public final String format (Object obj) {
	return format(obj, new StringBuffer(), new FieldPosition(0)).toString();
	}

	/**
	* Formats an object and appends the resulting text to a given string
	* buffer.
	* If the <code>pos</code> argument identifies a field used by the format,
	* then its indices are set to the beginning and end of the first such
	* field encountered.
	*
	* @param obj The object to format
	* @param toAppendTo where the text is to be appended
	* @param pos A <code>FieldPosition</code> identifying a field
	* in the formatted text
	* @return the string buffer passed in as <code>toAppendTo</code>,
	* with formatted text appended
	* @exception NullPointerException if <code>toAppendTo</code> or
	* <code>pos</code> is null
	* @exception IllegalArgumentException if the Format cannot format the given
	* object
	*/
	public abstract StringBuffer format(Object obj,
	StringBuffer toAppendTo,
	FieldPosition pos);

	/**
	* Formats an Object producing an <code>AttributedCharacterIterator</code>.
	* You can use the returned <code>AttributedCharacterIterator</code>
	* to build the resulting String, as well as to determine information
	* about the resulting String.
	* <p>
	* Each attribute key of the AttributedCharacterIterator will be of type
	* <code>Field</code>. It is up to each <code>Format</code> implementation
	* to define what the legal values are for each attribute in the
	* <code>AttributedCharacterIterator</code>, but typically the attribute
	* key is also used as the attribute value.
	* <p>The default implementation creates an
	* <code>AttributedCharacterIterator</code> with no attributes. Subclasses
	* that support fields should override this and create an
	* <code>AttributedCharacterIterator</code> with meaningful attributes.
	*
	* @exception NullPointerException if obj is null.
	* @exception IllegalArgumentException when the Format cannot format the
	* given object.
	* @param obj The object to format
	* @return AttributedCharacterIterator describing the formatted value.
	* @since 1.4
	*/
	public AttributedCharacterIterator formatToCharacterIterator(Object obj) {
	return createAttributedCharacterIterator(format(obj));
	}

	/**
	* Parses text from a string to produce an object.
	* <p>
	* The method attempts to parse text starting at the index given by
	* <code>pos</code>.
	* If parsing succeeds, then the index of <code>pos</code> is updated
	* to the index after the last character used (parsing does not necessarily
	* use all characters up to the end of the string), and the parsed
	* object is returned. The updated <code>pos</code> can be used to
	* indicate the starting point for the next call to this method.
	* If an error occurs, then the index of <code>pos</code> is not
	* changed, the error index of <code>pos</code> is set to the index of
	* the character where the error occurred, and null is returned.
	*
	* @param source A <code>String</code>, part of which should be parsed.
	* @param pos A <code>ParsePosition</code> object with index and error
	* index information as described above.
	* @return An <code>Object</code> parsed from the string. In case of
	* error, returns null.
	* @exception NullPointerException if <code>pos</code> is null.
	*/
	public abstract Object parseObject (String source, ParsePosition pos);

	/**
	* Parses text from the beginning of the given string to produce an object.
	* The method may not use the entire text of the given string.
	*
	* @param source A <code>String</code> whose beginning should be parsed.
	* @return An <code>Object</code> parsed from the string.
	* @exception ParseException if the beginning of the specified string
	* cannot be parsed.
	*/
	public Object parseObject(String source) throws ParseException {
	ParsePosition pos = new ParsePosition(0);
	Object result = parseObject(source, pos);
	if (pos.index == 0) {
	throw new ParseException("Format.parseObject(String) failed",
	pos.errorIndex);
	}
	return result;
	}

	/**
	* Creates and returns a copy of this object.
	*
	* @return a clone of this instance.
	*/
	public Object clone() {
	try {
	return super.clone();
	} catch (CloneNotSupportedException e) {
	// will never happen
	throw new InternalError(e);
	}
	}

	//
	// Convenience methods for creating AttributedCharacterIterators from
	// different parameters.
	//

	/**
	* Creates an <code>AttributedCharacterIterator</code> for the String
	* <code>s</code>.
	*
	* @param s String to create AttributedCharacterIterator from
	* @return AttributedCharacterIterator wrapping s
	*/
	AttributedCharacterIterator createAttributedCharacterIterator(String s) {
	AttributedString as = new AttributedString(s);

	return as.getIterator();
	}

	/**
	* Creates an <code>AttributedCharacterIterator</code> containing the
	* concatenated contents of the passed in
	* <code>AttributedCharacterIterator</code>s.
	*
	* @param iterators AttributedCharacterIterators used to create resulting
	* AttributedCharacterIterators
	* @return AttributedCharacterIterator wrapping passed in
	* AttributedCharacterIterators
	*/
	AttributedCharacterIterator createAttributedCharacterIterator(
	AttributedCharacterIterator[] iterators) {
	AttributedString as = new AttributedString(iterators);

	return as.getIterator();
	}

	/**
	* Returns an AttributedCharacterIterator with the String
	* <code>string</code> and additional key/value pair <code>key</code>,
	* <code>value</code>.
	*
	* @param string String to create AttributedCharacterIterator from
	* @param key Key for AttributedCharacterIterator
	* @param value Value associated with key in AttributedCharacterIterator
	* @return AttributedCharacterIterator wrapping args
	*/
	AttributedCharacterIterator createAttributedCharacterIterator(
	String string, AttributedCharacterIterator.Attribute key,
	Object value) {
	AttributedString as = new AttributedString(string);

	as.addAttribute(key, value);
	return as.getIterator();
	}

	/**
	* Creates an AttributedCharacterIterator with the contents of
	* <code>iterator</code> and the additional attribute <code>key</code>
	* <code>value</code>.
	*
	* @param iterator Initial AttributedCharacterIterator to add arg to
	* @param key Key for AttributedCharacterIterator
	* @param value Value associated with key in AttributedCharacterIterator
	* @return AttributedCharacterIterator wrapping args
	*/
	AttributedCharacterIterator createAttributedCharacterIterator(
	AttributedCharacterIterator iterator,
	AttributedCharacterIterator.Attribute key, Object value) {
	AttributedString as = new AttributedString(iterator);

	as.addAttribute(key, value);
	return as.getIterator();
	}


	/**
	* Defines constants that are used as attribute keys in the
	* <code>AttributedCharacterIterator</code> returned
	* from <code>Format.formatToCharacterIterator</code> and as
	* field identifiers in <code>FieldPosition</code>.
	*
	* @since 1.4
	*/
	public static class Field extends AttributedCharacterIterator.Attribute {

	// Proclaim serial compatibility with 1.4 FCS
	private static final long serialVersionUID = 276966692217360283L;

	/**
	* Creates a Field with the specified name.
	*
	* @param name Name of the attribute
	*/
	protected Field(String name) {
	super(name);
	}
	}


	/**
	* FieldDelegate is notified by the various <code>Format</code>
	* implementations as they are formatting the Objects. This allows for
	* storage of the individual sections of the formatted String for
	* later use, such as in a <code>FieldPosition</code> or for an
	* <code>AttributedCharacterIterator</code>.
	* <p>
	* Delegates should NOT assume that the <code>Format</code> will notify
	* the delegate of fields in any particular order.
	*
	* @see FieldPosition#getFieldDelegate
	* @see CharacterIteratorFieldDelegate
	*/
	interface FieldDelegate {
	/**
	* Notified when a particular region of the String is formatted. This
	* method will be invoked if there is no corresponding integer field id
	* matching <code>attr</code>.
	*
	* @param attr Identifies the field matched
	* @param value Value associated with the field
	* @param start Beginning location of the field, will be >= 0
	* @param end End of the field, will be >= start and <= buffer.length()
	* @param buffer Contains current formatted value, receiver should
	* NOT modify it.
	*/
	public void formatted(Format.Field attr, Object value, int start,
	int end, StringBuffer buffer);

	/**
	* Notified when a particular region of the String is formatted.
	*
	* @param fieldID Identifies the field by integer
	* @param attr Identifies the field matched
	* @param value Value associated with the field
	* @param start Beginning location of the field, will be >= 0
	* @param end End of the field, will be >= start and <= buffer.length()
	* @param buffer Contains current formatted value, receiver should
	* NOT modify it.
	*/
	public void formatted(int fieldID, Format.Field attr, Object value,
	int start, int end, StringBuffer buffer);
	}
	}

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