/*
 * @(#)HTML.java	1.27 01/11/29
 *
 * Copyright 2002 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */
package javax.swing.text.html;

import java.io.Serializable;
import java.util.Hashtable;
import javax.swing.text.AttributeSet;
import javax.swing.text.StyleContext;

/**
 * Constants used in the HTMLDocument.  These
 * are basically tag and attribute definitions.
 *
 * @author  Timothy Prinzing
 * @author  Sunita Mani
 *
 * @version 1.27 11/29/01
 */
public class HTML {

    /**
     * Typesafe enumeration for an html tag.  Although the
     * set of html tags is a closed set, we have let the
     * set open so that people can add their own tag types
     * to their custom parser and still communicate to the
     * reader.
     */
    public static class Tag {

        protected Tag(String id) {
	    this(id, false, false);
	}

	protected Tag(String id, boolean causesBreak, boolean isBlock) {
	    name = id;
	    this.breakTag = causesBreak;
	    this.blockTag = isBlock;
	}

	/**
	 * Block tags are tags that add structure to
	 * a document.
	 */
	public boolean isBlock() {
	    return blockTag;
	}

	/**
	 * If the tag causes a line break, to the flow of
	 * data, then this method will return true.
	 */
	public boolean breaksFlow() {
	    return breakTag;
	}

	public boolean isPreformatted() {
	    return (this == PRE || this == TEXTAREA);
	}

	/**
	 * Return the string representation of the
	 * tag.
	 */
        public String toString() {
	    return name;
	}

	private boolean blockTag;
	private boolean breakTag;
	private String name;
	private boolean unknown;

    	// --- Tag Names -----------------------------------

    	public static final Tag A = new Tag("a");
    	public static final Tag ADDRESS = new Tag("address");
    	public static final Tag APPLET = new Tag("applet");
    	public static final Tag AREA = new Tag("area");
    	public static final Tag B = new Tag("b");
    	public static final Tag BASE = new Tag("base");
    	public static final Tag BASEFONT = new Tag("basefont");
    	public static final Tag BIG = new Tag("big");
    	public static final Tag BLOCKQUOTE = new Tag("blockquote", true, true);
    	public static final Tag BODY = new Tag("body", true, true);
    	public static final Tag BR = new Tag("br", true, false);
    	public static final Tag CAPTION = new Tag("caption");
    	public static final Tag CENTER = new Tag("center", true, false);
    	public static final Tag CITE = new Tag("cite");
    	public static final Tag CODE = new Tag("code");
    	public static final Tag DD = new Tag("dd", true, true);
    	public static final Tag DFN = new Tag("dfn");
    	public static final Tag DIR = new Tag("dir", true, true);
    	public static final Tag DIV = new Tag("div", true, true);
    	public static final Tag DL = new Tag("dl", true, true);
    	public static final Tag DT = new Tag("dt", true, true);
    	public static final Tag EM = new Tag("em");
    	public static final Tag FONT = new Tag("font");
    	public static final Tag FORM = new Tag("form", true, false);
	public static final Tag FRAME = new Tag("frame");
	public static final Tag FRAMESET = new Tag("frameset");
    	public static final Tag H1 = new Tag("h1", true, true);
    	public static final Tag H2 = new Tag("h2", true, true);
    	public static final Tag H3 = new Tag("h3", true, true);
    	public static final Tag H4 = new Tag("h4", true, true);
    	public static final Tag H5 = new Tag("h5", true, true);
    	public static final Tag H6 = new Tag("h6", true, true);
    	public static final Tag HEAD = new Tag("head", true, true);
    	public static final Tag HR = new Tag("hr", true, false);
    	public static final Tag HTML = new Tag("html", true, false);
    	public static final Tag I = new Tag("i");
    	public static final Tag IMG = new Tag("img");
    	public static final Tag INPUT = new Tag("input");
    	public static final Tag ISINDEX = new Tag("isindex", true, false);
    	public static final Tag KBD = new Tag("kbd");
    	public static final Tag LI = new Tag("li", true, true);
    	public static final Tag LINK = new Tag("link");
    	public static final Tag MAP = new Tag("map");
    	public static final Tag MENU = new Tag("menu", true, true);
    	public static final Tag META = new Tag("meta");
	public static final Tag NOFRAMES = new Tag("noframes", true, true);
    	public static final Tag OBJECT = new Tag("object");
    	public static final Tag OL = new Tag("ol", true, true);
    	public static final Tag OPTION = new Tag("option");
    	public static final Tag P = new Tag("p", true, true);
    	public static final Tag PARAM = new Tag("param");
    	public static final Tag PRE = new Tag("pre", true, true);
    	public static final Tag SAMP = new Tag("samp");
    	public static final Tag SCRIPT = new Tag("script");
    	public static final Tag SELECT = new Tag("select");
    	public static final Tag SMALL = new Tag("small");
    	public static final Tag STRIKE = new Tag("strike");
    	public static final Tag S = new Tag("s");
    	public static final Tag STRONG = new Tag("strong");
    	public static final Tag STYLE = new Tag("style");
    	public static final Tag SUB = new Tag("sub");
    	public static final Tag SUP = new Tag("sup");
    	public static final Tag TABLE = new Tag("table", false, true);
    	public static final Tag TD = new Tag("td", true, true);
    	public static final Tag TEXTAREA = new Tag("textarea");
    	public static final Tag TH = new Tag("th", true, true);
    	public static final Tag TITLE = new Tag("title", true, true);
    	public static final Tag TR = new Tag("tr", false, true);
    	public static final Tag TT = new Tag("tt");
    	public static final Tag U = new Tag("u");
    	public static final Tag UL = new Tag("ul", true, true);
    	public static final Tag VAR = new Tag("var");

	/**
	 * All text content must be in a paragraph element.
	 * If a paragraph didn't exist when content was
	 * encountered, a paragraph is manufactured.
	 * <p>
	 * This is a tag synthesized by the html reader.
	 * Since elements are identified by their tag type,
	 * we create a some fake tag types to mark the elements
	 * that were manufactured.
	 */
	public static final Tag IMPLIED = new Tag("p-implied");

	/**
	 * All text content is labeled with this tag.
	 * <p>
	 * This is a tag synthesized by the html reader.
	 * Since elements are identified by their tag type,
	 * we create a some fake tag types to mark the elements
	 * that were manufactured.
	 */
	public static final Tag CONTENT = new Tag("content");

	/**
	 * All comments are labeled with this tag.
	 * <p>
	 * This is a tag synthesized by the html reader.
	 * Since elements are identified by their tag type,
	 * we create a some fake tag types to mark the elements
	 * that were manufactured.
	 */
	public static final Tag COMMENT = new Tag("comment");

	static final Tag allTags[]  = {
	    A, ADDRESS, APPLET, AREA, B, BASE, BASEFONT, BIG,
	    BLOCKQUOTE, BODY, BR, CAPTION, CENTER, CITE, CODE,
	    DD, DFN, DIR, DIV, DL, DT, EM, FONT, FORM, FRAME,
	    FRAMESET, H1, H2, H3, H4, H5, H6, HEAD, HR, HTML,
	    I, IMG, INPUT, ISINDEX, KBD, LI, LINK, MAP, MENU,
	    META, NOFRAMES, OBJECT, OL, OPTION, P, PARAM,
	    PRE, SAMP, SCRIPT, SELECT, SMALL, STRIKE, S,
	    STRONG, STYLE, SUB, SUP, TABLE, TD, TEXTAREA,
	    TH, TITLE, TR, TT, U, UL, VAR	
	};

    }

    // There is no unique instance of UnknownTag, so we allow it to be
    // Serializable.
    public static class UnknownTag extends Tag implements Serializable {
	
	public UnknownTag(String id) {
	    super(id);
	}

	public int hashCode() {
	    return toString().hashCode();
	}

	/**
	 * Compares this object to the specifed object.
	 * The result is <code>true</code> if and only if the argument is not
	 * <code>null</code> and is a <code>UnknownTag</code> object with the same
	 * name.
	 * @param     obj   the object to compare this tag with.
	 * @return    <code>true</code> if the objects are equal;
	 *            <code>false</code> otherwise.
	 */
        public boolean equals(Object obj) {
	    if (obj instanceof UnknownTag) {
		return toString().equals(obj.toString());
	    }
	    return false;
	}
    }

    /**
     * Typesafe enumeration representing an html
     * attribute.
     */
    public static final class Attribute {

	Attribute(String id) {
	    name = id;
	}

	public String toString() {
	    return name;
	}

	private String name;

	public static final Attribute SIZE = new Attribute("size");
	public static final Attribute COLOR = new Attribute("color");
	public static final Attribute CLEAR = new Attribute("clear");
	public static final Attribute BACKGROUND = new Attribute("background");
	public static final Attribute BGCOLOR = new Attribute("bgcolor");
	public static final Attribute TEXT = new Attribute("text");
	public static final Attribute LINK = new Attribute("link");
	public static final Attribute VLINK = new Attribute("vlink");
	public static final Attribute ALINK = new Attribute("alink");
	public static final Attribute WIDTH = new Attribute("width");
	public static final Attribute HEIGHT = new Attribute("height");
	public static final Attribute ALIGN = new Attribute("align");
	public static final Attribute NAME = new Attribute("name");
	public static final Attribute HREF = new Attribute("href");
	public static final Attribute REL = new Attribute("rel");
	public static final Attribute REV = new Attribute("rev");
	public static final Attribute TITLE = new Attribute("title");
	public static final Attribute TARGET = new Attribute("target");
	public static final Attribute SHAPE = new Attribute("shape");
	public static final Attribute COORDS = new Attribute("coords");
	public static final Attribute ISMAP = new Attribute("ismap");
	public static final Attribute NOHREF = new Attribute("nohref");
	public static final Attribute ALT = new Attribute("alt");
	public static final Attribute ID = new Attribute("id");
	public static final Attribute SRC = new Attribute("src");
	public static final Attribute HSPACE = new Attribute("hspace");
	public static final Attribute VSPACE = new Attribute("vspace");
	public static final Attribute USEMAP = new Attribute("usemap");
	public static final Attribute LOWSRC = new Attribute("lowsrc");
	public static final Attribute CODEBASE = new Attribute("codebase");
	public static final Attribute CODE = new Attribute("code");
	public static final Attribute ARCHIVE = new Attribute("archive");
	public static final Attribute VALUE = new Attribute("value");
	public static final Attribute VALUETYPE = new Attribute("valuetype");
	public static final Attribute TYPE = new Attribute("type");
	public static final Attribute CLASS = new Attribute("class");
	public static final Attribute STYLE = new Attribute("style");
	public static final Attribute LANG = new Attribute("lang");
	public static final Attribute FACE = new Attribute("face");
	public static final Attribute DIR = new Attribute("dir");
	public static final Attribute DECLARE = new Attribute("declare");
	public static final Attribute CLASSID = new Attribute("classid");
	public static final Attribute DATA = new Attribute("data");
	public static final Attribute CODETYPE = new Attribute("codetype");
	public static final Attribute STANDBY = new Attribute("standby");
	public static final Attribute BORDER = new Attribute("border");
	public static final Attribute SHAPES = new Attribute("shapes");
	public static final Attribute NOSHADE = new Attribute("noshade");
	public static final Attribute COMPACT = new Attribute("compact");
	public static final Attribute START = new Attribute("start");
	public static final Attribute ACTION = new Attribute("action");
	public static final Attribute METHOD = new Attribute("method");
	public static final Attribute ENCTYPE = new Attribute("enctype");
	public static final Attribute CHECKED = new Attribute("checked");
	public static final Attribute MAXLENGTH = new Attribute("maxlength");
	public static final Attribute MULTIPLE = new Attribute("multiple");
	public static final Attribute SELECTED = new Attribute("selected");
	public static final Attribute ROWS = new Attribute("rows");
	public static final Attribute COLS = new Attribute("cols");
	public static final Attribute DUMMY = new Attribute("dummy");
	public static final Attribute CELLSPACING = new Attribute("cellspacing");
	public static final Attribute CELLPADDING = new Attribute("cellpadding");
	public static final Attribute VALIGN = new Attribute("valign");
	public static final Attribute HALIGN = new Attribute("halign");
	public static final Attribute NOWRAP = new Attribute("nowrap");
	public static final Attribute ROWSPAN = new Attribute("rowspan");
	public static final Attribute COLSPAN = new Attribute("colspan");
	public static final Attribute PROMPT = new Attribute("prompt");
	public static final Attribute HTTPEQUIV = new Attribute("http-equiv");
	public static final Attribute CONTENT = new Attribute("content");
	public static final Attribute LANGUAGE = new Attribute("language");
	public static final Attribute VERSION = new Attribute("version");
	public static final Attribute N = new Attribute("n");
	public static final Attribute FRAMEBORDER = new Attribute("frameborder");
	public static final Attribute MARGINWIDTH = new Attribute("marginwidth");
	public static final Attribute MARGINHEIGHT = new Attribute("marginheight");
	public static final Attribute SCROLLING = new Attribute("scrolling");
	public static final Attribute NORESIZE = new Attribute("noresize");
	public static final Attribute ENDTAG = new Attribute("endtag");
	public static final Attribute COMMENT = new Attribute("comment");
	static final Attribute MEDIA = new Attribute("media");

	static final Attribute allAttributes[] = {
	    FACE,
	    COMMENT,
	    SIZE,
	    COLOR,
	    CLEAR,
	    BACKGROUND,
	    BGCOLOR,
	    TEXT,
	    LINK,
	    VLINK,
	    ALINK,
	    WIDTH,
	    HEIGHT,
	    ALIGN,
	    NAME,
	    HREF,
            REL,
            REV,
            TITLE,
            TARGET,
            SHAPE,
            COORDS,
            ISMAP,
            NOHREF,
            ALT,
            ID,
            SRC,
            HSPACE,
            VSPACE,
            USEMAP,
            LOWSRC,
            CODEBASE,
            CODE,
            ARCHIVE,
            VALUE,
            VALUETYPE,
            TYPE,
            CLASS,
            STYLE,
            LANG,
            DIR,
            DECLARE,
            CLASSID,
            DATA,
            CODETYPE,
            STANDBY,
            BORDER,
            SHAPES,
            NOSHADE,
            COMPACT,
            START,
            ACTION,
            METHOD,
            ENCTYPE,
            CHECKED,
            MAXLENGTH,
            MULTIPLE,
            SELECTED,
            ROWS,
            COLS,
            DUMMY,
            CELLSPACING,
            CELLPADDING,
            VALIGN,
            HALIGN,
            NOWRAP,
            ROWSPAN,
            COLSPAN,
            PROMPT,
            HTTPEQUIV,
            CONTENT,
            LANGUAGE,
            VERSION,
            N,
            FRAMEBORDER,
            MARGINWIDTH,
            MARGINHEIGHT,
            SCROLLING,
            NORESIZE,
            MEDIA,
	    ENDTAG
	};
    }

    // The secret to 71, is that, given that the Hashtable contents
    // never change once the static initialization happens, the initial size 
    // that the hashtable grew to was determined, and then that very size
    // is used.
    //
    private static final Hashtable tagHashtable = new Hashtable(71);

    static {

	for (int i = 0; i < Tag.allTags.length; i++ ) {
	    tagHashtable.put(Tag.allTags[i].toString(), Tag.allTags[i]);
	    StyleContext.registerStaticAttributeKey(Tag.allTags[i]);
	}
	StyleContext.registerStaticAttributeKey(Tag.IMPLIED);
	StyleContext.registerStaticAttributeKey(Tag.CONTENT);
	StyleContext.registerStaticAttributeKey(Tag.COMMENT);
	for (int i = 0; i < Attribute.allAttributes.length; i++) {
	    StyleContext.registerStaticAttributeKey(Attribute.
						    allAttributes[i]);
	}
    }

    /**
     * This is the set of actual html tags that
     * are known about the the default html reader.
     * This set does not include tags that are
     * manufactured by the reader.
     */
    public static Tag[] getAllTags() {
	Tag[] tags = new Tag[Tag.allTags.length];
	System.arraycopy(Tag.allTags, 0, tags, 0, Tag.allTags.length);
	return tags;
    }

    /**
     * Fetch a tag constant for a well-known tag name (i.e. one of
     * the tags in the set <code>allTags</code>).  If the given
     * name does not represent one of the well-known tags, then
     * null will be returned.
     */
    public static Tag getTag(String tagName) {

	Object t =  tagHashtable.get(tagName);
	return (t == null ? null : (Tag)t);
    }

    /**
     * Fetch an integer attribute value.  Attribute values
     * are stored as a string, and this is a convenience method
     * to convert to an actual integer.
     *
     * @param attr the set of attributes to use to try to fetch a value
     * @param key the key to use to fetch the value.
     * @param def the default value to use if the attribute isn't
     *  defined or there is an error converting to an integer.
     */
    public static int getIntegerAttributeValue(AttributeSet attr,
					       Attribute key, int def) {
	int value = def;
	String istr = (String) attr.getAttribute(key);
	if (istr != null) {
	    try {
		value = Integer.valueOf(istr).intValue();
	    } catch (NumberFormatException e) {
		value = def;
	    }
	}
	return value;
    }

    //  This is used in cases where the value for the attribute has not
    //  been specified.
    //
    public static final String NULL_ATTRIBUTE_VALUE = "#DEFAULT";

    // size determined similar to size of tagHashtable
    private static final Hashtable attHashtable = new Hashtable(77);

    static {

	for (int i = 0; i < Attribute.allAttributes.length; i++ ) {
	    attHashtable.put(Attribute.allAttributes[i].toString(), Attribute.allAttributes[i]);
	}
    }

    /**
     * This is the set of html attributes recognized.
     */
    public static Attribute[] getAllAttributeKeys() {
	Attribute[] attributes = new Attribute[Attribute.allAttributes.length];
	System.arraycopy(Attribute.allAttributes, 0, 
			 attributes, 0, Attribute.allAttributes.length);
	return attributes;
    }

    /**
     * Fetch an attribute constant for a well-known attribute name
     * (i.e. one of the attributes in the set <code>allAttributes</code>).
     * If the given name does not represent one of the well-known attributes,
     * then null will be returned.
     */
    public static Attribute getAttributeKey(String attName) {
	Object a = attHashtable.get(attName);
	if (a == null) {
	  return null;
	}
	return (Attribute)a;
    }

}