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package javax.swing.text.html.parser;

import java.util.Hashtable;
import java.util.BitSet;
import java.io.*;
import sun.awt.AppContext;


An element as described in a DTD using the ELEMENT construct.
This is essential the description of a tag. It describes the
type, content model, attributes, attribute types etc. It is used
to correctly parse a document by the Parser.

Author:Arthur van Hoff
See Also:
/**
 * An element as described in a DTD using the ELEMENT construct.
 * This is essential the description of a tag. It describes the
 * type, content model, attributes, attribute types etc. It is used
 * to correctly parse a document by the Parser.
 *
 * @see DTD
 * @see AttributeList
 * @author Arthur van Hoff
 */
@SuppressWarnings("serial") // Same-version serialization only
public final
class Element implements DTDConstants, Serializable {

    
The element index

/**
     * The element index
     */
    public int index;

    
The name of the element

/**
     * The name of the element
     */
    public String name;

    
true if the start tag can be omitted 
/**
     * {@code true} if the start tag can be omitted
     */
    public boolean oStart;

    
true if the end tag can be omitted 
/**
     * {@code true} if the end tag can be omitted
     */
    public boolean oEnd;

    
The set of elements that can occur inside the element

/**
     * The set of elements that can occur inside the element
     */
    public BitSet inclusions;

    
The set of elements that must not occur inside the element

/**
     * The set of elements that must not occur inside the element
     */
    public BitSet exclusions;

    
The element type

/**
     * The element type
     */
    public int type = ANY;

    
The content model

/**
     * The content model
     */
    public ContentModel content;

    
The attributes

/**
     * The attributes
     */
    public AttributeList atts;

    
A field to store user data. Mostly used to store
style sheets.

/**
     * A field to store user data. Mostly used to store
     * style sheets.
     */
    public Object data;

    Element() {
    }

    
Create a new element.

Params:
  • name –   the name of the element
  • index –  the index
/**
     * Create a new element.
     *
     * @param name   the name of the element
     * @param index  the index
     */
    Element(String name, int index) {
        this.name = name;
        this.index = index;
        if (index > getMaxIndex()) {
            AppContext.getAppContext().put(MAX_INDEX_KEY, index);
        }
    }

    private static final Object MAX_INDEX_KEY = new Object();

    static int getMaxIndex() {
        Integer value = (Integer) AppContext.getAppContext().get(MAX_INDEX_KEY);
        return (value != null)
                ? value.intValue()
                : 0;
    }

    
Get the name of the element.

Returns: the name of the element
/**
     * Get the name of the element.
     *
     * @return  the name of the element
     */
    public String getName() {
        return name;
    }

    
Return true if the start tag can be omitted.

Returns: true if the start tag can be omitted
/**
     * Return true if the start tag can be omitted.
     *
     * @return  {@code true} if the start tag can be omitted
     */
    public boolean omitStart() {
        return oStart;
    }

    
Return true if the end tag can be omitted.

Returns: true if the end tag can be omitted
/**
     * Return true if the end tag can be omitted.
     *
     * @return  {@code true} if the end tag can be omitted
     */
    public boolean omitEnd() {
        return oEnd;
    }

    
Get type.

Returns: the type of the element
/**
     * Get type.
     *
     * @return  the type of the element
     */
    public int getType() {
        return type;
    }

    
Get content model

Returns: the content model
/**
     * Get content model
     *
     * @return  the content model
     */
    public ContentModel getContent() {
        return content;
    }

    
Get the attributes.

Returns: the AttributeList specifying the element
/**
     * Get the attributes.
     *
     * @return  the {@code AttributeList} specifying the element
     */
    public AttributeList getAttributes() {
        return atts;
    }

    
Get index.

Returns:the element index
/**
     * Get index.
     *
     * @return the element index
     */
    public int getIndex() {
        return index;
    }

    
Check if empty

Returns: true if the current element is empty
/**
     * Check if empty
     *
     * @return  true if the current element is empty
     */
    public boolean isEmpty() {
        return type == EMPTY;
    }

    
Convert to a string.

Returns: a string representation for the given Element instance
/**
     * Convert to a string.
     *
     * @return  a string representation for the given {@code Element} instance
     */
    public String toString() {
        return name;
    }

    
Get an attribute by name.

Params:
  • name –  the attribute name
Returns:the AttributeList for the given name
/**
     * Get an attribute by name.
     *
     * @param name  the attribute name
     *
     * @return the {@code AttributeList} for the given {@code name}
     */
    public AttributeList getAttribute(String name) {
        for (AttributeList a = atts ; a != null ; a = a.next) {
            if (a.name.equals(name)) {
                return a;
            }
        }
        return null;
    }

    
Get an attribute by value.

Params:
  • value –  the string representation of value
Returns: the AttributeList for the given value
/**
     * Get an attribute by value.
     *
     * @param value  the string representation of value
     *
     * @return  the {@code AttributeList} for the given {@code value}
     */
    public AttributeList getAttributeByValue(String value) {
        for (AttributeList a = atts ; a != null ; a = a.next) {
            if ((a.values != null) && a.values.contains(value)) {
                return a;
            }
        }
        return null;
    }


    static Hashtable<String, Integer> contentTypes = new Hashtable<String, Integer>();

    static {
        contentTypes.put("CDATA", Integer.valueOf(CDATA));
        contentTypes.put("RCDATA", Integer.valueOf(RCDATA));
        contentTypes.put("EMPTY", Integer.valueOf(EMPTY));
        contentTypes.put("ANY", Integer.valueOf(ANY));
    }

    
Converts nm to type. Returns appropriate DTDConstants if the nm is equal to CDATA, RCDATA, EMPTY or ANY, 0 otherwise. 
Params:
  • nm – a name
Returns:appropriate DTDConstants if the nm is equal to CDATA, RCDATA, EMPTY or ANY, 0 otherwise.
/**
     * Converts {@code nm} to type. Returns appropriate DTDConstants
     * if the {@code nm} is equal to CDATA, RCDATA, EMPTY or ANY, 0 otherwise.
     *
     * @param nm a name
     * @return appropriate DTDConstants if the {@code nm} is equal to
     * CDATA, RCDATA, EMPTY or ANY, 0 otherwise.
     */
    public static int name2type(String nm) {
        Integer val = contentTypes.get(nm);
        return (val != null) ? val.intValue() : 0;
    }
}