htmlelementimpl.java

Java的面向对象数据库系统的源代码

/**
 * org/ozone-db/xml/dom/html/HTMLElementImpl.java
 *
 * The contents of this file are subject to the OpenXML Public
 * License Version 1.0; you may not use this file except in compliance
 * with the License. You may obtain a copy of the License at
 * http://www.openxml.org/license.html
 *
 * THIS SOFTWARE IS DISTRIBUTED ON AN "AS IS" BASIS WITHOUT WARRANTY
 * OF ANY KIND, EITHER EXPRESSED OR IMPLIED. THE INITIAL DEVELOPER
 * AND ALL CONTRIBUTORS SHALL NOT BE LIABLE FOR ANY DAMAGES AS A
 * RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
 * DERIVATIVES. SEE THE LICENSE FOR THE SPECIFIC LANGUAGE GOVERNING
 * RIGHTS AND LIMITATIONS UNDER THE LICENSE.
 *
 * The Initial Developer of this code under the License is Assaf Arkin.
 * Portions created by Assaf Arkin are Copyright (C) 1998, 1999.
 * All Rights Reserved.
 */


package org.ozoneDB.xml.dom.html;


import org.ozoneDB.xml.dom.DOMExceptionImpl;
import org.ozoneDB.xml.dom.ElementImpl;
import org.ozoneDB.xml.dom.NodeImpl;
import org.w3c.dom.*;
import org.w3c.dom.html.HTMLElement;
import org.w3c.dom.html.HTMLFormElement;


/**
 * Implements an HTML-specific element, an {@link org.w3c.dom.Element} that
 * will only appear inside HTML documents. This element extends {@link
 * org.openxml.dom.ElementImpl} by adding methods for directly manipulating
 * HTML-specific attributes. All HTML elements gain access to the
 * <code>id</code>,  <code>title</code>, <code>lang</code>, <code>dir</code>
 * and <code>class</code> attributes. Other elements add their own specific
 * attributes.
 * <P>
 * Note that some support is provided by {@link NodeImpl}
 * directly: translating all tag names to upper case and all attribute names
 * to lower case.
 *
 *
 * @version $Revision: 1.2 $ $Date: 2003/11/20 23:18:42 $
 * @author <a href="mailto:[e-mail]">Assaf Arkin</a>
 * @see org.w3c.dom.html.HTMLElement
 * @see ElementImpl
 */
public class HTMLElementImpl extends ElementImpl implements HTMLElement {


    public String getId() {
        return getAttribute( "id" );
    }


    public void setId( String id ) {
        setAttribute( "id", id );
    }


    public String getTitle() {
        return getAttribute( "title" );
    }


    public void setTitle( String title ) {
        setAttribute( "title", title );
    }


    public String getLang() {
        return getAttribute( "lang" );
    }


    public void setLang( String lang ) {
        setAttribute( "lang", lang );
    }


    public String getDir() {
        return getAttribute( "dir" );
    }


    public void setDir( String dir ) {
        setAttribute( "dir", dir );
    }


    public String getClassName() {
        return getAttribute( "class" );
    }


    public void setClassName( String className ) {
        setAttribute( "class", className );
    }


    /**
     * Convenience method used to translate an attribute value into an integer
     * value. Returns the integer value or zero if the attribute is not a
     * valid numeric string.
     *
     * @param value The value of the attribute
     * @return The integer value, or zero if not a valid numeric string
     */
    int toInteger( String value ) {
        try {
            return Integer.parseInt( value );
        } catch (NumberFormatException except) {
            return 0;
        }
    }


    /**
     * Convenience method used to translate an attribute value into a boolean
     * value. If the attribute has an associated value (even an empty string),
     * it is set and true is returned. If the attribute does not exist, false
     * is returend.
     *
     * @param name The value of the attribute
     * @return True or false depending on whether the attribute has been set
     */
    boolean toBoolean( String name ) {
        return getAttribute( name ) != null;
    }


    /**
     * Convenience method used to set a boolean attribute. If the value is true,
     * the attribute is set to an empty string. If the value is false, the attribute
     * is removed. HTML 4.0 understands empty strings as set attributes.
     *
     * @param name The name of the attribute
     * @param value The value of the attribute
     */
    void setAttribute( String name, boolean value ) {
        if (value) {
            setAttribute( name, "" );
        } else {
            removeAttribute( name );
        }
    }


    /**
     * Convenience method used to capitalize a one-off attribute value before it
     * is returned. For example, the align values "LEFT" and "left" will both
     * return as "Left".
     *
     * @param value The value of the attribute
     * @return The capitalized value
     */
    String capitalize( String value ) {
        char[] chars;
        int i;

        // Convert string to charactares. Convert the first one to upper case,
        // the other characters to lower case, and return the converted string.
        chars = value.toCharArray();
        if (chars.length > 0) {
            chars[0] = Character.toUpperCase( chars[0] );
            for (i = 1; i < chars.length; ++i) {
                chars[i] = Character.toLowerCase( chars[i] );
            }
            return String.valueOf( chars );
        }
        return value;
    }


    /**
     * Convenience method used to capitalize a one-off attribute value before it
     * is returned. For example, the align values "LEFT" and "left" will both
     * return as "Left".
     *
     * @param name The name of the attribute
     * @return The capitalized value
     */
    String getCapitalized( String name ) {
        String value;
        char[] chars;
        int i;

        value = getAttribute( name );
        if (value != null) {
            // Convert string to charactares. Convert the first one to upper case,
            // the other characters to lower case, and return the converted string.
            chars = value.toCharArray();
            if (chars.length > 0) {
                chars[0] = Character.toUpperCase( chars[0] );
                for (i = 1; i < chars.length; ++i) {
                    chars[i] = Character.toLowerCase( chars[i] );
                }
                return String.valueOf( chars );
            }
        }
        return value;
    }


    /**
     * Convenience method returns the form in which this form element is contained.
     * This method is exposed for form elements through the DOM API, but other
     * elements have no access to it through the API.
     */
    public HTMLFormElement getForm() {
        Node parent;

        parent = getParentNode();
        while (parent != null) {
            if (parent instanceof HTMLFormElement) {
                return (HTMLFormElement)parent;
            }
            parent = parent.getParentNode();
        }
        return null;
    }


    protected Node castNewChild( Node newChild ) throws DOMException {
        // Same method appears in HTMLElementImpl and HTMLDocumentImpl.

        if (newChild == null) {
            throw new DOMExceptionImpl( DOMException.HIERARCHY_REQUEST_ERR, "Child reference is null." );
        }
        if (!(newChild instanceof NodeImpl)) {
            throw new DOMExceptionImpl( DOMException.HIERARCHY_REQUEST_ERR,
                    "Child is not a compatible type for this node." );
        }

        // newChild must be HTMLElement, Text, Comment, DocumentFragment or
        // ProcessingInstruction. CDATASection and EntityReference not supported
        // in HTML documents.
        if (!(newChild instanceof ElementImpl || newChild instanceof Comment || newChild instanceof Text
                || newChild instanceof DocumentFragment || newChild instanceof ProcessingInstruction)) {
            throw new DOMExceptionImpl( DOMException.HIERARCHY_REQUEST_ERR,
                    "Child is not a compatible type for this node." );
        }
        return (NodeImpl)newChild;
    }


    /**
     * Constructor required owner document and element tag name. Will be called
     * by the constructor of specific element types but with a known tag name.
     * Assures that the owner document is an HTML element.
     *
     * @param owner The owner HTML document
     * @param tagName The element's tag name
     */
    HTMLElementImpl( HTMLDocumentImpl owner, String tagName ) {
        super( owner, tagName.toUpperCase() );
    }


}