htmldocument.java

Mobile 应用程序使用 Java Micro Edition (Java ME) 平台

         * @return the <code>AttributeSet</code> for this tag, or
         *	<code>null</code> if none can be found
	 */
	public abstract AttributeSet getAttributes();

	/**
	 * Returns the start of the range for which the current occurrence of
	 * the tag is defined and has the same attributes.
         *
         * @return the start of the range, or -1 if it can't be found
	 */
	public abstract int getStartOffset();
	
	/**
	 * Returns the end of the range for which the current occurrence of
	 * the tag is defined and has the same attributes.
         *
         * @return the end of the range
	 */
	public abstract int getEndOffset();

	/**
	 * Move the iterator forward to the next occurrence
	 * of the tag it represents.
	 */
	public abstract void next();

	/**
	 * Indicates if the iterator is currently
	 * representing an occurrence of a tag.  If
	 * false there are no more tags for this iterator.
         * @return true if the iterator is currently representing an
         *		occurrence of a tag, otherwise returns false
	 */
	public abstract boolean isValid();

	/**
	 * Type of tag this iterator represents.
	 */
	public abstract HTML.Tag getTag();
    }

    /**
     * An iterator to iterate over a particular type of tag.
     */
    static class LeafIterator extends Iterator {

	LeafIterator(HTML.Tag t, Document doc) {
	    tag = t;
	    pos = new ElementIterator(doc);
	    endOffset = 0;
	    next();
	}

	/**
	 * Returns the attributes for this tag.
         * @return the <code>AttributeSet</code> for this tag,
         *		or <code>null</code> if none can be found
	 */
	public AttributeSet getAttributes() {
	    Element elem = pos.current();
	    if (elem != null) {
		AttributeSet a = (AttributeSet) 
		    elem.getAttributes().getAttribute(tag);
                if (a == null) {
                    a = (AttributeSet)elem.getAttributes(); 
                }
		return a;
	    }
	    return null;
	}

	/**
	 * Returns the start of the range for which the current occurrence of
	 * the tag is defined and has the same attributes.
         *
         * @return the start of the range, or -1 if it can't be found
	 */
	public int getStartOffset() {
	    Element elem = pos.current();
	    if (elem != null) {
		return elem.getStartOffset();
	    }
	    return -1;
	}
	
	/**
	 * Returns the end of the range for which the current occurrence of
	 * the tag is defined and has the same attributes.
         *
         * @return the end of the range
	 */
	public int getEndOffset() {
	    return endOffset;
	}

	/**
	 * Moves the iterator forward to the next occurrence
	 * of the tag it represents.
	 */
	public void next() {
	    for (nextLeaf(pos); isValid(); nextLeaf(pos)) {
		Element elem = pos.current();
		if (elem.getStartOffset() >= endOffset) {
		    AttributeSet a = pos.current().getAttributes();

		    if (a.isDefined(tag) ||
                        a.getAttribute(StyleConstants.NameAttribute) == tag) {

			// we found the next one
			setEndOffset();
			break;
		    }
		}
	    }
	}

	/**
	 * Returns the type of tag this iterator represents.
         *
         * @return the <code>HTML.Tag</code> that this iterator represents.
         * @see javax.swing.text.html.HTML.Tag
	 */
        public HTML.Tag getTag() {
	    return tag;
	}

        /**
         * Returns true if the current position is not <code>null</code>.
         * @return true if current position is not <code>null</code>,
         *		otherwise returns false
         */
	public boolean isValid() {
	    return (pos.current() != null);
	}

	/**
	 * Moves the given iterator to the next leaf element.
         * @param iter  the iterator to be scanned
	 */
	void nextLeaf(ElementIterator iter) {
	    for (iter.next(); iter.current() != null; iter.next()) {
		Element e = iter.current();
		if (e.isLeaf()) {
		    break;
		}
	    }
	}

	/**
	 * Marches a cloned iterator forward to locate the end
	 * of the run.  This sets the value of <code>endOffset</code>.
	 */
	void setEndOffset() {
	    AttributeSet a0 = getAttributes();
	    endOffset = pos.current().getEndOffset();
	    ElementIterator fwd = (ElementIterator) pos.clone();
	    for (nextLeaf(fwd); fwd.current() != null; nextLeaf(fwd)) {
		Element e = fwd.current();
		AttributeSet a1 = (AttributeSet) e.getAttributes().getAttribute(tag);
		if ((a1 == null) || (! a1.equals(a0))) {
		    break;
		}
		endOffset = e.getEndOffset();
	    }
	}

	private int endOffset;
	private HTML.Tag tag;
	private ElementIterator pos;

    }

    /**
     * An HTML reader to load an HTML document with an HTML
     * element structure.  This is a set of callbacks from
     * the parser, implemented to create a set of elements
     * tagged with attributes.  The parse builds up tokens
     * (ElementSpec) that describe the element subtree desired,
     * and burst it into the document under the protection of
     * a write lock using the insert method on the document
     * outer class.
     * <p>
     * The reader can be configured by registering actions
     * (of type <code>HTMLDocument.HTMLReader.TagAction</code>)
     * that describe how to handle the action.  The idea behind
     * the actions provided is that the most natural text editing
     * operations can be provided if the element structure boils
     * down to paragraphs with runs of some kind of style 
     * in them.  Some things are more naturally specified 
     * structurally, so arbitrary structure should be allowed 
     * above the paragraphs, but will need to be edited with structural
     * actions.  The implication of this is that some of the
     * HTML elements specified in the stream being parsed will
     * be collapsed into attributes, and in some cases paragraphs
     * will be synthesized.  When HTML elements have been
     * converted to attributes, the attribute key will be of
     * type HTML.Tag, and the value will be of type AttributeSet
     * so that no information is lost.  This enables many of the
     * existing actions to work so that the user can type input,
     * hit the return key, backspace, delete, etc and have a 
     * reasonable result.  Selections can be created, and attributes
     * applied or removed, etc.  With this in mind, the work done
     * by the reader can be categorized into the following kinds
     * of tasks:
     * <dl>
     * <dt>Block
     * <dd>Build the structure like it's specified in the stream.
     * This produces elements that contain other elements.
     * <dt>Paragraph
     * <dd>Like block except that it's expected that the element
     * will be used with a paragraph view so a paragraph element
     * won't need to be synthesized.
     * <dt>Character
     * <dd>Contribute the element as an attribute that will start
     * and stop at arbitrary text locations.  This will ultimately
     * be mixed into a run of text, with all of the currently 
     * flattened HTML character elements.
     * <dt>Special
     * <dd>Produce an embedded graphical element.
     * <dt>Form
     * <dd>Produce an element that is like the embedded graphical
     * element, except that it also has a component model associated
     * with it.
     * <dt>Hidden
     * <dd>Create an element that is hidden from view when the
     * document is being viewed read-only, and visible when the
     * document is being edited.  This is useful to keep the
     * model from losing information, and used to store things
     * like comments and unrecognized tags.
     *
     * </dl>
     * <p>
     * Currently, &lt;APPLET&gt;, &lt;PARAM&gt;, &lt;MAP&gt;, &lt;AREA&gt;, &lt;LINK&gt;,
     * &lt;SCRIPT&gt; and &lt;STYLE&gt; are unsupported.
     *
     * <p>
     * The assignment of the actions described is shown in the
     * following table for the tags defined in <code>HTML.Tag</code>.<P>
     * <table border=1 summary="HTML tags and assigned actions">
     * <tr><th>Tag</th><th>Action</th></tr>
     * <tr><td><code>HTML.Tag.A</code>         <td>CharacterAction
     * <tr><td><code>HTML.Tag.ADDRESS</code>   <td>CharacterAction
     * <tr><td><code>HTML.Tag.APPLET</code>    <td>HiddenAction
     * <tr><td><code>HTML.Tag.AREA</code>      <td>AreaAction
     * <tr><td><code>HTML.Tag.B</code>         <td>CharacterAction
     * <tr><td><code>HTML.Tag.BASE</code>      <td>BaseAction
     * <tr><td><code>HTML.Tag.BASEFONT</code>  <td>CharacterAction
     * <tr><td><code>HTML.Tag.BIG</code>       <td>CharacterAction
     * <tr><td><code>HTML.Tag.BLOCKQUOTE</code><td>BlockAction
     * <tr><td><code>HTML.Tag.BODY</code>      <td>BlockAction
     * <tr><td><code>HTML.Tag.BR</code>        <td>SpecialAction
     * <tr><td><code>HTML.Tag.CAPTION</code>   <td>BlockAction
     * <tr><td><code>HTML.Tag.CENTER</code>    <td>BlockAction
     * <tr><td><code>HTML.Tag.CITE</code>      <td>CharacterAction
     * <tr><td><code>HTML.Tag.CODE</code>      <td>CharacterAction
     * <tr><td><code>HTML.Tag.DD</code>        <td>BlockAction
     * <tr><td><code>HTML.Tag.DFN</code>       <td>CharacterAction
     * <tr><td><code>HTML.Tag.DIR</code>       <td>BlockAction
     * <tr><td><code>HTML.Tag.DIV</code>       <td>BlockAction
     * <tr><td><code>HTML.Tag.DL</code>        <td>BlockAction
     * <tr><td><code>HTML.Tag.DT</code>        <td>ParagraphAction
     * <tr><td><code>HTML.Tag.EM</code>        <td>CharacterAction
     * <tr><td><code>HTML.Tag.FONT</code>      <td>CharacterAction
     * <tr><td><code>HTML.Tag.FORM</code>      <td>As of 1.4 a BlockAction
     * <tr><td><code>HTML.Tag.FRAME</code>     <td>SpecialAction
     * <tr><td><code>HTML.Tag.FRAMESET</code>  <td>BlockAction
     * <tr><td><code>HTML.Tag.H1</code>        <td>ParagraphAction
     * <tr><td><code>HTML.Tag.H2</code>        <td>ParagraphAction
     * <tr><td><code>HTML.Tag.H3</code>        <td>ParagraphAction
     * <tr><td><code>HTML.Tag.H4</code>        <td>ParagraphAction
     * <tr><td><code>HTML.Tag.H5</code>        <td>ParagraphAction
     * <tr><td><code>HTML.Tag.H6</code>        <td>ParagraphAction
     * <tr><td><code>HTML.Tag.HEAD</code>      <td>HeadAction
     * <tr><td><code>HTML.Tag.HR</code>        <td>SpecialAction
     * <tr><td><code>HTML.Tag.HTML</code>      <td>BlockAction
     * <tr><td><code>HTML.Tag.I</code>         <td>CharacterAction
     * <tr><td><code>HTML.Tag.IMG</code>       <td>SpecialAction
     * <tr><td><code>HTML.Tag.INPUT</code>     <td>FormAction
     * <tr><td><code>HTML.Tag.ISINDEX</code>   <td>IsndexAction
     * <tr><td><code>HTML.Tag.KBD</code>       <td>CharacterAction
     * <tr><td><code>HTML.Tag.LI</code>        <td>BlockAction
     * <tr><td><code>HTML.Tag.LINK</code>      <td>LinkAction
     * <tr><td><code>HTML.Tag.MAP</code>       <td>MapAction
     * <tr><td><code>HTML.Tag.MENU</code>      <td>BlockAction
     * <tr><td><code>HTML.Tag.META</code>      <td>MetaAction
     * <tr><td><code>HTML.Tag.NOFRAMES</code>  <td>BlockAction
     * <tr><td><code>HTML.Tag.OBJECT</code>    <td>SpecialAction
     * <tr><td><code>HTML.Tag.OL</code>        <td>BlockAction
     * <tr><td><code>HTML.Tag.OPTION</code>    <td>FormAction
     * <tr><td><code>HTML.Tag.P</code>         <td>ParagraphAction
     * <tr><td><code>HTML.Tag.PARAM</code>     <td>HiddenAction
     * <tr><td><code>HTML.Tag.PRE</code>       <td>PreAction
     * <tr><td><code>HTML.Tag.SAMP</code>      <td>CharacterAction
     * <tr><td><code>HTML.Tag.SCRIPT</code>    <td>HiddenAction
     * <tr><td><code>HTML.Tag.SELECT</code>    <td>FormAction
     * <tr><td><code>HTML.Tag.SMALL</code>     <td>CharacterAction
     * <tr><td><code>HTML.Tag.STRIKE</code>    <td>CharacterAction
     * <tr><td><code>HTML.Tag.S</code>         <td>CharacterAction
     * <tr><td><code>HTML.Tag.STRONG</code>    <td>CharacterAction
     * <tr><td><code>HTML.Tag.STYLE</code>     <td>StyleAction
     * <tr><td><code>HTML.Tag.SUB</code>       <td>CharacterAction
     * <tr><td><code>HTML.Tag.SUP</code>       <td>CharacterAction
     * <tr><td><code>HTML.Tag.TABLE</code>     <td>BlockAction
     * <tr><td><code>HTML.Tag.TD</code>        <td>BlockAction
     * <tr><td><code>HTML.Tag.TEXTAREA</code>  <td>FormAction
     * <tr><td><code>HTML.Tag.TH</code>        <td>BlockAction
     * <tr><td><code>HTML.Tag.TITLE</code>     <td>TitleAction
     * <tr><td><code>HTML.Tag.TR</code>        <td>BlockAction
     * <tr><td><code>HTML.Tag.TT</code>        <td>CharacterAction
     * <tr><td><code>HTML.Tag.U</code>         <td>CharacterAction
     * <tr><td><code>HTML.Tag.UL</code>        <td>BlockAction
     * <tr><td><code>HTML.Tag.VAR</code>       <td>CharacterAction
     * </table>
     * <p>
     * Once &lt;/html> is encountered, the Actions are no longer notified.
     */ 
    public class HTMLReader extends HTMLEditorKit.ParserCallback {

	public HTMLReader(int offset) {
	    this(offset, 0, 0, null);
	}

        public HTMLReader(int offset, int popDepth, int pushDepth,
			  HTML.Tag insertTag) {
	    this(offset, popDepth, pushDepth, insertTag, true, false, true);
	}

	/**
	 * Generates a RuntimeException (will eventually generate
	 * a BadLocationException when API changes are alloced) if inserting
	 * into non empty document, <code>insertTag</code> is
         * non-<code>null</code>, and <code>offset</code> is not in the body.
	 */
	// PENDING(sky): Add throws BadLocationException and remove
	// RuntimeException
        HTMLReader(int offset, int popDepth, int pushDepth,
		   HTML.Tag insertTag, boolean insertInsertTag,
		   boolean insertAfterImplied, boolean wantsTrailingNewline) {
	    emptyDocument = (getLength() == 0);
	    isStyleCSS = "text/css".equals(getDefaultStyleSheetType());
	    this.offset = offset;
	    threshold = HTMLDocument.this.getTokenThreshold();
	    tagMap = new Hashtable(57);
	    TagAction na = new TagAction();
	    TagAction ba = new BlockAction();
	    TagAction pa = new ParagraphAction();
	    TagAction ca = new CharacterAction();
	    TagAction sa = new SpecialAction();
	    TagAction fa = new FormAction();
	    TagAction ha = new HiddenAction();
	    TagAction conv = new ConvertAction();

	    // register handlers for the well known tags
	    tagMap.put(HTML.Tag.A, new AnchorAction());
	    tagMap.put(HTML.Tag.ADDRESS, ca);
	    tagMap.put(HTML.Tag.APPLET, ha);
	    tagMap.put(HTML.Tag.AREA, new AreaAction());
	    tagMap.put(HTML.Tag.B, conv);
	    tagMap.put(HTML.Tag.BASE, new BaseAction());
	    tagMap.put(HTML.Tag.BASEFONT, ca);