htmleditorkit.java

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

	public InsertHTMLTextAction(String name, String html,
				    HTML.Tag parentTag,
				    HTML.Tag addTag,
				    HTML.Tag alternateParentTag,
				    HTML.Tag alternateAddTag) {
	    this(name, html, parentTag, addTag, alternateParentTag,
		 alternateAddTag, true);
	}

	/* public */
	InsertHTMLTextAction(String name, String html,
				    HTML.Tag parentTag,
				    HTML.Tag addTag,
				    HTML.Tag alternateParentTag,
				    HTML.Tag alternateAddTag,
				    boolean adjustSelection) {
	    super(name);
	    this.html = html;
	    this.parentTag = parentTag;
	    this.addTag = addTag;
	    this.alternateParentTag = alternateParentTag;
	    this.alternateAddTag = alternateAddTag;
	    this.adjustSelection = adjustSelection;
	}

	/**
	 * A cover for HTMLEditorKit.insertHTML. If an exception it
	 * thrown it is wrapped in a RuntimeException and thrown.
	 */
	protected void insertHTML(JEditorPane editor, HTMLDocument doc,
				  int offset, String html, int popDepth,
				  int pushDepth, HTML.Tag addTag) {
	    try {
		getHTMLEditorKit(editor).insertHTML(doc, offset, html,
						    popDepth, pushDepth,
						    addTag);
	    } catch (IOException ioe) {
		throw new RuntimeException("Unable to insert: " + ioe);
	    } catch (BadLocationException ble) {
		throw new RuntimeException("Unable to insert: " + ble);
	    }
	}

	/**
	 * This is invoked when inserting at a boundary. It determines
	 * the number of pops, and then the number of pushes that need
	 * to be performed, and then invokes insertHTML.
	 * @since 1.3
	 */
	protected void insertAtBoundary(JEditorPane editor, HTMLDocument doc,
					int offset, Element insertElement,
					String html, HTML.Tag parentTag,
					HTML.Tag addTag) {
	    insertAtBoundry(editor, doc, offset, insertElement, html,
			    parentTag, addTag);
	}

	/**
	 * This is invoked when inserting at a boundary. It determines
	 * the number of pops, and then the number of pushes that need
	 * to be performed, and then invokes insertHTML.
	 * @deprecated As of Java 2 platform v1.3, use insertAtBoundary
	 */
        @Deprecated
	protected void insertAtBoundry(JEditorPane editor, HTMLDocument doc,
				       int offset, Element insertElement,
				       String html, HTML.Tag parentTag,
				       HTML.Tag addTag) {
	    // Find the common parent.
	    Element e;
	    Element commonParent;
	    boolean isFirst = (offset == 0);

	    if (offset > 0 || insertElement == null) {
		e = doc.getDefaultRootElement();
		while (e != null && e.getStartOffset() != offset &&
		       !e.isLeaf()) {
		    e = e.getElement(e.getElementIndex(offset));
		}
		commonParent = (e != null) ? e.getParentElement() : null;
	    }
	    else {
		// If inserting at the origin, the common parent is the
		// insertElement.
		commonParent = insertElement;
	    }
	    if (commonParent != null) {
		// Determine how many pops to do.
		int pops = 0;
		int pushes = 0;
		if (isFirst && insertElement != null) {
		    e = commonParent;
		    while (e != null && !e.isLeaf()) {
			e = e.getElement(e.getElementIndex(offset));
			pops++;
		    }
		}
		else {
		    e = commonParent;
		    offset--;
		    while (e != null && !e.isLeaf()) {
			e = e.getElement(e.getElementIndex(offset));
			pops++;
		    }

		    // And how many pushes
		    e = commonParent;
		    offset++;
		    while (e != null && e != insertElement) {
			e = e.getElement(e.getElementIndex(offset));
			pushes++;
		    }
		}
		pops = Math.max(0, pops - 1);

		// And insert!
		insertHTML(editor, doc, offset, html, pops, pushes, addTag);
	    }
	}

	/**
	 * If there is an Element with name <code>tag</code> at
	 * <code>offset</code>, this will invoke either insertAtBoundary
	 * or <code>insertHTML</code>. This returns true if there is
	 * a match, and one of the inserts is invoked.
	 */
	/*protected*/
	boolean insertIntoTag(JEditorPane editor, HTMLDocument doc,
			      int offset, HTML.Tag tag, HTML.Tag addTag) {
	    Element e = findElementMatchingTag(doc, offset, tag);
	    if (e != null && e.getStartOffset() == offset) {
		insertAtBoundary(editor, doc, offset, e, html,
				 tag, addTag);
		return true;
	    }
	    else if (offset > 0) {
		int depth = elementCountToTag(doc, offset - 1, tag);
		if (depth != -1) {
		    insertHTML(editor, doc, offset, html, depth, 0, addTag);
		    return true;
		}
	    }
	    return false;
	}

	/**
	 * Called after an insertion to adjust the selection.
	 */
	/* protected */
	void adjustSelection(JEditorPane pane, HTMLDocument doc, 
			     int startOffset, int oldLength) {
	    int newLength = doc.getLength();
	    if (newLength != oldLength && startOffset < newLength) {
		if (startOffset > 0) {
		    String text;
		    try {
			text = doc.getText(startOffset - 1, 1);
		    } catch (BadLocationException ble) {
			text = null;
		    }
		    if (text != null && text.length() > 0 &&
			text.charAt(0) == '\n') {
			pane.select(startOffset, startOffset);
		    }
		    else {
			pane.select(startOffset + 1, startOffset + 1);
		    }
		}
		else {
		    pane.select(1, 1);
		}
	    }
	}

        /**
         * Inserts the HTML into the document.
         *
         * @param ae the event
         */
        public void actionPerformed(ActionEvent ae) {
	    JEditorPane editor = getEditor(ae);
	    if (editor != null) {
		HTMLDocument doc = getHTMLDocument(editor);
		int offset = editor.getSelectionStart();
		int length = doc.getLength();
		boolean inserted;
		// Try first choice
		if (!insertIntoTag(editor, doc, offset, parentTag, addTag) &&
		    alternateParentTag != null) {
		    // Then alternate.
		    inserted = insertIntoTag(editor, doc, offset,
					     alternateParentTag,
					     alternateAddTag);
		}
		else {
		    inserted = true;
		}
		if (adjustSelection && inserted) {
		    adjustSelection(editor, doc, offset, length);
		}
	    }
	}

	/** HTML to insert. */
	protected String html;
	/** Tag to check for in the document. */
	protected HTML.Tag parentTag;
	/** Tag in HTML to start adding tags from. */
	protected HTML.Tag addTag;
	/** Alternate Tag to check for in the document if parentTag is
	 * not found. */
	protected HTML.Tag alternateParentTag;
	/** Alternate tag in HTML to start adding tags from if parentTag
	 * is not found and alternateParentTag is found. */
	protected HTML.Tag alternateAddTag;
	/** True indicates the selection should be adjusted after an insert. */
	boolean adjustSelection;
    }


    /**
     * InsertHRAction is special, at actionPerformed time it will determine
     * the parent HTML.Tag based on the paragraph element at the selection
     * start.
     */
    static class InsertHRAction extends InsertHTMLTextAction {
	InsertHRAction() {
	    super("InsertHR", "<hr>", null, HTML.Tag.IMPLIED, null, null,
		  false);
	}

        /**
         * Inserts the HTML into the document.
         *
         * @param ae the event
         */
        public void actionPerformed(ActionEvent ae) {
	    JEditorPane editor = getEditor(ae);
	    if (editor != null) {
		HTMLDocument doc = getHTMLDocument(editor);
		int offset = editor.getSelectionStart();
		Element paragraph = doc.getParagraphElement(offset);
		if (paragraph.getParentElement() != null) {
		    parentTag = (HTML.Tag)paragraph.getParentElement().
		                  getAttributes().getAttribute
		                  (StyleConstants.NameAttribute);
		    super.actionPerformed(ae);
		}
	    }
	}
	
    }

    /*
     * Returns the object in an AttributeSet matching a key
     */
    static private Object getAttrValue(AttributeSet attr, HTML.Attribute key) {
	Enumeration names = attr.getAttributeNames();
	while (names.hasMoreElements()) {
	    Object nextKey = names.nextElement();
	    Object nextVal = attr.getAttribute(nextKey);
	    if (nextVal instanceof AttributeSet) {
		Object value = getAttrValue((AttributeSet)nextVal, key);
		if (value != null) {
		    return value;
		}
	    } else if (nextKey == key) {
		return nextVal;
	    }	
	}
	return null;
    }

    /*
     * Action to move the focus on the next or previous hypertext link 
     * or object. TODO: This method relies on support from the 
     * javax.accessibility package.  The text package should support
     * keyboard navigation of text elements directly.
     */
    static class NavigateLinkAction extends TextAction 
        implements CaretListener {

	private static int prevHypertextOffset = -1;
	private static boolean foundLink = false;
        private static FocusHighlightPainter focusPainter =
	    new FocusHighlightPainter(null);
	private Object selectionTag;
	private boolean focusBack = false;

        /*
         * Create this action with the appropriate identifier. 
         */
        public NavigateLinkAction(String actionName) {
            super(actionName);
	    if ("previous-link-action".equals(actionName)) {
		focusBack = true;
	    }
        }
	
	/**
	 * Called when the caret position is updated.
	 *
	 * @param e the caret event
	 */
	public void caretUpdate(CaretEvent e) {
	    if (foundLink) {
		foundLink = false;
		// TODO: The AccessibleContext for the editor should register
		// as a listener for CaretEvents and forward the events to
		// assistive technologies listening for such events.
		Object src = e.getSource();
		if (src instanceof JTextComponent) {
		    ((JTextComponent)src).getAccessibleContext().firePropertyChange(
                        AccessibleContext.ACCESSIBLE_HYPERTEXT_OFFSET,
		        new Integer(prevHypertextOffset),
		        new Integer(e.getDot()));
		}
	    }
	}

        /*
	 * The operation to perform when this action is triggered. 
	 */
        public void actionPerformed(ActionEvent e) {
            JTextComponent comp = getTextComponent(e);
	    if (comp == null || comp.isEditable()) {
		return;
	    }
	    Document doc = comp.getDocument();
	    if (doc == null) {
		return;
	    }
	    // TODO: Should start successive iterations from the
	    // current caret position.
	    ElementIterator ei = new ElementIterator(doc);

	    int currentOffset = comp.getCaretPosition();
	    int prevStartOffset = -1;
	    int prevEndOffset = -1;
		
	    // highlight the next link or object after the current caret position
	    Element nextElement = null;
	    while ((nextElement = ei.next()) != null) {
		String name = nextElement.getName();
		AttributeSet attr = nextElement.getAttributes();
		
		Object href = getAttrValue(attr, HTML.Attribute.HREF);
		if (!(name.equals(HTML.Tag.OBJECT.toString())) && href == null) {
		    continue;
		}
		
		int elementOffset = nextElement.getStartOffset();
		if (focusBack) {
		    if (elementOffset >= currentOffset &&
			prevStartOffset >= 0) {

			foundLink = true;
			comp.setCaretPosition(prevStartOffset);
			moveCaretPosition(comp, prevStartOffset, 
					  prevEndOffset);
			prevHypertextOffset = prevStartOffset;
			return;
		    }
		} else { // focus forward
		    if (elementOffset > currentOffset) {

			foundLink = true;
			comp.setCaretPosition(elementOffset);
			moveCaretPosition(comp, elementOffset,
					  nextElement.getEndOffset());
			prevHypertextOffset = elementOffset;
			return;
		    } 
		}
		prevStartOffset = nextElement.getStartOffset();
		prevEndOffset = nextElement.getEndOffset();
	    }
            if (focusBack && prevStartOffset >= 0) {
                foundLink = true;
                comp.setCaretPosition(prevStartOffset);
                moveCaretPosition(comp, prevStartOffset, 
                                  prevEndOffset);