domnode.java

gcc的组建

    if (event == null)
      {
        event = getMutationEvent();
      }
    if (event != null)
      {
        doFree = true;
      }
    else
      {
        event = new DomEvent.DomMutationEvent(null);
      }
    event.initMutationEvent("DOMNodeRemoved",
                            true /* bubbles */, false /* nocancel */,
                            this /* related */, null, null, null, (short) 0);
    target.dispatchEvent(event);

    // XXX should really visit every descendant of 'target'
    // and sent a DOMNodeRemovedFromDocument event to it...
    // bleech, there's no way to keep that acceptably fast.

    event.target = null;
    event.relatedNode = null;
    event.currentNode = null;
    if (doFree)
      {
        eventDataLock = false;
      }
    // else we created more work for the GC
  }

  //
  // Avoid creating lots of memory management work, by using a simple
  // allocation strategy for the mutation event objects that get used
  // at least once per tree modification.  We can't use stack allocation,
  // so we do the next simplest thing -- more or less, static allocation.
  // Concurrent notifications should be rare, anyway.
  //
  // Returns the preallocated object, which needs to be carefully freed,
  // or null to indicate the caller needs to allocate their own.
  //
  static private DomEvent.DomMutationEvent getMutationEvent()
  {
    synchronized (lockNode)
      {
        if (eventDataLock)
          {
            return null;
          }
        eventDataLock = true;
        return mutationEvent;
      }
  }

  // NOTE:  this is manually inlined in the insertion
  // and removal event methods above; change in sync.
  static private void freeMutationEvent()
  {
    // clear fields to enable GC
    mutationEvent.clear();
    eventDataLock = false;
  }

  void setDepth(int depth)
  {
    this.depth = depth;
    for (DomNode ctx = first; ctx != null; ctx = ctx.next)
      {
        ctx.setDepth(depth + 1);
      }
  }

  /**
   * <b>DOM L1</b>
   * Appends the specified node to this node's list of children.
   * Document subclasses must override this to enforce the restrictions
   * that there be only one element and document type child.
   *
   * <p> Causes a DOMNodeInserted mutation event to be reported.
   * Will first cause a DOMNodeRemoved event to be reported if the
   * parameter already has a parent.  If the new child is a document
   * fragment node, both events will be reported for each child of
   * the fragment; the order in which children are removed and
   * inserted is implementation-specific.
   *
   * <p> If this DOM has been compiled without mutation event support,
   * these events will not be reported.
   */
  public Node appendChild(Node newChild)
  {
    try
      {
        DomNode	child = (DomNode) newChild;

        if (child.nodeType == DOCUMENT_FRAGMENT_NODE)
          {
            // Append all nodes in the fragment to this node
            for (DomNode ctx = child.first; ctx != null; ctx = ctx.next)
              {
                checkMisc(ctx);
              }
            for (DomNode ctx = child.first; ctx != null; )
              {
                DomNode ctxNext = ctx.next;
                appendChild(ctx);
                ctx = ctxNext;
              }
          }
        else
          {
            checkMisc(child);
            if (child.parent != null)
              {
                child.parent.removeChild(child);
              }
            child.parent = this;
            child.index = length++;
            child.setDepth(depth + 1);
            child.next = null;
            if (last == null)
              {
                first = child;
                child.previous = null;
              }
            else
              {
                last.next = child;
                child.previous = last;
              }
            last = child;

            if (reportMutations)
              {
                insertionEvent(null, child);
              }
          }

        return child;
      }
    catch (ClassCastException e)
      {
        throw new DomDOMException(DOMException.WRONG_DOCUMENT_ERR,
                                  null, newChild, 0);
    }
  }

  /**
   * <b>DOM L1</b>
   * Inserts the specified node in this node's list of children.
   * Document subclasses must override this to enforce the restrictions
   * that there be only one element and document type child.
   *
   * <p> Causes a DOMNodeInserted mutation event to be reported.  Will
   * first cause a DOMNodeRemoved event to be reported if the newChild
   * parameter already has a parent. If the new child is a document
   * fragment node, both events will be reported for each child of
   * the fragment; the order in which children are removed and inserted
   * is implementation-specific.
   *
   * <p> If this DOM has been compiled without mutation event support,
   * these events will not be reported.
   */
  public Node insertBefore(Node newChild, Node refChild)
  {
    if (refChild == null)
      {
        return appendChild(newChild);
      }

    try
      {
        DomNode	child = (DomNode) newChild;
        DomNode ref = (DomNode) refChild;
        
        if (child.nodeType == DOCUMENT_FRAGMENT_NODE)
          {
            // Append all nodes in the fragment to this node
            for (DomNode ctx = child.first; ctx != null; ctx = ctx.next)
              {
                checkMisc(ctx);
              }
            for (DomNode ctx = child.first; ctx != null; )
              {
                DomNode ctxNext = ctx.next;
                insertBefore(ctx, ref);
                ctx = ctxNext;
              }
          }
        else
          {
            checkMisc(child);
            if (ref == null || ref.parent != this)
              {
                throw new DomDOMException(DOMException.NOT_FOUND_ERR,
                                          null, ref, 0);
              }
            if (ref == child)
              {
                throw new DomDOMException(DOMException.HIERARCHY_REQUEST_ERR,
                                          "can't insert node before itself",
                                          ref, 0);
              }
        
            if (child.parent != null)
              {
                child.parent.removeChild(child);
              }
            child.parent = this;
            int i = ref.index;
            child.setDepth(depth + 1);
            child.next = ref;
            if (ref.previous != null)
              {
                ref.previous.next = child;
              }
            child.previous = ref.previous;
            ref.previous = child;
            if (first == ref)
              {
                first = child;
              }
            // index renumbering
            for (DomNode ctx = child; ctx != null; ctx = ctx.next)
              {
                ctx.index = i++;
              }

            if (reportMutations)
              {
                insertionEvent(null, child);
              }
          }
        
        return child;
      }
    catch (ClassCastException e)
      {
        throw new DomDOMException(DOMException.WRONG_DOCUMENT_ERR,
                                  null, newChild, 0);
      }
  }

  /**
   * <b>DOM L1</b>
   * Replaces the specified node in this node's list of children.
   * Document subclasses must override this to test the restrictions
   * that there be only one element and document type child.
   *
   * <p> Causes DOMNodeRemoved and DOMNodeInserted mutation event to be
   * reported.  Will cause another DOMNodeRemoved event to be reported if
   * the newChild parameter already has a parent.  These events may be
   * delivered in any order, except that the event reporting removal
   * from such an existing parent will always be delivered before the
   * event reporting its re-insertion as a child of some other node.
   * The order in which children are removed and inserted is implementation
   * specific.
   *
   * <p> If your application needs to depend on the in which those removal
   * and insertion events are delivered, don't use this API.  Instead,
   * invoke the removeChild and insertBefore methods directly, to guarantee
   * a specific delivery order.  Similarly, don't use document fragments,
   * Otherwise your application code may not work on a DOM which implements
   * this method differently.
   *
   * <p> If this DOM has been compiled without mutation event support,
   * these events will not be reported.
   */
  public Node replaceChild(Node newChild, Node refChild)
  {
    try
      {
        DomNode child = (DomNode) newChild;
        DomNode ref = (DomNode) refChild;
        
        DomEvent.DomMutationEvent event = getMutationEvent();
        boolean doFree = (event != null);
            
        if (child.nodeType == DOCUMENT_FRAGMENT_NODE)
          {
            // Append all nodes in the fragment to this node
            for (DomNode ctx = child.first; ctx != null; ctx = ctx.next)
              {
                checkMisc(ctx);
              }
            if (ref == null || ref.parent != this)
              {
                throw new DomDOMException(DOMException.NOT_FOUND_ERR,
                                          null, ref, 0);
              }
            
            if (reportMutations)
              {
                removalEvent(event, ref);
              }
            length--;
            length += child.length;
            
            if (child.length == 0)
              {
                // Removal
                if (ref.previous != null)
                  {
                    ref.previous.next = ref.next;
                  }
                if (ref.next != null)
                  {
                    ref.next.previous = ref.previous;
                  }
                if (first == ref)
                  {
                    first = ref.next;
                  }
                if (last == ref)
                  {
                    last = ref.previous;
                  }
              }
            else
              {
                int i = ref.index;
                for (DomNode ctx = child.first; ctx != null; ctx = ctx.next)
                  {
                    // Insertion
                    ctx.parent = this;
                    ctx.index = i++;
                    ctx.setDepth(ref.depth);
                    if (ctx == child.first)
                      {
                        ctx.previous = ref.previous;
                      }
                    if (ctx == child.last)
                      {
                        ctx.next = ref.next;
                      }
                  }
                if (first == ref)
                  {
                    first = child.first;
                  }
                if (last == ref)
                  {
                    last = child.last;
                  }
              }
          }
        else
          {
            checkMisc(child);
            if (ref == null || ref.parent != this)
              {
                throw new DomDOMException(DOMException.NOT_FOUND_ERR,
                                          null, ref, 0);
              }
        
            if (reportMutations)
              {
                removalEvent(event, ref);
              }
            
            if (child.parent != null)
              {
                child.parent.removeChild(child);
              }
            child.parent = this;
            child.index = ref.index;
            child.setDepth(ref.depth);
            if (ref.previous != null)
              {
                ref.previous.next = child;
              }
            child.previous = ref.previous;
            if (ref.next != null)
              {
                ref.next.previous = child;
              }
            child.next = ref.next;
            if (first == ref)
              {
                first = child;
              }
            if (last == ref)
              {
                last = child;
              }

            if (reportMutations)
              {
                insertionEvent(event, child);
              }
            if (doFree)
              {
                freeMutationEvent();
              }
          }
        ref.parent = null;
        ref.index = 0;
        ref.setDepth(0);
        ref.previous = null;
        ref.next = null;
        
        return ref;
      }
    catch (ClassCastException e)
      {
        throw new DomDOMException(DOMException.WRONG_DOCUMENT_ERR,
                                  null, newChild, 0);
      }
  }

  /**
   * <b>DOM L1</b>
   * Removes the specified child from this node's list of children,
   * or else reports an exception.
   *
   * <p> Causes a DOMNodeRemoved mutation event to be reported.
   *
   * <p> If this DOM has been compiled without mutation event support,
   * these events will not be reported.
   */
  public Node removeChild(Node refChild)
  {
    try
      {
        DomNode ref = (DomNode) refChild;

        if (ref == null || ref.parent != this)
          {
            throw new DomDOMException(DOMException.NOT_FOUND_ERR,
                                      null, ref, 0);
          }
        if (readonly && !owner.building)
          {
            throw new DomDOMException(DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                      null, this, 0);
          }
        
        for (DomNode child = first; child != null; child = child.next)
          {