1 files changed, 181 insertions, 0 deletions
diff --git a/libjava/classpath/javax/swing/text/ElementIterator.java b/libjava/classpath/javax/swing/text/ElementIterator.java
new file mode 100644
index 00000000000..a6a5ff618bd
--- /dev/null
+++ b/libjava/classpath/javax/swing/text/ElementIterator.java
@@ -0,0 +1,181 @@
+/* ElementIterator.java --
+   Copyright (C) 2005 Free Software Foundation, Inc.
+
+This file is part of GNU Classpath.
+
+GNU Classpath is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2, or (at your option)
+any later version.
+ 
+GNU Classpath is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with GNU Classpath; see the file COPYING.  If not, write to the
+Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+02110-1301 USA.
+
+Linking this library statically or dynamically with other modules is
+making a combined work based on this library.  Thus, the terms and
+conditions of the GNU General Public License cover the whole
+combination.
+
+As a special exception, the copyright holders of this library give you
+permission to link this library with independent modules to produce an
+executable, regardless of the license terms of these independent
+modules, and to copy and distribute the resulting executable under
+terms of your choice, provided that you also meet, for each linked
+independent module, the terms and conditions of the license of that
+module.  An independent module is a module which is not derived from
+or based on this library.  If you modify this library, you may extend
+this exception to your version of the library, but you are not
+obligated to do so.  If you do not wish to do so, delete this
+exception statement from your version. */
+
+package javax.swing.text;
+
+/**
+ * This class can be used to iterate over the {@link Element} tree of
+ * a {@link Document} or an {@link Element}.  This iterator performs
+ * an "in-order" traversal -- first it visits a node, then each of the
+ * node's children in order.  No locking is performed during the
+ * iteration; that is up to the caller.
+ */
+public class ElementIterator implements Cloneable
+{
+  // The root element.
+  private Element root;
+  // The current element.
+  private Element currentElement;
+  // The depth to which we have descended in the tree.
+  private int currentDepth;
+
+  // This is at least as big as the current depth, and at index N
+  // contains the index of the child element we're currently
+  // examining.
+  private int[] state;
+
+  // The previous item.
+  private Element previousItem;
+
+  /**
+   * Create a new ElementIterator to iterate over the given document.
+   * @param document the Document over which we iterate
+   */
+  public ElementIterator(Document document)
+  {
+    this.root = document.getDefaultRootElement();
+    this.currentElement = root;
+    this.state = new int[5];
+  }
+
+  /**
+   * Create a new ElementIterator to iterate over the given document.
+   * @param root the Document over which we iterate
+   */
+  public ElementIterator(Element root)
+  {
+    this.root = root;
+    this.currentElement = root;
+    this.state = new int[5];
+  }
+
+  /**
+   * Returns a new ElementIterator which is a clone of this
+   * ElementIterator.
+   */
+  public Object clone()
+  {
+    try
+      {
+	return super.clone();
+      }
+    catch (CloneNotSupportedException _)
+      {
+	// Can't happen.
+	return null;
+      }
+  }
+
+  /**
+   * Returns the current element.
+   */
+  public Element current()
+  {
+    return currentElement;
+  }
+
+  /**
+   * Returns the depth to which we have descended in the tree.
+   */
+  public int depth()
+  {
+    return currentDepth;
+  }
+
+  /**
+   * Returns the first element in the tree.
+   */
+  public Element first()
+  {
+    // Reset the iterator.
+    currentElement = root;
+    currentDepth = 0;
+    previousItem = null;
+    return root;
+  }
+
+  /**
+   * Advance the iterator and return the next element of the tree,
+   * performing an "in-order" traversal.
+   */
+  public Element next()
+  {
+    previousItem = currentElement;
+    if (currentElement == null)
+      return null;
+    if (! currentElement.isLeaf())
+      {
+	++currentDepth;
+	if (currentDepth > state.length)
+	  {
+	    int[] newState = new int[state.length * 2];
+	    System.arraycopy(state, 0, newState, 0, state.length);
+	    state = newState;
+	  }
+	state[currentDepth] = 0;
+	currentElement = currentElement.getElement(0);
+	return currentElement;
+      }
+
+    while (currentDepth > 0)
+      {
+	// At a leaf, or done with a non-leaf's children, so go up a
+	// level.
+	--currentDepth;
+	currentElement = currentElement.getParentElement();
+	++state[currentDepth];
+	if (state[currentDepth] < currentElement.getElementCount())
+	  {
+	    currentElement = currentElement.getElement(state[currentDepth]);
+	    return currentElement;
+	  }
+      }
+
+    currentElement = null;
+    return currentElement;
+  }
+
+  /**
+   * Returns the previous item.  Does not modify the iterator state.
+   */
+  public Element previous()
+  {
+    if (currentElement == null || currentElement == root)
+      return null;
+    return previousItem;
+  }
+}