--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwtx/text/edits/TextEditVisitor.d	Sat Aug 23 19:10:48 2008 +0200
@@ -0,0 +1,229 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2006 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ * Port to the D programming language:
+ *     Frank Benoit <benoit@tionex.de>
+ *******************************************************************************/
+module dwtx.text.edits.TextEditVisitor;
+
+import dwt.dwthelper.utils;
+
+/**
+ * A visitor for text edits.
+ * <p>
+ * For each different concrete text edit type <it>T</it> there is a method:
+ * <ul>
+ *   <li><code>public bool visit(<it>T</it> node)</code> - Visits the given edit to
+ *   perform some arbitrary operation. If <code>true </code> is returned, the given edit's
+ *   child edits will be visited next; however, if <code>false</code> is returned, the
+ *   given edit's child edits will not be visited. The default implementation provided by
+ *   this class calls a generic method <code>visitNode(<it>TextEdit</it> node)</code>.
+ *   Subclasses may reimplement these method as needed.</li>
+ * </ul>
+ * </p>
+ * <p>
+ * In addition, there are methods for visiting text edits in the
+ * abstract, regardless of node type:
+ * <ul>
+ *   <li><code>public void preVisit(TextEdit edit)</code> - Visits
+ *   the given edit to perform some arbitrary operation.
+ *   This method is invoked prior to the appropriate type-specific
+ *   <code>visit</code> method.
+ *   The default implementation of this method does nothing.
+ *   Subclasses may reimplement this method as needed.</li>
+ *
+ *   <li><code>public void postVisit(TextEdit edit)</code> - Visits
+ *   the given edit to perform some arbitrary operation.
+ *   This method is invoked after the appropriate type-specific
+ *   <code>endVisit</code> method.
+ *   The default implementation of this method does nothing.
+ *   Subclasses may reimplement this method as needed.</li>
+ * </ul>
+ * </p>
+ * <p>
+ * For edits with children, the child nodes are visited in increasing order.
+ * </p>
+ *
+ * @see TextEdit#accept(TextEditVisitor)
+ * @since 3.0
+ */
+public class TextEditVisitor {
+
+    /**
+     * Visits the given text edit prior to the type-specific visit.
+     * (before <code>visit</code>).
+     * <p>
+     * The default implementation does nothing. Subclasses may reimplement.
+     * </p>
+     *
+     * @param edit the node to visit
+     */
+    public void preVisit(TextEdit edit) {
+        // default implementation: do nothing
+    }
+
+    /**
+     * Visits the given text edit following the type-specific visit
+     * (after <code>endVisit</code>).
+     * <p>
+     * The default implementation does nothing. Subclasses may reimplement.
+     * </p>
+     *
+     * @param edit the node to visit
+     */
+    public void postVisit(TextEdit edit) {
+        // default implementation: do nothing
+    }
+
+    /**
+     * Visits the given text edit. This method is called by default from
+     * type-specific visits. It is not called by an edit's accept method.
+     * The default implementation returns <code>true</code>.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visitNode(TextEdit edit) {
+        return true;
+    }
+
+    /**
+     * Visits a <code>CopySourceEdit</code> instance.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visit(CopySourceEdit edit) {
+        return visitNode(edit);
+    }
+
+    /**
+     * Visits a <code>CopyTargetEdit</code> instance.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visit(CopyTargetEdit edit) {
+        return visitNode(edit);
+    }
+
+    /**
+     * Visits a <code>MoveSourceEdit</code> instance.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visit(MoveSourceEdit edit) {
+        return visitNode(edit);
+    }
+
+    /**
+     * Visits a <code>MoveTargetEdit</code> instance.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visit(MoveTargetEdit edit) {
+        return visitNode(edit);
+    }
+
+    /**
+     * Visits a <code>RangeMarker</code> instance.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visit(RangeMarker edit) {
+        return visitNode(edit);
+    }
+
+    /**
+     * Visits a <code>CopyingRangeMarker</code> instance.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visit(CopyingRangeMarker edit) {
+        return visitNode(edit);
+    }
+
+    /**
+     * Visits a <code>DeleteEdit</code> instance.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visit(DeleteEdit edit) {
+        return visitNode(edit);
+    }
+
+    /**
+     * Visits a <code>InsertEdit</code> instance.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visit(InsertEdit edit) {
+        return visitNode(edit);
+    }
+
+    /**
+     * Visits a <code>ReplaceEdit</code> instance.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visit(ReplaceEdit edit) {
+        return visitNode(edit);
+    }
+
+    /**
+     * Visits a <code>UndoEdit</code> instance.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visit(UndoEdit edit) {
+        return visitNode(edit);
+    }
+
+    /**
+     * Visits a <code>MultiTextEdit</code> instance.
+     *
+     * @param edit the node to visit
+     * @return If <code>true</code> is returned, the given node's child
+     *  nodes will be visited next; however, if <code>false</code> is
+     *  returned, the given node's child nodes will not be visited.
+     */
+    public bool visit(MultiTextEdit edit) {
+        return visitNode(edit);
+    }
+}