[gxml] DomTreeWalker: DomNodeIterator: new implementation

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 09e7195cafb323bfe7f0cfef91b4f61cf3cecb69
Author: Daniel Espinosa <esodan gmail com>
Date:   Thu Jul 11 18:19:45 2019 -0500

    DomTreeWalker: DomNodeIterator: new implementation

 gxml/Document.vala       |  8 +++---
 gxml/DomCollections.vala | 30 ++++++++++++++--------
 gxml/DomDocument.vala    | 19 ++++++++++----
 gxml/NodeIterator.vala   | 46 +++++++++++++++++++++++++++++++++
 gxml/TreeWalker.vala     | 43 ++++++++++++++-----------------
 gxml/XDocument.vala      | 66 ++++++------------------------------------------
 gxml/meson.build         |  2 ++
 7 files changed, 113 insertions(+), 101 deletions(-)
---
diff --git a/gxml/Document.vala b/gxml/Document.vala
index b7839e9..0cc57c7 100644
--- a/gxml/Document.vala
+++ b/gxml/Document.vala
@@ -292,12 +292,12 @@ public class GXml.Document : GXml.Node,
   }
 
   // NodeFilter.SHOW_ALL = 0xFFFFFFFF
-  public DomNodeIterator create_node_iterator (DomNode root, int what_to_show = (int) 0xFFFFFFFF, 
DomNodeFilter? filter = null)
+  public DomNodeIterator create_node_iterator (DomNode root, int what_to_show = (int) 0xFFFFFFFF)
   {
-    return new GDomNodeIterator (root, what_to_show, filter);
+    return new NodeIterator (root, what_to_show);
   }
-  public DomTreeWalker create_tree_walker (DomNode root, int what_to_show = (int) 0xFFFFFFFF, DomNodeFilter? 
filter = null) {
-      return new GDomTreeWalker (root, what_to_show, filter);
+  public DomTreeWalker create_tree_walker (DomNode root, int what_to_show = (int) 0xFFFFFFFF) {
+      return new TreeWalker (root, what_to_show);
   }
   // DomParentNode
   public DomHTMLCollection children {
diff --git a/gxml/DomCollections.vala b/gxml/DomCollections.vala
index 51652e8..b0a83a4 100644
--- a/gxml/DomCollections.vala
+++ b/gxml/DomCollections.vala
@@ -91,14 +91,21 @@ public interface GXml.DomHTMLCollection : GLib.Object, Gee.BidirList<GXml.DomEle
 
 
 /**
- * No implemented jet. This can lead to API changes in future versions.
+ * Document's node iterator.
+ *
+ * If you want to filter while you go though the tree
+ * set a handler for the {@link accept_node} signal
  */
 public interface GXml.DomNodeIterator : GLib.Object {
   public abstract DomNode root { get; }
   public abstract DomNode reference_node { get; }
   public abstract bool pointer_before_reference_node { get; }
+  /**
+   * This is a value of {@link DomNodeFilter} contant SHOW.
+   */
   public abstract int what_to_show { get; }
-  public abstract DomNodeFilter? filter { get; }
+
+  public signal DomNodeFilter.Filter accept_node (DomNode node);
 
   public abstract DomNode? next_node();
   public abstract DomNode? previous_node();
@@ -110,10 +117,11 @@ public interface GXml.DomNodeIterator : GLib.Object {
  * No implemented jet. This can lead to API changes in future versions.
  */
 public class GXml.DomNodeFilter : GLib.Object {
-  // Constants for acceptNode()
-  public const int FILTER_ACCEPT = 1;
-  public const int FILTER_REJECT = 2;
-  public const int FILTER_SKIP = 3;
+  public enum Filter {
+    ACCEPT = 1,
+    REJECT,
+    SKIP
+  }
 
   // Constants for whatToShow
   public const int SHOW_ALL = (int) 0xFFFFFFFF;
@@ -129,20 +137,22 @@ public class GXml.DomNodeFilter : GLib.Object {
   public const int SHOW_DOCUMENT_TYPE = (int) 0x200;
   public const int SHOW_DOCUMENT_FRAGMENT = (int) 0x400;
   public const int SHOW_NOTATION = (int) 0x800; // historical
-
-  public delegate int accept_node (DomNode node); // FIXME: Should be a User defined method
 }
 
 
 /**
- * No implemented jet. This can lead to API changes in future versions.
+ * Document tree walker.
+ *
+ * If you want to filter while you go though the tree
+ * set a handler for the {@link accept_node} signal
  */
 public interface GXml.DomTreeWalker : GLib.Object {
   public abstract DomNode root { get; }
   public abstract int what_to_show { get; }
-  public abstract DomNodeFilter? filter { get; }
   public abstract DomNode current_node { get; }
 
+  public signal DomNodeFilter.Filter accept_node (DomNode node);
+
   public abstract DomNode? parent_node();
   public abstract DomNode? first_child();
   public abstract DomNode? last_child();
diff --git a/gxml/DomDocument.vala b/gxml/DomDocument.vala
index 55004b1..7361362 100644
--- a/gxml/DomDocument.vala
+++ b/gxml/DomDocument.vala
@@ -60,16 +60,25 @@ public interface GXml.DomDocument : GLib.Object,
    */
   public abstract DomRange create_range();
 
-  // NodeFilter.SHOW_ALL = 0xFFFFFFFF
   /**
-   * No implemented jet. This can lead to API changes in future versions.
+   * Creates a {@link DomNodeIterator}.
+   *
+   * Consider to connect to {@link DomNodeIterator.accept_node} in order to
+   * filter the nodes you iterate on.
+   *
+   * See at {@link DomNodeFilter} fot the constant value of @what_to_show
    */
-  public abstract DomNodeIterator create_node_iterator (DomNode root, int whatToShow = (int) 0xFFFFFFFF, 
DomNodeFilter? filter = null);
+  public abstract DomNodeIterator create_node_iterator (DomNode root, int whatToShow = (int) 0xFFFFFFFF);
 
   /**
-   * No implemented jet. This can lead to API changes in future versions.
+   * Creates a {@link DomTreeWalker}.
+   *
+   * Consider to connect to {@link DomTreeWalker.accept_node} in order to
+   * filter the nodes you iterate on.
+   *
+   * See at {@link DomNodeFilter} fot the constant value of @what_to_show
    */
-  public abstract DomTreeWalker create_tree_walker (DomNode root, int what_to_show = (int) 0xFFFFFFFF, 
DomNodeFilter? filter = null);
+  public abstract DomTreeWalker create_tree_walker (DomNode root, int what_to_show = (int) 0xFFFFFFFF);
 
   /**
    * Writes a dump XML representation of document to a file.
diff --git a/gxml/NodeIterator.vala b/gxml/NodeIterator.vala
new file mode 100644
index 0000000..18bcca2
--- /dev/null
+++ b/gxml/NodeIterator.vala
@@ -0,0 +1,46 @@
+/* -*- Mode: vala; indent-tabs-mode: nil; c-basic-offset: 2; tab-width: 2 -*- */
+/*
+ *
+ * Copyright (C) 2016-2019  Daniel Espinosa <esodan gmail com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+
+ * This library 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
+ * Lesser General Public License for more details.
+
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors:
+ *      Daniel Espinosa <esodan gmail com>
+ */
+
+/**
+ * Implementation of {@link DomNodeIterator}
+ */
+public class GXml.NodeIterator : GLib.Object, GXml.DomNodeIterator {
+  protected DomNode _root;
+  protected DomNode _reference_node;
+  protected bool _pointer_before_reference_node;
+  protected int _what_to_show;
+
+  public NodeIterator (DomNode n, int what_to_show) {
+    _root = n;
+    _reference_node = _root;
+    _what_to_show = what_to_show;
+  }
+  public DomNode root { get { return _root; } }
+  public DomNode reference_node { get { return _reference_node; } }
+  public bool pointer_before_reference_node { get { return _pointer_before_reference_node; } }
+  public int what_to_show { get { return _what_to_show; } }
+
+  public DomNode? next_node() { return null; } // FIXME
+  public DomNode? previous_node() { return null; } // FIXME
+
+  public void detach() { return; } // FIXME
+}
diff --git a/gxml/TreeWalker.vala b/gxml/TreeWalker.vala
index a4e0239..6c7c1b5 100644
--- a/gxml/TreeWalker.vala
+++ b/gxml/TreeWalker.vala
@@ -20,32 +20,30 @@
  *      Daniel Espinosa <esodan gmail com>
  */
 
-
-[Version (since = "0.18")]
+/**
+ * Implementation of {@link DomTreeWalker}
+ */
 public class GXml.TreeWalker : GLib.Object, GXml.DomTreeWalker {
   protected DomNode _root;
   protected int _what_to_show;
-  protected DomNodeFilter? _filter;
   protected  DomNode _current_node = null;
 
   public DomNode root { get { return root; } }
   public int what_to_show { get { return _what_to_show; } }
-  public DomNodeFilter? filter { get { return _filter; } }
   public DomNode current_node { get { return _current_node; } }
 
-  public TreeWalker (DomNode root, DomNode current, int w, DomNodeFilter? filter) {
+  public TreeWalker (DomNode root, int w) {
     _root = root;
     _what_to_show = w;
-    _filter = filter;
-    _current_node = current;
+    _current_node = root;
   }
 
   public DomNode? parent_node() {
     if (current_node == null) return null;
     var p = current_node.parent_node;
     if (p == null) return null;
-    if (_filter != null) {
-      if (_filter.accept_node (p) != DomNodeFilter.FILTER_ACCEPT) return null;
+    if (accept_node (p) != DomNodeFilter.Filter.ACCEPT) {
+      return null;
     }
     if (p == root) return  null;
     _current_node = p;
@@ -74,17 +72,15 @@ public class GXml.TreeWalker : GLib.Object, GXml.DomTreeWalker {
     } else {
       n = current_node.last_child;
     }
-    if¡ (n == null) return null;
+    if (n == null) return null;
     while (n != null) {
-      var res = DomNodeFilter.FILTER_ACCEPT
-      if (_filter != null) {
-        res = _filter.accept_node (n);
-      }
-      if (res == DomNodeFilter.FILTER_ACCEPT) {
+      var res = DomNodeFilter.Filter.ACCEPT;
+      res = accept_node (n);
+      if (res == DomNodeFilter.Filter.ACCEPT) {
         _current_node = n;
         return _current_node;
       }
-      if (res == DomNodeFilter.FILTER_SKIP) {
+      if (res == DomNodeFilter.Filter.SKIP) {
         DomNode c = null;
         if (first) {
           c = n.first_child;
@@ -127,11 +123,9 @@ public class GXml.TreeWalker : GLib.Object, GXml.DomTreeWalker {
     }
     DomNode n = s;
     while (n != null) {
-      var res = DomNodeFilter.FILTER_ACCEPT;
-      if (_filter != null) {
-        res = _filter.accept_node (n);
-      }
-      if  (res == DomNodeFilter.FILTER_ACCEPT) {
+      var res = DomNodeFilter.Filter.ACCEPT;
+      res = accept_node (n);
+      if  (res == DomNodeFilter.Filter.ACCEPT) {
         _current_node = n;
         return _current_node;
       }
@@ -141,7 +135,7 @@ public class GXml.TreeWalker : GLib.Object, GXml.DomTreeWalker {
       } else {
         c = n.last_child;
       }
-      if  (res == DomNodeFilter.FILTER_REJECT || c == null) {
+      if  (res == DomNodeFilter.Filter.REJECT || c == null) {
         if (next) {
           s = n.next_sibling;
         } else {
@@ -150,9 +144,10 @@ public class GXml.TreeWalker : GLib.Object, GXml.DomTreeWalker {
       }
       n = n.parent_node;
       if (n == null || n == root) return null;
-      if (_filter != null) {
-        if (_filter.accept_node (n) == DomNodeFilter.FILTER_ACCEPT) return null;
+      if (accept_node (n) == DomNodeFilter.Filter.ACCEPT) {
+        return null;
       }
     }
+    return s; // FIXME:
   }
 }
diff --git a/gxml/XDocument.vala b/gxml/XDocument.vala
index 7ea4f5e..644af2e 100644
--- a/gxml/XDocument.vala
+++ b/gxml/XDocument.vala
@@ -160,7 +160,7 @@ public class GXml.XDocument : GXml.XNode,
     return true;
   }
   // DomDocument implementation
-  protected GImplementation _implementation = new GImplementation ();
+  protected DomImplementation _implementation = new XImplementation ();
   protected string _url = "about:blank";
   protected string _origin = "";
   protected string _compat_mode = "";
@@ -311,12 +311,12 @@ public class GXml.XDocument : GXml.XNode,
   }
 
   // NodeFilter.SHOW_ALL = 0xFFFFFFFF
-  public DomNodeIterator create_node_iterator (DomNode root, int what_to_show = (int) 0xFFFFFFFF, 
DomNodeFilter? filter = null)
+  public DomNodeIterator create_node_iterator (DomNode root, int what_to_show = (int) 0xFFFFFFFF)
   {
-    return new GDomNodeIterator (root, what_to_show, filter);
+    return new NodeIterator (root, what_to_show);
   }
-  public DomTreeWalker create_tree_walker (DomNode root, int what_to_show = (int) 0xFFFFFFFF, DomNodeFilter? 
filter = null) {
-      return new GDomTreeWalker (root, what_to_show, filter);
+  public DomTreeWalker create_tree_walker (DomNode root, int what_to_show = (int) 0xFFFFFFFF) {
+      return new TreeWalker (root, what_to_show);
   }
   // DomParentNode
   public DomHTMLCollection children {
@@ -369,7 +369,7 @@ public class GXml.XDocument : GXml.XNode,
 }
 
 
-public class GXml.GImplementation : GLib.Object, GXml.DomImplementation {
+internal class GXml.XImplementation : GLib.Object, GXml.DomImplementation {
   public DomDocumentType
     create_document_type (string qualified_name, string public_id, string system_id)
         throws GLib.Error
@@ -387,7 +387,7 @@ public class GXml.GImplementation : GLib.Object, GXml.DomImplementation {
 }
 
 
-public class GXml.XDocumentType : GXml.XChildNode,
+internal class GXml.XDocumentType : GXml.XChildNode,
                                   GXml.DomNode,
                                   GXml.DomChildNode,
                                   GXml.DomDocumentType
@@ -416,7 +416,7 @@ public class GXml.XDocumentType : GXml.XChildNode,
   }
 }
 
-public class GXml.XDocumentFragment : GXml.XDocument,
+internal class GXml.XDocumentFragment : GXml.XDocument,
               GXml.DomDocumentFragment
 {
   public XDocumentFragment (GXml.XDocument d)  {
@@ -424,53 +424,3 @@ public class GXml.XDocumentFragment : GXml.XDocument,
   }
 }
 
-
-public class GXml.GDomNodeIterator : GLib.Object, GXml.DomNodeIterator {
-  protected DomNode _root;
-  protected DomNode _reference_node;
-  protected bool _pointer_before_reference_node;
-  protected int _what_to_show;
-  protected DomNodeFilter _filter;
-  public GDomNodeIterator (DomNode n, int what_to_show, DomNodeFilter filter) {
-    _root = n;
-    _what_to_show = what_to_show;
-    _filter = filter;
-  }
-  public DomNode root { get { return _root; } }
-  public DomNode reference_node { get { return _reference_node; } }
-  public bool pointer_before_reference_node { get { return _pointer_before_reference_node; } }
-  public int what_to_show { get { return _what_to_show; } }
-  public DomNodeFilter? filter { get { return _filter; } }
-
-  public DomNode? next_node() { return null; } // FIXME
-  public DomNode? previous_node() { return null; } // FIXME
-
-  public void detach() { return; } // FIXME
-}
-
-
-public class GXml.GDomTreeWalker : GLib.Object, GXml.DomTreeWalker {
-  protected DomNode _root;
-  protected int _what_to_show;
-  protected DomNodeFilter? _filter;
-  protected  DomNode _current_node;
-
-  public DomNode root { get { return root; } }
-  public int what_to_show { get { return _what_to_show; } }
-  public DomNodeFilter? filter { get { return _filter; } }
-  public DomNode current_node { get { return _current_node; } }
-
-  public GDomTreeWalker (DomNode r, int w, DomNodeFilter f) {
-    _root = r;
-    _what_to_show = w;
-    _filter = f;
-  }
-
-  public DomNode? parent_node() { return null; }// FIXME
-  public DomNode? first_child() { return null; } // FIXME
-  public DomNode? last_child() { return null; }// FIXME
-  public DomNode? previous_sibling() { return null; }// FIXME
-  public DomNode? next_sibling() { return null; }// FIXME
-  public DomNode? previous_node() { return null; }// FIXME
-  public DomNode? next_node() { return null; }// FIXME
-}
diff --git a/gxml/meson.build b/gxml/meson.build
index 59772b6..49d49cf 100644
--- a/gxml/meson.build
+++ b/gxml/meson.build
@@ -63,6 +63,7 @@ valasources = files ([
        'IXsdSchema.vala',
        'LXPathObject.vala',
        'Node.vala',
+       'NodeIterator.vala',
        'NodeType.vala',
        'Object.vala',
        'Parser.vala',
@@ -72,6 +73,7 @@ valasources = files ([
        'StringRef.vala',
        'Text.vala',
        'TokenList.vala',
+       'TreeWalker.vala',
        'XAttribute.vala',
        'XCharacter.vala',
        'XChildNode.vala',