[gxml] DomTreeWalker: usin Vala/C style API convention

[Daniel Espinosa Ortiz <despinosa src gnome org>]

commit 9654570ef1203325f025644fa3346a16af65380b
Author: Daniel Espinosa <esodan gmail com>
Date:   Thu Mar 21 13:54:06 2019 -0600

    DomTreeWalker: usin Vala/C style API convention
    
    Fix https://gitlab.gnome.org/GNOME/gxml/issues/6

 examples/meson.build     |  1 +
 gxml/DomCollections.vala | 14 +++++++-------
 gxml/GXmlDocument.vala   | 14 +++++++-------
 3 files changed, 15 insertions(+), 14 deletions(-)
---
diff --git a/examples/meson.build b/examples/meson.build
index 3e15c22..d2ddf9e 100644
--- a/examples/meson.build
+++ b/examples/meson.build
@@ -1 +1,2 @@
 subdir('vala')
+subdir('c')
diff --git a/gxml/DomCollections.vala b/gxml/DomCollections.vala
index 3d35f63..d9ee510 100644
--- a/gxml/DomCollections.vala
+++ b/gxml/DomCollections.vala
@@ -143,13 +143,13 @@ public interface GXml.DomTreeWalker : Object {
   public abstract DomNodeFilter? filter { get; }
   public abstract DomNode current_node { get; }
 
-  public abstract DomNode? parentNode();
-  public abstract DomNode? firstChild();
-  public abstract DomNode? lastChild();
-  public abstract DomNode? previousSibling();
-  public abstract DomNode? nextSibling();
-  public abstract DomNode? previousNode();
-  public abstract DomNode? nextNode();
+  public abstract DomNode? parent_node();
+  public abstract DomNode? first_child();
+  public abstract DomNode? last_child();
+  public abstract DomNode? previous_sibling();
+  public abstract DomNode? next_sibling();
+  public abstract DomNode? previous_node();
+  public abstract DomNode? next_node();
 }
 
 public interface GXml.DomNamedNodeMap : Object, Gee.Map<string,DomNode> {
diff --git a/gxml/GXmlDocument.vala b/gxml/GXmlDocument.vala
index 2944a57..7557725 100644
--- a/gxml/GXmlDocument.vala
+++ b/gxml/GXmlDocument.vala
@@ -483,11 +483,11 @@ public class GXml.GDomTreeWalker : Object, GXml.DomTreeWalker {
     _filter = f;
   }
 
-  public DomNode? parentNode() { return null; }// FIXME
-  public DomNode? firstChild() { return null; } // FIXME
-  public DomNode? lastChild() { return null; }// FIXME
-  public DomNode? previousSibling() { return null; }// FIXME
-  public DomNode? nextSibling() { return null; }// FIXME
-  public DomNode? previousNode() { return null; }// FIXME
-  public DomNode? nextNode() { return null; }// FIXME
+  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
 }