Base::Reader: support reading child element with the same name as parent

Future GuiDocument.xml will save recursive tree item expansion status
using child element with the same name as the parent.

src/Base/Reader.cpp

@@ -252,10 +252,18 @@ void Base::XMLReader::readElement(const char* ElementName)
              (ElementName && LocalName != ElementName));
 }
 
-void Base::XMLReader::readEndElement(const char* ElementName)
+int Base::XMLReader::level() const {
+    return Level;
+}
+
+void Base::XMLReader::readEndElement(const char* ElementName, int level)
 {
     // if we are already at the end of the current element
-    if (ReadType == EndElement && LocalName == ElementName) {
+    if (ReadType == EndElement 
+            && ElementName 
+            && LocalName == ElementName
+            && (level<0 || level==Level))
+    {
         return;
     }
     else if (ReadType == EndDocument) {
@@ -268,7 +276,10 @@ void Base::XMLReader::readEndElement(const char* ElementName)
         ok = read(); if (!ok) break;
         if (ReadType == EndDocument)
             break;
-    } while (ReadType != EndElement || (ElementName && LocalName != ElementName));
+    } while (ReadType != EndElement 
+                || (ElementName 
+                    && (LocalName != ElementName
+                        || (level>=0 && level!=Level))));
 }
 
 void Base::XMLReader::readCharacters(void)

src/Base/Reader.h

@@ -134,10 +134,26 @@ public:
     //@{
     /// get the local name of the current Element
     const char* localName(void) const;
+    /// get the current element level
+    int level() const;
     /// read until a start element is found (\<name\>) or start-end element (\<name/\>) (with special name if given)
     void readElement   (const char* ElementName=0);
-    /// read until an end element is found (with special name if given)
-    void readEndElement(const char* ElementName=0);
+
+    /** read until an end element is found
+     *
+     * @param ElementName: optional end element name to look for. If given, then
+     * the parser will read until this name is found.
+     *
+     * @param level: optional level to look for. If given, then the parser will
+     * read until this level. Note that the parse only increase the level when
+     * finding a start element, not start-end element, and decrease the level
+     * after finding an end element. So, if you obtain the parser level after
+     * calling readElement(), you should specify a level minus one when calling
+     * this function. This \c level parameter is only useful if you know the
+     * child element may have the same name as its parent, otherwise, using \c
+     * ElementName is enough.
+     */
+    void readEndElement(const char* ElementName=0, int level=-1);
     /// read until characters are found
     void readCharacters(void);
     /// read binary file