Don't Draw Hidden Sections (#24)

* added a simple snippet for hiding sections that are marked as display none

* updated the displaynone to work with the new implementation

lib/src/converter/visit.rs

@@ -4,15 +4,19 @@ pub trait XmlVisitor {
     fn visit(&mut self, node: Node);
 }
 
+pub fn is_valid_node(node: &Node) -> bool {
+    return node.is_element() && !node.attribute("style").unwrap_or_default().contains("display:none");
+}
+
 pub fn depth_first_visit(doc: &Document, visitor: &mut impl XmlVisitor) {
     let mut stack = doc
         .root()
         .children()
         .rev()
-        .filter(|x| x.is_element())
+        .filter(|x| is_valid_node(x))
         .collect::<Vec<_>>();
     while let Some(node) = stack.pop() {
         visitor.visit(node);
-        stack.extend(node.children().rev().filter(|x| x.is_element()));
+        stack.extend(node.children().rev().filter(|x| is_valid_node(x)));
     }
 }