Most of new_breadcrumbs_partial, just need to get the return working.

src/renderer/breadcrumb_tree.rs

@@ -1,13 +1,19 @@
 use crate::renderer::context_element::IntoContextElement;
 use std::borrow::Borrow;
+use std::rc::Rc;
 
 pub struct BreadcrumbTree<'a> {
     parent: Option<&'a BreadcrumbTree<'a>>,
     element: BreadcrumbTreeElement<'a>,
 }
 
+#[derive(Clone, Debug)]
 pub enum BreadcrumbTreeElement<'a> {
-    Owned(Box<dyn IntoContextElement>),
+    // Using Rc so that when we need to create BreadcrumbTrees with
+    // the same BreadcrumbTreeElement but a different parent (for
+    // example, when inserting behind the tail), we don't need to the
+    // copy the already owned/malloc'd data.
+    Owned(Rc<dyn IntoContextElement>),
     Borrowed(&'a dyn IntoContextElement),
 }
 
@@ -27,6 +33,10 @@ impl<'a> BreadcrumbTree<'a> {
         self.parent
     }
 
+    pub fn get_element(&self) -> &BreadcrumbTreeElement<'a> {
+        &self.element
+    }
+
     pub fn ice_iter(&'a self) -> impl Iterator<Item = &dyn IntoContextElement> {
         self.breadcrumb_iter().map(|b| b.get_ice())
     }
@@ -34,6 +44,14 @@ impl<'a> BreadcrumbTree<'a> {
     pub fn breadcrumb_iter(&'a self) -> BreadcrumbTreeIterator<'a> {
         BreadcrumbTreeIterator(Some(self))
     }
+
+    pub fn clone_to_new_parent(&self, parent: Option<&'a BreadcrumbTree>) -> Self {
+        // TODO: Maybe not needed anymore?
+        BreadcrumbTree {
+            parent: parent,
+            element: self.element.clone(),
+        }
+    }
 }
 
 impl<'a> Borrow<dyn IntoContextElement + 'a> for BreadcrumbTreeElement<'a> {