adding pub fn len in List

src/widgets/list.rs

@@ -128,6 +128,14 @@ impl<'a> List<'a> {
         self
     }
 
+    pub fn len(&self) -> usize {
+        self.items.len()
+    }
+
+    pub fn is_empty(&self) -> bool {
+        self.items.is_empty()
+    }
+
     fn get_items_bounds(
         &self,
         selected: Option<usize>,

tests/widgets_list.rs

@@ -9,6 +9,23 @@ use tui::{
     Terminal,
 };
 
+
+#[test]
+fn list_should_shows_the_length() {
+    let items = vec![
+        ListItem::new("Item 1"),
+        ListItem::new("Item 2"),
+        ListItem::new("Item 3"),
+    ];
+    let list = List::new(items);
+    assert_eq!(list.len(), 3);
+    assert_eq!(list.is_empty(), false);
+
+    let empty_list = List::new(vec![]);
+    assert_eq!(empty_list.len(), 0);
+    assert_eq!(empty_list.is_empty(), true);
+}
+
 #[test]
 fn widgets_list_should_highlight_the_selected_item() {
     let backend = TestBackend::new(10, 3);