diff --git a/fitnesstrax/app/src/components/day.rs b/fitnesstrax/app/src/components/day.rs
index 4692ac3..9e5a28b 100644
--- a/fitnesstrax/app/src/components/day.rs
+++ b/fitnesstrax/app/src/components/day.rs
@@ -248,9 +248,12 @@ impl Default for WeightViewPrivate {
             .halign(gtk::Align::Start)
             .can_focus(true)
             .build();
-        let edit = TextEntry::<si::Kilogram<f64>>::new("weight", None, &|w: &str| {
-            w.parse::<f64>().map(|w| w * si::KG).map_err(|_| ParseError)
-        });
+        let edit = TextEntry::<si::Kilogram<f64>>::new(
+            "weight",
+            None,
+            |w: &si::Kilogram<f64>| w.to_string(),
+            |w: &str| w.parse::<f64>().map(|w| w * si::KG).map_err(|_| ParseError),
+        );
 
         let current = view.clone();
 
diff --git a/fitnesstrax/app/src/components/text_entry.rs b/fitnesstrax/app/src/components/text_entry.rs
index 690e5d8..2220ec9 100644
--- a/fitnesstrax/app/src/components/text_entry.rs
+++ b/fitnesstrax/app/src/components/text_entry.rs
@@ -23,43 +23,65 @@ pub struct ParseError;
 pub struct TextEntry<T: Clone> {
     value: Rc<RefCell<Option<T>>>,
     widget: gtk::Entry,
+    renderer: Rc<Box<dyn Fn(&T) -> String>>,
+    validator: Rc<Box<dyn Fn(&str) -> Result<T, ParseError>>>,
 }
 
-impl<T: Clone> TextEntry<T> {
-    pub fn new(
-        placeholder: &str,
-        value: Option<T>,
-        validator: &'static dyn Fn(&str) -> Result<T, ParseError>,
-    ) -> Self {
+// I do not understand why the data should be 'static.
+impl<T: Clone + 'static> TextEntry<T> {
+    pub fn new<R, V>(placeholder: &str, value: Option<T>, renderer: R, validator: V) -> Self
+    where
+        R: Fn(&T) -> String + 'static,
+        V: Fn(&str) -> Result<T, ParseError> + 'static,
+    {
         let widget = gtk::Entry::builder().placeholder_text(placeholder).build();
+        match value {
+            Some(ref v) => widget.set_text(&renderer(&v)),
+            None => {}
+        }
 
         let s = Self {
             value: Rc::new(RefCell::new(value)),
             widget,
+            renderer: Rc::new(Box::new(renderer)),
+            validator: Rc::new(Box::new(validator)),
         };
 
         s.widget.buffer().connect_text_notify({
             let s = s.clone();
-            move |buffer| {
-                if buffer.text().is_empty() {
-                    *s.value.borrow_mut() = None;
-                }
-                match validator(buffer.text().as_str()) {
-                    Ok(v) => *s.value.borrow_mut() = Some(v),
-                    // need to change the border to provide a visual indicator of an error
-                    Err(_) => {}
-                }
-            }
+            move |buffer| s.handle_text_change(buffer)
         });
 
         s
     }
 
+    fn handle_text_change(&self, buffer: &gtk::EntryBuffer) {
+        if buffer.text().is_empty() {
+            *self.value.borrow_mut() = None;
+            self.widget.remove_css_class("error");
+            return;
+        }
+        match (self.validator)(buffer.text().as_str()) {
+            Ok(v) => {
+                *self.value.borrow_mut() = Some(v);
+                self.widget.remove_css_class("error");
+            }
+            // need to change the border to provide a visual indicator of an error
+            Err(_) => {
+                self.widget.add_css_class("error");
+            }
+        }
+    }
+
     pub fn value(&self) -> Option<T> {
         self.value.borrow().clone()
     }
 
     pub fn set_value(&self, value: Option<T>) {
+        match value {
+            Some(ref v) => self.widget.set_text(&(self.renderer)(&v)),
+            None => {}
+        }
         *self.value.borrow_mut() = value;
     }