Add with_id_mut and find_id_mut convenient methods.

src/lib.rs

@@ -427,6 +427,18 @@ impl Cursive {
         self.find(&view::Selector::Id(id), callback)
     }
 
+    /// Convenient method to find a view wrapped in [`RefCellView`].
+    ///
+    /// This looks for a `RefCellView<V>` with the given ID, and return
+    /// a mutable reference to the wrapped view.
+    ///
+    /// [`RefCellView`]: views/struct.RefCellView.html
+    pub fn find_id_mut<V>(&mut self, id: &str) -> Option<views::ViewRef<V>>
+        where V: View + Any
+    {
+        self.find_id(id, views::RefCellView::<V>::get_mut)
+    }
+
     /// Adds a global callback.
     ///
     /// Will be triggered on the given key press when no view catches it.

src/view/identifiable.rs

@@ -1,16 +1,26 @@
 use view::View;
-use views::IdView;
+use views::{IdView, RefCellView};
 
 /// Makes a view wrappable in an [`IdView`].
 ///
 /// [`IdView`]: ../views/struct.IdView.html
 pub trait Identifiable: View + Sized {
-    /// Wraps this view into an IdView with the given id.
+    /// Wraps this view into an `IdView` with the given id.
     ///
     /// This is just a shortcut for `IdView::new(id, self)`
     fn with_id(self, id: &str) -> IdView<Self> {
         IdView::new(id, self)
     }
+
+    /// Wraps this view into both a [`RefCellView`] and an `IdView`.
+    ///
+    /// This allows to call [`Cursive::find_id_mut`].
+    ///
+    /// [`RefCellView`]: ../views/struct.RefCellView.html
+    /// [`Cursive::find_id_mut`]: ../struct.Cursive.html#method.find_id_mut
+    fn with_id_mut(self, id: &str) -> IdView<RefCellView<Self>> {
+        RefCellView::new(self).with_id(id)
+    }
 }
 
 /// Any `View` implements this trait.