implement modal view wrapper

this wrapper swallows all events that were not processed by the child view. it
can be used for modal dialogs.

src/ui/mod.rs

@@ -1,5 +1,6 @@
 pub mod layout;
 pub mod listview;
+pub mod modal;
 pub mod playlists;
 pub mod queue;
 pub mod search;

src/ui/modal.rs

@@ -0,0 +1,22 @@
+use cursive::event::{Event, EventResult};
+use cursive::view::{View, ViewWrapper};
+
+pub struct Modal<T: View> {
+    inner: T,
+}
+
+impl<T: View> Modal<T> {
+    pub fn new(inner: T) -> Self {
+        Modal { inner: inner }
+    }
+}
+
+impl<T: View> ViewWrapper for Modal<T> {
+    wrap_impl!(self.inner: T);
+    fn wrap_on_event(&mut self, ch: Event) -> EventResult {
+        match self.inner.on_event(ch) {
+            EventResult::Consumed(cb) => EventResult::Consumed(cb),
+            _ => EventResult::Consumed(None),
+        }
+    }
+}