Restore hotkeys in `pane_grid` example

- Implement `subscription::events_with`
- Remove `pane_grid::KeyPressEvent`
- Return closest sibling in `pane_grid::State::close`

2 files changed, 36 insertions, 5 deletions

diff --git a/native/src/subscription.rs b/native/src/subscription.rs
index 0d002c6c..18750abf 100644
--- a/native/src/subscription.rs
+++ b/native/src/subscription.rs
@@ -43,5 +43,25 @@ use events::Events;
 /// [`Subscription`]: type.Subscription.html
 /// [`Event`]: ../enum.Event.html
 pub fn events() -> Subscription<Event> {
-    Subscription::from_recipe(Events)
+    Subscription::from_recipe(Events { f: Some })
+}
+
+/// Returns a [`Subscription`] that filters all the runtime events with the
+/// provided function, producing messages accordingly.
+///
+/// This subscription will call the provided function for every [`Event`]
+/// handled by the runtime. If the function:
+///
+/// - Returns `None`, the [`Event`] will be discarded.
+/// - Returns `Some` message, the `Message` will be produced.
+///
+/// [`Subscription`]: type.Subscription.html
+/// [`Event`]: ../enum.Event.html
+pub fn events_with<Message>(
+    f: fn(Event) -> Option<Message>,
+) -> Subscription<Message>
+where
+    Message: 'static + Send,
+{
+    Subscription::from_recipe(Events { f })
 }
diff --git a/native/src/subscription/events.rs b/native/src/subscription/events.rs
index ceae467d..a1ae6051 100644
--- a/native/src/subscription/events.rs
+++ b/native/src/subscription/events.rs
@@ -2,17 +2,26 @@ use crate::{
     subscription::{EventStream, Recipe},
     Event, Hasher,
 };
+use iced_futures::futures::future;
+use iced_futures::futures::StreamExt;
 use iced_futures::BoxStream;
 
-pub struct Events;
+pub struct Events<Message> {
+    pub(super) f: fn(Event) -> Option<Message>,
+}
 
-impl Recipe<Hasher, Event> for Events {
-    type Output = Event;
+impl<Message> Recipe<Hasher, Event> for Events<Message>
+where
+    Message: 'static + Send,
+{
+    type Output = Message;
 
     fn hash(&self, state: &mut Hasher) {
         use std::hash::Hash;
 
-        std::any::TypeId::of::<Self>().hash(state);
+        struct Marker;
+        std::any::TypeId::of::<Marker>().hash(state);
+        self.f.hash(state);
     }
 
     fn stream(
@@ -20,5 +29,7 @@ impl Recipe<Hasher, Event> for Events {
         event_stream: EventStream,
     ) -> BoxStream<Self::Output> {
         event_stream
+            .filter_map(move |event| future::ready((self.f)(event)))
+            .boxed()
     }
 }