Restore hotkeys in `pane_grid` example

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

9 files changed, 88 insertions, 45 deletions

diff --git a/examples/pane_grid/Cargo.toml b/examples/pane_grid/Cargo.toml
index 3d1631f1..e489f210 100644
--- a/examples/pane_grid/Cargo.toml
+++ b/examples/pane_grid/Cargo.toml
@@ -7,3 +7,4 @@ publish = false
 
 [dependencies]
 iced = { path = "../..", features = ["debug"] }
+iced_native = { path = "../../native" }
diff --git a/examples/pane_grid/src/main.rs b/examples/pane_grid/src/main.rs
index 36485e9a..d149f9c6 100644
--- a/examples/pane_grid/src/main.rs
+++ b/examples/pane_grid/src/main.rs
@@ -1,8 +1,9 @@
 use iced::{
-    button, keyboard, pane_grid, scrollable, Align, Button, Column, Container,
-    Element, HorizontalAlignment, Length, PaneGrid, Sandbox, Scrollable,
-    Settings, Text,
+    button, executor, keyboard, pane_grid, scrollable, Align, Application,
+    Button, Column, Command, Container, Element, HorizontalAlignment, Length,
+    PaneGrid, Scrollable, Settings, Subscription, Text,
 };
+use iced_native::{subscription, Event};
 
 pub fn main() -> iced::Result {
     Example::run(Settings::default())
@@ -26,24 +27,29 @@ enum Message {
     CloseFocused,
 }
 
-impl Sandbox for Example {
+impl Application for Example {
     type Message = Message;
+    type Executor = executor::Default;
+    type Flags = ();
 
-    fn new() -> Self {
+    fn new(_flags: ()) -> (Self, Command<Message>) {
         let (panes, _) = pane_grid::State::new(Content::new(0));
 
-        Example {
-            panes,
-            panes_created: 1,
-            focus: None,
-        }
+        (
+            Example {
+                panes,
+                panes_created: 1,
+                focus: None,
+            },
+            Command::none(),
+        )
     }
 
     fn title(&self) -> String {
         String::from("Pane grid - Iced")
     }
 
-    fn update(&mut self, message: Message) {
+    fn update(&mut self, message: Message) -> Command<Message> {
         match message {
             Message::Split(axis, pane) => {
                 let result = self.panes.split(
@@ -96,14 +102,30 @@ impl Sandbox for Example {
             }
             Message::Dragged(_) => {}
             Message::Close(pane) => {
-                let _ = self.panes.close(&pane);
+                if let Some((_, sibling)) = self.panes.close(&pane) {
+                    self.focus = Some(sibling);
+                }
             }
             Message::CloseFocused => {
                 if let Some(pane) = self.focus {
-                    let _ = self.panes.close(&pane);
+                    if let Some((_, sibling)) = self.panes.close(&pane) {
+                        self.focus = Some(sibling);
+                    }
                 }
             }
         }
+
+        Command::none()
+    }
+
+    fn subscription(&self) -> Subscription<Message> {
+        subscription::events_with(|event| match event {
+            Event::Keyboard(keyboard::Event::KeyPressed {
+                modifiers,
+                key_code,
+            }) if modifiers.control => handle_hotkey(key_code),
+            _ => None,
+        })
     }
 
     fn view(&mut self) -> Element<Message> {
@@ -137,11 +159,11 @@ impl Sandbox for Example {
     }
 }
 
-fn handle_hotkey(event: pane_grid::KeyPressEvent) -> Option<Message> {
+fn handle_hotkey(key_code: keyboard::KeyCode) -> Option<Message> {
     use keyboard::KeyCode;
     use pane_grid::{Axis, Direction};
 
-    let direction = match event.key_code {
+    let direction = match key_code {
         KeyCode::Up => Some(Direction::Up),
         KeyCode::Down => Some(Direction::Down),
         KeyCode::Left => Some(Direction::Left),
@@ -149,7 +171,7 @@ fn handle_hotkey(event: pane_grid::KeyPressEvent) -> Option<Message> {
         _ => None,
     };
 
-    match event.key_code {
+    match key_code {
         KeyCode::V => Some(Message::SplitFocused(Axis::Vertical)),
         KeyCode::H => Some(Message::SplitFocused(Axis::Horizontal)),
         KeyCode::W => Some(Message::CloseFocused),
diff --git a/glow/src/widget/pane_grid.rs b/glow/src/widget/pane_grid.rs
index 3c47b562..9e6d27d0 100644
--- a/glow/src/widget/pane_grid.rs
+++ b/glow/src/widget/pane_grid.rs
@@ -11,8 +11,8 @@
 use crate::Renderer;
 
 pub use iced_native::pane_grid::{
-    Axis, Configuration, Direction, DragEvent, Focus, KeyPressEvent, Node,
-    Pane, ResizeEvent, Split, State,
+    Axis, Configuration, Direction, DragEvent, Focus, Node, Pane, ResizeEvent,
+    Split, State,
 };
 
 /// A collection of panes distributed using either vertical or horizontal splits
diff --git a/graphics/src/widget/pane_grid.rs b/graphics/src/widget/pane_grid.rs
index 5b0eb391..1bc01c03 100644
--- a/graphics/src/widget/pane_grid.rs
+++ b/graphics/src/widget/pane_grid.rs
@@ -20,8 +20,8 @@ use iced_native::{
 };
 
 pub use iced_native::pane_grid::{
-    Axis, Configuration, Content, Direction, DragEvent, Focus, KeyPressEvent,
-    Pane, ResizeEvent, Split, State, TitleBar,
+    Axis, Configuration, Content, Direction, DragEvent, Focus, Pane,
+    ResizeEvent, Split, State, TitleBar,
 };
 
 /// A collection of panes distributed using either vertical or horizontal splits
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()
     }
 }
diff --git a/native/src/widget/pane_grid.rs b/native/src/widget/pane_grid.rs
index 584b2ba4..7d9659e9 100644
--- a/native/src/widget/pane_grid.rs
+++ b/native/src/widget/pane_grid.rs
@@ -29,8 +29,8 @@ pub use state::{Focus, State};
 pub use title_bar::TitleBar;
 
 use crate::{
-    container, keyboard, layout, mouse, overlay, row, text, Clipboard, Element,
-    Event, Hasher, Layout, Length, Point, Rectangle, Size, Vector, Widget,
+    container, layout, mouse, overlay, row, text, Clipboard, Element, Event,
+    Hasher, Layout, Length, Point, Rectangle, Size, Vector, Widget,
 };
 
 /// A collection of panes distributed using either vertical or horizontal splits
@@ -336,18 +336,6 @@ pub struct ResizeEvent {
     pub ratio: f32,
 }
 
-/// An event produced during a key press interaction of a [`PaneGrid`].
-///
-/// [`PaneGrid`]: struct.PaneGrid.html
-#[derive(Debug, Clone, Copy)]
-pub struct KeyPressEvent {
-    /// The key that was pressed.
-    pub key_code: keyboard::KeyCode,
-
-    /// The state of the modifier keys when the key was pressed.
-    pub modifiers: keyboard::ModifiersState,
-}
-
 impl<'a, Message, Renderer> Widget<Message, Renderer>
     for PaneGrid<'a, Message, Renderer>
 where
diff --git a/native/src/widget/pane_grid/state.rs b/native/src/widget/pane_grid/state.rs
index e2793641..be36b070 100644
--- a/native/src/widget/pane_grid/state.rs
+++ b/native/src/widget/pane_grid/state.rs
@@ -227,12 +227,13 @@ impl<T> State<T> {
         let _ = self.internal.layout.resize(split, ratio);
     }
 
-    /// Closes the given [`Pane`] and returns its internal state, if it exists.
+    /// Closes the given [`Pane`] and returns its internal state and its closest
+    /// sibling, if it exists.
     ///
     /// [`Pane`]: struct.Pane.html
-    pub fn close(&mut self, pane: &Pane) -> Option<T> {
-        if let Some(_) = self.internal.layout.remove(pane) {
-            self.panes.remove(pane)
+    pub fn close(&mut self, pane: &Pane) -> Option<(T, Pane)> {
+        if let Some(sibling) = self.internal.layout.remove(pane) {
+            self.panes.remove(pane).map(|state| (state, sibling))
         } else {
             None
         }
diff --git a/wgpu/src/widget/pane_grid.rs b/wgpu/src/widget/pane_grid.rs
index 3c47b562..9e6d27d0 100644
--- a/wgpu/src/widget/pane_grid.rs
+++ b/wgpu/src/widget/pane_grid.rs
@@ -11,8 +11,8 @@
 use crate::Renderer;
 
 pub use iced_native::pane_grid::{
-    Axis, Configuration, Direction, DragEvent, Focus, KeyPressEvent, Node,
-    Pane, ResizeEvent, Split, State,
+    Axis, Configuration, Direction, DragEvent, Focus, Node, Pane, ResizeEvent,
+    Split, State,
 };
 
 /// A collection of panes distributed using either vertical or horizontal splits