Add EventTrigger, refactor OnEventView

src/backend/blt.rs

@@ -26,6 +26,7 @@ enum ColorRole {
     Background,
 }
 
+/// Backend using BearLibTerminal
 pub struct Backend {
     buttons_pressed: HashSet<MouseButton>,
     mouse_position: Vec2,
@@ -35,6 +36,7 @@ pub struct Backend {
 }
 
 impl Backend {
+    /// Creates a new BearLibTerminal-based backend.
     pub fn init() -> Box<backend::Backend> {
         terminal::open("Cursive", 80, 24);
         terminal::set(terminal::config::Window::empty().resizeable(true));

src/backend/curses/n.rs

@@ -1,3 +1,4 @@
+//! Ncurses-specific backend.
 extern crate ncurses;
 
 use std::cell::{Cell, RefCell};
@@ -23,6 +24,7 @@ use vec::Vec2;
 use self::super::split_i32;
 use self::ncurses::mmask_t;
 
+/// Backend using ncurses.
 pub struct Backend {
     current_style: Cell<ColorPair>,
 
@@ -200,6 +202,7 @@ fn write_to_tty(bytes: &[u8]) -> io::Result<()> {
 }
 
 impl Backend {
+    /// Creates a new ncurses-based backend.
     pub fn init() -> Box<backend::Backend> {
         let signals = Some(Signals::new(&[libc::SIGWINCH]).unwrap());
 

src/backend/curses/pan.rs

@@ -1,3 +1,4 @@
+//! Pancuses-specific backend.
 extern crate pancurses;
 
 use std::cell::{Cell, RefCell};
@@ -22,6 +23,7 @@ use vec::Vec2;
 use self::pancurses::mmask_t;
 use super::split_i32;
 
+/// Backend using pancurses.
 pub struct Backend {
     // Used
     current_style: Cell<ColorPair>,
@@ -84,7 +86,8 @@ impl InputParser {
                 pancurses::Input::Character(c) => Event::Char(c),
                 // TODO: Some key combos are not recognized by pancurses,
                 // but are sent as Unknown. We could still parse them here.
-                pancurses::Input::Unknown(code) => self.key_codes
+                pancurses::Input::Unknown(code) => self
+                    .key_codes
                     // pancurses does some weird keycode mapping
                     .get(&(code + 256 + 48))
                     .cloned()
@@ -286,6 +289,7 @@ fn find_closest_pair(pair: ColorPair) -> (i16, i16) {
 }
 
 impl Backend {
+    /// Creates a new pancurses-based backend.
     pub fn init() -> Box<backend::Backend> {
         // We need to create this now, before ncurses initialization
         // Otherwise ncurses starts its own signal handling and it's a mess.
@@ -523,18 +527,22 @@ where
         | pancurses::BUTTON2_DOUBLE_CLICKED
         | pancurses::BUTTON3_DOUBLE_CLICKED
         | pancurses::BUTTON4_DOUBLE_CLICKED
-        | pancurses::BUTTON5_DOUBLE_CLICKED => for _ in 0..2 {
+        | pancurses::BUTTON5_DOUBLE_CLICKED => {
-            f(MouseEvent::Press(button));
+            for _ in 0..2 {
-            f(MouseEvent::Release(button));
+                f(MouseEvent::Press(button));
-        },
+                f(MouseEvent::Release(button));
+            }
+        }
         pancurses::BUTTON1_TRIPLE_CLICKED
         | pancurses::BUTTON2_TRIPLE_CLICKED
         | pancurses::BUTTON3_TRIPLE_CLICKED
         | pancurses::BUTTON4_TRIPLE_CLICKED
-        | pancurses::BUTTON5_TRIPLE_CLICKED => for _ in 0..3 {
+        | pancurses::BUTTON5_TRIPLE_CLICKED => {
-            f(MouseEvent::Press(button));
+            for _ in 0..3 {
-            f(MouseEvent::Release(button));
+                f(MouseEvent::Press(button));
-        },
+                f(MouseEvent::Release(button));
+            }
+        }
         _ => debug!("Unknown event: {:032b}", bare_event),
     }
 }

src/backend/dummy.rs

@@ -8,12 +8,16 @@ use event::Event;
 use theme;
 use vec::Vec2;
 
+/// Dummy backend that does nothing and immediately exits.
+///
+/// Mostly used for testing.
 pub struct Backend {
     inner_sender: Sender<Option<Event>>,
     inner_receiver: Receiver<Option<Event>>,
 }
 
 impl Backend {
+    /// Creates a new dummy backend.
     pub fn init() -> Box<backend::Backend>
     where
         Self: Sized,

src/backend/termion.rs

@@ -31,6 +31,7 @@ use std::sync::atomic::{AtomicBool, Ordering};
 use std::sync::Arc;
 use std::thread;
 
+/// Backend using termion
 pub struct Backend {
     terminal: AlternateScreen<MouseTerminal<RawTerminal<Stdout>>>,
     current_style: Cell<theme::ColorPair>,
@@ -210,6 +211,7 @@ impl Effectable for theme::Effect {
 }
 
 impl Backend {
+    /// Creates a new termion-based backend.
     pub fn init() -> Box<backend::Backend> {
         print!("{}", termion::cursor::Hide);
 

src/event.rs

@@ -29,6 +29,91 @@ pub struct Callback(Rc<Box<Fn(&mut Cursive)>>);
 /// A boxed callback that can be run on `&mut Any`.
 pub type AnyCb<'a> = Box<FnMut(&mut Any) + 'a>;
 
+/// A trigger that only selects some types of events.
+pub struct EventTrigger(Box<Fn(&Event) -> bool>);
+
+impl EventTrigger {
+    /// Create a new `EventTrigger` using the given function as filter.
+    pub fn from_fn<F>(f: F) -> Self
+    where
+        F: 'static + Fn(&Event) -> bool,
+    {
+        EventTrigger(Box::new(f))
+    }
+
+    /// Checks if this trigger applies to the given `Event`.
+    pub fn apply(&self, event: &Event) -> bool {
+        (self.0)(event)
+    }
+
+    /// Returns an `EventTrigger` that only accepts arrow keys.
+    ///
+    /// Only bare arrow keys without modifiers (Shift, Ctrl, Alt) will be accepted.
+    pub fn arrows() -> Self {
+        Self::from_fn(|e| match e {
+            Event::Key(Key::Left)
+            | Event::Key(Key::Down)
+            | Event::Key(Key::Up)
+            | Event::Key(Key::Right) => true,
+            _ => false,
+        })
+    }
+
+    /// Returns an `EventTrigger` that only accepts mouse events.
+    pub fn mouse() -> Self {
+        Self::from_fn(|e| match e {
+            Event::Mouse { .. } => true,
+            _ => false,
+        })
+    }
+
+    /// Returns an `EventTrigger` that accepts any event.
+    pub fn any() -> Self {
+        Self::from_fn(|_| true)
+    }
+
+    /// Returns an `EventTrigger` that doesn't accept any event.
+    pub fn none() -> Self {
+        Self::from_fn(|_| true)
+    }
+
+    /// Returns an `EventTrigger` that applies if either `self` or `other` applies.
+    pub fn or<O>(self, other: O) -> Self
+    where
+        O: Into<EventTrigger>,
+    {
+        let other = other.into();
+        Self::from_fn(move |e| self.apply(e) || other.apply(e))
+    }
+}
+
+impl From<Event> for EventTrigger {
+    fn from(event: Event) -> Self {
+        Self::from_fn(move |e| *e == event)
+    }
+}
+
+impl From<char> for EventTrigger {
+    fn from(c: char) -> Self {
+        Self::from(Event::from(c))
+    }
+}
+
+impl From<Key> for EventTrigger {
+    fn from(k: Key) -> Self {
+        Self::from(Event::from(k))
+    }
+}
+
+impl<F> From<F> for EventTrigger
+where
+    F: 'static + Fn(&Event) -> bool,
+{
+    fn from(f: F) -> Self {
+        Self::from_fn(f)
+    }
+}
+
 impl Callback {
     /// Wraps the given function into a `Callback` object.
     pub fn from_fn<F>(f: F) -> Self

src/lib.rs

@@ -123,7 +123,6 @@ mod xy;
 mod div;
 mod utf8;
 
-#[doc(hidden)]
 pub mod backend;
 
 pub use cursive::{CbFunc, Cursive, ScreenId};

src/views/on_event_view.rs

@@ -1,5 +1,4 @@
-use event::{Callback, Event, EventResult};
+use event::{Callback, Event, EventResult, EventTrigger};
-use std::collections::HashMap;
 use std::rc::Rc;
 use view::{View, ViewWrapper};
 use Cursive;
@@ -10,10 +9,8 @@ use With;
 /// This view registers a set of callbacks tied to specific events, to be run
 /// in certain conditions.
 ///
-/// **Note**: only one callback can be registered per event. Trying to register
+/// * Some callbacks are called only for events ignored by the wrapped view.
-/// a new one will replace any existing one for that event.
 ///
-/// * Some callbacks are called only for vents ignored by the wrapped view
 ///   (those registered by [`on_event`] or [`on_event_inner`])
 /// * Others are processed first, and can control whether the child view should
 ///   be given the event (those registered by [`on_pre_event`] or
@@ -43,10 +40,10 @@ use With;
 /// ```
 pub struct OnEventView<T: View> {
     view: T,
-    callbacks: HashMap<Event, Action<T>>,
+    callbacks: Vec<(EventTrigger, Action<T>)>,
 }
 
-type InnerCallback<T> = Rc<Box<Fn(&mut T) -> Option<EventResult>>>;
+type InnerCallback<T> = Rc<Box<Fn(&mut T, &Event) -> Option<EventResult>>>;
 
 struct Action<T> {
     phase: TriggerPhase,
@@ -73,19 +70,19 @@ impl<T: View> OnEventView<T> {
     pub fn new(view: T) -> Self {
         OnEventView {
             view,
-            callbacks: HashMap::new(),
+            callbacks: Vec::new(),
         }
     }
 
     /// Registers a callback when the given event is ignored by the child.
     ///
     /// Chainable variant.
-    pub fn on_event<F, E>(self, event: E, cb: F) -> Self
+    pub fn on_event<F, E>(self, trigger: E, cb: F) -> Self
     where
-        E: Into<Event>,
+        E: Into<EventTrigger>,
         F: 'static + Fn(&mut Cursive),
     {
-        self.with(|s| s.set_on_event(event, cb))
+        self.with(|s| s.set_on_event(trigger, cb))
     }
 
     /// Registers a callback when the given event is received.
@@ -93,12 +90,12 @@ impl<T: View> OnEventView<T> {
     /// The child will never receive this event.
     ///
     /// Chainable variant.
-    pub fn on_pre_event<F, E>(self, event: E, cb: F) -> Self
+    pub fn on_pre_event<F, E>(self, trigger: E, cb: F) -> Self
     where
-        E: Into<Event>,
+        E: Into<EventTrigger>,
         F: 'static + Fn(&mut Cursive),
     {
-        self.with(|s| s.set_on_pre_event(event, cb))
+        self.with(|s| s.set_on_pre_event(trigger, cb))
     }
 
     /// Registers a callback when the given event is received.
@@ -111,12 +108,12 @@ impl<T: View> OnEventView<T> {
     ///   result.
     ///
     /// Chainable variant.
-    pub fn on_pre_event_inner<F, E>(self, event: E, cb: F) -> Self
+    pub fn on_pre_event_inner<F, E>(self, trigger: E, cb: F) -> Self
     where
-        E: Into<Event>,
+        E: Into<EventTrigger>,
-        F: Fn(&mut T) -> Option<EventResult> + 'static,
+        F: Fn(&mut T, &Event) -> Option<EventResult> + 'static,
     {
-        self.with(|s| s.set_on_pre_event_inner(event, cb))
+        self.with(|s| s.set_on_pre_event_inner(trigger, cb))
     }
 
     /// Registers a callback when the given event is ignored by the child.
@@ -126,41 +123,43 @@ impl<T: View> OnEventView<T> {
     /// If the result is not `None`, it will be processed as well.
     ///
     /// Chainable variant.
-    pub fn on_event_inner<F, E>(self, event: E, cb: F) -> Self
+    pub fn on_event_inner<F, E>(self, trigger: E, cb: F) -> Self
     where
-        E: Into<Event>,
+        E: Into<EventTrigger>,
-        F: Fn(&mut T) -> Option<EventResult> + 'static,
+        F: Fn(&mut T, &Event) -> Option<EventResult> + 'static,
     {
-        self.with(|s| s.set_on_event_inner(event, cb))
+        self.with(|s| s.set_on_event_inner(trigger, cb))
     }
 
     /// Registers a callback when the given event is ignored by the child.
-    pub fn set_on_event<F, E>(&mut self, event: E, cb: F)
+    pub fn set_on_event<F, E>(&mut self, trigger: E, cb: F)
     where
-        E: Into<Event>,
+        E: Into<EventTrigger>,
         F: Fn(&mut Cursive) + 'static,
     {
         let cb = Callback::from_fn(cb);
-        let action =
+        let action = move |_: &mut T, _: &Event| {
-            move |_: &mut T| Some(EventResult::Consumed(Some(cb.clone())));
+            Some(EventResult::Consumed(Some(cb.clone())))
+        };
 
-        self.set_on_event_inner(event, action);
+        self.set_on_event_inner(trigger, action);
     }
 
     /// Registers a callback when the given event is received.
     ///
     /// The child will never receive this event.
-    pub fn set_on_pre_event<F, E>(&mut self, event: E, cb: F)
+    pub fn set_on_pre_event<F, E>(&mut self, trigger: E, cb: F)
     where
-        E: Into<Event>,
+        E: Into<EventTrigger>,
         F: 'static + Fn(&mut Cursive),
     {
         let cb = Callback::from_fn(cb);
         // We want to clone the Callback every time we call the closure
-        let action =
+        let action = move |_: &mut T, _: &Event| {
-            move |_: &mut T| Some(EventResult::Consumed(Some(cb.clone())));
+            Some(EventResult::Consumed(Some(cb.clone())))
+        };
 
-        self.set_on_pre_event_inner(event, action);
+        self.set_on_pre_event_inner(trigger, action);
     }
 
     /// Registers a callback when the given event is received.
@@ -171,18 +170,18 @@ impl<T: View> OnEventView<T> {
     ///   usual.
     /// * Otherwise, it bypasses the child view and directly processes the
     ///   result.
-    pub fn set_on_pre_event_inner<F, E>(&mut self, event: E, cb: F)
+    pub fn set_on_pre_event_inner<F, E>(&mut self, trigger: E, cb: F)
     where
-        E: Into<Event>,
+        E: Into<EventTrigger>,
-        F: Fn(&mut T) -> Option<EventResult> + 'static,
+        F: Fn(&mut T, &Event) -> Option<EventResult> + 'static,
     {
-        self.callbacks.insert(
+        self.callbacks.push((
-            event.into(),
+            trigger.into(),
             Action {
                 phase: TriggerPhase::BeforeChild,
                 callback: Rc::new(Box::new(cb)),
             },
-        );
+        ));
     }
 
     /// Registers a callback when the given event is ignored by the child.
@@ -190,18 +189,18 @@ impl<T: View> OnEventView<T> {
     /// If the child view ignores the event, `cb` will be called with the
     /// child view as argument.
     /// If the result is not `None`, it will be processed as well.
-    pub fn set_on_event_inner<F, E>(&mut self, event: E, cb: F)
+    pub fn set_on_event_inner<F, E>(&mut self, trigger: E, cb: F)
     where
-        E: Into<Event>,
+        E: Into<EventTrigger>,
-        F: Fn(&mut T) -> Option<EventResult> + 'static,
+        F: Fn(&mut T, &Event) -> Option<EventResult> + 'static,
     {
-        self.callbacks.insert(
+        self.callbacks.push((
-            event.into(),
+            trigger.into(),
             Action {
                 phase: TriggerPhase::AfterChild,
                 callback: Rc::new(Box::new(cb)),
             },
-        );
+        ));
     }
 
     inner_getters!(self.view: T);
@@ -211,22 +210,44 @@ impl<T: View> ViewWrapper for OnEventView<T> {
     wrap_impl!(self.view: T);
 
     fn wrap_on_event(&mut self, event: Event) -> EventResult {
-        let action = self.callbacks.get(&event).cloned();
+        // Until we have better closure capture, define captured members separately.
-        let pre_child = action
+        let callbacks = &self.callbacks;
-            .as_ref()
+        let view = &mut self.view;
-            .map(|a| a.phase == TriggerPhase::BeforeChild)
-            .unwrap_or(false);
 
-        if pre_child {
+        // * First, check all pre-child callbacks. Combine them.
-            action
+        //   If any gets triggered and returns Some(...), stop right there.
-                .and_then(|a| (*a.callback)(&mut self.view))
+        // * Otherwise, give the event to the child view.
-                .unwrap_or_else(|| self.view.on_event(event))
+        //   If it returns EventResult::Consumed, stop right there.
-        } else {
+        // * Finally, check all post-child callbacks. Combine them.
-            self.view.on_event(event).or_else(|| {
+        //   And just return the result.
-                action
+
-                    .and_then(|a| (*a.callback)(&mut self.view))
+        // First step: check pre-child
-                    .unwrap_or(EventResult::Ignored)
+        callbacks
+            .iter()
+            .filter(|&(_, action)| action.phase == TriggerPhase::BeforeChild)
+            .filter(|&(trigger, _)| trigger.apply(&event))
+            .filter_map(|(_, action)| (*action.callback)(view, &event))
+            .fold(None, |s, r| match s {
+                // Return `Some()` if any pre-callback was present.
+                None => Some(r),
+                Some(c) => Some(c.and(r)),
+            })
+            .unwrap_or_else(|| {
+                // If it was None, it means no pre-callback was triggered.
+                // So let's give the view a chance!
+                view.on_event(event.clone())
+            })
+            .or_else(|| {
+                // No pre-child, and the child itself ignored the event?
+                // Let's have a closer look then, shall we?
+                callbacks
+                    .iter()
+                    .filter(|&(_, action)| {
+                        action.phase == TriggerPhase::AfterChild
+                    })
+                    .filter(|&(trigger, _)| trigger.apply(&event))
+                    .filter_map(|(_, action)| (*action.callback)(view, &event))
+                    .fold(EventResult::Ignored, EventResult::and)
             })
-        }
     }
 }