Add ViewPath and Cursive::find

Callbacks now include a path to the triggering view.
The Cursive root can find the View corresponding to a ViewPath.
In the future, ViewPaths may be returned when creating the layout.

src/event.rs

@@ -2,9 +2,12 @@
 
 use std::rc::Rc;
 
+use ::Cursive;
+use view::ViewPath;
+
 /// Callback is a function that can be triggered by an event.
 /// It has a mutable access to the cursive root.
-pub type Callback = Box<Fn(&mut super::Cursive)>;
+pub type Callback = Box<Fn(&mut Cursive, &ViewPath)>;
 
 /// Answer to an event notification.
 /// The event can be consumed or ignored.
@@ -12,5 +15,5 @@ pub enum EventResult {
     /// The event was ignored. The parent can keep handling it.
     Ignored,
     /// The event was consumed. An optionnal callback to run is attached.
-    Consumed(Option<Rc<Callback>>),
+    Consumed(Option<Rc<Callback>>, ViewPath),
 }

src/lib.rs

@@ -20,26 +20,23 @@
 //!     siv.run();
 //! }
 //! ```
-
 extern crate ncurses;
 
 pub mod event;
 pub mod view;
 pub mod printer;
 pub mod vec2;
-mod box_view;
-mod stack_view;
-mod text_view;
 
 mod div;
 
+use std::any::Any;
 use std::rc::Rc;
 use std::collections::HashMap;
 
 use vec2::Vec2;
 use view::View;
 use printer::Printer;
-use stack_view::StackView;
+use view::{StackView,ViewPath};
 
 use event::{EventResult,Callback};
 
@@ -47,6 +44,7 @@ use event::{EventResult,Callback};
 pub type ScreenId = usize;
 
 /// Central part of the cursive library.
+///
 /// It initializes ncurses on creation and cleans up on drop.
 /// To use it, you should populate it with views, layouts and callbacks,
 /// then start the event loop with run().
@@ -110,9 +108,23 @@ impl Cursive {
         self.active_screen = screen_id;
     }
 
+    fn find_any(&mut self, path: &ViewPath) -> Option<&mut Any> {
+        self.screen_mut().find(path)
+    }
+
+    /// Tries to find the view pointed to by the given path.
+    /// If the view is not found, or if it is not of the asked type,
+    /// it returns None.
+    pub fn find<V: View + Any>(&mut self, path: &ViewPath) -> Option<&mut V> {
+        match self.find_any(path) {
+            None => None,
+            Some(b) => b.downcast_mut::<V>(),
+        }
+    }
+
     /// Adds a global callback, triggered on the given key press when no view catches it.
     pub fn add_global_callback<F>(&mut self, key: i32, cb: F)
-        where F: Fn(&mut Cursive) + 'static
+        where F: Fn(&mut Cursive, &ViewPath) + 'static
     {
         self.global_callbacks.insert(key, Rc::new(Box::new(cb)));
     }
@@ -128,9 +140,11 @@ impl Cursive {
             None => return,
             Some(cb) => cb.clone(),
         };
-        cb(self);
+        // Not from a view, so no viewpath here
+        cb(self, &ViewPath::new());
     }
 
+    /// Returns the size of the screen, in characters.
     pub fn screen_size(&self) -> Vec2 {
         let mut x: i32 = 0;
         let mut y: i32 = 0;
@@ -180,12 +194,13 @@ impl Cursive {
             // If the event was ignored, it is our turn to play with it.
             match self.screen_mut().on_key_event(ch) {
                 EventResult::Ignored => self.on_key_event(ch),
-                EventResult::Consumed(None) => (),
+                EventResult::Consumed(None, _) => (),
-                EventResult::Consumed(Some(cb)) => cb(self),
+                EventResult::Consumed(Some(cb), path) => cb(self, &path),
             }
         }
     }
 
+    /// Stops the event loop.
     pub fn quit(&mut self) {
         self.running = false;
     }

src/main.rs

@@ -7,9 +7,13 @@ fn main() {
     let mut siv = Cursive::new();
 
     // We can quit by pressing q
-    siv.add_global_callback('q' as i32, |s| s.quit());
+    siv.add_global_callback('q' as i32, |s,_| s.quit());
 
     siv.add_layer(TextView::new("Hello World!\nPress q to quit the application."));
 
+    siv.add_global_callback('a' as i32, |s, _| {
+        //
+    });
+
     siv.run();
 }

src/to_view.rs

@@ -1,12 +0,0 @@
-use super::View;
-
-pub trait ToView {
-    fn to_view(self) -> Box<View>;
-}
-
-impl<'a> ToView for &'a str {
-    fn to_view(self) -> Box<View> {
-        Box::new(TextView::new(self))
-    }
-}
-

src/view/box_view.rs

@@ -1,6 +1,6 @@
 use event::EventResult;
 use vec2::{Vec2,ToVec2};
-use view::{View,SizeRequest};
+use super::{View,SizeRequest};
 use printer::Printer;
 
 /// BoxView is a wrapper around an other view, with a given minimum size.

src/view/key_event_view.rs

@@ -0,0 +1,59 @@
+use std::collections::HashMap;
+use std::rc::Rc;
+
+use ::Cursive;
+use event::{EventResult,Callback};
+use vec2::{Vec2};
+use super::{View,SizeRequest,ViewPath};
+use printer::Printer;
+
+/// A simple wrapper view that catches some ignored event from its child.
+///
+/// Events ignored by its child without a callback will stay ignored.
+pub struct KeyEventView {
+    content: Box<View>,
+    callbacks: HashMap<i32, Rc<Callback>>,
+}
+
+impl KeyEventView {
+    /// Wraps the given view in a new KeyEventView.
+    pub fn new<V: View + 'static>(view: V) -> Self {
+        KeyEventView {
+            content: Box::new(view),
+            callbacks: HashMap::new(),
+        }
+    }
+
+    /// Registers a callback when the given key is ignored by the child.
+    pub fn register<F>(mut self, key: i32, cb: F) -> Self
+        where F: Fn(&mut Cursive, &ViewPath) + 'static
+    {
+        self.callbacks.insert(key, Rc::new(Box::new(cb)));
+
+        self
+    }
+}
+
+impl View for KeyEventView {
+    fn on_key_event(&mut self, ch: i32) -> EventResult {
+        match self.content.on_key_event(ch) {
+            EventResult::Ignored => match self.callbacks.get(&ch) {
+                None => EventResult::Ignored,
+                Some(cb) => EventResult::Consumed(Some(cb.clone()), ViewPath::new()),
+            },
+            EventResult::Consumed(cb, path) => EventResult::Consumed(cb, path),
+        }
+    }
+
+    fn draw(&self, printer: &Printer) {
+        self.content.draw(printer)
+    }
+
+    fn get_min_size(&self, req: SizeRequest) -> Vec2 {
+        self.content.get_min_size(req)
+    }
+
+    fn layout(&mut self, size: Vec2) {
+        self.content.layout(size);
+    }
+}

src/view/mod.rs

@@ -1,11 +1,20 @@
 //! Defines various views to use when creating the layout.
 
+mod box_view;
+mod stack_view;
+mod text_view;
+mod key_event_view;
+mod view_path;
+
+use std::any::Any;
+
+pub use self::view_path::ViewPath;
+pub use self::key_event_view::KeyEventView;
+pub use self::box_view::BoxView;
+pub use self::stack_view::StackView;
+pub use self::text_view::TextView;
+
 use event::EventResult;
-
-pub use box_view::BoxView;
-pub use stack_view::StackView;
-pub use text_view::TextView;
-
 use vec2::Vec2;
 use printer::Printer;
 
@@ -43,4 +52,9 @@ pub trait View {
 
     /// Draws the view within the given bounds.
     fn draw(&self, &Printer);
+
+    /// Finds the view pointed to by the given path.
+    /// Returns None if the path doesn't lead to a view.
+    fn find(&mut self, &ViewPath) -> Option<&mut Any> { None }
 }
+

src/view/view_path.rs

@@ -0,0 +1,15 @@
+/// Represents a path to a single view in the layout.
+pub struct ViewPath {
+    /// List of turns to make on decision nodes when descending the view tree.
+    /// Simple nodes (with one fixed child) are skipped.
+    pub path: Vec<usize>,
+}
+
+impl ViewPath {
+    /// Creates a new empty path.
+    pub fn new() -> Self {
+        ViewPath {
+            path: Vec::new(),
+        }
+    }
+}