Merge branch 'refview'

Cargo.toml

@@ -1,19 +1,19 @@
 [package]
 authors = ["Alexandre Bury <alexandre.bury@gmail.com>"]
 build = "build.rs"
+categories = ["command-line-interface", "gui"]
 description = "A TUI (Text User Interface) library focused on ease-of-use."
 documentation = "https://gyscos.github.io/Cursive/cursive/index.html"
 exclude = ["doc", "assets"]
 keywords = ["ncurses", "TUI", "UI"]
-categories = ["command-line-interface", "gui"]
 license = "MIT"
 name = "cursive"
 readme = "Readme.md"
 repository = "https://github.com/gyscos/Cursive"
 version = "0.4.1"
 
-[badges]
+[badges.travis-ci]
-travis-ci = { repository = "gyscos/Cursive" }
+repository = "gyscos/Cursive"
 
 [build-dependencies.skeptic]
 optional = true
@@ -22,6 +22,7 @@ version = "0.7"
 [dependencies]
 num = "0.1"
 odds = "0.2"
+owning_ref = "0.2.4"
 toml = "0.3"
 unicode-segmentation = "1.0"
 unicode-width = "0.1"

doc/tutorial_2.md

@@ -144,7 +144,7 @@ fn main() {
     siv.run();
 }
 
-fn show_next(s: &mut Cursive) {
+fn show_next(_: &mut Cursive) {
     // Empty for now
 }
 ```

doc/tutorial_3.md

@@ -40,7 +40,9 @@ fn main() {
 
 fn add_name(s: &mut Cursive) {
     fn ok(s: &mut Cursive, name: &str) {
-        s.find_id::<SelectView<String>>("select").unwrap().add_item_str(name);
+        s.find_id("select", |view: &mut SelectView<String>| {
+            view.add_item_str(name)
+        });
         s.pop_layer();
     }
 
@@ -51,19 +53,25 @@ fn add_name(s: &mut Cursive) {
         .title("Enter a new name")
         .button("Ok", |s| {
             let name =
-                s.find_id::<EditView>("name").unwrap().get_content().clone();
+                s.find_id("name", |view: &mut EditView| {
+                    view.get_content().clone()
+                }).unwrap();
             ok(s, &name);
         })
         .button("Cancel", |s| s.pop_layer()));
 }
 
 fn delete_name(s: &mut Cursive) {
-    match s.find_id::<SelectView<String>>("select").unwrap().selected_id() {
+    let selection = s.find_id("select", |view: &mut SelectView<String>| {
+        view.selected_id()
+    }).unwrap();
+
+    match selection {
         None => s.add_layer(Dialog::info("No name to remove")),
         Some(focus) => {
-            s.find_id::<SelectView<String>>("select")
+            s.find_id("select", |view: &mut SelectView<String>| {
-                .unwrap()
+                view.remove_item(focus)
-                .remove_item(focus)
+            });
         }
     }
 }
@@ -224,8 +232,8 @@ Later, you can ask the Cursive root for this ID and get access to the view.
 Just what we need!
 
 Like `BoxView`, `IdView` can be used directly with [`IdView::new`], or through
-the [`Identifiable`] trait. [`Cursive::find_id`] can then give you a mutable
+the [`Identifiable`] trait. [`Cursive::find_id`] allows you to run a closure
-reference to the view.
+on the view.
 
 Here's what it looks like in action:
 
@@ -236,8 +244,9 @@ fn add_name(s: &mut Cursive) {
             .fixed_width(10))
         .title("Enter a new name")
         .button("Ok", |s| {
-            let name =
+            let name = s.find_id("name", |view: &mut EditView| {
-                s.find_id::<EditView>("name").unwrap().get_content().clone();
+                view.get_content().clone()
+            }).unwrap();
         })
         .button("Cancel", |s| s.pop_layer()));
 }
@@ -263,7 +272,9 @@ That way, we can update it with a new item:
 ```rust,ignore
 fn add_name(s: &mut Cursive) {
     fn ok(s: &mut Cursive, name: &str) {
-        s.find_id::<SelectView<String>>("select").unwrap().add_item_str(name);
+        s.find_id("select", |view: &mut SelectView<String>| {
+            view.add_item_str(name);
+        });
         s.pop_layer();
     }
 
@@ -273,8 +284,9 @@ fn add_name(s: &mut Cursive) {
             .fixed_width(10))
         .title("Enter a new name")
         .button("Ok", |s| {
-            let name =
+            let name = s.find_id("name", |v: &mut EditView| {
-                s.find_id::<EditView>("name").unwrap().get_content().clone();
+                v.get_content().clone()
+            }).unwrap();
             ok(s, &name);
         })
         .button("Cancel", |s| s.pop_layer()));
@@ -286,13 +298,13 @@ complicated:
 
 ```rust,ignore
 fn delete_name(s: &mut Cursive) {
-    match s.find_id::<SelectView<String>>("select").unwrap().selected_id() {
+    match s.find_id("select", |v: &mut SelectView<String>| {
+        v.selected_id()
+    }).unwrap() {
         None => s.add_layer(Dialog::info("No name to remove")),
-        Some(focus) => {
+        Some(focus) => s.find_id("select", |v: &mut SelectView<String>| {
-            s.find_id::<SelectView<String>>("select")
+            v.remove_item(focus)
-                .unwrap()
+        }),
-                .remove_item(focus)
-        }
     }
 }
 ```

examples/edit.rs

@@ -1,8 +1,8 @@
 extern crate cursive;
 
 use cursive::Cursive;
-use cursive::views::{Dialog, EditView, TextView};
 use cursive::traits::*;
+use cursive::views::{Dialog, EditView, TextView};
 
 fn main() {
     let mut siv = Cursive::new();
@@ -18,9 +18,9 @@ fn main() {
             .with_id("name")
             .fixed_width(20))
         .button("Ok", |s| {
-            let name = s.find_id::<EditView>("name")
+            let name =
-                .unwrap()
+                s.find_id("name", |view: &mut EditView| view.get_content())
-                .get_content();
+                    .unwrap();
             show_popup(s, &name);
         }));
 

examples/list_view.rs

@@ -1,9 +1,9 @@
 extern crate cursive;
 
 use cursive::Cursive;
+use cursive::traits::*;
 use cursive::views::{Checkbox, Dialog, EditView, LinearLayout, ListView,
                      SelectView, TextView};
-use cursive::traits::*;
 
 fn main() {
     let mut siv = Cursive::new();
@@ -25,11 +25,12 @@ fn main() {
                            .with_id("email2")
                            .fixed_width(10)))
             .child("Receive spam?",
-                   Checkbox::new().on_change(|s, checked| {
+                   Checkbox::new()
-                       for name in &["email1", "email2"] {
+                       .on_change(|s, checked| for name in &["email1",
-                           let view: &mut EditView = s.find_id(name).unwrap();
+                                                             "email2"] {
-                           view.set_enabled(checked);
+                           s.find_id(name, |view: &mut EditView| {
-                       }
+                               view.set_enabled(checked)
+                           });
                        }))
             .delimiter()
             .child("Age",
@@ -39,10 +40,8 @@ fn main() {
                        .item_str("19-30")
                        .item_str("31-40")
                        .item_str("41+"))
-            .with(|list| {
+            .with(|list| for i in 0..50 {
-                for i in 0..50 {
                 list.add_child(&format!("Item {}", i), EditView::new());
-                }
             })));
 
     siv.run();

examples/mutation.rs

@@ -13,9 +13,10 @@ fn show_popup(siv: &mut Cursive) {
                      Dialog::around(TextView::new("Tak!"))
                          .button("Change", |s| {
                              // Look for a view tagged "text". We _know_ it's there, so unwrap it.
-                             let view = s.find_id::<TextView>("text").unwrap();
+                             s.find_id("text", |view: &mut TextView| {
                                 let content: String = view.get_content().chars().rev().collect();
                                 view.set_content(content);
+                             });
                          })
                          .dismiss_button("Ok"));
 

examples/refcell_view.rs

@@ -0,0 +1,39 @@
+extern crate cursive;
+
+use cursive::Cursive;
+use cursive::view::{Boxable, Identifiable};
+use cursive::views::{LinearLayout, EditView, TextView, Dialog};
+
+fn main() {
+    let mut siv = Cursive::new();
+
+    // Create a dialog with 2 edit fields, and a text view.
+    // The text view indicates when the 2 fields content match.
+    siv.add_layer(Dialog::around(LinearLayout::vertical()
+            .child(EditView::new().on_edit(on_edit).with_id_mut("1"))
+            .child(EditView::new().on_edit(on_edit).with_id_mut("2"))
+            .child(TextView::new("match").with_id_mut("match"))
+            .fixed_width(10))
+        .button("Quit", Cursive::quit));
+
+    siv.run();
+}
+
+// Compare the content of the two edit views,
+// and update the TextView accordingly.
+//
+// We'll ignore the `content` and `cursor` arguments,
+// and directly retrieve the content from the `Cursive` root.
+fn on_edit(siv: &mut Cursive, _content: &str, _cursor: usize) {
+    // Get handles for each view.
+    let edit_1 = siv.find_id_mut::<EditView>("1").unwrap();
+    let edit_2 = siv.find_id_mut::<EditView>("2").unwrap();
+
+    // Directly compare references to edit_1 and edit_2.
+    let matches = edit_1.get_content() == edit_2.get_content();
+    siv.find_id("match", |v: &mut TextView| v.set_content(if matches {
+        "match"
+    } else {
+        "no match"
+    }));
+}

examples/slider.rs

@@ -1,8 +1,8 @@
 extern crate cursive;
 
 use cursive::Cursive;
-use cursive::views::{Dialog, SliderView};
 use cursive::traits::*;
+use cursive::views::{Dialog, SliderView};
 
 fn main() {
     let mut siv = Cursive::new();
@@ -14,7 +14,7 @@ fn main() {
             .value(7)
             .on_change(|s, v| {
                 let title = format!("[ {} ]", v);
-                s.find_id::<Dialog>("dialog").unwrap().set_title(title);
+                s.find_id("dialog", |view: &mut Dialog| view.set_title(title));
             })
             .on_enter(|s, v| {
                 s.pop_layer();

src/backend/blt.rs

@@ -1,12 +1,12 @@
 extern crate bear_lib_terminal;
 
-use ::backend;
-use ::event::{Event, Key};
 use self::bear_lib_terminal::Color as BltColor;
 use self::bear_lib_terminal::geometry::Size;
 use self::bear_lib_terminal::terminal::{self, Event as BltEvent, KeyCode};
+use backend;
+use event::{Event, Key};
 use std::collections::BTreeMap;
-use ::theme::{BaseColor, Color, ColorStyle, Effect};
+use theme::{BaseColor, Color, ColorStyle, Effect};
 
 pub struct Concrete {
     colours: BTreeMap<i16, (BltColor, BltColor)>,

src/backend/mod.rs

@@ -8,12 +8,12 @@ mod blt;
 #[cfg(any(feature = "ncurses", feature = "pancurses"))]
 mod curses;
 
+#[cfg(feature = "bear-lib-terminal")]
+pub use self::blt::*;
 #[cfg(any(feature = "ncurses", feature = "pancurses"))]
 pub use self::curses::*;
 #[cfg(feature = "termion")]
 pub use self::termion::*;
-#[cfg(feature = "bear-lib-terminal")]
-pub use self::blt::*;
 
 pub trait Backend {
     fn init() -> Self;

src/direction.rs

@@ -15,8 +15,8 @@
 //! * Relative direction: front or back.
 //!   Its actual direction depends on the orientation.
 
-use vec::Vec2;
 use XY;
+use vec::Vec2;
 
 /// Describes a vertical or horizontal orientation for a view.
 #[derive(Clone,Copy,Debug,PartialEq)]

src/lib.rs

@@ -64,11 +64,13 @@ extern crate unicode_segmentation;
 extern crate unicode_width;
 extern crate odds;
 extern crate num;
+extern crate owning_ref;
 
 #[cfg(feature = "termion")]
 #[macro_use]
 extern crate chan;
 
+
 macro_rules! println_stderr(
     ($($arg:tt)*) => { {
         use ::std::io::Write;
@@ -365,8 +367,11 @@ impl Cursive {
 
     /// Tries to find the view pointed to by the given selector.
     ///
+    /// Runs a closure on the view once it's found, and return the
+    /// result.
+    ///
     /// If the view is not found, or if it is not of the asked type,
-    /// it returns None.
+    /// returns None.
     ///
     /// # Examples
     ///
@@ -381,15 +386,18 @@ impl Cursive {
     ///                               .with_id("text"));
     ///
     /// siv.add_global_callback('p', |s| {
-    ///     s.find::<views::TextView>(&view::Selector::Id("text"))
+    ///     s.find(&view::Selector::Id("text"), |view: &mut views::TextView| {
-    ///      .unwrap()
+    ///         view.set_content("Text #2");
-    ///      .set_content("Text #2");
+    ///     });
     /// });
     /// # }
     /// ```
-    pub fn find<V: View + Any>(&mut self, sel: &view::Selector)
+    pub fn find<V, F, R>(&mut self, sel: &view::Selector, callback: F)
-                               -> Option<&mut V> {
+                         -> Option<R>
-        self.screen_mut().find(sel)
+        where V: View + Any,
+              F: FnOnce(&mut V) -> R
+    {
+        self.screen_mut().find(sel, callback)
     }
 
     /// Tries to find the view identified by the given id.
@@ -409,14 +417,29 @@ impl Cursive {
     ///                               .with_id("text"));
     ///
     /// siv.add_global_callback('p', |s| {
-    ///     s.find_id::<views::TextView>("text")
+    ///     s.find_id("text", |view: &mut views::TextView| {
-    ///      .unwrap()
+    ///         view.set_content("Text #2");
-    ///      .set_content("Text #2");
+    ///     });
     /// });
     /// # }
     /// ```
-    pub fn find_id<V: View + Any>(&mut self, id: &str) -> Option<&mut V> {
+    pub fn find_id<V, F, R>(&mut self, id: &str, callback: F) -> Option<R>
-        self.find(&view::Selector::Id(id))
+        where V: View + Any,
+              F: FnOnce(&mut V) -> R
+    {
+        self.find(&view::Selector::Id(id), callback)
+    }
+
+    /// Convenient method to find a view wrapped in [`RefCellView`].
+    ///
+    /// This looks for a `RefCellView<V>` with the given ID, and return
+    /// a mutable reference to the wrapped view.
+    ///
+    /// [`RefCellView`]: views/struct.RefCellView.html
+    pub fn find_id_mut<V>(&mut self, id: &str) -> Option<views::ViewRef<V>>
+        where V: View + Any
+    {
+        self.find_id(id, views::RefCellView::<V>::get_mut)
     }
 
     /// Moves the focus to the view identified by `id`.

src/menu.rs

@@ -165,12 +165,12 @@ impl MenuTree {
     /// Returns `None` if the given title was not found,
     /// or if it wasn't a subtree.
     pub fn find_subtree(&mut self, title: &str) -> Option<&mut MenuTree> {
-        self.find_item(title).and_then(|item| {
+        self.find_item(title)
-            if let MenuItem::Subtree(_, ref mut tree) = *item {
+            .and_then(|item| if let MenuItem::Subtree(_, ref mut tree) =
+                *item {
                 Some(Rc::make_mut(tree))
             } else {
                 None
-            }
             })
     }
 
@@ -191,5 +191,4 @@ impl MenuTree {
     pub fn is_empty(&self) -> bool {
         self.children.is_empty()
     }
-
 }

src/printer.rs

@@ -34,7 +34,9 @@ impl<'a> Printer<'a> {
     ///
     /// But nobody needs to know that.
     #[doc(hidden)]
-    pub fn new<T: Into<Vec2>>(size: T, theme: Theme, backend: &'a backend::Concrete) -> Self {
+    pub fn new<T: Into<Vec2>>(size: T, theme: Theme,
+                              backend: &'a backend::Concrete)
+                              -> Self {
         Printer {
             offset: Vec2::zero(),
             size: size.into(),

src/utils/mod.rs

@@ -14,7 +14,7 @@ pub struct Prefix {
     /// The length (in bytes) of the string.
     pub length: usize,
     /// The unicode-width of the string.
-    pub width: usize
+    pub width: usize,
 }
 
 /// Computes the length (number of bytes) and width of a prefix that fits in the given `width`.
@@ -42,7 +42,8 @@ pub struct Prefix {
 /// prefix(my_text.graphemes(true), 5, "");
 /// # }
 /// ```
-pub fn prefix<'a, I>(iter: I, available_width: usize, delimiter: &str) -> Prefix
+pub fn prefix<'a, I>(iter: I, available_width: usize, delimiter: &str)
+                     -> Prefix
     where I: Iterator<Item = &'a str>
 {
     let delimiter_width = delimiter.width();
@@ -74,7 +75,7 @@ pub fn prefix<'a, I>(iter: I, available_width: usize, delimiter: &str) -> Prefix
 
     Prefix {
         length: length,
-        width: current_width
+        width: current_width,
     }
 }
 

src/vec.rs

@@ -95,7 +95,7 @@ impl<T: Zero + Clone> XY<T> {
     }
 }
 
-impl <T: Into<XY<usize>>> From<T> for XY<isize> {
+impl<T: Into<XY<usize>>> From<T> for XY<isize> {
     fn from(t: T) -> Self {
         let other = t.into();
         Self::new(other.x as isize, other.y as isize)
@@ -115,7 +115,7 @@ impl From<(u32, u32)> for XY<usize> {
 }
 
 
-impl<T: Add<Output=T>, O: Into<XY<T>>> Add<O> for XY<T> {
+impl<T: Add<Output = T>, O: Into<XY<T>>> Add<O> for XY<T> {
     type Output = Self;
 
     fn add(self, other: O) -> Self {
@@ -123,7 +123,7 @@ impl<T: Add<Output=T>, O: Into<XY<T>>> Add<O> for XY<T> {
     }
 }
 
-impl<T: Sub<Output=T>, O: Into<XY<T>>> Sub<O> for XY<T> {
+impl<T: Sub<Output = T>, O: Into<XY<T>>> Sub<O> for XY<T> {
     type Output = Self;
 
     fn sub(self, other: O) -> Self {
@@ -131,7 +131,7 @@ impl<T: Sub<Output=T>, O: Into<XY<T>>> Sub<O> for XY<T> {
     }
 }
 
-impl <T: Clone + Div<Output=T>> Div<T> for XY<T> {
+impl<T: Clone + Div<Output = T>> Div<T> for XY<T> {
     type Output = Self;
 
     fn div(self, other: T) -> Self {

src/view/identifiable.rs

@@ -1,16 +1,26 @@
 use view::View;
-use views::IdView;
+use views::{IdView, RefCellView};
 
 /// Makes a view wrappable in an [`IdView`].
 ///
 /// [`IdView`]: ../views/struct.IdView.html
 pub trait Identifiable: View + Sized {
-    /// Wraps this view into an IdView with the given id.
+    /// Wraps this view into an `IdView` with the given id.
     ///
     /// This is just a shortcut for `IdView::new(id, self)`
     fn with_id(self, id: &str) -> IdView<Self> {
         IdView::new(id, self)
     }
+
+    /// Wraps this view into both a [`RefCellView`] and an `IdView`.
+    ///
+    /// This allows to call [`Cursive::find_id_mut`].
+    ///
+    /// [`RefCellView`]: ../views/struct.RefCellView.html
+    /// [`Cursive::find_id_mut`]: ../struct.Cursive.html#method.find_id_mut
+    fn with_id_mut(self, id: &str) -> IdView<RefCellView<Self>> {
+        RefCellView::new(self).with_id(id)
+    }
 }
 
 /// Any `View` implements this trait.

src/view/mod.rs

@@ -50,10 +50,6 @@ mod identifiable;
 mod boxable;
 
 
-use Printer;
-
-use direction::Direction;
-use event::{Event, EventResult};
 pub use self::boxable::Boxable;
 pub use self::identifiable::Identifiable;
 
@@ -65,9 +61,14 @@ pub use self::size_cache::SizeCache;
 pub use self::size_constraint::SizeConstraint;
 pub use self::view_path::ViewPath;
 pub use self::view_wrapper::ViewWrapper;
-use std::any::Any;
+use Printer;
-use vec::Vec2;
 
+use direction::Direction;
+use event::{Event, EventResult};
+use vec::Vec2;
+use views::RefCellView;
+
+use std::any::Any;
 
 /// Main trait defining a view behaviour.
 pub trait View {
@@ -122,8 +123,8 @@ pub trait View {
     /// Returns None if the path doesn't lead to a view.
     ///
     /// Default implementation always return `None`.
-    fn find_any(&mut self, &Selector) -> Option<&mut Any> {
+    fn find_any<'a>(&mut self, _: &Selector, _: Box<FnMut(&mut Any) + 'a>) {
-        None
+        // TODO: FnMut -> FnOnce once it works
     }
 
     /// Moves the focus to the view identified by the given selector.
@@ -157,17 +158,41 @@ pub trait Finder {
     ///
     /// If the view is not found, or if it is not of the asked type,
     /// it returns None.
-    fn find<V: View + Any>(&mut self, sel: &Selector) -> Option<&mut V>;
+    fn find<V, F, R>(&mut self, sel: &Selector, callback: F) -> Option<R>
+        where V: View + Any,
+              F: FnOnce(&mut V) -> R;
 
     /// Convenient method to use `find` with a `view::Selector::Id`.
-    fn find_id<V: View + Any>(&mut self, id: &str) -> Option<&mut V> {
+    fn find_id<V, F, R>(&mut self, id: &str, callback: F) -> Option<R>
-        self.find(&Selector::Id(id))
+        where V: View + Any,
+              F: FnOnce(&mut V) -> R
+    {
+        self.find(&Selector::Id(id), callback)
     }
 }
 
 impl<T: View> Finder for T {
-    fn find<V: View + Any>(&mut self, sel: &Selector) -> Option<&mut V> {
+    fn find<V, F, R>(&mut self, sel: &Selector, callback: F) -> Option<R>
-        self.find_any(sel).and_then(|b| b.downcast_mut::<V>())
+        where V: View + Any,
+              F: FnOnce(&mut V) -> R
+    {
+        let mut result = None;
+        {
+            let result_ref = &mut result;
+
+            let mut callback = Some(callback);
+            let callback = |v: &mut Any| if let Some(callback) =
+                callback.take() {
+                if v.is::<V>() {
+                    *result_ref = v.downcast_mut::<V>().map(|v| callback(v));
+                } else if v.is::<RefCellView<V>>() {
+                    *result_ref = v.downcast_mut::<RefCellView<V>>()
+                        .and_then(|v| v.with_view_mut(callback));
+                }
+            };
+            self.find_any(sel, Box::new(callback));
+        }
+        result
     }
 }
 

src/view/view_wrapper.rs

@@ -11,8 +11,8 @@ use view::{Selector, View};
 /// Default implementation forwards all calls to the child view.
 /// Overrides some methods as desired.
 ///
-/// You can use the [`wrap_impl!`] macro to define `get_view` and
+/// You can use the [`wrap_impl!`] macro to define `with_view` and
-/// `get_view_mut` for you.
+/// `with_view_mut` for you.
 ///
 /// [`wrap_impl!`]: ../macro.wrap_impl.html
 pub trait ViewWrapper {
@@ -20,49 +20,51 @@ pub trait ViewWrapper {
     type V: View;
 
     /// Get an immutable reference to the wrapped view.
-    fn get_view(&self) -> &Self::V;
+    fn with_view<F, R>(&self, f: F) -> Option<R> where F: FnOnce(&Self::V) -> R;
 
     /// Get a mutable reference to the wrapped view.
-    fn get_view_mut(&mut self) -> &mut Self::V;
+    fn with_view_mut<F, R>(&mut self, f: F) -> Option<R>
+        where F: FnOnce(&mut Self::V) -> R;
 
     /// Wraps the `draw` method.
     fn wrap_draw(&self, printer: &Printer) {
-        self.get_view().draw(printer);
+        self.with_view(|v| v.draw(printer));
     }
 
     /// Wraps the `required_size` method.
     fn wrap_required_size(&mut self, req: Vec2) -> Vec2 {
-        self.get_view_mut().required_size(req)
+        self.with_view_mut(|v| v.required_size(req)).unwrap_or_else(Vec2::zero)
     }
 
     /// Wraps the `on_event` method.
     fn wrap_on_event(&mut self, ch: Event) -> EventResult {
-        self.get_view_mut().on_event(ch)
+        self.with_view_mut(|v| v.on_event(ch)).unwrap_or(EventResult::Ignored)
     }
 
     /// Wraps the `layout` method.
     fn wrap_layout(&mut self, size: Vec2) {
-        self.get_view_mut().layout(size);
+        self.with_view_mut(|v| v.layout(size));
     }
 
     /// Wraps the `take_focus` method.
     fn wrap_take_focus(&mut self, source: Direction) -> bool {
-        self.get_view_mut().take_focus(source)
+        self.with_view_mut(|v| v.take_focus(source)).unwrap_or(false)
     }
 
     /// Wraps the `find` method.
-    fn wrap_find_any(&mut self, selector: &Selector) -> Option<&mut Any> {
+    fn wrap_find_any<'a>(&mut self, selector: &Selector,
-        self.get_view_mut().find_any(selector)
+                         callback: Box<FnMut(&mut Any) + 'a>) {
+        self.with_view_mut(|v| v.find_any(selector, callback));
     }
 
     /// Wraps the `focus_view` method.
     fn wrap_focus_view(&mut self, selector: &Selector) -> Result<(), ()> {
-        self.get_view_mut().focus_view(selector)
+        self.with_view_mut(|v| v.focus_view(selector)).unwrap_or(Err(()))
     }
 
     /// Wraps the `needs_relayout` method.
     fn wrap_needs_relayout(&self) -> bool {
-        self.get_view().needs_relayout()
+        self.with_view(|v| v.needs_relayout()).unwrap_or(true)
     }
 }
 
@@ -87,8 +89,9 @@ impl<T: ViewWrapper> View for T {
         self.wrap_take_focus(source)
     }
 
-    fn find_any(&mut self, selector: &Selector) -> Option<&mut Any> {
+    fn find_any<'a>(&mut self, selector: &Selector,
-        self.wrap_find_any(selector)
+                    callback: Box<FnMut(&mut Any) + 'a>) {
+        self.wrap_find_any(selector, callback)
     }
 
     fn needs_relayout(&self) -> bool {
@@ -102,7 +105,7 @@ impl<T: ViewWrapper> View for T {
 
 /// Convenient macro to implement the [`ViewWrapper`] trait.
 ///
-/// It defines the `get_view` and `get_view_mut` implementations,
+/// It defines the `with_view` and `with_view_mut` implementations,
 /// as well as the `type V` declaration.
 ///
 /// [`ViewWrapper`]: view/trait.ViewWrapper.html
@@ -126,12 +129,16 @@ macro_rules! wrap_impl {
     (self.$v:ident: $t:ty) => {
         type V = $t;
 
-        fn get_view(&self) -> &Self::V {
+        fn with_view<F, R>(&self, f: F) -> Option<R>
-            &self.$v
+            where F: FnOnce(&Self::V) -> R
+        {
+            Some(f(&self.$v))
         }
 
-        fn get_view_mut(&mut self) -> &mut Self::V {
+        fn with_view_mut<F, R>(&mut self, f: F) -> Option<R>
-            &mut self.$v
+            where F: FnOnce(&mut Self::V) -> R
+        {
+            Some(f(&mut self.$v))
         }
     };
 }

src/views/checkbox.rs

@@ -61,9 +61,7 @@ impl Checkbox {
     ///
     /// Chainable variant.
     pub fn checked(self) -> Self {
-        self.with(|s| {
+        self.with(|s| { s.check(); })
-            s.check();
-        })
     }
 
     /// Returns `true` if the checkbox is checked.
@@ -80,9 +78,7 @@ impl Checkbox {
     ///
     /// Chainable variant.
     pub fn unchecked(self) -> Self {
-        self.with(|s| {
+        self.with(|s| { s.uncheck(); })
-            s.uncheck();
-        })
     }
 
     /// Sets the checkbox state.

src/views/dialog.rs

@@ -399,8 +399,9 @@ impl View for Dialog {
         }
     }
 
-    fn find_any(&mut self, selector: &Selector) -> Option<&mut Any> {
+    fn find_any<'a>(&mut self, selector: &Selector,
-        self.content.find_any(selector)
+                    callback: Box<FnMut(&mut Any) + 'a>) {
+        self.content.find_any(selector, callback);
     }
 
     fn focus_view(&mut self, selector: &Selector) -> Result<(), ()> {

src/views/edit_view.rs

@@ -41,9 +41,8 @@ use view::View;
 ///         .with_id("name")
 ///         .fixed_width(20))
 ///     .button("Ok", |s| {
-///         let name = s.find_id::<EditView>("name")
+///         let name = s.find_id("name", |view: &mut EditView| view.get_content())
-///             .unwrap()
+///             .unwrap();
-///             .get_content();
 ///         show_popup(s, &name);
 ///     }));
 ///

src/views/id_view.rs

@@ -21,10 +21,11 @@ impl<T: View> IdView<T> {
 impl<T: View + Any> ViewWrapper for IdView<T> {
     wrap_impl!(self.view: T);
 
-    fn wrap_find_any(&mut self, selector: &Selector) -> Option<&mut Any> {
+    fn wrap_find_any<'a>(&mut self, selector: &Selector,
+                         mut callback: Box<FnMut(&mut Any) + 'a>) {
         match selector {
-            &Selector::Id(id) if id == self.id => Some(&mut self.view),
+            &Selector::Id(id) if id == self.id => callback(&mut self.view),
-            s => self.view.find_any(s),
+            s => self.view.find_any(s, callback),
         }
     }
 

src/views/layer.rs

@@ -10,12 +10,10 @@ pub struct Layer<T: View> {
     view: T,
 }
 
-impl <T: View> Layer<T> {
+impl<T: View> Layer<T> {
     /// Wraps the given view.
     pub fn new(view: T) -> Self {
-        Layer {
+        Layer { view: view }
-            view: view,
-        }
     }
 }
 

src/views/linear_layout.rs

@@ -395,11 +395,11 @@ impl View for LinearLayout {
         }
     }
 
-    fn find_any(&mut self, selector: &Selector) -> Option<&mut Any> {
+    fn find_any<'a>(&mut self, selector: &Selector,
-        self.children
+                    mut callback: Box<FnMut(&mut Any) + 'a>) {
-            .iter_mut()
+        for child in &mut self.children {
-            .filter_map(|c| c.view.find_any(selector))
+            child.view.find_any(selector, Box::new(|any| callback(any)));
-            .next()
+        }
     }
 
     fn focus_view(&mut self, selector: &Selector) -> Result<(), ()> {

src/views/list_view.rs

@@ -191,7 +191,6 @@ impl View for ListView {
             .unwrap_or(0) + 1;
 
         // println_stderr!("Offset: {}", offset);
-
         self.scrollbase.draw(printer, |printer, i| match self.children[i] {
             Child::Row(ref label, ref view) => {
                 printer.print((0, 0), label);
@@ -314,12 +313,13 @@ impl View for ListView {
         true
     }
 
-    fn find_any(&mut self, selector: &Selector) -> Option<&mut Any> {
+    fn find_any<'a>(&mut self, selector: &Selector,
-        self.children
+                    mut callback: Box<FnMut(&mut Any) + 'a>) {
+        for view in self.children
             .iter_mut()
-            .filter_map(Child::view)
+            .filter_map(Child::view) {
-            .filter_map(|v| v.find_any(selector))
+            view.find_any(selector, Box::new(|any| callback(any)));
-            .next()
+        }
     }
 
     fn focus_view(&mut self, selector: &Selector) -> Result<(), ()> {

src/views/menu_popup.rs

@@ -228,12 +228,9 @@ impl View for MenuPopup {
             Event::Key(Key::PageDown) => self.scroll_down(5, false),
 
             Event::Key(Key::Home) => self.focus = 0,
-            Event::Key(Key::End) => {
+            Event::Key(Key::End) => self.focus = self.menu.children.len() - 1,
-                self.focus = self.menu.children.len() - 1
-            }
 
-            Event::Key(Key::Right) if self.menu.children
+            Event::Key(Key::Right) if self.menu.children[self.focus]
-                                          [self.focus]
                 .is_subtree() => {
                 return match self.menu.children[self.focus] {
                     MenuItem::Subtree(_, ref tree) => {
@@ -243,8 +240,7 @@ impl View for MenuPopup {
 
                 };
             }
-            Event::Key(Key::Enter) if !self.menu.children
+            Event::Key(Key::Enter) if !self.menu.children[self.focus]
-                                           [self.focus]
                 .is_delimiter() => {
                 return match self.menu.children[self.focus] {
                     MenuItem::Leaf(_, ref cb) => {

src/views/mod.rs

@@ -52,6 +52,7 @@ mod menu_popup;
 mod panel;
 mod progress_bar;
 mod radio;
+mod refcell_view;
 mod select_view;
 mod slider_view;
 mod shadow_view;
@@ -78,6 +79,7 @@ pub use self::menubar::Menubar;
 pub use self::panel::Panel;
 pub use self::progress_bar::{Counter, ProgressBar};
 pub use self::radio::{RadioGroup, RadioButton};
+pub use self::refcell_view::{RefCellView, ViewRef};
 pub use self::select_view::SelectView;
 pub use self::shadow_view::ShadowView;
 pub use self::sized_view::SizedView;

src/views/progress_bar.rs

@@ -118,9 +118,7 @@ impl ProgressBar {
     pub fn start<F: FnOnce(Counter) + Send + 'static>(&mut self, f: F) {
         let counter: Counter = self.value.clone();
 
-        thread::spawn(move || {
+        thread::spawn(move || { f(counter); });
-            f(counter);
-        });
     }
 
     /// Starts a function in a separate thread, and monitor the progress.

src/views/refcell_view.rs

@@ -0,0 +1,49 @@
+
+
+use owning_ref::{RcRef, OwningHandle};
+
+use std::cell::{RefCell, RefMut};
+use std::rc::Rc;
+use view::{View, ViewWrapper};
+
+/// Wrapper around a view to provide interior mutability.
+pub struct RefCellView<V: View> {
+    view: Rc<RefCell<V>>,
+}
+
+/// Mutable reference to a view.
+pub type ViewRef<V> = OwningHandle<RcRef<RefCell<V>>, RefMut<'static, V>>;
+
+impl<V: View> RefCellView<V> {
+    /// Wraps `view` in a new `RefCellView`.
+    pub fn new(view: V) -> Self {
+        RefCellView { view: Rc::new(RefCell::new(view)) }
+    }
+
+    /// Gets mutable access to the inner view.
+    pub fn get_mut(&mut self) -> ViewRef<V> {
+        // TODO: return a standalone item (not tied to our lifetime)
+        // that bundles `self.view.clone()` and allow mutable reference to
+        // the inner view.
+        let cell_ref = RcRef::new(self.view.clone());
+
+        OwningHandle::new(cell_ref,
+                          |x| unsafe { x.as_ref() }.unwrap().borrow_mut())
+    }
+}
+
+impl<T: View> ViewWrapper for RefCellView<T> {
+    type V = T;
+
+    fn with_view<F, R>(&self, f: F) -> Option<R>
+        where F: FnOnce(&Self::V) -> R
+    {
+        self.view.try_borrow().ok().map(|v| f(&*v))
+    }
+
+    fn with_view_mut<F, R>(&mut self, f: F) -> Option<R>
+        where F: FnOnce(&mut Self::V) -> R
+    {
+        self.view.try_borrow_mut().ok().map(|mut v| f(&mut *v))
+    }
+}

src/views/slider_view.rs

@@ -55,9 +55,7 @@ impl SliderView {
     ///
     /// Chainable variant.
     pub fn value(self, value: usize) -> Self {
-        self.with(|s| {
+        self.with(|s| { s.set_value(value); })
-            s.set_value(value);
-        })
     }
 
     /// Sets a callback to be called when the slider is moved.
@@ -79,9 +77,7 @@ impl SliderView {
     fn get_change_result(&self) -> EventResult {
         EventResult::Consumed(self.on_change.clone().map(|cb| {
             let value = self.value;
-            Callback::from_fn(move |s| {
+            Callback::from_fn(move |s| { cb(s, value); })
-                cb(s, value);
-            })
         }))
     }
 
@@ -148,9 +144,7 @@ impl View for SliderView {
             Event::Key(Key::Enter) if self.on_enter.is_some() => {
                 let value = self.value;
                 let cb = self.on_enter.clone().unwrap();
-                EventResult::with_cb(move |s| {
+                EventResult::with_cb(move |s| { cb(s, value); })
-                    cb(s, value);
-                })
             }
             _ => EventResult::Ignored,
         }

src/views/stack_view.rs

@@ -180,11 +180,11 @@ impl View for StackView {
         }
     }
 
-    fn find_any(&mut self, selector: &Selector) -> Option<&mut Any> {
+    fn find_any<'a>(&mut self, selector: &Selector,
-        self.layers
+                    mut callback: Box<FnMut(&mut Any) + 'a>) {
-            .iter_mut()
+        for layer in &mut self.layers {
-            .filter_map(|l| l.view.find_any(selector))
+            layer.view.find_any(selector, Box::new(|any| callback(any)));
-            .next()
+        }
     }
 
     fn focus_view(&mut self, selector: &Selector) -> Result<(), ()> {

src/views/text_area.rs

@@ -375,10 +375,9 @@ impl View for TextArea {
             } else {
                 printer.size.x
             };
-            printer.with_effect(effect, |printer| {
+            printer.with_effect(effect,
-                for y in 0..printer.size.y {
+                                |printer| for y in 0..printer.size.y {
                                     printer.print_hline((0, y), w, " ");
-                }
                                 });
 
             // println_stderr!("Content: `{}`", &self.content);

src/views/text_view.rs

@@ -53,6 +53,11 @@ impl TextView {
         }
     }
 
+    /// Creates a new empty `TextView`.
+    pub fn empty() -> Self {
+        TextView::new("")
+    }
+
     /// Enable or disable the view's scrolling capabilities.
     ///
     /// When disabled, the view will never attempt to scroll
@@ -98,6 +103,13 @@ impl TextView {
         self
     }
 
+    /// Replace the text in this view.
+    ///
+    /// Chainable variant.
+    pub fn content<S: Into<String>>(self, content: S) -> Self {
+        self.with(|s| s.set_content(content))
+    }
+
     /// Replace the text in this view.
     pub fn set_content<S: Into<String>>(&mut self, content: S) {
         let content = content.into();