Add animated example.

Cargo.toml

@@ -28,3 +28,7 @@ path = "examples/lorem.rs"
 [[example]]
 name = "dialog"
 path = "examples/dialog.rs"
+
+[[example]]
+name = "logs"
+path = "examples/logs.rs"

examples/logs.rs

@@ -0,0 +1,103 @@
+extern crate cursive;
+
+use std::sync::mpsc;
+use std::thread;
+
+use cursive::Cursive;
+use cursive::printer::Printer;
+use cursive::view::{View,FullView};
+
+fn main() {
+    // As usual, create the Cursive root
+    let mut siv = Cursive::new();
+
+    // We want to refresh the page even when no input is given.
+    siv.set_fps(10);
+    siv.add_global_callback('q' as i32, |s,_| s.quit());
+
+    // A channel will communicate data from our running task to the UI.
+    let (tx,rx) = mpsc::channel();
+
+    // Generate data in a separate thread.
+    thread::spawn(|| { generate_logs(tx); });
+
+    // And sets the view to read from the other end of the channel.
+    siv.add_layer(FullView::new(BufferView::new(200, rx)));
+
+    siv.run();
+}
+
+// We will only simulate log generation here.
+// In real life, this may come from a running task, a separate process, ...
+fn generate_logs(tx: mpsc::Sender<String>) {
+    let mut i = 1;
+    loop {
+        let line = format!("Interesting log line {}", i);
+        i += 1;
+        match tx.send(line) {
+            Err(_) => panic!("Uh?..."),
+            Ok(_) => (),
+        }
+        thread::sleep_ms(30);
+    }
+}
+
+// Let's define a buffer view, that shows the last lines from a stream.
+struct BufferView {
+    // We will emulate a ring buffer
+    buffer: Vec<String>,
+    // Current position in the buffer
+    pos: usize,
+    // Receiving end of the stream
+    rx: mpsc::Receiver<String>,
+}
+
+impl BufferView {
+    // Creates a new view with the given buffer size
+    fn new(size: usize, rx: mpsc::Receiver<String>) -> Self {
+        BufferView {
+            rx: rx,
+            buffer: (0..size).map(|_| String::new()).collect(),
+            pos: 0,
+        }
+    }
+
+    // Reads available data from the stream into the buffer
+    fn update(&mut self) {
+        let mut i = self.pos;
+        while let Ok(line) = self.rx.try_recv() {
+            i = (i+1) % self.buffer.len();
+            self.buffer[i] = line;
+            self.pos = i;
+        }
+    }
+
+    // Chain together the two parts of the buffer to appear as a circular one.
+    // The signature is quite ugly, but basically we return an iterator:
+    // a Chain of two slice iterators.
+    fn ring<'a>(&'a self) -> std::iter::Chain<std::slice::Iter<'a,String>, std::slice::Iter<'a,String>> {
+        // The main buffer is "circular" starting at self.pos
+        // So we chain the two parts as one
+        self.buffer[self.pos..].iter().chain(self.buffer[..self.pos].iter())
+    }
+}
+
+impl View for BufferView {
+    fn draw(&mut self, printer: &Printer, _: bool) {
+        // Before drawing, we'll want to update the buffer
+        self.update();
+
+        // If the buffer is large enough, we can fill the window
+        if self.buffer.len() > printer.size.y as usize {
+            // We'll only print the last entries that fit.
+            // So discard entries if there are too many.
+            let discard = self.buffer.len() - printer.size.y as usize;
+            // And we discard the first entries if needed
+            for (i, line) in self.ring().skip(discard).enumerate() {
+                printer.print((0,i as u32), line);
+            }
+        } else {
+
+        }
+    }
+}

examples/lorem.rs

@@ -1,8 +1,7 @@
 extern crate cursive;
 
 use cursive::Cursive;
-use cursive::view::TextView;
+use cursive::view::{TextView,Dialog};
-use cursive::view::Dialog;
 
 use std::fs::File;
 use std::io::Read;

src/lib.rs

@@ -37,6 +37,7 @@ pub use margins::Margins;
 use std::any::Any;
 use std::rc::Rc;
 use std::collections::HashMap;
+use std::sync::mpsc;
 
 use vec::Vec2;
 use view::View;
@@ -93,6 +94,17 @@ impl Cursive {
         res
     }
 
+    /// Regularly redraws everything, even when no input is given.
+    ///
+    /// Call with fps=0 to disable (default value).
+    pub fn set_fps(&self, fps: u32) {
+        if fps == 0 {
+            ncurses::timeout(-1);
+        } else {
+            ncurses::timeout(1000 / fps as i32);
+        }
+    }
+
     /// Returns a mutable reference to the currently active screen.
     pub fn screen_mut(&mut self) -> &mut StackView {
         let id = self.active_screen;
@@ -122,6 +134,7 @@ impl Cursive {
     }
 
     fn find_any(&mut self, path: &ViewPath) -> Option<&mut Any> {
+        // Internal find method that returns a Any object.
         self.screen_mut().find(path)
     }
 
@@ -190,7 +203,7 @@ impl Cursive {
         // And the big event loop begins!
         while self.running {
             // Do we need to redraw everytime?
-            // Probably actually.
+            // Probably, actually.
             // TODO: Do we actually need to clear everytime?
             ncurses::clear();
             // TODO: Do we need to re-layout everytime?

src/view/button.rs

@@ -28,7 +28,7 @@ impl Button {
 
 impl View for Button {
 
-    fn draw(&self, printer: &Printer, focused: bool) {
+    fn draw(&mut self, printer: &Printer, focused: bool) {
         let style = if !focused { color::PRIMARY } else { color::HIGHLIGHT };
         let x = printer.size.x - 1;
 

src/view/dialog.rs

@@ -74,13 +74,13 @@ impl Dialog {
 }
 
 impl View for Dialog {
-    fn draw(&self, printer: &Printer, focused: bool) {
+    fn draw(&mut self, printer: &Printer, focused: bool) {
 
         // This will be the height used by the buttons.
         let mut height = 0;
         // Current horizontal position of the next button we'll draw.
         let mut x = 0;
-        for (i,button) in self.buttons.iter().enumerate().rev() {
+        for (i,button) in self.buttons.iter_mut().enumerate().rev() {
             let size = button.size;
             let offset = printer.size - self.borders.bot_right() - self.padding.bot_right() - size - Vec2::new(x, 0);
             // Add some special effect to the focused button

src/view/full_view.rs

@@ -0,0 +1,33 @@
+use view::{View,ViewWrapper,SizeRequest,DimensionRequest};
+use vec::Vec2;
+
+pub struct FullView<T: View> {
+    pub view: T,
+}
+
+impl <T: View> FullView<T> {
+    pub fn new(view: T) -> Self {
+        FullView {
+            view: view,
+        }
+    }
+}
+
+impl <T: View> ViewWrapper for FullView<T> {
+    wrap_impl!(&self.view);
+
+    fn wrap_get_min_size(&self, req: SizeRequest) -> Vec2 {
+        let w = match req.w {
+            DimensionRequest::Fixed(w) => w,
+            DimensionRequest::AtMost(w) => w,
+            DimensionRequest::Unknown => self.view.get_min_size(req).x,
+        };
+        let h = match req.h {
+            DimensionRequest::Fixed(h) => h,
+            DimensionRequest::AtMost(h) => h,
+            DimensionRequest::Unknown => self.view.get_min_size(req).y,
+        };
+
+        Vec2::new(w,h)
+    }
+}

src/view/mod.rs

@@ -9,6 +9,7 @@ mod view_path;
 mod dialog;
 mod button;
 mod sized_view;
+mod full_view;
 
 use std::any::Any;
 
@@ -21,6 +22,7 @@ pub use self::dialog::Dialog;
 pub use self::button::Button;
 pub use self::sized_view::SizedView;
 pub use self::view_wrapper::ViewWrapper;
+pub use self::full_view::FullView;
 
 use event::EventResult;
 use vec::{Vec2,ToVec2};
@@ -89,7 +91,7 @@ pub trait View {
     fn layout(&mut self, Vec2) { }
 
     /// Draws the view with the given printer (includes bounds) and focus.
-    fn draw(&self, printer: &Printer, focused: bool);
+    fn draw(&mut self, printer: &Printer, focused: bool);
 
     /// Finds the view pointed to by the given path.
     /// Returns None if the path doesn't lead to a view.

src/view/stack_view.rs

@@ -45,9 +45,9 @@ impl StackView {
 
 
 impl View for StackView {
-    fn draw(&self, printer: &Printer, focused: bool) {
+    fn draw(&mut self, printer: &Printer, focused: bool) {
         ncurses::wrefresh(printer.win);
-        for v in self.layers.iter() {
+        for v in self.layers.iter_mut() {
             // Center the view
             v.view.draw(&Printer::new(v.win.unwrap(), v.size), focused);
 

src/view/text_view.rs

@@ -112,7 +112,7 @@ impl <'a> Iterator for LinesIterator<'a> {
 }
 
 impl View for TextView {
-    fn draw(&self, printer: &Printer, _: bool) {
+    fn draw(&mut self, printer: &Printer, _: bool) {
         // We don't have a focused view
 
         let lines = self.content.split("\n")

src/view/view_wrapper.rs

@@ -11,8 +11,8 @@ pub trait ViewWrapper {
     fn get_view_mut(&mut self) -> &mut View;
 
     /// Wraps the draw method.
-    fn wrap_draw(&self, printer: &Printer, focused: bool) {
+    fn wrap_draw(&mut self, printer: &Printer, focused: bool) {
-        self.get_view().draw(printer, focused);
+        self.get_view_mut().draw(printer, focused);
     }
 
     /// Wraps the get_min_size method.
@@ -37,7 +37,7 @@ pub trait ViewWrapper {
 }
 
 impl <T: ViewWrapper> View for T {
-    fn draw(&self, printer: &Printer, focused: bool) {
+    fn draw(&mut self, printer: &Printer, focused: bool) {
         self.wrap_draw(printer, focused);
     }