Switch to a futures-compatible API

src/lib.rs

@@ -2,10 +2,18 @@
 //!
 //! # Building a window
 //!
-//! There are two ways to create a window:
+//! Before you can build a window, you first need to build an `EventsLoop`. This is done with the
+//! `EventsLoop::new()` function. Example:
 //!
-//!  - Calling `Window::new()`.
-//!  - Calling `let builder = WindowBuilder::new()` then `builder.build()`.
+//! ```no_run
+//! use winit::EventsLoop;
+//! let events_loop = EventsLoop::new();
+//! ```
+//!
+//! Once this is done there are two ways to create a window:
+//!
+//!  - Calling `Window::new(&events_loop)`.
+//!  - Calling `let builder = WindowBuilder::new()` then `builder.build(&events_loop)`.
 //!
 //! The first way is the simpliest way and will give you default values for everything.
 //!
@@ -14,11 +22,58 @@
 //!
 //! # Events handling
 //!
-//! Once a window has been created, you can handle the events that it generates. There are two ways
-//! to do so: with `poll_events` or with `wait_events`. The former returns an iterator that ends
-//! when no event is available, and the latter returns an iterator that blocks and waits for events
-//! if none is available. Depending on which kind of program you're writing, you usually choose
-//! one or the other.
+//! Once a window has been created, it will *generate events*. For example whenever the user moves
+//! the window, resizes the window, moves the mouse, etc. an event is generated.
+//!
+//! The events generated by a window can be retreived from the `EventsLoop` the window was created
+//! with.
+//!
+//! There are two ways to do so. The first is to call `events_loop.poll_events(...)`, which will
+//! retreive all the events pending on the windows and immediately return after no new event is
+//! available. You usually want to use this method in application that render continuously on the
+//! screen, such as video games.
+//!
+//! ```no_run
+//! use winit::Event;
+//! use winit::WindowEvent;
+//! # use winit::EventsLoop;
+//! # let events_loop = EventsLoop::new();
+//!
+//! loop {
+//!     events_loop.poll_events(|event| {
+//!         match event {
+//!             Event::WindowEvent { event: WindowEvent::Resized(w, h), .. } => {
+//!                 println!("The window was resized to {}x{}", w, h);
+//!             },
+//!             _ => ()
+//!         }
+//!     });
+//! }
+//! ```
+//!
+//! The second way is to call `events_loop.run_forever(...)`. As its name tells, it will run
+//! forever unless it is stopped by calling `events_loop.interrupt()`.
+//!
+//! ```no_run
+//! use winit::Event;
+//! use winit::WindowEvent;
+//! # use winit::EventsLoop;
+//! # let events_loop = EventsLoop::new();
+//!
+//! events_loop.run_forever(|event| {
+//!     match event {
+//!         Event::WindowEvent { event: WindowEvent::Closed, .. } => {
+//!             println!("The window was closed ; stopping");
+//!             events_loop.interrupt();
+//!         },
+//!         _ => ()
+//!     }
+//! });
+//! ```
+//!
+//! If you use multiple windows, the `WindowEvent` event has a member named `window_id`. You can
+//! compare it with the value returned by the `id()` method of `Window` in order to know which
+//! window has received the event.
 //!
 //! # Drawing on the window
 //!
@@ -86,22 +141,29 @@ pub mod os;
 /// # Example
 ///
 /// ```no_run
+/// use winit::Event;
+/// use winit::EventsLoop;
 /// use winit::Window;
-/// let window = Window::new().unwrap();
+/// use winit::WindowEvent;
+///
+/// let events_loop = EventsLoop::new();
+/// let window = Window::new(&events_loop).unwrap();
 ///
-/// loop {
-///     for event in window.wait_events() {
-///         match event {
-///             // process events here
-///             _ => ()
-///         }
+/// events_loop.run_forever(|event| {
+///     match event {
+///         Event::WindowEvent { event: WindowEvent::Closed, .. } => {
+///             events_loop.interrupt();
+///         },
+///         _ => ()
 ///     }
-/// }
+/// });
 /// ```
 pub struct Window {
     window: platform::Window2,
 }
 
+/// Provides a way to retreive events from the windows that were registered to it.
+// TODO: document usage in multiple threads
 pub struct EventsLoop {
     events_loop: Arc<platform::EventsLoop>,
 }
@@ -114,20 +176,25 @@ impl EventsLoop {
         }
     }
 
+    /// Fetches all the events that are pending, calls the callback function for each of them,
+    /// and returns.
     #[inline]
     pub fn poll_events<F>(&self, callback: F)
         where F: FnMut(Event)
     {
         self.events_loop.poll_events(callback)
     }
 
+    /// Runs forever until `interrupt()` is called. Whenever an event happens, calls the callback.
     #[inline]
     pub fn run_forever<F>(&self, callback: F)
         where F: FnMut(Event)
     {
         self.events_loop.run_forever(callback)
     }
 
+    /// If we called `run_forever()`, stops the process of waiting for events.
+    // TODO: what if we're waiting from multiple threads?
     #[inline]
     pub fn interrupt(&self) {
         self.events_loop.interrupt()

src/window.rs

@@ -119,7 +119,7 @@ impl WindowBuilder {
 impl Window {
     /// Creates a new OpenGL context, and a Window for platforms where this is appropriate.
     ///
-    /// This function is equivalent to `WindowBuilder::new().build()`.
+    /// This function is equivalent to `WindowBuilder::new().build(events_loop)`.
     ///
     /// Error should be very rare and only occur in case of permission denied, incompatible system,
     ///  out of memory, etc.