From 8fcd6767148eaa3a516c58d16238d842ef32d26a Mon Sep 17 00:00:00 2001
From: Pierre Krieger <pierre.krieger1708@gmail.com>
Date: Mon, 19 Jan 2015 13:04:14 +0100
Subject: [PATCH] Iterators returned by wait_events and poll_events are now
 persistent

---
 examples/fullscreen.rs  |  2 +-
 examples/multiwindow.rs |  2 +-
 examples/window.rs      |  2 +-
 src/lib.rs              | 38 ++++++++++++++++++++++++++++++--------
 4 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/examples/fullscreen.rs b/examples/fullscreen.rs
index 7c2ece8a..c07edaa0 100644
--- a/examples/fullscreen.rs
+++ b/examples/fullscreen.rs
@@ -47,6 +47,6 @@ fn main() {
         context.draw_frame((0.0, 1.0, 0.0, 1.0));
         window.swap_buffers();
 
-        println!("{:?}", window.wait_events().collect::<Vec<glutin::Event>>());
+        println!("{:?}", window.wait_events().next());
     }
 }
diff --git a/examples/multiwindow.rs b/examples/multiwindow.rs
index cd57d2e0..115d5f2a 100644
--- a/examples/multiwindow.rs
+++ b/examples/multiwindow.rs
@@ -47,6 +47,6 @@ fn run(window: glutin::Window, color: (f32, f32, f32, f32)) {
         context.draw_frame(color);
         window.swap_buffers();
 
-        window.wait_events().collect::<Vec<glutin::Event>>();
+        window.wait_events().next();
     }
 }
diff --git a/examples/window.rs b/examples/window.rs
index 37966c48..1d3b6158 100644
--- a/examples/window.rs
+++ b/examples/window.rs
@@ -30,6 +30,6 @@ fn main() {
         context.draw_frame((0.0, 1.0, 0.0, 1.0));
         window.swap_buffers();
 
-        println!("{:?}", window.wait_events().collect::<Vec<glutin::Event>>());
+        println!("{:?}", window.wait_events().next());
     }
 }
diff --git a/src/lib.rs b/src/lib.rs
index 12a908cf..aa1be570 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -537,22 +537,22 @@ impl Window {
         self.window.set_inner_size(x, y)
     }
 
-    /// Returns an iterator to all the events that are currently in the window's events queue.
+    /// Returns an iterator that poll for the next event in the window's events queue.
+    /// Returns `None` if there is no event in the queue.
     ///
     /// Contrary to `wait_events`, this function never blocks.
     #[inline]
     pub fn poll_events(&self) -> PollEventsIterator {
-        PollEventsIterator { data: self.window.poll_events().into_iter() }
+        PollEventsIterator { window: self, data: self.window.poll_events().into_iter() }
     }
 
-    /// Waits for an event, then returns an iterator to all the events that are currently
-    ///  in the window's events queue.
+    /// Returns an iterator that returns events one by one, blocking if necessary until one is
+    /// available.
     ///
-    /// If there are no events in queue when you call the function,
-    ///  this function will block until there is one.
+    /// The iterator never returns `None`.
     #[inline]
     pub fn wait_events(&self) -> WaitEventsIterator {
-        WaitEventsIterator { data: self.window.wait_events().into_iter() }
+        WaitEventsIterator { window: self, data: self.window.wait_events().into_iter() }
     }
 
     /// Sets the context as the current context.
@@ -697,13 +697,24 @@ impl gl_common::GlFunctionsSource for HeadlessContext {
 /// An iterator for the `poll_events` function.
 // Implementation note: we retreive the list once, then serve each element by one by one.
 // This may change in the future.
+#[cfg(feature = "window")]
 pub struct PollEventsIterator<'a> {
+    window: &'a Window,
     data: RingBufIter<Event>,
 }
 
+#[cfg(feature = "window")]
 impl<'a> Iterator for PollEventsIterator<'a> {
     type Item = Event;
     fn next(&mut self) -> Option<Event> {
+        if let Some(ev) = self.data.next() {
+            return Some(ev);
+        }
+
+        let PollEventsIterator { window, data } = self.window.poll_events();
+        self.window = window;
+        self.data = data;
+
         self.data.next()
     }
 }
@@ -711,14 +722,25 @@ impl<'a> Iterator for PollEventsIterator<'a> {
 /// An iterator for the `wait_events` function.
 // Implementation note: we retreive the list once, then serve each element by one by one.
 // This may change in the future.
+#[cfg(feature = "window")]
 pub struct WaitEventsIterator<'a> {
+    window: &'a Window,
     data: RingBufIter<Event>,
 }
 
+#[cfg(feature = "window")]
 impl<'a> Iterator for WaitEventsIterator<'a> {
     type Item = Event;
     fn next(&mut self) -> Option<Event> {
-        self.data.next()
+        if let Some(ev) = self.data.next() {
+            return Some(ev);
+        }
+
+        let WaitEventsIterator { window, data } = self.window.wait_events();
+        self.window = window;
+        self.data = data;
+
+        self.next()
     }
 }