Fully invert windows control flow so win32 calls into winit's callback

Author: Osspial

examples/timer.rs

@@ -1,5 +1,6 @@
 extern crate winit;
 use std::time::{Duration, Instant};
+use winit::{Event, WindowEvent, StartCause, ControlFlow};
 
 fn main() {
     let events_loop = winit::EventLoop::new();
@@ -13,20 +14,16 @@ fn main() {
         println!("{:?}", event);
 
         match event {
-            winit::Event::NewEvents(winit::StartCause::Init) =>
-                *control_flow = winit::ControlFlow::WaitTimeout(Duration::new(1, 0)),
-            winit::Event::NewEvents(winit::StartCause::TimeoutExpired{..}) => {
-                *control_flow = winit::ControlFlow::WaitTimeout(Duration::new(1, 0));
+            Event::NewEvents(StartCause::Init) =>
+                *control_flow = ControlFlow::WaitUntil(Instant::now() + Duration::new(1, 0)),
+            Event::NewEvents(StartCause::ResumeTimeReached{..}) => {
+                *control_flow = ControlFlow::WaitUntil(Instant::now() + Duration::new(1, 0));
                 println!("\nTimer\n");
             },
-            winit::Event::NewEvents(winit::StartCause::WaitCancelled{start, requested_duration}) => {
-                println!("{:?}", Instant::now() - start);
-                *control_flow = winit::ControlFlow::WaitTimeout(requested_duration.unwrap().checked_sub(Instant::now() - start).unwrap_or(Duration::new(0, 0)));
-            }
-            winit::Event::WindowEvent {
-                event: winit::WindowEvent::CloseRequested,
+            Event::WindowEvent {
+                event: WindowEvent::CloseRequested,
                 ..
-            } => *control_flow = winit::ControlFlow::Exit,
+            } => *control_flow = ControlFlow::Exit,
             _ => ()
         }
     });

src/events.rs

@@ -1,4 +1,4 @@
-use std::time::{Duration, Instant};
+use std::time::Instant;
 use std::path::PathBuf;
 
 use {DeviceId, LogicalPosition, LogicalSize, WindowId};
@@ -48,19 +48,19 @@ impl<T> Event<T> {
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
 pub enum StartCause {
-    /// Sent if the time specified by `ControlFlow::WaitTimeout` has been elapsed. Contains the
-    /// moment the timeout was requested and the requested duration of the timeout. The actual
-    /// duration is guaranteed to be greater than or equal to the requested timeout.
-    TimeoutExpired {
+    /// Sent if the time specified by `ControlFlow::WaitUntil` has been reached. Contains the
+    /// moment the timeout was requested and the requested resume time. The actual resume time is
+    /// guaranteed to be equal to or after the requested resume time.
+    ResumeTimeReached {
         start: Instant,
-        requested_duration: Duration,
+        requested_resume: Instant
     },
 
     /// Sent if the OS has new events to send to the window, after a wait was requested. Contains
-    /// the moment the wait was requested, and if a wait timout was requested, its duration.
+    /// the moment the wait was requested and the resume time, if requested.
     WaitCancelled {
         start: Instant,
-        requested_duration: Option<Duration>
+        requested_resume: Option<Instant>
     },
 
     /// Sent if the event loop is being resumed after the loop's control flow was set to

src/lib.rs

@@ -93,7 +93,7 @@ extern crate percent_encoding;
 #[cfg(any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd", target_os = "netbsd", target_os = "openbsd"))]
 extern crate smithay_client_toolkit as sctk;
 
-use std::time::Duration;
+use std::time::Instant;
 pub(crate) use dpi::*; // TODO: Actually change the imports throughout the codebase.
 pub use events::*;
 pub use window::{AvailableMonitorsIter, MonitorId};
@@ -186,8 +186,8 @@ pub enum ControlFlow {
     /// When the current loop iteration finishes, suspend the thread until another event arrives.
     Wait,
     /// When the current loop iteration finishes, suspend the thread until either another event
-    /// arrives or the timeout expires.
-    WaitTimeout(Duration),
+    /// arrives or the given time is reached.
+    WaitUntil(Instant),
     /// When the current loop iteration finishes, immediately begin a new iteration regardless of
     /// whether or not new events are available to process.
     Poll,

src/platform/windows/drop_handler.rs

@@ -24,7 +24,7 @@ pub struct FileDropHandlerData {
     pub interface: IDropTarget,
     refcount: AtomicUsize,
     window: HWND,
-    event_sender: Sender<Event<()>>
+    // event_sender: Sender<Event<()>>
 }
 
 pub struct FileDropHandler {
@@ -33,14 +33,14 @@ pub struct FileDropHandler {
 
 #[allow(non_snake_case)]
 impl FileDropHandler {
-    pub fn new(window: HWND, event_sender: Sender<Event<()>>) -> FileDropHandler {
+    pub fn new(window: HWND/*, event_sender: Sender<Event<()>>*/) -> FileDropHandler {
         let data = Box::new(FileDropHandlerData {
             interface: IDropTarget {
                 lpVtbl: &DROP_TARGET_VTBL as *const IDropTargetVtbl,
             },
             refcount: AtomicUsize::new(1),
             window,
-            event_sender,
+            // event_sender,
         });
         FileDropHandler {
             data: Box::into_raw(data),
@@ -186,7 +186,7 @@ impl FileDropHandler {
 
 impl FileDropHandlerData {
     fn send_event(&self, event: Event<()>) {
-        self.event_sender.send(event).ok();
+        // self.event_sender.send(event).ok();
     }
 }