Remove lifetime from the Event

Lifetimes don't work nicely when dealing with multithreaded environments
in the current design of the existing winit's event handling model, so
remove it in favor of `InnerSizeWriter` fences passed to client, so they
could try to update the size.

Fixes rust-windowing#1387.

Author: kchibisov

CHANGELOG.md

@@ -9,6 +9,8 @@ And please only add new entries to the top of this list, right below the `# Unre
 # Unreleased
 
 - On Windows, added `WindowBuilderExtWindows::with_class_name` to customize the internal class name.
+- **Breaking:** Remove lifetime parameter from `Event` and `WindowEvent`.
+- **Breaking:** `ScaleFactorChanged` now contains a writer instead of a reference to update inner size.
 - On iOS, always wake the event loop when transitioning from `ControlFlow::Poll` to `ControlFlow::Poll`.
 - **Breaking:** `ActivationTokenDone` event which could be requested with the new `startup_notify` module, see its docs for more.
 - On Wayland, make double clicking and moving the CSD frame more reliable.

examples/child_window.rs

@@ -46,7 +46,7 @@ fn main() -> Result<(), impl std::error::Error> {
 
     println!("parent window: {parent_window:?})");
 
-    event_loop.run(move |event: Event<'_, ()>, event_loop, control_flow| {
+    event_loop.run(move |event: Event<()>, event_loop, control_flow| {
         *control_flow = ControlFlow::Wait;
 
         if let Event::WindowEvent { event, window_id } = event {

examples/multithreaded.rs

@@ -195,9 +195,7 @@ fn main() -> Result<(), impl std::error::Error> {
                 }
                 _ => {
                     if let Some(tx) = window_senders.get(&window_id) {
-                        if let Some(event) = event.to_static() {
-                            tx.send(event).unwrap();
-                        }
+                        tx.send(event).unwrap();
                     }
                 }
             },

src/error.rs

@@ -8,6 +8,8 @@ use crate::platform_impl;
 pub enum ExternalError {
     /// The operation is not supported by the backend.
     NotSupported(NotSupportedError),
+    /// The operation was ignored.
+    Ignored,
     /// The OS cannot perform the operation.
     Os(OsError),
 }
@@ -74,6 +76,7 @@ impl fmt::Display for ExternalError {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
         match self {
             ExternalError::NotSupported(e) => e.fmt(f),
+            ExternalError::Ignored => write!(f, "Operation was ignored"),
             ExternalError::Os(e) => e.fmt(f),
         }
     }