From c65b4030c39bd6b8b937b66cacfbeda116c94bba Mon Sep 17 00:00:00 2001
From: Mikko Lehtonen <scoopr@iki.fi>
Date: Wed, 21 Apr 2021 00:10:58 +0300
Subject: [PATCH] macos: Handle resizes synchronously

Allows for a lot better resize behaviour on macos, when allowed
to redraw the frame within the resize event callback.
---
 CHANGELOG.md                               |  1 +
 src/platform_impl/macos/app_state.rs       |  4 ++++
 src/platform_impl/macos/window_delegate.rs | 12 +++++++++---
 3 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a14bc047d4..719632cc8d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,7 @@
 - On Windows, added `WindowExtWindows::set_enable` to allow creating modal popup windows.
 - On macOS, emit `RedrawRequested` events immediately while the window is being resized.
 - Implement `Default`, `Hash`, and `Eq` for `LogicalPosition`, `PhysicalPosition`, `LogicalSize`, and `PhysicalSize`.
+- On macOS, emit `Resized` events immediately from the callback.
 
 # 0.24.0 (2020-12-09)
 
diff --git a/src/platform_impl/macos/app_state.rs b/src/platform_impl/macos/app_state.rs
index 59cf0f2aac..2906c83a67 100644
--- a/src/platform_impl/macos/app_state.rs
+++ b/src/platform_impl/macos/app_state.rs
@@ -331,6 +331,10 @@ impl AppState {
         HANDLER.handle_nonuser_event(EventWrapper::StaticEvent(Event::RedrawRequested(window_id)));
     }
 
+    pub fn handle_event(wrapper: EventWrapper) {
+        HANDLER.handle_nonuser_event(wrapper);
+    }
+
     pub fn queue_event(wrapper: EventWrapper) {
         if !unsafe { msg_send![class!(NSThread), isMainThread] } {
             panic!("Event queued from different thread: {:#?}", wrapper);
diff --git a/src/platform_impl/macos/window_delegate.rs b/src/platform_impl/macos/window_delegate.rs
index c226a66d7a..f844562927 100644
--- a/src/platform_impl/macos/window_delegate.rs
+++ b/src/platform_impl/macos/window_delegate.rs
@@ -97,12 +97,18 @@ impl WindowDelegateState {
         AppState::queue_event(wrapper);
     }
 
-    pub fn emit_resize_event(&mut self) {
+    pub fn handle_resize_event(&mut self) {
         let rect = unsafe { NSView::frame(*self.ns_view) };
         let scale_factor = self.get_scale_factor();
         let logical_size = LogicalSize::new(rect.size.width as f64, rect.size.height as f64);
         let size = logical_size.to_physical(scale_factor);
-        self.emit_event(WindowEvent::Resized(size));
+
+        let event = Event::WindowEvent {
+            window_id: WindowId(get_window_id(*self.ns_window)),
+            event: WindowEvent::Resized(size),
+        };
+
+        AppState::handle_event(EventWrapper::StaticEvent(event));
     }
 
     fn emit_move_event(&mut self) {
@@ -287,7 +293,7 @@ extern "C" fn window_will_close(this: &Object, _: Sel, _: id) {
 extern "C" fn window_did_resize(this: &Object, _: Sel, _: id) {
     trace!("Triggered `windowDidResize:`");
     with_state(this, |state| {
-        state.emit_resize_event();
+        state.handle_resize_event();
         state.emit_move_event();
     });
     trace!("Completed `windowDidResize:`");