From 530ff5420b6f6abba1cb5c1249d58398c91e48e2 Mon Sep 17 00:00:00 2001
From: simlay <simlay@users.noreply.github.com>
Date: Sat, 21 Dec 2019 16:35:18 -0800
Subject: [PATCH] Implement revamped `RedrawRequested` on iOS. (#1299)

* Implement revamped `RedrawRequested` on iOS

* Added RedrawEventsCleared to events_cleared logic

* Fixed from comments

* Added RedrawEventsCleared to draw_rect handler.

* Fixed out of order `RedrawEventsCleared` events.

* cargo fmt
---
 src/platform_impl/ios/app_state.rs | 22 ++++++++++------------
 src/platform_impl/ios/view.rs      |  8 ++++----
 2 files changed, 14 insertions(+), 16 deletions(-)

diff --git a/src/platform_impl/ios/app_state.rs b/src/platform_impl/ios/app_state.rs
index 6009a26a..e1b82be1 100644
--- a/src/platform_impl/ios/app_state.rs
+++ b/src/platform_impl/ios/app_state.rs
@@ -12,7 +12,7 @@ use std::{
 use objc::runtime::{BOOL, YES};
 
 use crate::{
-    event::{Event, StartCause, WindowEvent},
+    event::{Event, StartCause},
     event_loop::ControlFlow,
     platform_impl::platform::{
         event_loop::{EventHandler, Never},
@@ -51,11 +51,7 @@ enum UserCallbackTransitionResult<'a> {
 
 impl Event<Never> {
     fn is_redraw(&self) -> bool {
-        if let Event::WindowEvent {
-            window_id: _,
-            event: WindowEvent::RedrawRequested,
-        } = self
-        {
+        if let Event::RedrawRequested(_) = self {
             true
         } else {
             false
@@ -776,16 +772,18 @@ pub unsafe fn handle_main_events_cleared() {
 
     // User events are always sent out at the end of the "MainEventLoop"
     handle_user_events();
-    handle_nonuser_event(Event::EventsCleared);
+    handle_nonuser_event(Event::MainEventsCleared);
 
     let mut this = AppState::get_mut();
-    let redraw_events = this
+    let mut redraw_events: Vec<Event<Never>> = this
         .main_events_cleared_transition()
         .into_iter()
-        .map(|window| Event::WindowEvent {
-            window_id: RootWindowId(window.into()),
-            event: WindowEvent::RedrawRequested,
-        });
+        .map(|window| Event::RedrawRequested(RootWindowId(window.into())))
+        .collect();
+
+    if !redraw_events.is_empty() {
+        redraw_events.push(Event::RedrawEventsCleared);
+    }
     drop(this);
 
     handle_nonuser_events(redraw_events);
diff --git a/src/platform_impl/ios/view.rs b/src/platform_impl/ios/view.rs
index f729299a..622b351b 100644
--- a/src/platform_impl/ios/view.rs
+++ b/src/platform_impl/ios/view.rs
@@ -102,10 +102,10 @@ unsafe fn get_view_class(root_view_class: &'static Class) -> &'static Class {
             unsafe {
                 let window: id = msg_send![object, window];
                 assert!(!window.is_null());
-                app_state::handle_nonuser_event(Event::WindowEvent {
-                    window_id: RootWindowId(window.into()),
-                    event: WindowEvent::RedrawRequested,
-                });
+                app_state::handle_nonuser_events(
+                    std::iter::once(Event::RedrawRequested(RootWindowId(window.into())))
+                        .chain(std::iter::once(Event::RedrawEventsCleared)),
+                );
                 let superclass: &'static Class = msg_send![object, superclass];
                 let () = msg_send![super(object, superclass), drawRect: rect];
             }