Request a redraw only on relevant events

examples/integration/src/main.rs

@@ -119,16 +119,19 @@ pub fn main() {
                 }
             }
             Event::MainEventsCleared => {
-                // We update iced
+                // If there are events pending
-                let _ = state.update(
+                if !state.is_queue_empty() {
-                    None,
+                    // We update iced
-                    viewport.logical_size(),
+                    let _ = state.update(
-                    &mut renderer,
+                        None,
-                    &mut debug,
+                        viewport.logical_size(),
-                );
+                        &mut renderer,
+                        &mut debug,
+                    );
 
-                // and request a redraw
+                    // and request a redraw
-                window.request_redraw();
+                    window.request_redraw();
+                }
             }
             Event::RedrawRequested(_) => {
                 if resized {

glutin/src/application.rs

@@ -95,6 +95,10 @@ pub fn run<A, E, C>(
 
     event_loop.run(move |event, _, control_flow| match event {
         event::Event::MainEventsCleared => {
+            if state.is_queue_empty() {
+                return;
+            }
+
             let command = runtime.enter(|| {
                 state.update(
                     clipboard.as_ref().map(|c| c as _),

native/src/program/state.rs

@@ -88,6 +88,13 @@ where
         self.queued_messages.push(message);
     }
 
+    /// Returns whether the event queue of the [`State`] is empty or not.
+    ///
+    /// [`State`]: struct.State.html
+    pub fn is_queue_empty(&self) -> bool {
+        self.queued_events.is_empty() && self.queued_messages.is_empty()
+    }
+
     /// Processes all the queued events and messages, rebuilding and redrawing
     /// the widgets of the linked [`Program`] if necessary.
     ///
@@ -102,10 +109,6 @@ where
         renderer: &mut P::Renderer,
         debug: &mut Debug,
     ) -> Option<Command<P::Message>> {
-        if self.queued_events.is_empty() && self.queued_messages.is_empty() {
-            return None;
-        }
-
         let mut user_interface = build_user_interface(
             &mut self.program,
             self.cache.take().unwrap(),

winit/src/application.rs

@@ -150,6 +150,10 @@ pub fn run<A, E, C>(
 
     event_loop.run(move |event, _, control_flow| match event {
         event::Event::MainEventsCleared => {
+            if state.is_queue_empty() {
+                return;
+            }
+
             let command = runtime.enter(|| {
                 state.update(
                     clipboard.as_ref().map(|c| c as _),