Show how to close a child viewport in the example

crates/eframe/src/epi/mod.rs

@@ -123,6 +123,7 @@ pub trait App {
     ///
     /// This is called for the root viewport ([`egui::ViewportId::ROOT`]).
     /// Use [`egui::Context::show_viewport`] to spawn additional viewports (windows).
+    /// (A "viewport" in egui means an native OS window).
     fn update(&mut self, ctx: &egui::Context, frame: &mut Frame);
 
     /// Get a handle to the app.

crates/eframe/src/native/epi_integration.rs

@@ -85,7 +85,7 @@ pub fn window_builder<E>(
         ..
     } = native_options;
 
-    let mut viewport_builder = egui::ViewportBuilder::ROOT
+    let mut viewport_builder = egui::ViewportBuilder::DEFAULTS
         .with_title(title)
         .with_decorations(*decorated)
         .with_fullscreen(*fullscreen)