App::prevent_shutdown()

CHANGELOG.md

@@ -140,6 +140,8 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   directly, including getting a reference to the underlying winit Window.
 - `Modal` is a new layer widget that presents a single widget as a modal
   session.
+- `App::prevent_shutdown()` returns a guard that prevents the application from
+  closing automatically when the final window is closed.
 
 
 [139]: https://github.com/khonsulabs/cushy/issues/139

src/app.rs

@@ -352,8 +352,25 @@ impl App {
     pub fn monitors(&self) -> Option<Monitors> {
         self.app.as_ref().and_then(kludgine::app::App::monitors)
     }
+
+    /// Creates a guard that prevents this app from shutting down.
+    ///
+    /// If the app is not currently running, this function returns None.
+    ///
+    /// Once a guard is allocated the app will not be closed automatically when
+    /// the final window is closed. If the final shutdown guard is dropped while
+    /// no windows are open, the app will be closed.
+    #[allow(clippy::missing_panics_doc, clippy::must_use_candidate)]
+    pub fn prevent_shutdown(&self) -> Option<ShutdownGuard> {
+        self.app
+            .as_ref()
+            .and_then(kludgine::app::App::prevent_shutdown)
+    }
 }
 
+/// A guard preventing an [`App`] from shutting down.
+pub type ShutdownGuard = kludgine::app::ShutdownGuard<WindowCommand>;
+
 impl Application for App {
     fn cushy(&self) -> &Cushy {
         &self.cushy

src/lib.rs

@@ -34,7 +34,9 @@ use std::ops::{Add, AddAssign, Sub, SubAssign};
 
 #[cfg(feature = "tokio")]
 pub use app::TokioRuntime;
-pub use app::{App, AppRuntime, Application, Cushy, DefaultRuntime, Open, PendingApp, Run};
+pub use app::{
+    App, AppRuntime, Application, Cushy, DefaultRuntime, Open, PendingApp, Run, ShutdownGuard,
+};
 /// A macro to create a `main()` function with less boilerplate.
 ///
 /// When creating applications that support multiple windows, this attribute