client: Add a DestroyOnDrop wrapper that calls destructor on Drop

Author: ids1024

wayland-client/src/lib.rs

@@ -321,6 +321,31 @@ pub trait Proxy: Clone + std::fmt::Debug + Sized {
     }
 }
 
+/// Trait for instances of [`Proxy`] that have destructors
+pub trait ProxyDestroy: Proxy {
+    /// Sends the destructor request to the proxy, which is usually called `.destroy()`
+    fn call_proxy_destructor(&self);
+}
+
+/// Wrap a [`ProxyDestroy`] instance to automatically call the destructor on
+/// drop.
+#[derive(Debug, Eq, PartialEq, Hash)]
+pub struct DestroyOnDrop<T: ProxyDestroy>(T);
+
+impl<T: ProxyDestroy> Drop for DestroyOnDrop<T> {
+    fn drop(&mut self) {
+        self.0.call_proxy_destructor();
+    }
+}
+
+impl<T: ProxyDestroy> std::ops::Deref for DestroyOnDrop<T> {
+    type Target = T;
+
+    fn deref(&self) -> &T {
+        &self.0
+    }
+}
+
 /// Wayland dispatching error
 #[derive(Debug)]
 pub enum DispatchError {

wayland-scanner/src/client_gen.rs

@@ -49,6 +49,26 @@ fn generate_objects_for(interface: &Interface) -> TokenStream {
     };
     let doc_attr = to_doc_attr(&docs);
 
+    let destructor_trait_impl = if let Some(destructor) =
+        interface.requests.iter().find(|msg| msg.typ == Some(Type::Destructor))
+    {
+        // TODO split off shared code into function
+        let method_name = format_ident!(
+            "{}{}",
+            if is_keyword(&destructor.name) { "_" } else { "" },
+            destructor.name
+        );
+        quote! {
+            impl super::wayland_client::ProxyDestroy for #iface_name {
+                fn call_proxy_destructor(&self) {
+                    self.#method_name();
+                }
+            }
+        }
+    } else {
+        quote! {}
+    };
+
     quote! {
         #mod_doc
         pub mod #mod_name {
@@ -173,6 +193,8 @@ fn generate_objects_for(interface: &Interface) -> TokenStream {
                 }
             }
 
+            #destructor_trait_impl
+
             impl #iface_name {
                 #methods
             }