Use delegate crate to simplify things a bit.

Cargo.lock

@@ -871,6 +871,7 @@ dependencies = [
  "clap",
  "cosmic-comp-config",
  "cosmic-config",
+ "delegate",
  "env_logger",
  "futures-channel",
  "gbm",
@@ -1042,6 +1043,17 @@ version = "0.3.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "5c297a1c74b71ae29df00c3e22dd9534821d60eb9af5a0192823fa2acea70c2a"
 
+[[package]]
+name = "delegate"
+version = "0.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b4801d755ab05b6e25cbbf1afc342993aafa00e572409f9ee21633a19e609d9f"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 2.0.41",
+]
+
 [[package]]
 name = "derivative"
 version = "2.2.0"

Cargo.toml

@@ -19,6 +19,7 @@ tokio = "1.23.0"
 wayland-protocols = "0.31.0"
 zbus = { version = "3.7.0", default-features = false, features = ["tokio"] }
 once_cell = "1.18.0"
+delegate = "0.11.0"
 
 [profile.dev]
 # Not usable at opt-level 0, at least with software renderer

src/widgets/image_bg.rs

@@ -27,28 +27,18 @@ pub struct ImageBg<'a, Msg> {
 }
 
 impl<'a, Msg> Widget<Msg, cosmic::Renderer> for ImageBg<'a, Msg> {
-    fn tag(&self) -> tree::Tag {
-        self.content.as_widget().tag()
-    }
+    delegate::delegate! {
+        to self.content.as_widget() {
+            fn tag(&self) -> tree::Tag;
+            fn state(&self) -> tree::State;
+            fn children(&self) -> Vec<Tree>;
+            fn width(&self) -> Length;
+            fn height(&self) -> Length;
+        }
 
-    fn state(&self) -> tree::State {
-        self.content.as_widget().state()
-    }
-
-    fn children(&self) -> Vec<Tree> {
-        self.content.as_widget().children()
-    }
-
-    fn diff(&mut self, tree: &mut Tree) {
-        self.content.as_widget_mut().diff(tree);
-    }
-
-    fn width(&self) -> Length {
-        self.content.as_widget().width()
-    }
-
-    fn height(&self) -> Length {
-        self.content.as_widget().height()
+        to self.content.as_widget_mut() {
+            fn diff(&mut self, tree: &mut Tree);
+        }
     }
 
     fn layout(