Introduce black_box and chain in widget::operation

widget/src/button.rs

@@ -236,7 +236,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn Operation<()>,
+        operation: &mut dyn Operation,
     ) {
         operation.container(None, layout.bounds(), &mut |operation| {
             self.content.as_widget().operate(

widget/src/column.rs

@@ -222,7 +222,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn Operation<()>,
+        operation: &mut dyn Operation,
     ) {
         operation.container(None, layout.bounds(), &mut |operation| {
             self.children

widget/src/container.rs

@@ -245,7 +245,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn Operation<()>,
+        operation: &mut dyn Operation,
     ) {
         operation.container(
             self.id.as_ref().map(|id| &id.0),

widget/src/helpers.rs

@@ -289,7 +289,7 @@ where
             state: &mut Tree,
             layout: Layout<'_>,
             renderer: &Renderer,
-            operation: &mut dyn operation::Operation<()>,
+            operation: &mut dyn operation::Operation,
         ) {
             self.content
                 .as_widget()
@@ -491,7 +491,7 @@ where
             tree: &mut Tree,
             layout: Layout<'_>,
             renderer: &Renderer,
-            operation: &mut dyn operation::Operation<()>,
+            operation: &mut dyn operation::Operation,
         ) {
             let children = [&self.base, &self.top]
                 .into_iter()

widget/src/keyed/column.rs

@@ -265,7 +265,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn Operation<()>,
+        operation: &mut dyn Operation,
     ) {
         operation.container(None, layout.bounds(), &mut |operation| {
             self.children

widget/src/lazy.rs

@@ -182,7 +182,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn widget::Operation<()>,
+        operation: &mut dyn widget::Operation,
     ) {
         self.with_element(|element| {
             element.as_widget().operate(

widget/src/lazy/component.rs

@@ -59,7 +59,7 @@ pub trait Component<Message, Theme = crate::Theme, Renderer = crate::Renderer> {
     fn operate(
         &self,
         _state: &mut Self::State,
-        _operation: &mut dyn widget::Operation<()>,
+        _operation: &mut dyn widget::Operation,
     ) {
     }
 
@@ -172,7 +172,7 @@ where
 
     fn rebuild_element_with_operation(
         &self,
-        operation: &mut dyn widget::Operation<()>,
+        operation: &mut dyn widget::Operation,
     ) {
         let heads = self.state.borrow_mut().take().unwrap().into_heads();
 
@@ -358,7 +358,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn widget::Operation<()>,
+        operation: &mut dyn widget::Operation,
     ) {
         self.rebuild_element_with_operation(operation);
 

widget/src/lazy/responsive.rs

@@ -161,7 +161,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn widget::Operation<()>,
+        operation: &mut dyn widget::Operation,
     ) {
         let state = tree.state.downcast_mut::<State>();
         let mut content = self.content.borrow_mut();

widget/src/mouse_area.rs

@@ -178,7 +178,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn Operation<()>,
+        operation: &mut dyn Operation,
     ) {
         self.content.as_widget().operate(
             &mut tree.children[0],

widget/src/pane_grid.rs

@@ -324,7 +324,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn widget::Operation<()>,
+        operation: &mut dyn widget::Operation,
     ) {
         operation.container(None, layout.bounds(), &mut |operation| {
             self.contents

widget/src/pane_grid/content.rs

@@ -214,7 +214,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn widget::Operation<()>,
+        operation: &mut dyn widget::Operation,
     ) {
         let body_layout = if let Some(title_bar) = &self.title_bar {
             let mut children = layout.children();

widget/src/pane_grid/title_bar.rs

@@ -278,7 +278,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn widget::Operation<()>,
+        operation: &mut dyn widget::Operation,
     ) {
         let mut children = layout.children();
         let padded = children.next().unwrap();

widget/src/row.rs

@@ -218,7 +218,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn Operation<()>,
+        operation: &mut dyn Operation,
     ) {
         operation.container(None, layout.bounds(), &mut |operation| {
             self.children
@@ -470,7 +470,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn Operation<()>,
+        operation: &mut dyn Operation,
     ) {
         self.row.operate(tree, layout, renderer, operation);
     }

widget/src/scrollable.rs

@@ -415,7 +415,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn Operation<()>,
+        operation: &mut dyn Operation,
     ) {
         let state = tree.state.downcast_mut::<State>();
 

widget/src/stack.rs

@@ -189,7 +189,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn Operation<()>,
+        operation: &mut dyn Operation,
     ) {
         operation.container(None, layout.bounds(), &mut |operation| {
             self.children

widget/src/text_editor.rs

@@ -885,7 +885,7 @@ where
         tree: &mut widget::Tree,
         _layout: Layout<'_>,
         _renderer: &Renderer,
-        operation: &mut dyn widget::Operation<()>,
+        operation: &mut dyn widget::Operation,
     ) {
         let state = tree.state.downcast_mut::<State<Highlighter>>();
 

widget/src/text_input.rs

@@ -542,7 +542,7 @@ where
         tree: &mut Tree,
         _layout: Layout<'_>,
         _renderer: &Renderer,
-        operation: &mut dyn Operation<()>,
+        operation: &mut dyn Operation,
     ) {
         let state = tree.state.downcast_mut::<State<Renderer::Paragraph>>();
 

widget/src/themer.rs

@@ -104,7 +104,7 @@ where
         tree: &mut Tree,
         layout: Layout<'_>,
         renderer: &Renderer,
-        operation: &mut dyn Operation<()>,
+        operation: &mut dyn Operation,
     ) {
         self.content
             .as_widget()
@@ -236,7 +236,7 @@ where
                 &mut self,
                 layout: Layout<'_>,
                 renderer: &Renderer,
-                operation: &mut dyn Operation<()>,
+                operation: &mut dyn Operation,
             ) {
                 self.content.operate(layout, renderer, operation);
             }