Lots of owork on a calculator example, transparency, etc.

lib/ruin_app/src/input.rs

@@ -124,6 +124,9 @@ pub(crate) struct InputState {
     pub(crate) current_cursor: CursorIcon,
     pub(crate) focused_element: Option<ElementId>,
     pub(crate) text_selection: Rc<TextSelectionState>,
+    pub(crate) hovered_elements: Signal<Vec<ElementId>>,
+    pub(crate) pressed_elements: Signal<Vec<ElementId>>,
+    pub(crate) interaction_version: Signal<u64>,
 }
 
 impl InputState {
@@ -132,6 +135,9 @@ impl InputState {
             current_cursor: CursorIcon::Default,
             focused_element: None,
             text_selection: Rc::new(TextSelectionState::new()),
+            hovered_elements: Signal::new(Vec::new()),
+            pressed_elements: Signal::new(Vec::new()),
+            interaction_version: Signal::new(0),
         }
     }
 }