Trim the Rust ComponentWindow API and implementation a little bit

* Remove the `new` function from the main impl and use the slightly
  less visible From conversion trait
* Make the inner Rc<Window> pub(crate) instead of pub
* Instead, provide a public as_any() accessor that the Qt backend can use

sixtyfps_runtime/corelib/window.rs

@@ -197,7 +197,7 @@ impl Window {
         self.mouse_input_state.set(crate::input::process_mouse_input(
             component,
             event,
-            &ComponentWindow::new(self.clone()),
+            &self.clone().into(),
             self.mouse_input_state.take(),
         ));
     }
@@ -210,8 +210,7 @@ impl Window {
     pub fn process_key_input(self: Rc<Self>, event: &KeyEvent) {
         let mut item = self.focus_item.borrow().clone();
         while let Some(focus_item) = item.upgrade() {
-            let window = &ComponentWindow::new(self.clone());
-            if focus_item.borrow().as_ref().key_event(event, window)
+            if focus_item.borrow().as_ref().key_event(event, &self.clone().into())
                 == crate::input::KeyEventResult::EventAccepted
             {
                 return;
@@ -237,7 +236,7 @@ impl Window {
     /// Sets the focus to the item pointed to by item_ptr. This will remove the focus from any
     /// currently focused item.
     pub fn set_focus_item(self: Rc<Self>, focus_item: &ItemRc) {
-        let window = ComponentWindow::new(self.clone());
+        let window = &self.clone().into();
 
         if let Some(old_focus_item) = self.as_ref().focus_item.borrow().upgrade() {
             old_focus_item
@@ -254,7 +253,7 @@ impl Window {
     /// Sets the focus on the window to true or false, depending on the have_focus argument.
     /// This results in WindowFocusReceived and WindowFocusLost events.
     pub fn set_focus(self: Rc<Self>, have_focus: bool) {
-        let window = ComponentWindow::new(self.clone());
+        let window = &self.clone().into();
         let event = if have_focus {
             crate::input::FocusEvent::WindowReceivedFocus
         } else {
@@ -309,15 +308,15 @@ impl core::ops::Deref for Window {
 /// of components to the screen.
 #[repr(C)]
 #[derive(Clone)]
-pub struct ComponentWindow(pub std::rc::Rc<Window>);
+pub struct ComponentWindow(pub(crate) std::rc::Rc<Window>);
+
+impl From<std::rc::Rc<Window>> for ComponentWindow {
+    fn from(inner: std::rc::Rc<Window>) -> Self {
+        Self(inner)
+    }
+}
 
 impl ComponentWindow {
-    /// Creates a new instance of a ComponentWindow based on the given window implementation. Only used
-    /// internally.
-    pub fn new(window_impl: std::rc::Rc<Window>) -> Self {
-        Self(window_impl)
-    }
-
     /// Registers the window with the windowing system, in order to render the component's items and react
     /// to input events once the event loop spins.
     pub fn show(&self) {
@@ -374,6 +373,11 @@ impl ComponentWindow {
     pub fn close_popup(&self) {
         self.0.platform_window.get().unwrap().clone().close_popup()
     }
+
+    /// Return self as any so the backend can upcast
+    pub fn as_any(&self) -> &dyn core::any::Any {
+        self.0.as_any()
+    }
 }
 
 /// This module contains the functions needed to interface with the event loop and window traits

sixtyfps_runtime/rendering_backends/gl/graphics_window.rs

@@ -20,7 +20,7 @@ use corelib::input::{KeyboardModifiers, MouseEvent};
 use corelib::items::ItemRef;
 use corelib::layout::Orientation;
 use corelib::slice::Slice;
-use corelib::window::{ComponentWindow, PlatformWindow};
+use corelib::window::PlatformWindow;
 use corelib::Property;
 use corelib::SharedString;
 use sixtyfps_corelib as corelib;
@@ -346,7 +346,7 @@ impl GraphicsWindow {
         self.mouse_input_state.set(corelib::input::process_mouse_input(
             component,
             event,
-            &ComponentWindow::new(self.self_weak.upgrade().unwrap()),
+            &self.self_weak.upgrade().unwrap().into(),
             self.mouse_input_state.take(),
         ));
 

sixtyfps_runtime/rendering_backends/gl/lib.rs

@@ -1547,12 +1547,12 @@ fn to_femtovg_color(col: &Color) -> femtovg::Color {
 
 #[cfg(target_arch = "wasm32")]
 pub fn create_gl_window_with_canvas_id(canvas_id: String) -> ComponentWindow {
-    let window = sixtyfps_corelib::window::Window::new(|window| {
+    sixtyfps_corelib::window::Window::new(|window| {
         GraphicsWindow::new(window, move |window_builder| {
             GLRenderer::new(window_builder, &canvas_id)
         })
-    });
-    ComponentWindow(window)
+    })
+    .into()
 }
 
 #[doc(hidden)]
@@ -1573,7 +1573,7 @@ thread_local!(pub(crate) static IMAGE_CACHE: RefCell<images::ImageCache> = Defau
 pub struct Backend;
 impl sixtyfps_corelib::backend::Backend for Backend {
     fn create_window(&'static self) -> ComponentWindow {
-        let window = sixtyfps_corelib::window::Window::new(|window| {
+        sixtyfps_corelib::window::Window::new(|window| {
             GraphicsWindow::new(window, |window_builder| {
                 GLRenderer::new(
                     window_builder,
@@ -1581,8 +1581,8 @@ impl sixtyfps_corelib::backend::Backend for Backend {
                     "canvas",
                 )
             })
-        });
-        ComponentWindow(window)
+        })
+        .into()
     }
 
     fn run_event_loop(&'static self, behavior: sixtyfps_corelib::backend::EventLoopQuitBehavior) {

sixtyfps_runtime/rendering_backends/qt/lib.rs

@@ -116,9 +116,7 @@ impl sixtyfps_corelib::backend::Backend for Backend {
         panic!("The Qt backend needs Qt");
         #[cfg(not(no_qt))]
         {
-            let window =
-                sixtyfps_corelib::window::Window::new(|window| qt_window::QtWindow::new(window));
-            ComponentWindow::new(window)
+            sixtyfps_corelib::window::Window::new(|window| qt_window::QtWindow::new(window)).into()
         }
     }
 

sixtyfps_runtime/rendering_backends/qt/qt_window.rs

@@ -1496,7 +1496,7 @@ pub(crate) mod ffi {
     pub extern "C" fn sixtyfps_qt_get_widget(
         window: &sixtyfps_corelib::window::ComponentWindow,
     ) -> *mut c_void {
-        <dyn std::any::Any>::downcast_ref(window.0.as_any())
+        <dyn std::any::Any>::downcast_ref(window.as_any())
             .map_or(std::ptr::null_mut(), |win: &QtWindow| {
                 win.widget_ptr().cast::<c_void>().as_ptr()
             })

sixtyfps_runtime/rendering_backends/testing/lib.rs

@@ -34,7 +34,7 @@ pub struct TestingBackend {
 
 impl sixtyfps_corelib::backend::Backend for TestingBackend {
     fn create_window(&'static self) -> ComponentWindow {
-        ComponentWindow::new(Window::new(|_| Rc::new(TestingWindow::default())))
+        Window::new(|_| Rc::new(TestingWindow::default())).into()
     }
 
     fn run_event_loop(&'static self, _behavior: sixtyfps_corelib::backend::EventLoopQuitBehavior) {