Make set_origin method take WidgetState rather than LayoutCx

This allows it to be called from the event method

src/app.rs

@@ -250,7 +250,7 @@ where
                 let mut layout_cx = LayoutCx::new(&mut cx_state, &mut self.root_state);
                 let bc = BoxConstraints::tight(self.size);
                 root_pod.layout(&mut layout_cx, &bc);
-                root_pod.set_origin(&mut layout_cx, Point::ORIGIN);
+                root_pod.set_origin(layout_cx.widget_state, Point::ORIGIN);
             }
             if root_pod
                 .state

src/widget/core.rs

@@ -95,7 +95,7 @@ pub struct Pod {
 }
 
 #[derive(Debug)]
-pub(crate) struct WidgetState {
+pub struct WidgetState {
     pub(crate) id: Id,
     pub(crate) flags: PodFlags,
     /// The origin of the child in the parent's coordinate space.
@@ -486,18 +486,23 @@ impl Pod {
     /// The widget container can also call `set_origin` from other context, but calling `set_origin`
     /// after the widget received [`LifeCycle::ViewContextChanged`] and before the next event results
     /// in an inconsistent state of the widget tree.
-    pub fn set_origin(&mut self, cx: &mut LayoutCx, origin: Point) {
+    pub fn set_origin(&mut self, parent_state: &mut WidgetState, origin: Point) {
         if origin != self.state.origin {
             self.state.origin = origin;
             // request paint is called on the parent instead of this widget, since this widget's
             // fragment does not change.
-            cx.view_context_changed();
-            cx.request_paint();
+            parent_state.flags |= PodFlags::REQUEST_PAINT;
+            parent_state.flags |= PodFlags::VIEW_CONTEXT_CHANGED;
 
             self.state.flags.insert(PodFlags::VIEW_CONTEXT_CHANGED);
         }
     }
 
+    /// Get the widgets size (as returned by the layout method)
+    pub fn get_size(&mut self) -> Size {
+        self.state.size
+    }
+
     // Return true if hot state has changed
     fn set_hot_state(
         widget: &mut dyn AnyWidget,

src/widget/linear_layout.rs

@@ -70,7 +70,7 @@ impl Widget for LinearLayout {
 
         for (index, child) in self.children.iter_mut().enumerate() {
             let size = child.layout(cx, &child_bc);
-            child.set_origin(cx, self.axis.pack(major_used, 0.0));
+            child.set_origin(cx.widget_state, self.axis.pack(major_used, 0.0));
             major_used += self.axis.major(size);
             if index < child_count - 1 {
                 major_used += self.spacing;