Track retained layout validity explicitly

core/src/widget/mod.rs

@@ -15,20 +15,6 @@ pub use tag::*;
 pub use view::*;
 pub use widgets::*;
 
-/// What may be done to a widget's drawing when the box it was given changes
-/// on this axis, instead of drawing it again. Asked per axis, because wrapped
-/// text reads the width it is offered and not the height.
-#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
-pub enum OnResize {
-    Scale,
-    /// Reserved: nothing reads this yet, so a widget saying it is redrawn.
-    /// Keeping an unchanged drawing in a bigger box needs the widget to say
-    /// *where* in that box it should sit, which is the alignment work.
-    Translate,
-    #[default]
-    Redraw,
-}
-
 pub trait Widget: Any {
     /// Draws the widget, and returns what it used of the box it was given.
     fn draw(&mut self, painter: &mut Painter) -> Size;
@@ -39,10 +25,6 @@ pub trait Widget: Any {
     fn size_hint(&self, _axis: Axis) -> Option<Len> {
         None
     }
-
-    fn on_resize(&self, _axis: Axis) -> OnResize {
-        OnResize::default()
-    }
 }
 
 impl Widget for () {
@@ -54,10 +36,6 @@ impl Widget for () {
     fn size_hint(&self, _axis: Axis) -> Option<Len> {
         Some(Len::default())
     }
-
-    fn on_resize(&self, _axis: Axis) -> OnResize {
-        OnResize::Scale
-    }
 }
 
 impl dyn Widget {