fix on_id widget refcount leak (-> memory leak)

src/layout/widget.rs

@@ -1,6 +1,6 @@
 use crate::{
     core::WidgetPtr,
-    layout::{Len, Painter, SizeCtx, StaticWidgetId, Ui, WidgetId, WidgetIdFn},
+    layout::{Len, Painter, SizeCtx, Ui, WidgetId, WidgetIdFn},
 };
 
 use std::{any::Any, marker::PhantomData};
@@ -26,7 +26,9 @@ pub struct FnTag;
 
 pub trait WidgetLike<Tag> {
     type Widget: 'static;
+
     fn add(self, ui: &mut Ui) -> WidgetId<Self::Widget>;
+
     fn with_id<W2>(
         self,
         f: impl FnOnce(&mut Ui, WidgetId<Self::Widget>) -> WidgetId<W2>,
@@ -39,18 +41,14 @@ pub trait WidgetLike<Tag> {
             f(ui, id)
         }
     }
-    fn add_static(self, ui: &mut Ui) -> StaticWidgetId<Self::Widget>
-    where
-        Self: Sized,
-    {
-        self.add(ui).into_static()
-    }
+
     fn set_root(self, ui: &mut Ui)
     where
         Self: Sized,
     {
         ui.set_root(self);
     }
+
     fn set_ptr(self, ptr: &WidgetId<WidgetPtr>, ui: &mut Ui)
     where
         Self: Sized,