move widgets on draw if region size is same

src/layout/id.rs

@@ -10,7 +10,7 @@ use std::{
 
 use crate::{
     layout::{FnTag, Ui, Widget, WidgetLike, WidgetTag},
-    util::{CopyId, Id, RefCounter},
+    util::{Id, RefCounter},
 };
 
 pub struct AnyWidget;
@@ -44,7 +44,7 @@ pub struct WidgetId<W = AnyWidget> {
 #[repr(C)]
 pub struct StaticWidgetId<W = AnyWidget> {
     pub(super) ty: TypeId,
-    pub(super) id: CopyId,
+    pub(super) id: Id,
     _pd: PhantomData<W>,
 }
 
@@ -57,7 +57,7 @@ impl<W> std::fmt::Debug for WidgetId<W> {
 impl<W> Clone for WidgetId<W> {
     fn clone(&self) -> Self {
         Self {
-            id: self.id.duplicate(),
+            id: self.id,
             ty: self.ty,
             counter: self.counter.clone(),
             send: self.send.clone(),
@@ -89,7 +89,7 @@ impl<W> WidgetId<W> {
     }
 
     pub fn key(&self) -> Id {
-        self.id.duplicate()
+        self.id
     }
 
     pub(super) fn cast_type<W2>(self) -> WidgetId<W2> {
@@ -105,7 +105,7 @@ impl<W> WidgetId<W> {
         self.is_static.store(true, Ordering::Release);
         StaticWidgetId {
             ty: self.ty,
-            id: self.id.copyable(),
+            id: self.id,
             _pd: PhantomData,
         }
     }
@@ -116,7 +116,7 @@ impl WidgetId {
         let send = self.send.clone();
         drop(std::mem::replace(
             self,
-            Self::new(other.id.id(), self.ty, send, true),
+            Self::new(other.id, self.ty, send, true),
         ));
     }
 }
@@ -124,7 +124,7 @@ impl WidgetId {
 impl<W> Drop for WidgetId<W> {
     fn drop(&mut self) {
         if self.counter.drop() && !self.is_static.load(Ordering::Acquire) {
-            let _ = self.send.send(self.id.duplicate());
+            let _ = self.send.send(self.id);
         }
     }
 }
@@ -194,7 +194,7 @@ impl<W: 'static, F: FnOnce(&mut Ui) -> WidgetId<W>> WidgetLike<IdFnTag> for F {
 
 impl<W> StaticWidgetId<W> {
     pub fn to_id(&self, send: &Sender<Id>) -> WidgetId<W> {
-        WidgetId::new(self.id.id(), self.ty, send.clone(), true)
+        WidgetId::new(self.id, self.ty, send.clone(), true)
     }
     pub fn any(self) -> StaticWidgetId<AnyWidget> {
         // SAFETY: self is repr(C)