texture freeing + render updates done a bit nicer

src/layout/id.rs

@@ -1,14 +1,9 @@
-use std::{
-    any::TypeId,
-    marker::PhantomData,
-    sync::{
-        Arc,
-        atomic::{AtomicU32, Ordering},
-        mpsc::Sender,
-    },
-};
+use std::{any::TypeId, marker::PhantomData};
 
-use crate::{FnTag, Ui, Widget, WidgetLike, WidgetTag, util::Id};
+use crate::{
+    FnTag, Ui, UiMsg, UiMsgSender, Widget, WidgetLike, WidgetTag,
+    util::{Id, RefCounter},
+};
 
 pub struct AnyWidget;
 
@@ -22,8 +17,8 @@ pub struct AnyWidget;
 pub struct WidgetId<W = AnyWidget> {
     pub(super) ty: TypeId,
     pub(super) id: Id,
-    pub(super) refcount: Arc<AtomicU32>,
-    pub(super) send: Sender<Id>,
+    counter: RefCounter,
+    send: UiMsgSender,
     _pd: PhantomData<W>,
 }
 
@@ -35,11 +30,10 @@ impl<W> std::fmt::Debug for WidgetId<W> {
 
 impl<W> Clone for WidgetId<W> {
     fn clone(&self) -> Self {
-        self.refcount.fetch_add(1, Ordering::Release);
         Self {
             id: self.id.duplicate(),
             ty: self.ty,
-            refcount: self.refcount.clone(),
+            counter: self.counter.clone(),
             send: self.send.clone(),
             _pd: PhantomData,
         }
@@ -47,11 +41,11 @@ impl<W> Clone for WidgetId<W> {
 }
 
 impl<W> WidgetId<W> {
-    pub(super) fn new(id: Id, ty: TypeId, send: Sender<Id>) -> Self {
+    pub(super) fn new(id: Id, ty: TypeId, send: UiMsgSender) -> Self {
         Self {
             ty,
             id,
-            refcount: AtomicU32::new(0).into(),
+            counter: RefCounter::new(),
             send,
             _pd: PhantomData,
         }
@@ -72,15 +66,14 @@ impl<W> WidgetId<W> {
     }
 
     pub fn refs(&self) -> u32 {
-        self.refcount.load(Ordering::Acquire)
+        self.counter.refs()
     }
 }
 
 impl<W> Drop for WidgetId<W> {
     fn drop(&mut self) {
-        let refs = self.refcount.fetch_sub(1, Ordering::Release);
-        if refs == 0 {
-            let _ = self.send.send(self.id.duplicate());
+        if self.counter.drop() {
+            let _ = self.send.send(UiMsg::FreeWidget(self.id.duplicate()));
         }
     }
 }