move widgets on draw if region size is same

src/render/primitive.rs

@@ -132,7 +132,7 @@ impl Primitives {
             if i == self.instances.len() {
                 return None;
             }
-            let id = self.assoc[i].duplicate();
+            let id = self.assoc[i];
             let old = self.instances.len();
             Some(PrimitiveChange { id, old, new: i })
         })
@@ -150,6 +150,11 @@ impl Primitives {
     pub fn instances(&self) -> &Vec<PrimitiveInstance> {
         &self.instances
     }
+
+    pub fn region_mut(&mut self, h: &PrimitiveHandle) -> &mut UiRegion {
+        self.updated = true;
+        &mut self.instances[h.inst_idx].region
+    }
 }
 
 pub struct PrimitiveChange {