diff --git a/core/src/event/manager.rs b/core/src/event/manager.rs
index 1c49664..0e737c3 100644
--- a/core/src/event/manager.rs
+++ b/core/src/event/manager.rs
@@ -1,17 +1,19 @@
 use crate::{
     ActiveData, Event, EventCtx, EventFn, EventIdCtx, EventLike, IdLike, LayerId, Widget,
-    WidgetData, WidgetEventFn, WidgetId, WidgetRef,
-    util::{HashMap, TypeMap},
+    WidgetEventFn, WidgetId, WidgetRef,
+    util::{HashMap, HashSet, TypeMap},
 };
 use std::{any::TypeId, rc::Rc};
 
 pub struct EventManager<State> {
+    widget_to_types: HashMap<WidgetId, HashSet<TypeId>>,
     types: TypeMap<dyn EventManagerLike<State>>,
 }
 
 impl<State> Default for EventManager<State> {
     fn default() -> Self {
         Self {
+            widget_to_types: Default::default(),
             types: Default::default(),
         }
     }
@@ -29,6 +31,10 @@ impl<State: 'static> EventManager<State> {
         f: impl for<'a> WidgetEventFn<State, <E::Event as Event>::Data<'a>, W>,
     ) {
         self.get_type::<E>().register(id, event, f);
+        self.widget_to_types
+            .entry(id.id())
+            .or_default()
+            .insert(Self::type_key::<E>());
     }
 
     pub fn type_key<E: EventLike>() -> TypeId {
@@ -38,25 +44,25 @@ impl<State: 'static> EventManager<State> {
 
 pub trait EventsLike {
     fn remove(&mut self, id: WidgetId);
-    fn draw(&mut self, data: &WidgetData, active: &ActiveData);
-    fn undraw(&mut self, data: &WidgetData, active: &ActiveData);
+    fn draw(&mut self, active: &ActiveData);
+    fn undraw(&mut self, active: &ActiveData);
 }
 
 impl<State: 'static> EventsLike for EventManager<State> {
     fn remove(&mut self, id: WidgetId) {
-        for m in self.types.values_mut() {
-            m.remove(id);
+        for t in self.widget_to_types.get(&id).into_flat_iter() {
+            self.types.get_mut(t).unwrap().remove(id);
         }
     }
 
-    fn draw(&mut self, data: &WidgetData, active: &ActiveData) {
-        for t in &data.event_mgrs {
+    fn draw(&mut self, active: &ActiveData) {
+        for t in self.widget_to_types.get(&active.id).into_flat_iter() {
             self.types.get_mut(t).unwrap().draw(active);
         }
     }
 
-    fn undraw(&mut self, data: &WidgetData, active: &ActiveData) {
-        for t in &data.event_mgrs {
+    fn undraw(&mut self, active: &ActiveData) {
+        for t in self.widget_to_types.get(&active.id).into_flat_iter() {
             self.types.get_mut(t).unwrap().undraw(active);
         }
     }
diff --git a/core/src/event/rsc.rs b/core/src/event/rsc.rs
index 26004a7..0da7214 100644
--- a/core/src/event/rsc.rs
+++ b/core/src/event/rsc.rs
@@ -25,12 +25,6 @@ pub trait HasEvents: Sized + HasState + HasUi {
         Self::State: 'static,
     {
         self.events_mut().register(id, event, f);
-        self.ui_mut()
-            .widgets
-            .data_mut(id)
-            .unwrap()
-            .event_mgrs
-            .insert(EventManager::<Self::State>::type_key::<E>());
     }
 }
 
diff --git a/core/src/lib.rs b/core/src/lib.rs
index 145c54a..f60415a 100644
--- a/core/src/lib.rs
+++ b/core/src/lib.rs
@@ -11,6 +11,7 @@
 #![feature(associated_type_defaults)]
 #![feature(unsize)]
 #![feature(coerce_unsized)]
+#![feature(option_into_flat_iter)]
 
 mod attr;
 mod event;
diff --git a/core/src/ui/draw_state.rs b/core/src/ui/draw_state.rs
index 4bd29f2..555acb7 100644
--- a/core/src/ui/draw_state.rs
+++ b/core/src/ui/draw_state.rs
@@ -80,9 +80,8 @@ impl<'a> DrawState<'a> {
 
     pub fn redraw_all(&mut self) {
         // free all resources & cache
-        for (id, active) in self.ui.active.drain() {
-            let data = self.ui.widgets.data(id).unwrap();
-            self.events.undraw(data, &active);
+        for (_, active) in self.ui.active.drain() {
+            self.events.undraw(&active);
         }
         self.ui.cache.clear();
         self.ui.free(self.events);
@@ -170,8 +169,7 @@ impl<'a> DrawState<'a> {
         }
 
         // update modules
-        let data = self.ui.widgets.data(id).unwrap();
-        self.events.draw(data, &active);
+        self.events.draw(&active);
         self.active.insert(id, active);
     }
 
@@ -202,8 +200,7 @@ impl<'a> DrawState<'a> {
             active.textures.clear();
             self.textures.free();
             if undraw {
-                let data = self.ui.widgets.data(id).unwrap();
-                self.events.undraw(data, active);
+                self.events.undraw(active);
             }
         }
         active
diff --git a/core/src/widget/data.rs b/core/src/widget/data.rs
index 68ef4f3..8d693e7 100644
--- a/core/src/widget/data.rs
+++ b/core/src/widget/data.rs
@@ -1,11 +1,8 @@
-use std::any::TypeId;
-
-use crate::{Widget, util::HashSet};
+use crate::Widget;
 
 pub struct WidgetData {
     pub widget: Box<dyn Widget>,
     pub label: String,
-    pub event_mgrs: HashSet<TypeId>,
     /// dynamic borrow checking
     pub borrowed: bool,
 }
@@ -20,7 +17,6 @@ impl WidgetData {
             widget: Box::new(widget),
             label,
             borrowed: false,
-            event_mgrs: Default::default(),
         }
     }
 }
diff --git a/src/default/sense.rs b/src/default/sense.rs
index ff45e26..446c395 100644
--- a/src/default/sense.rs
+++ b/src/default/sense.rs
@@ -148,7 +148,7 @@ impl<State: RunEvents> SensorUi<State> for State {
         let mut active = std::mem::take(&mut self.events_mut().get_type::<CursorSense>().active);
         for layer in layers.indices().rev() {
             let mut sensed = false;
-            for (id, sensor) in active.get_mut(&layer).into_iter().flatten() {
+            for (id, sensor) in active.get_mut(&layer).into_flat_iter() {
                 let shape = self.ui().active.get(id).unwrap().region;
                 let region = shape.to_px(window_size);
                 let in_shape = cursor.exists && region.contains(cursor.pos);
diff --git a/src/lib.rs b/src/lib.rs
index ff2fd78..7d776fa 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -3,6 +3,7 @@
 #![feature(gen_blocks)]
 #![feature(associated_type_defaults)]
 #![feature(unsize)]
+#![feature(option_into_flat_iter)]
 
 pub mod default;
 pub mod event;