diff --git a/src/core/image.rs b/src/core/image.rs
index 3dc19e2..4cfd10a 100644
--- a/src/core/image.rs
+++ b/src/core/image.rs
@@ -15,7 +15,7 @@ impl Widget for Image {
     }
 }
 
-pub fn image<Ctx>(image: impl LoadableImage) -> impl WidgetFn<Image, Ctx> {
+pub fn image(image: impl LoadableImage) -> impl WidgetFn<Image> {
     let image = image.get_image().expect("Failed to load image");
     move |ui| Image {
         handle: ui.add_texture(image),
diff --git a/src/core/text.rs b/src/core/text.rs
index 093875b..da0e684 100644
--- a/src/core/text.rs
+++ b/src/core/text.rs
@@ -116,10 +116,10 @@ impl TextBuilder {
     }
 }
 
-impl<Ctx> FnOnce<(&mut Ui<Ctx>,)> for TextBuilder {
+impl FnOnce<(&mut Ui,)> for TextBuilder {
     type Output = Text;
 
-    extern "rust-call" fn call_once(self, args: (&mut Ui<Ctx>,)) -> Self::Output {
+    extern "rust-call" fn call_once(self, args: (&mut Ui,)) -> Self::Output {
         let mut buf =
             TextBuffer::new_empty(Metrics::new(self.attrs.font_size, self.attrs.line_height));
         buf.set_text(
diff --git a/src/core/text_edit.rs b/src/core/text_edit.rs
index 2adb655..ad59e3d 100644
--- a/src/core/text_edit.rs
+++ b/src/core/text_edit.rs
@@ -255,10 +255,10 @@ impl TextInputResult {
     }
 }
 
-impl<Ctx> FnOnce<(&mut Ui<Ctx>,)> for TextEditBuilder {
+impl FnOnce<(&mut Ui,)> for TextEditBuilder {
     type Output = TextEdit;
 
-    extern "rust-call" fn call_once(self, args: (&mut Ui<Ctx>,)) -> Self::Output {
+    extern "rust-call" fn call_once(self, args: (&mut Ui,)) -> Self::Output {
         let mut text = TextEdit {
             buf: TextBuffer::new_empty(Metrics::new(self.attrs.font_size, self.attrs.line_height)),
             attrs: self.attrs,
diff --git a/src/core/trait_fns.rs b/src/core/trait_fns.rs
index dd75ab1..fac192c 100644
--- a/src/core/trait_fns.rs
+++ b/src/core/trait_fns.rs
@@ -1,34 +1,34 @@
 use super::*;
 use crate::prelude::*;
 
-pub trait CoreWidget<W, Ctx, Tag> {
-    fn pad(self, padding: impl Into<Padding>) -> impl WidgetFn<Padded, Ctx>;
-    fn align(self, align: Align) -> impl WidgetFn<Aligned, Ctx>;
-    fn center(self) -> impl WidgetFn<Aligned, Ctx>;
-    fn label(self, label: impl Into<String>) -> impl WidgetIdFn<W, Ctx>;
-    fn size(self, size: impl Into<Vec2>) -> impl WidgetFn<Sized, Ctx>;
+pub trait CoreWidget<W, Tag> {
+    fn pad(self, padding: impl Into<Padding>) -> impl WidgetFn<Padded>;
+    fn align(self, align: Align) -> impl WidgetFn<Aligned>;
+    fn center(self) -> impl WidgetFn<Aligned>;
+    fn label(self, label: impl Into<String>) -> impl WidgetIdFn<W>;
+    fn size(self, size: impl Into<Vec2>) -> impl WidgetFn<Sized>;
 }
 
-impl<W: WidgetLike<Ctx, Tag>, Ctx, Tag> CoreWidget<W::Widget, Ctx, Tag> for W {
-    fn pad(self, padding: impl Into<Padding>) -> impl WidgetFn<Padded, Ctx> {
+impl<W: WidgetLike<Tag>, Tag> CoreWidget<W::Widget, Tag> for W {
+    fn pad(self, padding: impl Into<Padding>) -> impl WidgetFn<Padded> {
         |ui| Padded {
             padding: padding.into(),
             inner: self.add(ui).any(),
         }
     }
 
-    fn align(self, align: Align) -> impl WidgetFn<Aligned, Ctx> {
+    fn align(self, align: Align) -> impl WidgetFn<Aligned> {
         move |ui| Aligned {
             inner: self.add(ui).any(),
             align,
         }
     }
 
-    fn center(self) -> impl WidgetFn<Aligned, Ctx> {
+    fn center(self) -> impl WidgetFn<Aligned> {
         self.align(Align::Center)
     }
 
-    fn label(self, label: impl Into<String>) -> impl WidgetIdFn<W::Widget, Ctx> {
+    fn label(self, label: impl Into<String>) -> impl WidgetIdFn<W::Widget> {
         |ui| {
             let id = self.add(ui);
             ui.set_label(&id, label.into());
@@ -36,7 +36,7 @@ impl<W: WidgetLike<Ctx, Tag>, Ctx, Tag> CoreWidget<W::Widget, Ctx, Tag> for W {
         }
     }
 
-    fn size(self, size: impl Into<Vec2>) -> impl WidgetFn<Sized, Ctx> {
+    fn size(self, size: impl Into<Vec2>) -> impl WidgetFn<Sized> {
         move |ui| Sized {
             inner: self.add(ui).any(),
             size: size.into(),
@@ -44,20 +44,20 @@ impl<W: WidgetLike<Ctx, Tag>, Ctx, Tag> CoreWidget<W::Widget, Ctx, Tag> for W {
     }
 }
 
-pub trait CoreWidgetArr<const LEN: usize, Ctx, Tag> {
-    fn span(self, dir: Dir, lengths: impl IntoSpanLens<LEN>) -> impl WidgetFn<Span, Ctx>;
-    fn stack(self) -> impl WidgetFn<Stack, Ctx>;
+pub trait CoreWidgetArr<const LEN: usize, Tag> {
+    fn span(self, dir: Dir, lengths: impl IntoSpanLens<LEN>) -> impl WidgetFn<Span>;
+    fn stack(self) -> impl WidgetFn<Stack>;
 }
 
-impl<const LEN: usize, Wa: WidgetArrLike<LEN, Ctx, Tag>, Ctx, Tag> CoreWidgetArr<LEN, Ctx, Tag> for Wa {
-    fn span(self, dir: Dir, lengths: impl IntoSpanLens<LEN>) -> impl WidgetFn<Span, Ctx> {
+impl<const LEN: usize, Wa: WidgetArrLike<LEN, Tag>, Tag> CoreWidgetArr<LEN, Tag> for Wa {
+    fn span(self, dir: Dir, lengths: impl IntoSpanLens<LEN>) -> impl WidgetFn<Span> {
         let lengths = lengths.into_lens();
         move |ui| Span {
             children: self.ui(ui).arr.into_iter().zip(lengths).collect(),
             dir,
         }
     }
-    fn stack(self) -> impl WidgetFn<Stack, Ctx> {
+    fn stack(self) -> impl WidgetFn<Stack> {
         move |ui| Stack {
             children: self.ui(ui).arr.to_vec(),
         }
diff --git a/src/layout/event.rs b/src/layout/event.rs
index 8202d30..81fa5a5 100644
--- a/src/layout/event.rs
+++ b/src/layout/event.rs
@@ -1,10 +1,10 @@
 use crate::{
-    layout::{Ui, UiModule, Widget, WidgetId, WidgetIdFn, WidgetLike},
+    layout::{IdFnTag, Ui, UiModule, Widget, WidgetId, WidgetIdFn, WidgetLike},
     util::Id,
 };
 
 pub trait UiCtx {
-    fn ui(&mut self) -> &mut Ui<Self>
+    fn ui(&mut self) -> &mut Ui
     where
         Self: Sized;
 }
@@ -22,13 +22,17 @@ pub trait EventFn<Ctx, Data>: FnMut(&mut Ctx, Data) + 'static {}
 impl<F: FnMut(&mut Ctx, Data) + 'static, Ctx, Data> EventFn<Ctx, Data> for F {}
 
 pub trait Eventable<W, Ctx, Tag> {
-    fn on<E: Event<Ctx>>(self, event: E, f: impl EventFn<Ctx, E::Data>) -> impl WidgetIdFn<W, Ctx>;
+    fn on<E: Event<Ctx>>(
+        self,
+        event: E,
+        f: impl EventFn<Ctx, E::Data>,
+    ) -> impl WidgetIdFn<W> + Eventable<W, Ctx, IdFnTag>;
 
     fn id_on<E: Event<Ctx>>(
         self,
         event: E,
         f: impl FnMut(&WidgetId<W>, &mut Ctx, E::Data) + 'static,
-    ) -> impl WidgetIdFn<W, Ctx>
+    ) -> impl WidgetIdFn<W> + Eventable<W, Ctx, IdFnTag>
     where
         W: Widget;
 
@@ -36,18 +40,29 @@ pub trait Eventable<W, Ctx, Tag> {
         self,
         event: E,
         f: impl FnMut(&mut W, E::Data) + 'static,
-    ) -> impl WidgetIdFn<W, Ctx>
+    ) -> impl WidgetIdFn<W> + Eventable<W, Ctx, IdFnTag>
     where
         W: Widget,
         Ctx: UiCtx;
 }
 
-impl<W: WidgetLike<Ctx, Tag>, Ctx, Tag> Eventable<W::Widget, Ctx, Tag> for W {
+pub trait Ctxable<W, Tag> {
+    /// sets context which lets event functions work without needing to specify generics
+    fn ctx<Ctx>(self) -> impl WidgetLike<Tag> + Eventable<W, Ctx, Tag>;
+}
+
+impl<W: WidgetLike<Tag>, Tag> Ctxable<W::Widget, Tag> for W {
+    fn ctx<Ctx>(self) -> impl WidgetLike<Tag> + Eventable<W::Widget, Ctx, Tag> {
+        self
+    }
+}
+
+impl<W: WidgetLike<Tag>, Ctx, Tag> Eventable<W::Widget, Ctx, Tag> for W {
     fn on<E: Event<Ctx>>(
         self,
         event: E,
         f: impl EventFn<Ctx, E::Data>,
-    ) -> impl WidgetIdFn<W::Widget, Ctx> {
+    ) -> impl WidgetIdFn<W::Widget> + Eventable<W::Widget, Ctx, IdFnTag> {
         move |ui| {
             let id = self.add(ui);
             ui.modules
@@ -61,7 +76,7 @@ impl<W: WidgetLike<Ctx, Tag>, Ctx, Tag> Eventable<W::Widget, Ctx, Tag> for W {
         self,
         event: E,
         mut f: impl FnMut(&WidgetId<W::Widget>, &mut Ctx, E::Data) + 'static,
-    ) -> impl WidgetIdFn<W::Widget, Ctx>
+    ) -> impl WidgetIdFn<W::Widget> + Eventable<W::Widget, Ctx, IdFnTag>
     where
         W::Widget: Widget,
     {
@@ -75,7 +90,7 @@ impl<W: WidgetLike<Ctx, Tag>, Ctx, Tag> Eventable<W::Widget, Ctx, Tag> for W {
         self,
         event: E,
         mut f: impl FnMut(&mut W::Widget, E::Data) + 'static,
-    ) -> impl WidgetIdFn<W::Widget, Ctx>
+    ) -> impl WidgetIdFn<W::Widget> + Eventable<W::Widget, Ctx, IdFnTag>
     where
         W::Widget: Widget,
         Ctx: UiCtx,
diff --git a/src/layout/id.rs b/src/layout/id.rs
index c04fba5..91c6241 100644
--- a/src/layout/id.rs
+++ b/src/layout/id.rs
@@ -131,14 +131,14 @@ impl<W> Drop for WidgetId<W> {
 pub struct IdTag;
 pub struct IdFnTag;
 
-pub trait WidgetIdFn<W, Ctx>: FnOnce(&mut Ui<Ctx>) -> WidgetId<W> {}
-impl<W, F: FnOnce(&mut Ui<Ctx>) -> WidgetId<W>, Ctx> WidgetIdFn<W, Ctx> for F {}
+pub trait WidgetIdFn<W>: FnOnce(&mut Ui) -> WidgetId<W> {}
+impl<W, F: FnOnce(&mut Ui) -> WidgetId<W>> WidgetIdFn<W> for F {}
 
 /// TODO: does this ever make sense to use? it allows for invalid ids
-pub trait Idable<Ctx, Tag> {
+pub trait Idable<Tag> {
     type Widget: Widget;
-    fn set(self, ui: &mut Ui<Ctx>, id: &WidgetId<Self::Widget>);
-    fn id(self, id: &WidgetId<Self::Widget>) -> impl WidgetIdFn<Self::Widget, Ctx>
+    fn set(self, ui: &mut Ui, id: &WidgetId<Self::Widget>);
+    fn id(self, id: &WidgetId<Self::Widget>) -> impl WidgetIdFn<Self::Widget>
     where
         Self: Sized,
     {
@@ -148,7 +148,7 @@ pub trait Idable<Ctx, Tag> {
             id
         }
     }
-    fn id_static(self, id: StaticWidgetId<Self::Widget>) -> impl WidgetIdFn<Self::Widget, Ctx>
+    fn id_static(self, id: StaticWidgetId<Self::Widget>) -> impl WidgetIdFn<Self::Widget>
     where
         Self: Sized,
     {
@@ -160,33 +160,33 @@ pub trait Idable<Ctx, Tag> {
     }
 }
 
-impl<W: Widget, Ctx> Idable<Ctx, WidgetTag> for W {
+impl<W: Widget> Idable<WidgetTag> for W {
     type Widget = W;
 
-    fn set(self, ui: &mut Ui<Ctx>, id: &WidgetId<Self::Widget>) {
+    fn set(self, ui: &mut Ui, id: &WidgetId<Self::Widget>) {
         ui.set(id, self);
     }
 }
 
-impl<F: FnOnce(&mut Ui<Ctx>) -> W, W: Widget, Ctx> Idable<Ctx, FnTag> for F {
+impl<F: FnOnce(&mut Ui) -> W, W: Widget> Idable<FnTag> for F {
     type Widget = W;
 
-    fn set(self, ui: &mut Ui<Ctx>, id: &WidgetId<Self::Widget>) {
+    fn set(self, ui: &mut Ui, id: &WidgetId<Self::Widget>) {
         let w = self(ui);
         ui.set(id, w);
     }
 }
 
-impl<W: 'static, Ctx> WidgetLike<Ctx, IdTag> for WidgetId<W> {
+impl<W: 'static> WidgetLike<IdTag> for WidgetId<W> {
     type Widget = W;
-    fn add(self, _: &mut Ui<Ctx>) -> WidgetId<W> {
+    fn add(self, _: &mut Ui) -> WidgetId<W> {
         self
     }
 }
 
-impl<W: 'static, F: FnOnce(&mut Ui<Ctx>) -> WidgetId<W>, Ctx> WidgetLike<Ctx, IdFnTag> for F {
+impl<W: 'static, F: FnOnce(&mut Ui) -> WidgetId<W>> WidgetLike<IdFnTag> for F {
     type Widget = W;
-    fn add(self, ui: &mut Ui<Ctx>) -> WidgetId<W> {
+    fn add(self, ui: &mut Ui) -> WidgetId<W> {
         self(ui)
     }
 }
@@ -200,9 +200,9 @@ impl<W> StaticWidgetId<W> {
     }
 }
 
-impl<W: 'static, Ctx> WidgetLike<Ctx, IdTag> for StaticWidgetId<W> {
+impl<W: 'static> WidgetLike<IdTag> for StaticWidgetId<W> {
     type Widget = W;
-    fn add(self, ui: &mut Ui<Ctx>) -> WidgetId<W> {
+    fn add(self, ui: &mut Ui) -> WidgetId<W> {
         self.id(&ui.send)
     }
 }
diff --git a/src/layout/ui.rs b/src/layout/ui.rs
index fdf181d..e3e2c43 100644
--- a/src/layout/ui.rs
+++ b/src/layout/ui.rs
@@ -10,13 +10,11 @@ use crate::{
 };
 use std::{
     any::{Any, TypeId},
-    marker::PhantomData,
     ops::{Index, IndexMut},
     sync::mpsc::{Receiver, Sender, channel},
 };
 
-// TODO: remove generic
-pub struct Ui<Ctx> {
+pub struct Ui {
     root: Option<WidgetId>,
     pub(super) widgets: Widgets,
     updates: Vec<Id>,
@@ -31,17 +29,16 @@ pub struct Ui<Ctx> {
 
     pub(crate) active: ActiveWidgets,
     pub modules: Modules,
-    _pd: PhantomData<Ctx>,
 }
 
-impl<Ctx> Ui<Ctx> {
-    pub fn add<W: Widget, Tag>(&mut self, w: impl WidgetLike<Ctx, Tag, Widget = W>) -> WidgetId<W> {
+impl Ui {
+    pub fn add<W: Widget, Tag>(&mut self, w: impl WidgetLike<Tag, Widget = W>) -> WidgetId<W> {
         w.add(self)
     }
 
     pub fn add_static<W: Widget, Tag>(
         &mut self,
-        w: impl WidgetLike<Ctx, Tag, Widget = W>,
+        w: impl WidgetLike<Tag, Widget = W>,
     ) -> StaticWidgetId<W> {
         let id = w.add(self);
         id.into_static()
@@ -70,7 +67,7 @@ impl<Ctx> Ui<Ctx> {
         self.widgets.insert(id.id.duplicate(), w);
     }
 
-    pub fn set_root<Tag>(&mut self, w: impl WidgetLike<Ctx, Tag>) {
+    pub fn set_root<Tag>(&mut self, w: impl WidgetLike<Tag>) {
         self.root = Some(w.add(self).any());
         self.full_redraw = true;
     }
@@ -184,7 +181,7 @@ impl<Ctx> Ui<Ctx> {
     }
 }
 
-impl<W: Widget, Ctx> Index<&WidgetId<W>> for Ui<Ctx> {
+impl<W: Widget> Index<&WidgetId<W>> for Ui {
     type Output = W;
 
     fn index(&self, id: &WidgetId<W>) -> &Self::Output {
@@ -192,14 +189,14 @@ impl<W: Widget, Ctx> Index<&WidgetId<W>> for Ui<Ctx> {
     }
 }
 
-impl<W: Widget, Ctx> IndexMut<&WidgetId<W>> for Ui<Ctx> {
+impl<W: Widget> IndexMut<&WidgetId<W>> for Ui {
     fn index_mut(&mut self, id: &WidgetId<W>) -> &mut Self::Output {
         self.updates.push(id.id.duplicate());
         self.get_mut(id).unwrap()
     }
 }
 
-impl<W: Widget, Ctx> Index<StaticWidgetId<W>> for Ui<Ctx> {
+impl<W: Widget> Index<StaticWidgetId<W>> for Ui {
     type Output = W;
 
     fn index(&self, id: StaticWidgetId<W>) -> &Self::Output {
@@ -207,7 +204,7 @@ impl<W: Widget, Ctx> Index<StaticWidgetId<W>> for Ui<Ctx> {
     }
 }
 
-impl<W: Widget, Ctx> IndexMut<StaticWidgetId<W>> for Ui<Ctx> {
+impl<W: Widget> IndexMut<StaticWidgetId<W>> for Ui {
     fn index_mut(&mut self, id: StaticWidgetId<W>) -> &mut Self::Output {
         self.updates.push(id.id.id());
         self.widgets.get_static_mut(&id).unwrap()
@@ -224,7 +221,7 @@ impl dyn Widget {
     }
 }
 
-impl<Ctx> Default for Ui<Ctx> {
+impl Default for Ui {
     fn default() -> Self {
         let (send, recv) = channel();
         Self {
@@ -240,7 +237,6 @@ impl<Ctx> Default for Ui<Ctx> {
             recv,
             size: Vec2::ZERO,
             modules: Modules::default(),
-            _pd: PhantomData,
         }
     }
 }
diff --git a/src/layout/widget.rs b/src/layout/widget.rs
index d00d924..9763ce9 100644
--- a/src/layout/widget.rs
+++ b/src/layout/widget.rs
@@ -12,13 +12,13 @@ pub trait Widget: Any {
 pub struct WidgetTag;
 pub struct FnTag;
 
-pub trait WidgetLike<Ctx, Tag> {
+pub trait WidgetLike<Tag> {
     type Widget: 'static;
-    fn add(self, ui: &mut Ui<Ctx>) -> WidgetId<Self::Widget>;
+    fn add(self, ui: &mut Ui) -> WidgetId<Self::Widget>;
     fn with_id<W2>(
         self,
-        f: impl FnOnce(&mut Ui<Ctx>, WidgetId<Self::Widget>) -> WidgetId<W2>,
-    ) -> impl WidgetIdFn<W2, Ctx>
+        f: impl FnOnce(&mut Ui, WidgetId<Self::Widget>) -> WidgetId<W2>,
+    ) -> impl WidgetIdFn<W2>
     where
         Self: Sized,
     {
@@ -27,13 +27,13 @@ pub trait WidgetLike<Ctx, Tag> {
             f(ui, id)
         }
     }
-    fn add_static(self, ui: &mut Ui<Ctx>) -> StaticWidgetId<Self::Widget>
+    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<Ctx>)
+    fn set_root(self, ui: &mut Ui)
     where
         Self: Sized,
     {
@@ -44,19 +44,19 @@ pub trait WidgetLike<Ctx, Tag> {
 /// A function that returns a widget given a UI.
 /// Useful for defining trait functions on widgets that create a parent widget so that the children
 /// don't need to be IDs yet
-pub trait WidgetFn<W: Widget, Ctx>: FnOnce(&mut Ui<Ctx>) -> W {}
-impl<W: Widget, F: FnOnce(&mut Ui<Ctx>) -> W, Ctx> WidgetFn<W, Ctx> for F {}
+pub trait WidgetFn<W: Widget>: FnOnce(&mut Ui) -> W {}
+impl<W: Widget, F: FnOnce(&mut Ui) -> W> WidgetFn<W> for F {}
 
-impl<W: Widget, F: FnOnce(&mut Ui<Ctx>) -> W, Ctx> WidgetLike<Ctx, FnTag> for F {
+impl<W: Widget, F: FnOnce(&mut Ui) -> W> WidgetLike<FnTag> for F {
     type Widget = W;
-    fn add(self, ui: &mut Ui<Ctx>) -> WidgetId<W> {
+    fn add(self, ui: &mut Ui) -> WidgetId<W> {
         self(ui).add(ui)
     }
 }
 
-impl<W: Widget, Ctx> WidgetLike<Ctx, WidgetTag> for W {
+impl<W: Widget> WidgetLike<WidgetTag> for W {
     type Widget = W;
-    fn add(self, ui: &mut Ui<Ctx>) -> WidgetId<W> {
+    fn add(self, ui: &mut Ui) -> WidgetId<W> {
         ui.add_widget(self)
     }
 }
@@ -76,21 +76,21 @@ impl<const LEN: usize, Ws> WidgetArr<LEN, Ws> {
 }
 
 pub struct ArrTag;
-pub trait WidgetArrLike<const LEN: usize, Ctx, Tags> {
+pub trait WidgetArrLike<const LEN: usize, Tags> {
     type Ws;
-    fn ui(self, ui: &mut Ui<Ctx>) -> WidgetArr<LEN, Self::Ws>;
+    fn ui(self, ui: &mut Ui) -> WidgetArr<LEN, Self::Ws>;
 }
 
-impl<const LEN: usize, Ws, Ctx> WidgetArrLike<LEN, Ctx, ArrTag> for WidgetArr<LEN, Ws> {
+impl<const LEN: usize, Ws> WidgetArrLike<LEN, ArrTag> for WidgetArr<LEN, Ws> {
     type Ws = Ws;
-    fn ui(self, _: &mut Ui<Ctx>) -> WidgetArr<LEN, Ws> {
+    fn ui(self, _: &mut Ui) -> WidgetArr<LEN, Ws> {
         self
     }
 }
 
-impl<W: WidgetLike<Ctx, WidgetTag>, Ctx> WidgetArrLike<1, Ctx, WidgetTag> for W {
+impl<W: WidgetLike<WidgetTag>> WidgetArrLike<1, WidgetTag> for W {
     type Ws = (W::Widget,);
-    fn ui(self, ui: &mut Ui<Ctx>) -> WidgetArr<1, (W::Widget,)> {
+    fn ui(self, ui: &mut Ui) -> WidgetArr<1, (W::Widget,)> {
         WidgetArr::new([self.add(ui).any()])
     }
 }
@@ -101,9 +101,9 @@ macro_rules! impl_widget_arr {
         impl_widget_arr!($n;$($W)*;$(${concat($W,Tag)})*);
     };
     ($n:expr;$($W:ident)*;$($Tag:ident)*) => {
-        impl<Ctx, $($W: WidgetLike<Ctx, $Tag>,$Tag,)*> WidgetArrLike<$n, Ctx, ($($Tag,)*)> for ($($W,)*) {
+        impl<$($W: WidgetLike<$Tag>,$Tag,)*> WidgetArrLike<$n, ($($Tag,)*)> for ($($W,)*) {
             type Ws = ($($W::Widget,)*);
-            fn ui(self, ui: &mut Ui<Ctx>) -> WidgetArr<$n, ($($W::Widget,)*)> {
+            fn ui(self, ui: &mut Ui) -> WidgetArr<$n, ($($W::Widget,)*)> {
                 #[allow(non_snake_case)]
                 let ($($W,)*) = self;
                 WidgetArr::new(
diff --git a/src/render/mod.rs b/src/render/mod.rs
index cacceb6..7764cee 100644
--- a/src/render/mod.rs
+++ b/src/render/mod.rs
@@ -57,7 +57,7 @@ impl UiRenderer {
         }
     }
 
-    pub fn update<Ctx>(&mut self, device: &Device, queue: &Queue, ui: &mut Ui<Ctx>) {
+    pub fn update(&mut self, device: &Device, queue: &Queue, ui: &mut Ui) {
         self.active.clear();
         for (i, ulayer) in ui.layers.iter_mut() {
             self.active.push(i);
diff --git a/src/testing/input.rs b/src/testing/input.rs
index dd9014c..5998afc 100644
--- a/src/testing/input.rs
+++ b/src/testing/input.rs
@@ -9,7 +9,7 @@ pub struct Input {
 }
 
 impl Input {
-    pub fn event(&mut self, event: &WindowEvent) {
+    pub fn event(&mut self, event: &WindowEvent) -> bool {
         match event {
             WindowEvent::CursorMoved { position, .. } => {
                 self.cursor.pos = Vec2::new(position.x as f32, position.y as f32);
@@ -28,8 +28,9 @@ impl Input {
             WindowEvent::CursorLeft { .. } => {
                 self.cursor.exists = false;
             }
-            _ => (),
+            _ => return false,
         }
+        true
     }
 
     pub fn end_frame(&mut self) {
diff --git a/src/testing/mod.rs b/src/testing/mod.rs
index 282a340..1cb814b 100644
--- a/src/testing/mod.rs
+++ b/src/testing/mod.rs
@@ -19,7 +19,7 @@ pub fn main() {
 pub struct Client {
     renderer: Renderer,
     input: Input,
-    ui: Ui<Client>,
+    ui: Ui,
     info: WidgetId<Text>,
     focus: Option<WidgetId<TextEdit>>,
 }
@@ -155,7 +155,8 @@ impl Client {
 
         let switch_button = |color, to, label| {
             let rect = rect(color)
-                .id_on(Sense::click(), move |id, ctx: &mut Client, _| {
+                .ctx::<Client>()
+                .id_on(Sense::click(), move |id, ctx, _| {
                     ctx.ui[main].inner.set_static(to);
                     ctx.ui[id].color = color.darker(0.3);
                 })
@@ -201,16 +202,18 @@ impl Client {
     }
 
     pub fn event(&mut self, event: WindowEvent, event_loop: &ActiveEventLoop) {
-        self.input.event(&event);
+        let input_changed = self.input.event(&event);
         let cursor_state = self.cursor_state().clone();
-        let window_size = self.window_size();
         if let Some(focus) = &self.focus
             && cursor_state.buttons.left.is_start()
         {
             self.ui.text(focus).deselect();
             self.focus = None;
         }
-        run_sensors(self, &cursor_state, window_size);
+        if input_changed {
+            let window_size = self.window_size();
+            run_sensors(self, &cursor_state, window_size);
+        }
         match event {
             WindowEvent::CloseRequested => event_loop.exit(),
             WindowEvent::RedrawRequested => {
@@ -249,7 +252,7 @@ impl Client {
 }
 
 impl UiCtx for Client {
-    fn ui(&mut self) -> &mut Ui<Self> {
+    fn ui(&mut self) -> &mut Ui {
         &mut self.ui
     }
 }
diff --git a/src/testing/render/mod.rs b/src/testing/render/mod.rs
index adb4353..d57b4ad 100644
--- a/src/testing/render/mod.rs
+++ b/src/testing/render/mod.rs
@@ -21,7 +21,7 @@ pub struct Renderer {
 }
 
 impl Renderer {
-    pub fn update<Ctx>(&mut self, updates: &mut Ui<Ctx>) {
+    pub fn update(&mut self, updates: &mut Ui) {
         self.ui.update(&self.device, &self.queue, updates);
     }