add module system and move sensor into core with it

src/layout/event.rs

@@ -0,0 +1,85 @@
+use crate::{
+    layout::{Ui, UiModule, Widget, WidgetId, WidgetIdFn, WidgetLike},
+    util::Id,
+};
+
+pub trait UiCtx {
+    fn ui(&mut self) -> &mut Ui<Self>
+    where
+        Self: Sized;
+}
+
+pub trait Event<Ctx>: Sized {
+    type Module: UiModule + EventModule<Ctx, Self> + Default;
+    type Data;
+}
+
+pub trait EventModule<Ctx, E: Event<Ctx>> {
+    fn register(&mut self, id: Id, event: E, f: impl EventFn<Ctx, E::Data>);
+}
+
+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 id_on<E: Event<Ctx>>(
+        self,
+        event: E,
+        f: impl FnMut(&WidgetId<W>, &mut Ctx, E::Data) + 'static,
+    ) -> impl WidgetIdFn<W, Ctx>
+    where
+        W: Widget;
+
+    fn edit_on<E: Event<Ctx>>(
+        self,
+        event: E,
+        f: impl FnMut(&mut W, E::Data) + 'static,
+    ) -> impl WidgetIdFn<W, Ctx>
+    where
+        W: Widget,
+        Ctx: UiCtx;
+}
+
+impl<W: WidgetLike<Ctx, 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> {
+        move |ui| {
+            let id = self.add(ui);
+            ui.modules
+                .get_mut::<E::Module>()
+                .register(id.id.duplicate(), event, f);
+            id
+        }
+    }
+
+    fn id_on<E: Event<Ctx>>(
+        self,
+        event: E,
+        mut f: impl FnMut(&WidgetId<W::Widget>, &mut Ctx, E::Data) + 'static,
+    ) -> impl WidgetIdFn<W::Widget, Ctx>
+    where
+        W::Widget: Widget,
+    {
+        self.with_id(move |ui, id| {
+            let id2 = id.clone();
+            id.on(event, move |ctx, pos| f(&id2, ctx, pos)).add(ui)
+        })
+    }
+
+    fn edit_on<E: Event<Ctx>>(
+        self,
+        event: E,
+        mut f: impl FnMut(&mut W::Widget, E::Data) + 'static,
+    ) -> impl WidgetIdFn<W::Widget, Ctx>
+    where
+        W::Widget: Widget,
+        Ctx: UiCtx,
+    {
+        self.id_on(event, move |id, ctx, pos| f(&mut ctx.ui()[id], pos))
+    }
+}