TAG TECHNOLOGY

src/core/sense.rs

@@ -0,0 +1,35 @@
+use std::marker::PhantomData;
+
+use crate::{Painter, Widget, WidgetFn, WidgetId, WidgetLike};
+
+pub struct Sensor<F: SenseFn<Ctx>, Ctx> {
+    inner: WidgetId,
+    f: F,
+    _pd: PhantomData<Ctx>,
+}
+
+impl<F: SenseFn<Ctx>, Ctx: 'static> Widget<Ctx> for Sensor<F, Ctx> {
+    fn draw(&self, painter: &mut Painter<Ctx>) {
+        (self.f)(painter.ctx_mut());
+        painter.draw(&self.inner);
+    }
+}
+
+pub trait SenseFn<Ctx> = Fn(&mut Ctx) + 'static;
+
+pub trait Sensable<Ctx: 'static, Tag> {
+    fn sense<F: SenseFn<Ctx>>(self, f: F) -> impl WidgetFn<Sensor<F, Ctx>, Ctx>;
+}
+
+impl<W: WidgetLike<Ctx, Tag>, Ctx: 'static, Tag> Sensable<Ctx, Tag> for W {
+    fn sense<F: SenseFn<Ctx>>(self, f: F) -> impl WidgetFn<Sensor<F, Ctx>, Ctx> {
+        |ui| {
+            let inner = self.add(ui).erase_type();
+            Sensor {
+                inner,
+                f,
+                _pd: PhantomData,
+            }
+        }
+    }
+}