use derive macro in examples

hui-examples/examples/ui_test_5_input.rs

@@ -1,7 +1,6 @@
 use hui::{
-  color, size,
+  color, size, Signal,
   draw::TextureFormat,
-  signal::Signal,
   layout::{Alignment, Direction},
   element::{
     container::Container,
@@ -13,11 +12,11 @@ use hui::{
   },
 };
 
+#[derive(Signal)]
 enum CounterSignal {
   Increment,
   Decrement,
 }
-impl Signal for CounterSignal {}
 
 #[path = "../boilerplate.rs"]
 #[macro_use]

hui-examples/examples/ui_test_6_slider.rs

@@ -9,14 +9,13 @@ use hui::{
     UiElementExt,
   },
   layout::{Alignment, Direction},
-  signal::Signal,
-  size,
+  size, Signal,
 };
 
+#[derive(Signal)]
 enum CounterSignal {
   ChangeValue(u32)
 }
-impl Signal for CounterSignal {}
 
 #[path = "../boilerplate.rs"]
 #[macro_use]

hui-examples/examples/ui_test_7_9patch.rs

@@ -11,7 +11,7 @@ use hui::{
   frame::nine_patch::{NinePatchAsset, NinePatchFrame},
   layout::Alignment,
   rect::Rect,
-  signal::Signal,
+  Signal,
   size,
 };
 
@@ -19,8 +19,8 @@ use hui::{
 #[macro_use]
 mod boilerplate;
 
+#[derive(Signal)]
 struct SetValue(f32);
-impl Signal for SetValue {}
 
 ui_main!(
   "hUI: 9-Patch demo",