From 789aeecec296d7d3301509d32153022927ff33e4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Franti=C5=A1ek=20Boh=C3=A1=C4=8Dek?=
 <fandabohacek@gmail.com>
Date: Fri, 28 Jul 2023 21:24:30 +0200
Subject: [PATCH] feat(src): add basic button representation

---
 src/button.rs | 99 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 src/button.rs

diff --git a/src/button.rs b/src/button.rs
new file mode 100644
index 0000000..26a4f6b
--- /dev/null
+++ b/src/button.rs
@@ -0,0 +1,99 @@
+use core::convert::Infallible;
+
+use alloc::boxed::Box;
+use core::marker::PhantomData;
+use embedded_hal::digital::v2::InputPin;
+
+pub struct ActiveHigh;
+pub struct ActiveLow;
+
+const DEBOUNCE: u8 = 2;
+const LONG_PRESS: u8 = 5;
+
+#[derive(PartialEq, Eq)]
+pub enum ButtonState {
+    Off,
+    JustPressed,
+    LongPress,
+    Click,
+    DoubleClick,
+    Released,
+}
+
+pub struct Button<ActiveLevel> {
+    pin: Box<dyn InputPin<Error = Infallible>>,
+    debounce: u8,
+    prev_state: bool,
+    level: PhantomData<ActiveLevel>,
+}
+
+pub trait ActiveLevel {
+    fn raw_is_pressed(pin_state: bool) -> bool;
+}
+
+impl ActiveLevel for ActiveHigh {
+    fn raw_is_pressed(pin_state: bool) -> bool {
+        pin_state
+    }
+}
+
+impl ActiveLevel for ActiveLow {
+    fn raw_is_pressed(pin_state: bool) -> bool {
+        !pin_state
+    }
+}
+
+impl<ACTIVELEVEL: ActiveLevel> Button<ACTIVELEVEL> {
+    pub fn new(pin: Box<dyn InputPin<Error = Infallible>>) -> Self {
+        Self {
+            pin,
+            debounce: 0,
+            prev_state: false,
+            level: PhantomData::<ACTIVELEVEL>,
+        }
+    }
+
+    pub fn raw_is_pressed(&self) -> bool {
+        ACTIVELEVEL::raw_is_pressed(self.pin.is_high().unwrap())
+    }
+
+    pub fn is_just_pressed(&self) -> bool {
+        self.raw_is_pressed() && self.debounce == DEBOUNCE
+    }
+
+    pub fn is_pressed(&self) -> bool {
+        self.raw_is_pressed() && self.debounce >= DEBOUNCE
+    }
+
+    pub fn is_long_pressed(&self) -> bool {
+        self.raw_is_pressed() && self.debounce >= LONG_PRESS
+    }
+
+    pub fn state(&self) -> ButtonState {
+        if !self.raw_is_pressed() {
+            ButtonState::Off
+        } else if self.is_just_pressed() {
+            ButtonState::JustPressed
+        } else if self.is_long_pressed() {
+            ButtonState::LongPress
+        } else {
+            ButtonState::Off
+        }
+    }
+
+    pub fn update(&mut self) {
+        let raw_pressed = self.raw_is_pressed();
+
+        if raw_pressed != self.prev_state {
+            self.debounce = 0;
+        } else if self.debounce < u8::MAX {
+            self.debounce += 1;
+        }
+
+        self.prev_state = raw_pressed;
+    }
+
+    pub fn reset() {
+        // resets is_clicked etc.
+    }
+}
-- 
2.48.1