message: Use `value` in `Slider` to store the `previous` value
diff: @@ -147,7 +147,6 @@ where
  #[derive(Debug, Clone, Copy, PartialEq, Default)]
  pub struct State {
  is_dragging: bool,
  - previous: Option<f64>,
  }
  impl State {
  @@ -220,14 +219,10 @@ where
  }
  };
  - if let Some(previous) = self.state.previous {
  - if (new_value.into() - previous).abs() > f64::EPSILON {
  + if (self.value.into() - new_value.into()).abs() > f64::EPSILON {
  messages.push((self.on_change)(new_value));
  - self.state.previous = Some(new_value.into());
  - }
  - } else {
  - messages.push((self.on_change)(new_value));
  - self.state.previous = Some(new_value.into());
  +
  + self.value = new_value;
  }
  };
  