Create iced_core and iced_native

core/src/widget/slider.rs

@@ -0,0 +1,123 @@
+//! Display an interactive selector of a single value from a range of values.
+//!
+//! A [`Slider`] has some local [`State`].
+//!
+//! [`Slider`]: struct.Slider.html
+//! [`State`]: struct.State.html
+use crate::Length;
+
+use std::ops::RangeInclusive;
+use std::rc::Rc;
+
+/// An horizontal bar and a handle that selects a single value from a range of
+/// values.
+///
+/// A [`Slider`] will try to fill the horizontal space of its container.
+///
+/// [`Slider`]: struct.Slider.html
+///
+/// # Example
+/// ```
+/// use iced_core::{slider, Slider};
+///
+/// pub enum Message {
+///     SliderChanged(f32),
+/// }
+///
+/// let state = &mut slider::State::new();
+/// let value = 50.0;
+///
+/// Slider::new(state, 0.0..=100.0, value, Message::SliderChanged);
+/// ```
+///
+/// ![Slider drawn by Coffee's renderer](https://github.com/hecrj/coffee/blob/bda9818f823dfcb8a7ad0ff4940b4d4b387b5208/images/ui/slider.png?raw=true)
+pub struct Slider<'a, Message> {
+    /// The state of the slider
+    pub state: &'a mut State,
+
+    /// The range of the slider
+    pub range: RangeInclusive<f32>,
+
+    /// The current value of the slider
+    pub value: f32,
+
+    /// The function to produce messages on change
+    pub on_change: Rc<Box<dyn Fn(f32) -> Message>>,
+
+    pub width: Length,
+}
+
+impl<'a, Message> std::fmt::Debug for Slider<'a, Message> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("Slider")
+            .field("state", &self.state)
+            .field("range", &self.range)
+            .field("value", &self.value)
+            .finish()
+    }
+}
+
+impl<'a, Message> Slider<'a, Message> {
+    /// Creates a new [`Slider`].
+    ///
+    /// It expects:
+    ///   * the local [`State`] of the [`Slider`]
+    ///   * an inclusive range of possible values
+    ///   * the current value of the [`Slider`]
+    ///   * a function that will be called when the [`Slider`] is dragged.
+    ///   It receives the new value of the [`Slider`] and must produce a
+    ///   `Message`.
+    ///
+    /// [`Slider`]: struct.Slider.html
+    /// [`State`]: struct.State.html
+    pub fn new<F>(
+        state: &'a mut State,
+        range: RangeInclusive<f32>,
+        value: f32,
+        on_change: F,
+    ) -> Self
+    where
+        F: 'static + Fn(f32) -> Message,
+    {
+        Slider {
+            state,
+            value: value.max(*range.start()).min(*range.end()),
+            range,
+            on_change: Rc::new(Box::new(on_change)),
+            width: Length::Fill,
+        }
+    }
+
+    /// Sets the width of the [`Slider`].
+    ///
+    /// [`Slider`]: struct.Slider.html
+    pub fn width(mut self, width: Length) -> Self {
+        self.width = width;
+        self
+    }
+}
+
+/// The local state of a [`Slider`].
+///
+/// [`Slider`]: struct.Slider.html
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
+pub struct State {
+    pub is_dragging: bool,
+}
+
+impl State {
+    /// Creates a new [`State`].
+    ///
+    /// [`State`]: struct.State.html
+    pub fn new() -> State {
+        State::default()
+    }
+
+    /// Returns whether the associated [`Slider`] is currently being dragged or
+    /// not.
+    ///
+    /// [`Slider`]: struct.Slider.html
+    pub fn is_dragging(&self) -> bool {
+        self.is_dragging
+    }
+}