Draft Scrollable widget (no clipping yet!)

core/src/widget/scrollable.rs

@@ -0,0 +1,122 @@
+use crate::{Align, Column, Justify, Length};
+
+#[derive(Debug)]
+pub struct Scrollable<'a, Element> {
+    pub state: &'a mut State,
+    pub height: Length,
+    pub align_self: Option<Align>,
+    pub align_items: Align,
+    pub content: Column<Element>,
+}
+
+impl<'a, Element> Scrollable<'a, Element> {
+    pub fn new(state: &'a mut State) -> Self {
+        Scrollable {
+            state,
+            height: Length::Shrink,
+            align_self: None,
+            align_items: Align::Start,
+            content: Column::new(),
+        }
+    }
+
+    /// Sets the vertical spacing _between_ elements.
+    ///
+    /// Custom margins per element do not exist in Iced. You should use this
+    /// method instead! While less flexible, it helps you keep spacing between
+    /// elements consistent.
+    pub fn spacing(mut self, units: u16) -> Self {
+        self.content = self.content.spacing(units);
+        self
+    }
+
+    /// Sets the padding of the [`Column`].
+    ///
+    /// [`Column`]: struct.Column.html
+    pub fn padding(mut self, units: u16) -> Self {
+        self.content = self.content.padding(units);
+        self
+    }
+
+    /// Sets the width of the [`Column`].
+    ///
+    /// [`Column`]: struct.Column.html
+    pub fn width(mut self, width: Length) -> Self {
+        self.content = self.content.width(width);
+        self
+    }
+
+    /// Sets the height of the [`Column`].
+    ///
+    /// [`Column`]: struct.Column.html
+    pub fn height(mut self, height: Length) -> Self {
+        self.height = height;
+        self
+    }
+
+    /// Sets the maximum width of the [`Column`].
+    ///
+    /// [`Column`]: struct.Column.html
+    pub fn max_width(mut self, max_width: Length) -> Self {
+        self.content = self.content.max_width(max_width);
+        self
+    }
+
+    /// Sets the maximum height of the [`Column`] in pixels.
+    ///
+    /// [`Column`]: struct.Column.html
+    pub fn max_height(mut self, max_height: Length) -> Self {
+        self.content = self.content.max_height(max_height);
+        self
+    }
+
+    /// Sets the alignment of the [`Column`] itself.
+    ///
+    /// This is useful if you want to override the default alignment given by
+    /// the parent container.
+    ///
+    /// [`Column`]: struct.Column.html
+    pub fn align_self(mut self, align: Align) -> Self {
+        self.align_self = Some(align);
+        self
+    }
+
+    /// Sets the horizontal alignment of the contents of the [`Column`] .
+    ///
+    /// [`Column`]: struct.Column.html
+    pub fn align_items(mut self, align_items: Align) -> Self {
+        self.align_items = align_items;
+        self
+    }
+
+    /// Sets the vertical distribution strategy for the contents of the
+    /// [`Column`] .
+    ///
+    /// [`Column`]: struct.Column.html
+    pub fn justify_content(mut self, justify: Justify) -> Self {
+        self.content = self.content.justify_content(justify);
+        self
+    }
+
+    /// Adds an element to the [`Column`].
+    ///
+    /// [`Column`]: struct.Column.html
+    pub fn push<E>(mut self, child: E) -> Scrollable<'a, Element>
+    where
+        E: Into<Element>,
+    {
+        self.content = self.content.push(child);
+        self
+    }
+}
+
+#[derive(Debug, Clone, Copy, Default)]
+pub struct State {
+    pub offset: u32,
+}
+
+impl State {
+    pub fn new() -> Self {
+        State::default()
+    }
+}