Merge pull request #138 from hecrj/feature/empty-widget

`Space` widget

native/src/mouse_cursor.rs

@@ -22,3 +22,9 @@ pub enum MouseCursor {
     /// The cursor is over a text widget.
     Text,
 }
+
+impl Default for MouseCursor {
+    fn default() -> MouseCursor {
+        MouseCursor::OutOfBounds
+    }
+}

native/src/widget.rs

@@ -29,6 +29,7 @@ pub mod radio;
 pub mod row;
 pub mod scrollable;
 pub mod slider;
+pub mod space;
 pub mod svg;
 pub mod text;
 pub mod text_input;
@@ -52,6 +53,8 @@ pub use scrollable::Scrollable;
 #[doc(no_inline)]
 pub use slider::Slider;
 #[doc(no_inline)]
+pub use space::Space;
+#[doc(no_inline)]
 pub use svg::Svg;
 #[doc(no_inline)]
 pub use text::Text;

native/src/widget/space.rs

@@ -0,0 +1,104 @@
+//! Distribute content vertically.
+use std::hash::Hash;
+
+use crate::{
+    layout, Element, Hasher, Layout, Length, Point, Rectangle, Size, Widget,
+};
+
+/// An amount of empty space.
+///
+/// It can be useful if you want to fill some space with nothing.
+#[derive(Debug)]
+pub struct Space {
+    width: Length,
+    height: Length,
+}
+
+impl Space {
+    /// Creates an amount of empty [`Space`] with the given width and height.
+    ///
+    /// [`Space`]: struct.Space.html
+    pub fn new(width: Length, height: Length) -> Self {
+        Space { width, height }
+    }
+
+    /// Creates an amount of horizontal [`Space`].
+    ///
+    /// [`Space`]: struct.Space.html
+    pub fn with_width(width: Length) -> Self {
+        Space {
+            width,
+            height: Length::Shrink,
+        }
+    }
+
+    /// Creates an amount of vertical [`Space`].
+    ///
+    /// [`Space`]: struct.Space.html
+    pub fn with_height(height: Length) -> Self {
+        Space {
+            width: Length::Shrink,
+            height,
+        }
+    }
+}
+
+impl<'a, Message, Renderer> Widget<Message, Renderer> for Space
+where
+    Renderer: self::Renderer,
+{
+    fn width(&self) -> Length {
+        self.width
+    }
+
+    fn height(&self) -> Length {
+        self.height
+    }
+
+    fn layout(
+        &self,
+        _renderer: &Renderer,
+        limits: &layout::Limits,
+    ) -> layout::Node {
+        let limits = limits.width(self.width).height(self.height);
+
+        layout::Node::new(limits.resolve(Size::ZERO))
+    }
+
+    fn draw(
+        &self,
+        renderer: &mut Renderer,
+        layout: Layout<'_>,
+        _cursor_position: Point,
+    ) -> Renderer::Output {
+        renderer.draw(layout.bounds())
+    }
+
+    fn hash_layout(&self, state: &mut Hasher) {
+        std::any::TypeId::of::<Space>().hash(state);
+        self.width.hash(state);
+        self.height.hash(state);
+    }
+}
+
+/// The renderer of an amount of [`Space`].
+///
+/// [`Space`]: struct.Space.html
+pub trait Renderer: crate::Renderer {
+    /// Draws an amount of empty [`Space`].
+    ///
+    /// You should most likely return an empty primitive here.
+    ///
+    /// [`Space`]: struct.Space.html
+    fn draw(&mut self, bounds: Rectangle) -> Self::Output;
+}
+
+impl<'a, Message, Renderer> From<Space> for Element<'a, Message, Renderer>
+where
+    Renderer: self::Renderer,
+    Message: 'static,
+{
+    fn from(space: Space) -> Element<'a, Message, Renderer> {
+        Element::new(space)
+    }
+}