Merge remote-tracking branch 'origin/master' into feat/multi-window-support

# Conflicts:
#	Cargo.toml
#	core/src/window/icon.rs
#	core/src/window/id.rs
#	core/src/window/position.rs
#	core/src/window/settings.rs
#	examples/integration/src/main.rs
#	examples/integration_opengl/src/main.rs
#	glutin/src/application.rs
#	native/src/subscription.rs
#	native/src/window.rs
#	runtime/src/window/action.rs
#	src/lib.rs
#	src/window.rs
#	winit/Cargo.toml
#	winit/src/application.rs
#	winit/src/icon.rs
#	winit/src/settings.rs
#	winit/src/window.rs

1 files changed, 65 insertions, 0 deletions

diff --git a/core/src/layout.rs b/core/src/layout.rs
new file mode 100644
index 00000000..04954fb9
--- /dev/null
+++ b/core/src/layout.rs
@@ -0,0 +1,65 @@
+//! Position your widgets properly.
+mod limits;
+mod node;
+
+pub mod flex;
+
+pub use limits::Limits;
+pub use node::Node;
+
+use crate::{Point, Rectangle, Vector};
+
+/// The bounds of a [`Node`] and its children, using absolute coordinates.
+#[derive(Debug, Clone, Copy)]
+pub struct Layout<'a> {
+    position: Point,
+    node: &'a Node,
+}
+
+impl<'a> Layout<'a> {
+    /// Creates a new [`Layout`] for the given [`Node`] at the origin.
+    pub fn new(node: &'a Node) -> Self {
+        Self::with_offset(Vector::new(0.0, 0.0), node)
+    }
+
+    /// Creates a new [`Layout`] for the given [`Node`] with the provided offset
+    /// from the origin.
+    pub fn with_offset(offset: Vector, node: &'a Node) -> Self {
+        let bounds = node.bounds();
+
+        Self {
+            position: Point::new(bounds.x, bounds.y) + offset,
+            node,
+        }
+    }
+
+    /// Returns the position of the [`Layout`].
+    pub fn position(&self) -> Point {
+        self.position
+    }
+
+    /// Returns the bounds of the [`Layout`].
+    ///
+    /// The returned [`Rectangle`] describes the position and size of a
+    /// [`Node`].
+    pub fn bounds(&self) -> Rectangle {
+        let bounds = self.node.bounds();
+
+        Rectangle {
+            x: self.position.x,
+            y: self.position.y,
+            width: bounds.width,
+            height: bounds.height,
+        }
+    }
+
+    /// Returns an iterator over the [`Layout`] of the children of a [`Node`].
+    pub fn children(self) -> impl Iterator<Item = Layout<'a>> {
+        self.node.children().iter().map(move |node| {
+            Layout::with_offset(
+                Vector::new(self.position.x, self.position.y),
+                node,
+            )
+        })
+    }
+}