Introduce flex layouting 🎈

1 files changed, 61 insertions, 0 deletions

diff --git a/src/layout/flex.rs b/src/layout/flex.rs
new file mode 100644
index 00000000..faddc95a
--- /dev/null
+++ b/src/layout/flex.rs
@@ -0,0 +1,61 @@
+//! Flexible and lazy layouting of boxes.
+
+use super::{Layouter, LayoutContext, BoxLayout};
+
+
+/// A flex layout consists of a yet unarranged list of boxes.
+#[derive(Debug, Clone)]
+pub struct FlexLayout {
+    /// The sublayouts composing this layout.
+    layouts: Vec<BoxLayout>,
+}
+
+impl FlexLayout {
+    /// Compute the layout.
+    pub fn into_box(self) -> BoxLayout {
+        // TODO: Do the justification.
+        unimplemented!()
+    }
+}
+
+/// Layouts boxes next to each other (inline-style) lazily.
+#[derive(Debug)]
+pub struct FlexLayouter<'a, 'p> {
+    ctx: &'a LayoutContext<'a, 'p>,
+    layouts: Vec<BoxLayout>,
+}
+
+impl<'a, 'p> FlexLayouter<'a, 'p> {
+    /// Create a new flex layouter.
+    pub fn new(ctx: &'a LayoutContext<'a, 'p>) -> FlexLayouter<'a, 'p> {
+        FlexLayouter {
+            ctx,
+            layouts: vec![],
+        }
+    }
+
+    /// Add a sublayout.
+    pub fn add_box(&mut self, layout: BoxLayout) {
+        self.layouts.push(layout);
+    }
+
+    /// Add all sublayouts of another flex layout.
+    pub fn add_flexible(&mut self, layout: FlexLayout) {
+        self.layouts.extend(layout.layouts);
+    }
+}
+
+impl Layouter for FlexLayouter<'_, '_> {
+    type Layout = FlexLayout;
+
+    /// Finish the layouting and create a flexible layout from this.
+    fn finish(self) -> FlexLayout {
+        FlexLayout {
+            layouts: self.layouts
+        }
+    }
+
+    fn is_empty(&self) -> bool {
+        self.layouts.is_empty()
+    }
+}