Implement LinearLayout::important_area

src/rect.rs

@@ -1,4 +1,5 @@
 //! Rectangles on the 2D character grid.
+use std::ops::Add;
 
 use vec::Vec2;
 
@@ -21,6 +22,16 @@ where
     }
 }
 
+impl <T> Add<T> for Rect
+where T: Into<Vec2> {
+    type Output = Rect;
+
+    fn add(mut self, rhs: T) -> Self {
+        self.offset(rhs);
+        self
+    }
+}
+
 impl Rect {
     /// Creates a new `Rect` with the given position and size.
     ///

src/views/linear_layout.rs

@@ -3,6 +3,7 @@ use With;
 use XY;
 use direction;
 use event::{Event, EventResult, Key};
+use rect::Rect;
 use std::any::Any;
 use std::cmp::min;
 use std::ops::Deref;
@@ -574,4 +575,14 @@ impl View for LinearLayout {
 
         Err(())
     }
+
+    fn important_area(&self, _: Vec2) -> Rect {
+        let mut iterator = ChildIterator::new(self.children.iter(), self.orientation, usize::max_value());
+        let item = iterator.nth(self.focus).unwrap();
+
+        let rect = item.child.view.important_area(item.child.size);
+        let offset = self.orientation.make_vec(item.offset, 0);
+
+        rect + offset
+    }
 }