output, tui: Stack implementation

output/src/ops/stack.rs

@@ -1,3 +1,85 @@
+use crate::*;
+
+pub struct Stack<E, F> {
+    __: PhantomData<E>,
+    direction: Direction,
+    callback:  F
+}
+impl<E, F> Stack<E, F> {
+    pub fn new (direction: Direction, callback: F) -> Self {
+        Self { direction, callback, __: Default::default(), }
+    }
+    pub fn north (callback: F) -> Self {
+        Self::new(Direction::North, callback)
+    }
+    pub fn south (callback: F) -> Self {
+        Self::new(Direction::South, callback)
+    }
+    pub fn east (callback: F) -> Self {
+        Self::new(Direction::East, callback)
+    }
+    pub fn west (callback: F) -> Self {
+        Self::new(Direction::West, callback)
+    }
+}
+impl<E: Output, F: Fn(&mut dyn FnMut(&dyn Render<E>)->())->()> Content<E> for Stack<E, F> {
+    fn layout (&self, mut to: E::Area) -> E::Area {
+        let mut x = to.x();
+        let mut y = to.y();
+        let mut w = to.w();
+        let mut h = to.h();
+        (self.callback)(&mut move |component: &dyn Render<E>|{
+            let layout = component.layout([x, y, w, h].into());
+            match self.direction {
+                Direction::North => {
+                    todo!()
+                },
+                Direction::South => {
+                    y = y + layout.h();
+                    h = h.minus(layout.h());
+                },
+                Direction::East  => {
+                    x = x + layout.w();
+                    w = w.minus(layout.w());
+                },
+                Direction::West  => {
+                    todo!()
+                },
+                _ => unreachable!(),
+            }
+        });
+        to
+    }
+    fn render (&self, to: &mut E) {
+        let mut x = to.x();
+        let mut y = to.y();
+        let mut w = to.w();
+        let mut h = to.h();
+        (self.callback)(&mut move |component: &dyn Render<E>|{
+            let layout = component.layout([x, y, w, h].into());
+            match self.direction {
+                Direction::North => {
+                    todo!()
+                },
+                Direction::South => {
+                    y = y + layout.h();
+                    h = h.minus(layout.h());
+                    to.place(layout, component);
+                },
+                Direction::East  => {
+                    x = x + layout.w();
+                    w = w.minus(layout.w());
+                    to.place(layout, component);
+                },
+                Direction::West  => {
+                    todo!()
+                },
+                _ => unreachable!()
+            }
+        });
+    }
+}
+
 /*Stack::down(|add|{
     let mut i = 0;
     for (_, name) in self.dirs.iter() {