Start work on views system

src/views/vertical_layout.rs

@@ -0,0 +1,59 @@
+use crate::views::{Bounds, View};
+
+pub struct VerticalLayout {
+    pub views: Vec<Box<dyn View>>,
+}
+
+impl VerticalLayout {
+    pub fn new(views: Vec<Box<dyn View>>) -> Self {
+        Self { views }
+    }
+}
+
+impl View for VerticalLayout {
+    fn draw(&self, renderer: &mut crate::render::Renderer, x: f32, y: f32, w: f32, h: f32) {
+        let mut cur_y = y;
+
+        for view in &self.views {
+            let (vx, vy) = view.bounds(w, h);
+
+            let vx = match vx {
+                super::Bounds::MatchParent => w,
+                super::Bounds::Pixels(x) => x,
+            };
+
+            let vy = match vy {
+                super::Bounds::MatchParent => h,
+                super::Bounds::Pixels(x) => x,
+            };
+
+            view.draw(renderer, x, cur_y, w.min(vx), vy);
+            cur_y += vy;
+            if cur_y > h {
+                return;
+            }
+        }
+    }
+
+    fn bounds(&self, pw: f32, ph: f32) -> (Bounds, Bounds) {
+        let (mut maxx, mut totaly): (f32, f32) = (0., 0.);
+        for view in &self.views {
+            let (vx, vy) = view.bounds(pw, ph);
+
+            let vx = match vx {
+                super::Bounds::MatchParent => pw,
+                super::Bounds::Pixels(x) => x,
+            };
+
+            let vy = match vy {
+                super::Bounds::MatchParent => ph,
+                super::Bounds::Pixels(x) => x,
+            };
+
+            maxx = maxx.max(vx);
+            totaly += vy;
+        }
+
+        (Bounds::Pixels(maxx), Bounds::Pixels(totaly))
+    }
+}