Add Block widget

showbits-common/src/widgets/block.rs

@@ -0,0 +1,77 @@
+use palette::Srgba;
+use taffy::Layout;
+
+use crate::{color, Rect, Vec2, View, Widget};
+
+pub struct Block {
+    border: Srgba,
+    background: Srgba,
+}
+
+impl Block {
+    pub fn new() -> Self {
+        Self {
+            border: color::TRANSPARENT,
+            background: color::TRANSPARENT,
+        }
+    }
+
+    pub fn border(mut self, color: Srgba) -> Self {
+        self.border = color;
+        self
+    }
+
+    pub fn background(mut self, color: Srgba) -> Self {
+        self.background = color;
+        self
+    }
+}
+
+impl Default for Block {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl<C> Widget<C> for Block {
+    fn draw_below(
+        &mut self,
+        _ctx: &mut C,
+        view: &mut View<'_>,
+        layout: &Layout,
+    ) -> anyhow::Result<()> {
+        let area = view.area();
+
+        // Background
+        view.rect(area, self.background);
+
+        // And now... the border!
+        //
+        // It is important not to draw pixels twice in case the border color is
+        // transparent. That's why the logic below is a bit more complex.
+        let left = layout.border.left as i32;
+        let right = layout.border.right as i32;
+        let top = layout.border.top as i32;
+        let bottom = layout.border.bottom as i32;
+        if top > 0 {
+            let border = Rect::from_nw(area.corner_nw(), area.size().with_y(top));
+            view.rect(border, self.border);
+        }
+        if bottom > 0 {
+            let border = Rect::from_sw(area.corner_sw(), area.size().with_y(bottom));
+            view.rect(border, self.border);
+        }
+        if left > 0 {
+            let nw = area.corner_nw() + Vec2::new(0, top);
+            let size = Vec2::new(left, area.size().y - top - bottom);
+            view.rect(Rect::from_nw(nw, size), self.border);
+        }
+        if right > 0 {
+            let ne = area.corner_ne() + Vec2::new(0, top);
+            let size = Vec2::new(right, area.size().y - top - bottom);
+            view.rect(Rect::from_ne(ne, size), self.border);
+        }
+
+        Ok(())
+    }
+}