modularize core

src/core/render.rs

@@ -0,0 +1,54 @@
+use crate::core::*;
+
+/// Trait for things that render to the display.
+pub trait Render {
+    // Render something to an area of the buffer.
+    // Returns area used by component.
+    // This is insufficient but for the most basic dynamic layout algorithms.
+    fn render (&self, _b: &mut Buffer, _a: Rect) -> Usually<Rect> {
+        Ok(Rect { x: 0, y: 0, width: 0, height: 0 })
+    }
+    fn min_width (&self) -> u16 {
+        0
+    }
+    fn max_width (&self) -> u16 {
+        u16::MAX
+    }
+    fn min_height (&self) -> u16 {
+        0
+    }
+    fn max_height (&self) -> u16 {
+        u16::MAX
+    }
+}
+
+impl Render for Box<dyn Device> {
+    fn render (&self, b: &mut Buffer, a: Rect) -> Usually<Rect> {
+        (**self).render(b, a)
+    }
+}
+
+impl WidgetRef for &dyn Render {
+    fn render_ref (&self, area: Rect, buf: &mut Buffer) {
+        Render::render(*self, buf, area).expect("Failed to render device.");
+    }
+}
+
+impl WidgetRef for dyn Render {
+    fn render_ref (&self, area: Rect, buf: &mut Buffer) {
+        Render::render(self, buf, area).expect("Failed to render device.");
+    }
+}
+
+pub trait Blit {
+    // Render something to X, Y coordinates in a buffer, ignoring width/height.
+    fn blit (&self, buf: &mut Buffer, x: u16, y: u16, style: Option<Style>);
+}
+
+impl<T: AsRef<str>> Blit for T {
+    fn blit (&self, buf: &mut Buffer, x: u16, y: u16, style: Option<Style>) {
+        if x < buf.area.width && y < buf.area.height {
+            buf.set_string(x, y, self.as_ref(), style.unwrap_or(Style::default()))
+        }
+    }
+}