Add Border widget

examples/hello_world_widgets.rs

@@ -2,18 +2,20 @@ use std::convert::Infallible;
 
 use crossterm::event::Event;
 use crossterm::style::{ContentStyle, Stylize};
-use toss::widgets::Text;
+use toss::widgets::{Border, BorderLook, Text};
 use toss::{Styled, Terminal, Widget};
 
 fn widget() -> impl Widget<Infallible> {
-    Text::new(
+    Border::new(Text::new(
         Styled::new("Hello world!", ContentStyle::default().green())
             .then_plain("\n")
             .then(
                 "Press any key to exit",
                 ContentStyle::default().on_dark_blue(),
             ),
-    )
+    ))
+    .look(BorderLook::LINE_DOUBLE)
+    .style(ContentStyle::default().dark_red())
 }
 
 fn render_frame(term: &mut Terminal) {

src/widgets.rs

@@ -1,3 +1,5 @@
+mod border;
 mod text;
 
+pub use border::*;
 pub use text::*;

src/widgets/border.rs

@@ -0,0 +1,201 @@
+use async_trait::async_trait;
+use crossterm::style::ContentStyle;
+
+use crate::{AsyncWidget, Frame, Pos, Size, Widget};
+
+#[derive(Debug, Clone, Copy)]
+pub struct BorderLook {
+    pub top_left: &'static str,
+    pub top_right: &'static str,
+    pub bottom_left: &'static str,
+    pub bottom_right: &'static str,
+    pub top: &'static str,
+    pub bottom: &'static str,
+    pub left: &'static str,
+    pub right: &'static str,
+}
+
+impl BorderLook {
+    /// ```
+    /// +-------+
+    /// | Hello |
+    /// +-------+
+    /// ```
+    pub const ASCII: Self = Self {
+        top_left: "+",
+        top_right: "+",
+        bottom_left: "+",
+        bottom_right: "+",
+        top: "-",
+        bottom: "-",
+        left: "|",
+        right: "|",
+    };
+
+    /// ```
+    /// ┌───────┐
+    /// │ Hello │
+    /// └───────┘
+    /// ```
+    pub const LINE: Self = Self {
+        top_left: "┌",
+        top_right: "┐",
+        bottom_left: "└",
+        bottom_right: "┘",
+        top: "─",
+        bottom: "─",
+        left: "│",
+        right: "│",
+    };
+
+    /// ```
+    /// ┏━━━━━━━┓
+    /// ┃ Hello ┃
+    /// ┗━━━━━━━┛
+    /// ```
+    pub const LINE_HEAVY: Self = Self {
+        top_left: "┏",
+        top_right: "┓",
+        bottom_left: "┗",
+        bottom_right: "┛",
+        top: "━",
+        bottom: "━",
+        left: "┃",
+        right: "┃",
+    };
+
+    /// ```
+    /// ╔═══════╗
+    /// ║ Hello ║
+    /// ╚═══════╝
+    /// ```
+    pub const LINE_DOUBLE: Self = Self {
+        top_left: "╔",
+        top_right: "╗",
+        bottom_left: "╚",
+        bottom_right: "╝",
+        top: "═",
+        bottom: "═",
+        left: "║",
+        right: "║",
+    };
+}
+
+impl Default for BorderLook {
+    fn default() -> Self {
+        Self::LINE
+    }
+}
+
+pub struct Border<I> {
+    inner: I,
+    look: BorderLook,
+    style: ContentStyle,
+}
+
+impl<I> Border<I> {
+    pub fn new(inner: I) -> Self {
+        Self {
+            inner,
+            look: BorderLook::default(),
+            style: ContentStyle::default(),
+        }
+    }
+
+    pub fn look(mut self, look: BorderLook) -> Self {
+        self.look = look;
+        self
+    }
+
+    pub fn style(mut self, style: ContentStyle) -> Self {
+        self.style = style;
+        self
+    }
+
+    fn draw_border(&self, frame: &mut Frame) {
+        let size = frame.size();
+        let right = size.width.saturating_sub(1).into();
+        let bottom = size.height.saturating_sub(1).into();
+
+        for y in 1..bottom {
+            frame.write(Pos::new(right, y), (self.look.right, self.style));
+            frame.write(Pos::new(0, y), (self.look.left, self.style));
+        }
+
+        for x in 1..right {
+            frame.write(Pos::new(x, bottom), (self.look.bottom, self.style));
+            frame.write(Pos::new(x, 0), (self.look.top, self.style));
+        }
+
+        frame.write(
+            Pos::new(right, bottom),
+            (self.look.bottom_right, self.style),
+        );
+        frame.write(Pos::new(0, bottom), (self.look.bottom_left, self.style));
+        frame.write(Pos::new(right, 0), (self.look.top_right, self.style));
+        frame.write(Pos::new(0, 0), (self.look.top_left, self.style));
+    }
+
+    fn push_inner(&self, frame: &mut Frame) {
+        let mut size = frame.size();
+        size.width = size.width.saturating_sub(2);
+        size.height = size.height.saturating_sub(2);
+
+        frame.push(Pos::new(1, 1), size);
+    }
+}
+
+impl<E, I> Widget<E> for Border<I>
+where
+    I: Widget<E>,
+{
+    fn size(
+        &self,
+        frame: &mut Frame,
+        max_width: Option<u16>,
+        max_height: Option<u16>,
+    ) -> Result<Size, E> {
+        let max_width = max_width.map(|w| w.saturating_sub(2));
+        let max_height = max_height.map(|h| h.saturating_sub(2));
+        let size = self.inner.size(frame, max_width, max_height)?;
+        Ok(size + Size::new(2, 2))
+    }
+
+    fn draw(self, frame: &mut Frame) -> Result<(), E> {
+        self.draw_border(frame);
+
+        self.push_inner(frame);
+        self.inner.draw(frame)?;
+        frame.pop();
+
+        Ok(())
+    }
+}
+
+#[async_trait]
+impl<E, I> AsyncWidget<E> for Border<I>
+where
+    I: AsyncWidget<E> + Send + Sync,
+{
+    async fn size(
+        &self,
+        frame: &mut Frame,
+        max_width: Option<u16>,
+        max_height: Option<u16>,
+    ) -> Result<Size, E> {
+        let max_width = max_width.map(|w| w.saturating_sub(2));
+        let max_height = max_height.map(|h| h.saturating_sub(2));
+        let size = self.inner.size(frame, max_width, max_height).await?;
+        Ok(size + Size::new(2, 2))
+    }
+
+    async fn draw(self, frame: &mut Frame) -> Result<(), E> {
+        self.draw_border(frame);
+
+        self.push_inner(frame);
+        self.inner.draw(frame).await?;
+        frame.pop();
+
+        Ok(())
+    }
+}