add react block for use in react-style components

src/interactive/react.rs

@@ -200,4 +200,183 @@ mod terminal {
     }
 }
 
+mod block {
+    //! Derived from TUI-rs, license: MIT, Copyright (c) 2016 Florian Dehau
+    use crate::interactive::react::Component;
+    use std::borrow::{Borrow, BorrowMut};
+    use std::marker::PhantomData;
+    use tui::{
+        buffer::Buffer,
+        layout::Rect,
+        style::Color,
+        style::Style,
+        symbols::line,
+        widgets::{Borders, Widget},
+    };
+
+    pub fn fill_background(area: Rect, buf: &mut Buffer, color: Color) {
+        for y in area.top()..area.bottom() {
+            for x in area.left()..area.right() {
+                buf.get_mut(x, y).set_bg(color);
+            }
+        }
+    }
+
+    #[derive(Clone, Copy, Default)]
+    pub struct Block<'a, T>(PhantomData<&'a T>);
+
+    pub struct BlockProps<'a> {
+        /// Optional title place on the upper left of the block
+        title: Option<&'a str>,
+        /// Title style
+        title_style: Style,
+        /// Visible borders
+        borders: Borders,
+        /// Border style
+        border_style: Style,
+        /// Widget style
+        style: Style,
+    }
+
+    impl<'a> Default for BlockProps<'a> {
+        fn default() -> BlockProps<'a> {
+            BlockProps {
+                title: None,
+                title_style: Default::default(),
+                borders: Borders::NONE,
+                border_style: Default::default(),
+                style: Default::default(),
+            }
+        }
+    }
+
+    impl<'a> BlockProps<'a> {
+        /// Compute the inner area of a block based on its border visibility rules.
+        pub fn inner(&self, area: Rect) -> Rect {
+            if area.width < 2 || area.height < 2 {
+                return Rect::default();
+            }
+            let mut inner = area;
+            if self.borders.intersects(Borders::LEFT) {
+                inner.x += 1;
+                inner.width -= 1;
+            }
+            if self.borders.intersects(Borders::TOP) || self.title.is_some() {
+                inner.y += 1;
+                inner.height -= 1;
+            }
+            if self.borders.intersects(Borders::RIGHT) {
+                inner.width -= 1;
+            }
+            if self.borders.intersects(Borders::BOTTOM) {
+                inner.height -= 1;
+            }
+            inner
+        }
+    }
+
+    impl<'a, T> Component for Block<'a, T> {
+        type Props = BlockProps<'a>;
+        type PropsMut = ();
+
+        fn render(
+            &mut self,
+            props: impl Borrow<Self::Props>,
+            _: impl BorrowMut<Self::PropsMut>,
+            area: Rect,
+            buf: &mut Buffer,
+        ) {
+            if area.width < 2 || area.height < 2 {
+                return;
+            }
+            let BlockProps {
+                title,
+                title_style,
+                borders,
+                border_style,
+                style,
+            } = props.borrow();
+
+            fill_background(area, buf, style.bg);
+
+            // Sides
+            if borders.intersects(Borders::LEFT) {
+                for y in area.top()..area.bottom() {
+                    buf.get_mut(area.left(), y)
+                        .set_symbol(line::VERTICAL)
+                        .set_style(*border_style);
+                }
+            }
+            if borders.intersects(Borders::TOP) {
+                for x in area.left()..area.right() {
+                    buf.get_mut(x, area.top())
+                        .set_symbol(line::HORIZONTAL)
+                        .set_style(*border_style);
+                }
+            }
+            if borders.intersects(Borders::RIGHT) {
+                let x = area.right() - 1;
+                for y in area.top()..area.bottom() {
+                    buf.get_mut(x, y)
+                        .set_symbol(line::VERTICAL)
+                        .set_style(*border_style);
+                }
+            }
+            if borders.intersects(Borders::BOTTOM) {
+                let y = area.bottom() - 1;
+                for x in area.left()..area.right() {
+                    buf.get_mut(x, y)
+                        .set_symbol(line::HORIZONTAL)
+                        .set_style(*border_style);
+                }
+            }
+
+            // Corners
+            if borders.contains(Borders::LEFT | Borders::TOP) {
+                buf.get_mut(area.left(), area.top())
+                    .set_symbol(line::TOP_LEFT)
+                    .set_style(*border_style);
+            }
+            if borders.contains(Borders::RIGHT | Borders::TOP) {
+                buf.get_mut(area.right() - 1, area.top())
+                    .set_symbol(line::TOP_RIGHT)
+                    .set_style(*border_style);
+            }
+            if borders.contains(Borders::LEFT | Borders::BOTTOM) {
+                buf.get_mut(area.left(), area.bottom() - 1)
+                    .set_symbol(line::BOTTOM_LEFT)
+                    .set_style(*border_style);
+            }
+            if borders.contains(Borders::RIGHT | Borders::BOTTOM) {
+                buf.get_mut(area.right() - 1, area.bottom() - 1)
+                    .set_symbol(line::BOTTOM_RIGHT)
+                    .set_style(*border_style);
+            }
+
+            if area.width > 2 {
+                if let Some(title) = title {
+                    let lx = if borders.intersects(Borders::LEFT) {
+                        1
+                    } else {
+                        0
+                    };
+                    let rx = if borders.intersects(Borders::RIGHT) {
+                        1
+                    } else {
+                        0
+                    };
+                    let width = area.width - lx - rx;
+                    buf.set_stringn(
+                        area.left() + lx,
+                        area.top(),
+                        title,
+                        width as usize,
+                        *title_style,
+                    );
+                }
+            }
+        }
+    }
+}
+
 pub use terminal::*;