ulmus 0.5.0

An Elm architecture TUI framework
Documentation 
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use crossterm::{cursor, event::MouseEvent, Command as _};

use super::Widget;
use crate::{Area, Message};

pub struct Border {
	inner: Box<dyn Widget>,

	top: String,
	bottom: String,
	left: String,
	right: String,
	top_left: String,
	top_right: String,
	bottom_left: String,
	bottom_right: String,

	forward: bool,
}

impl Border {
	pub fn new(
		inner: Box<dyn Widget>,

		top: String,
		bottom: String,
		left: String,
		right: String,
		top_left: String,
		top_right: String,
		bottom_left: String,
		bottom_right: String,
	) -> Box<Border> {
		Box::new(Border {
			inner,
			forward: false,

			top,
			bottom,
			left,
			right,
			top_left,
			top_right,
			bottom_left,
			bottom_right,
		})
	}

	pub fn forward(mut self: Box<Border>, yes: bool) -> Box<Border> {
		self.forward = yes;
		self
	}
}

impl Widget for Border {
	fn get_width_hint(&self) -> u16 {
		self.inner.get_width_hint()
			+ self.left.len() as u16
			+ self.right.len() as u16
	}

	fn get_height_hint(&self) -> u16 {
		self.inner.get_height_hint()
			+ self.top.len() as u16
			+ self.bottom.len() as u16
	}

	#[allow(unused_must_use)]
	fn render(&self, area: Area) -> String {
		let mut out = String::new();

		cursor::MoveTo(area.x, area.y).write_ansi(&mut out);
		out += &self.top_left;
		out += &self.top.repeat((area.width - 2).into());
		out += &self.top_right;

		for i in 1..area.height {
			cursor::MoveTo(area.x, area.y + i).write_ansi(&mut out);
			out += &self.left;
		}
		for i in 1..area.height {
			cursor::MoveTo(area.x + area.width - 1, area.y + i)
				.write_ansi(&mut out);
			out += &self.right;
		}

		cursor::MoveTo(area.x, area.y + area.height)
			.write_ansi(&mut out);
		out += &self.bottom_left;
		out += &self.bottom.repeat((area.width - 2).into());
		out += &self.bottom_right;

		out += &self.inner.render(Area {
			x: area.x + 1,
			y: area.y + 1,
			width: area.width - 2,
			height: area.height - 2,
		});

		out
	}

	fn process_mouse(&self, event: MouseEvent, area: Area) -> Message {
		// TODO: true length
		// TODO: area methods
		// XXX: overall, that's some ugly, ugly code.  Terminal length
		// should probably be implemented via a trait.
		let inner_area = Area {
			x: area.x + self.left.len() as u16,
			y: area.y + self.top.len() as u16,
			width: area.width
				- self.left.len() as u16 - self.right.len()
				as u16,
			height: area.height
				- self.top.len() as u16 - self.bottom.len()
				as u16,
		};

		if self.forward && area.contains(event) {
			// TODO: this won't work, because the child widget
			// checks if the event is inside the inner area.
			// Duplicating this check in every widget was a bad idea
			// anyways.  It should be done on program level.
			return self.inner.process_mouse(event, inner_area);
		}
		if !self.forward && inner_area.contains(event) {
			return self.inner.process_mouse(event, inner_area);
		}

		return Message::empty();
	}
}