tek/src/view/border.rs

use crate::core::*;

pub trait BorderStyle {
    const NW: &'static str = "";
    const N:  &'static str = "";
    const NE: &'static str = "";
    const E:  &'static str = "";
    const SE: &'static str = "";
    const S:  &'static str = "";
    const SW: &'static str = "";
    const W:  &'static str = "";

    fn draw (&self, buf: &mut Buffer, area: Rect) {
        self.draw_horizontal(buf, area);
        self.draw_vertical(buf, area);
        self.draw_corners(buf, area);
    }

    fn draw_horizontal (&self, buf: &mut Buffer, area: Rect) {
        let style = self.style();
        for x in area.x..(area.x+area.width).saturating_sub(1) {
            Self::N.blit(buf, x, area.y, style);
            Self::S.blit(buf, x, area.y + area.height - 1, style);
        }
    }

    fn draw_vertical (&self, buf: &mut Buffer, area: Rect) {
        let style = self.style();
        for y in area.y..(area.y+area.height).saturating_sub(1) {
            Self::W.blit(buf, area.x, y, style);
            Self::E.blit(buf, area.x + area.width - 1, y, style);
        }
    }

    fn draw_corners (&self, buf: &mut Buffer, area: Rect) {
        let style = self.style();
        Self::NW.blit(buf, area.x, area.y, style);
        Self::NE.blit(buf, area.x + area.width - 1, area.y, style);
        Self::SW.blit(buf, area.x, area.y + area.height - 1, style);
        Self::SE.blit(buf, area.x + area.width - 1, area.y + area.height - 1, style);
    }

    fn style (&self) -> Option<Style> {
        None
    }
}

pub struct Lozenge(pub Style);

impl BorderStyle for Lozenge {
    const N:  &'static str = "─";
    const S:  &'static str = "─";
    const NW: &'static str = "╭";
    const W:  &'static str = "│";
    const SW: &'static str = "╰";
    const NE: &'static str = "╮";
    const E:  &'static str = "│";
    const SE: &'static str = "╯";

    fn style (&self) -> Option<Style> {
        Some(self.0)
    }
}

pub struct Quarter(pub Style);

impl BorderStyle for Quarter {
    const N:  &'static str = "▔";
    const S:  &'static str = "▁";
    const NW: &'static str = "▎";
    const W:  &'static str = "▎";
    const SW: &'static str = "▎";
    const NE: &'static str = "🮇";
    const E:  &'static str = "🮇";
    const SE: &'static str = "🮇";

    fn style (&self) -> Option<Style> {
        Some(self.0)
    }
}

pub struct QuarterV(pub Style);

impl BorderStyle for QuarterV {
    const NW: &'static str = "▎";
    const W:  &'static str = "▎";
    const SW: &'static str = "▎";
    const NE: &'static str = "🮇";
    const E:  &'static str = "🮇";
    const SE: &'static str = "🮇";

    fn style (&self) -> Option<Style> {
        Some(self.0)
    }
}

const LOZENGE: [[&'static str;3];3] = [
    ["╭", "─", "╮"],
    ["│", " ", "│"],
    ["╰", "─", "╯"],
];

pub fn lozenge_left (buf: &mut Buffer, x: u16, y1: u16, h: u16, style: Option<Style>) {
    let y2 = y1 + h;
    let y3 = y2.saturating_sub(1);
    for y in y1..y2 {
        if y == y1 {
            LOZENGE[0][0]
        } else if y == y3 {
            LOZENGE[2][0]
        } else {
            LOZENGE[1][0]
        }.blit(buf, x, y, style)
    }
}

pub fn lozenge_right (buf: &mut Buffer, x: u16, y1: u16, h: u16, style: Option<Style>) {
    let y2 = y1 + h;
    let y3 = y2.saturating_sub(1);
    for y in y1..y2 {
        if y == y1 {
            LOZENGE[0][2]
        } else if y == y3 {
            LOZENGE[2][2]
        } else {
            LOZENGE[1][2]
        }.blit(buf, x, y, style)
    }
}