knurling/src/widgets.rs

use crate::window::Size;
use pango::LayoutExt;

#[derive(Debug,Clone,Copy)]
pub enum Located {
    FromLeft(i32),
    FromRight(i32),
}

pub struct Config<'r> {
    pub left: Vec<&'r Widget>,
    pub right: Vec<&'r Widget>,
}

impl<'r> Config<'r> {
    pub fn draw(&self, d: &Drawing) {
        let mut offset = 10;
        for w in self.left.iter() {
            offset += 10 + w.draw(d, Located::FromLeft(offset));
        }
        offset = 10;
        for w in self.right.iter() {
            offset += 10 + w.draw(d, Located::FromRight(offset));
        }
    }
}

impl Located {
    fn draw_text(&self, d: &Drawing, msg: &str) -> i32 {
        d.lyt.set_text(msg);
        let (w, _) = d.lyt.get_size();
        d.ctx.move_to(self.target_x(d, w / pango::SCALE), 4.0);
        pangocairo::functions::show_layout(d.ctx, d.lyt);
        w / pango::SCALE
    }

    fn target_x(&self, d: &Drawing, w: i32) -> f64 {
        match self {
            Located::FromLeft(x) => *x as f64,
            Located::FromRight(x) => (d.size.wd - (x + w)) as f64,
        }
    }
}

pub struct Drawing<'t> {
    pub ctx: &'t cairo::Context,
    pub lyt: &'t pango::Layout,
    pub size: Size,
}

pub trait Widget {
    fn draw(&self, d: &Drawing, loc: Located) -> i32;
}

#[derive(Debug)]
pub struct Time {
    fmt: String,
}

impl Time {
    pub fn new() -> Time {
        Time {
            fmt: format!("%a %b %d %H:%M")
        }
    }
}

impl Widget for Time {
    fn draw(&self, d: &Drawing, loc: Located) -> i32 {
        let now = time::now();
        loc.draw_text(d, &time::strftime(&self.fmt, &now).unwrap())
    }
}


#[derive(Debug)]
pub struct Text<'t> {
    text: &'t str,
}

impl<'t> Text<'t> {
    pub fn new(text: &str) -> Text {
        Text { text }
    }
}

impl<'t> Widget for Text<'t> {
    fn draw(&self, d: &Drawing, loc: Located) -> i32 {
        loc.draw_text(d, &self.text)
    }
}


pub struct SmallBox;

impl Widget for SmallBox {
    fn draw(&self, d: &Drawing, loc: Located) -> i32 {
        let sz = d.size.ht - 8;
        let x = loc.target_x(d, sz);
        d.ctx.rectangle(x, 4.0, sz as f64, sz as f64);
        d.ctx.fill();
        sz
    }
}