Initial conversion of Calendar into widget

src/app.rs

@@ -438,7 +438,7 @@ impl TTApp {
             .constraints([Constraint::Min(0)].as_ref())
             .split(f.size());
         let today = Local::today();
-        let c = &Calendar::new(today.year().into()).to_string()[..];
+        let c = &Calendar::default().to_string()[..];
         let p = Paragraph::new(Text::from(c))
             .alignment(Alignment::Left)
             .block(Block::default().borders(Borders::ALL).title("Calendar"));

src/calendar.rs

@@ -8,6 +8,19 @@ const COL_WIDTH: usize = 21;
 use Day::*;
 use Month::*;
 
+use chrono::{Datelike, Local, NaiveDateTime, TimeZone};
+
+use tui::{
+    buffer::Buffer,
+    layout::Rect,
+    style::Style,
+    symbols,
+    widgets::{Block, Widget},
+};
+
+use std::cmp::min;
+use unicode_width::UnicodeWidthStr;
+
 #[derive(Clone, Copy, Debug)]
 #[repr(u8)]
 pub enum Day {
@@ -132,13 +145,21 @@ impl fmt::Display for Month {
     }
 }
 
-pub struct Calendar {
+#[derive(Debug, Clone)]
+pub struct Calendar<'a> {
+    pub block: Option<Block<'a>>,
     pub year: i64,
+    pub style: Style,
 }
 
-impl Calendar {
-    pub fn new(year: i64) -> Self {
-        Self { year }
+impl<'a> Default for Calendar<'a> {
+    fn default() -> Calendar<'a> {
+        let today = Local::today();
+        Calendar {
+            block: None,
+            year: today.year().into(),
+            style: Default::default(),
+        }
     }
 }
 
@@ -146,8 +167,87 @@ fn is_leap_year(year: i64) -> bool {
     (year % 4 == 0 && year % 100 != 0) || year % 400 == 0
 }
 
-impl fmt::Display for Calendar {
+// impl <'a> Widget for Calendar<'a> {
+//     fn render(mut self, area: Rect, buf: &mut Buffer) {
+//         buf.set_style(area, self.style);
+
+//         let area = match self.block.take() {
+//             Some(b) => {
+//                 let inner_area = b.inner(area);
+//                 b.render(area, buf);
+//                 inner_area
+//             }
+//             None => area,
+//         };
+
+//         if area.height < 7 {
+//             return
+//         }
+
+//         let style = self.style;
+//         let today = Local::today();
+//         let cols = area.width;
+
+//         let year = self.year;
+//         let leap_year = is_leap_year(year);
+//         let months = [Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov, Dec];
+//         let mut dates = [
+//             0..Jan.len(),
+//             0..Feb.leap_len(leap_year),
+//             0..Mar.len(),
+//             0..Apr.len(),
+//             0..May.len(),
+//             0..Jun.len(),
+//             0..Jul.len(),
+//             0..Aug.len(),
+//             0..Sep.len(),
+//             0..Oct.len(),
+//             0..Nov.len(),
+//             0..Dec.len(),
+//         ];
+//         let chunks = dates.chunks_mut(cols as usize).zip(months.chunks(cols as usize));
+//         let mut y = 0;
+//         for (days_chunk, months) in chunks {
+//             for month in months {
+//                 write!(f, "{:>1$} ", month, COL_WIDTH)?;
+//             }
+//             y += 1;
+//             for month in months {
+//                 write!(f, "{:>1$} ", " S  M  T  W  T  F  S", COL_WIDTH)?;
+//             }
+//             y += 1;
+//             for (days, mon) in days_chunk.iter_mut().zip(months.iter()) {
+//                 let first_day = mon.first_day(year) as u8;
+//                 for _ in 0..(first_day) {
+//                     f.write_str("   ")?;
+//                 }
+//                 for _ in 0..(7 - first_day) {
+//                     write!(f, "{:>3}", days.next().unwrap() + 1)?;
+//                 }
+//                 f.write_str(" ")?;
+//             }
+//             y += 1;
+//             while !days_chunk.iter().all(|r| r.start == r.end) {
+//                 for days in days_chunk.iter_mut() {
+//                     for _ in 0..7 {
+//                         match days.next() {
+//                             Some(s) => write!(f, "{:>3}", s + 1)?,
+//                             None => f.write_str("   ")?,
+//                         }
+//                     }
+//                     f.write_str(" ")?;
+//                 }
+//                 y += 1;
+//             }
+//             y += 1;
+//         }
+
+//     }
+// }
+
+impl<'a> fmt::Display for Calendar<'a> {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        let today = Local::today();
         let cols = f.width().unwrap_or(3);
         let year = self.year;
         let leap_year = is_leap_year(year);