Initial vendor packages

Signed-off-by: Valentin Popov <valentin@popov.link>

1 files changed, 987 insertions, 0 deletions

diff --git a/vendor/indicatif/src/style.rs b/vendor/indicatif/src/style.rs
new file mode 100644
index 0000000..01b220f
--- /dev/null
+++ b/vendor/indicatif/src/style.rs
@@ -0,0 +1,987 @@
+use std::collections::HashMap;
+use std::fmt::{self, Write};
+use std::mem;
+#[cfg(not(target_arch = "wasm32"))]
+use std::time::Instant;
+
+use console::{measure_text_width, Style};
+#[cfg(target_arch = "wasm32")]
+use instant::Instant;
+#[cfg(feature = "unicode-segmentation")]
+use unicode_segmentation::UnicodeSegmentation;
+
+use crate::format::{
+    BinaryBytes, DecimalBytes, FormattedDuration, HumanBytes, HumanCount, HumanDuration,
+    HumanFloatCount,
+};
+use crate::state::{ProgressState, TabExpandedString, DEFAULT_TAB_WIDTH};
+
+#[derive(Clone)]
+pub struct ProgressStyle {
+    tick_strings: Vec<Box<str>>,
+    progress_chars: Vec<Box<str>>,
+    template: Template,
+    // how unicode-big each char in progress_chars is
+    char_width: usize,
+    tab_width: usize,
+    pub(crate) format_map: HashMap<&'static str, Box<dyn ProgressTracker>>,
+}
+
+#[cfg(feature = "unicode-segmentation")]
+fn segment(s: &str) -> Vec<Box<str>> {
+    UnicodeSegmentation::graphemes(s, true)
+        .map(|s| s.into())
+        .collect()
+}
+
+#[cfg(not(feature = "unicode-segmentation"))]
+fn segment(s: &str) -> Vec<Box<str>> {
+    s.chars().map(|x| x.to_string().into()).collect()
+}
+
+#[cfg(feature = "unicode-width")]
+fn measure(s: &str) -> usize {
+    unicode_width::UnicodeWidthStr::width(s)
+}
+
+#[cfg(not(feature = "unicode-width"))]
+fn measure(s: &str) -> usize {
+    s.chars().count()
+}
+
+/// finds the unicode-aware width of the passed grapheme cluters
+/// panics on an empty parameter, or if the characters are not equal-width
+fn width(c: &[Box<str>]) -> usize {
+    c.iter()
+        .map(|s| measure(s.as_ref()))
+        .fold(None, |acc, new| {
+            match acc {
+                None => return Some(new),
+                Some(old) => assert_eq!(old, new, "got passed un-equal width progress characters"),
+            }
+            acc
+        })
+        .unwrap()
+}
+
+impl ProgressStyle {
+    /// Returns the default progress bar style for bars
+    pub fn default_bar() -> Self {
+        Self::new(Template::from_str("{wide_bar} {pos}/{len}").unwrap())
+    }
+
+    /// Returns the default progress bar style for spinners
+    pub fn default_spinner() -> Self {
+        Self::new(Template::from_str("{spinner} {msg}").unwrap())
+    }
+
+    /// Sets the template string for the progress bar
+    ///
+    /// Review the [list of template keys](../index.html#templates) for more information.
+    pub fn with_template(template: &str) -> Result<Self, TemplateError> {
+        Ok(Self::new(Template::from_str(template)?))
+    }
+
+    pub(crate) fn set_tab_width(&mut self, new_tab_width: usize) {
+        self.tab_width = new_tab_width;
+        self.template.set_tab_width(new_tab_width);
+    }
+
+    fn new(template: Template) -> Self {
+        let progress_chars = segment("█░");
+        let char_width = width(&progress_chars);
+        Self {
+            tick_strings: "⠁⠁⠉⠙⠚⠒⠂⠂⠒⠲⠴⠤⠄⠄⠤⠠⠠⠤⠦⠖⠒⠐⠐⠒⠓⠋⠉⠈⠈ "
+                .chars()
+                .map(|c| c.to_string().into())
+                .collect(),
+            progress_chars,
+            char_width,
+            template,
+            format_map: HashMap::default(),
+            tab_width: DEFAULT_TAB_WIDTH,
+        }
+    }
+
+    /// Sets the tick character sequence for spinners
+    ///
+    /// Note that the last character is used as the [final tick string][Self::get_final_tick_str()].
+    /// At least two characters are required to provide a non-final and final state.
+    pub fn tick_chars(mut self, s: &str) -> Self {
+        self.tick_strings = s.chars().map(|c| c.to_string().into()).collect();
+        // Format bar will panic with some potentially confusing message, better to panic here
+        // with a message explicitly informing of the problem
+        assert!(
+            self.tick_strings.len() >= 2,
+            "at least 2 tick chars required"
+        );
+        self
+    }
+
+    /// Sets the tick string sequence for spinners
+    ///
+    /// Note that the last string is used as the [final tick string][Self::get_final_tick_str()].
+    /// At least two strings are required to provide a non-final and final state.
+    pub fn tick_strings(mut self, s: &[&str]) -> Self {
+        self.tick_strings = s.iter().map(|s| s.to_string().into()).collect();
+        // Format bar will panic with some potentially confusing message, better to panic here
+        // with a message explicitly informing of the problem
+        assert!(
+            self.progress_chars.len() >= 2,
+            "at least 2 tick strings required"
+        );
+        self
+    }
+
+    /// Sets the progress characters `(filled, current, to do)`
+    ///
+    /// You can pass more than three for a more detailed display.
+    /// All passed grapheme clusters need to be of equal width.
+    pub fn progress_chars(mut self, s: &str) -> Self {
+        self.progress_chars = segment(s);
+        // Format bar will panic with some potentially confusing message, better to panic here
+        // with a message explicitly informing of the problem
+        assert!(
+            self.progress_chars.len() >= 2,
+            "at least 2 progress chars required"
+        );
+        self.char_width = width(&self.progress_chars);
+        self
+    }
+
+    /// Adds a custom key that owns a [`ProgressTracker`] to the template
+    pub fn with_key<S: ProgressTracker + 'static>(mut self, key: &'static str, f: S) -> Self {
+        self.format_map.insert(key, Box::new(f));
+        self
+    }
+
+    /// Sets the template string for the progress bar
+    ///
+    /// Review the [list of template keys](../index.html#templates) for more information.
+    pub fn template(mut self, s: &str) -> Result<Self, TemplateError> {
+        self.template = Template::from_str(s)?;
+        Ok(self)
+    }
+
+    fn current_tick_str(&self, state: &ProgressState) -> &str {
+        match state.is_finished() {
+            true => self.get_final_tick_str(),
+            false => self.get_tick_str(state.tick),
+        }
+    }
+
+    /// Returns the tick string for a given number
+    pub fn get_tick_str(&self, idx: u64) -> &str {
+        &self.tick_strings[(idx as usize) % (self.tick_strings.len() - 1)]
+    }
+
+    /// Returns the tick string for the finished state
+    pub fn get_final_tick_str(&self) -> &str {
+        &self.tick_strings[self.tick_strings.len() - 1]
+    }
+
+    fn format_bar(&self, fract: f32, width: usize, alt_style: Option<&Style>) -> BarDisplay<'_> {
+        // The number of clusters from progress_chars to write (rounding down).
+        let width = width / self.char_width;
+        // The number of full clusters (including a fractional component for a partially-full one).
+        let fill = fract * width as f32;
+        // The number of entirely full clusters (by truncating `fill`).
+        let entirely_filled = fill as usize;
+        // 1 if the bar is not entirely empty or full (meaning we need to draw the "current"
+        // character between the filled and "to do" segment), 0 otherwise.
+        let head = usize::from(fill > 0.0 && entirely_filled < width);
+
+        let cur = if head == 1 {
+            // Number of fine-grained progress entries in progress_chars.
+            let n = self.progress_chars.len().saturating_sub(2);
+            let cur_char = if n <= 1 {
+                // No fine-grained entries. 1 is the single "current" entry if we have one, the "to
+                // do" entry if not.
+                1
+            } else {
+                // Pick a fine-grained entry, ranging from the last one (n) if the fractional part
+                // of fill is 0 to the first one (1) if the fractional part of fill is almost 1.
+                n.saturating_sub((fill.fract() * n as f32) as usize)
+            };
+            Some(cur_char)
+        } else {
+            None
+        };
+
+        // Number of entirely empty clusters needed to fill the bar up to `width`.
+        let bg = width.saturating_sub(entirely_filled).saturating_sub(head);
+        let rest = RepeatedStringDisplay {
+            str: &self.progress_chars[self.progress_chars.len() - 1],
+            num: bg,
+        };
+
+        BarDisplay {
+            chars: &self.progress_chars,
+            filled: entirely_filled,
+            cur,
+            rest: alt_style.unwrap_or(&Style::new()).apply_to(rest),
+        }
+    }
+
+    pub(crate) fn format_state(
+        &self,
+        state: &ProgressState,
+        lines: &mut Vec<String>,
+        target_width: u16,
+    ) {
+        let mut cur = String::new();
+        let mut buf = String::new();
+        let mut wide = None;
+
+        let pos = state.pos();
+        let len = state.len().unwrap_or(pos);
+        for part in &self.template.parts {
+            match part {
+                TemplatePart::Placeholder {
+                    key,
+                    align,
+                    width,
+                    truncate,
+                    style,
+                    alt_style,
+                } => {
+                    buf.clear();
+                    if let Some(tracker) = self.format_map.get(key.as_str()) {
+                        tracker.write(state, &mut TabRewriter(&mut buf, self.tab_width));
+                    } else {
+                        match key.as_str() {
+                            "wide_bar" => {
+                                wide = Some(WideElement::Bar { alt_style });
+                                buf.push('\x00');
+                            }
+                            "bar" => buf
+                                .write_fmt(format_args!(
+                                    "{}",
+                                    self.format_bar(
+                                        state.fraction(),
+                                        width.unwrap_or(20) as usize,
+                                        alt_style.as_ref(),
+                                    )
+                                ))
+                                .unwrap(),
+                            "spinner" => buf.push_str(self.current_tick_str(state)),
+                            "wide_msg" => {
+                                wide = Some(WideElement::Message { align });
+                                buf.push('\x00');
+                            }
+                            "msg" => buf.push_str(state.message.expanded()),
+                            "prefix" => buf.push_str(state.prefix.expanded()),
+                            "pos" => buf.write_fmt(format_args!("{pos}")).unwrap(),
+                            "human_pos" => {
+                                buf.write_fmt(format_args!("{}", HumanCount(pos))).unwrap();
+                            }
+                            "len" => buf.write_fmt(format_args!("{len}")).unwrap(),
+                            "human_len" => {
+                                buf.write_fmt(format_args!("{}", HumanCount(len))).unwrap();
+                            }
+                            "percent" => buf
+                                .write_fmt(format_args!("{:.*}", 0, state.fraction() * 100f32))
+                                .unwrap(),
+                            "bytes" => buf.write_fmt(format_args!("{}", HumanBytes(pos))).unwrap(),
+                            "total_bytes" => {
+                                buf.write_fmt(format_args!("{}", HumanBytes(len))).unwrap();
+                            }
+                            "decimal_bytes" => buf
+                                .write_fmt(format_args!("{}", DecimalBytes(pos)))
+                                .unwrap(),
+                            "decimal_total_bytes" => buf
+                                .write_fmt(format_args!("{}", DecimalBytes(len)))
+                                .unwrap(),
+                            "binary_bytes" => {
+                                buf.write_fmt(format_args!("{}", BinaryBytes(pos))).unwrap();
+                            }
+                            "binary_total_bytes" => {
+                                buf.write_fmt(format_args!("{}", BinaryBytes(len))).unwrap();
+                            }
+                            "elapsed_precise" => buf
+                                .write_fmt(format_args!("{}", FormattedDuration(state.elapsed())))
+                                .unwrap(),
+                            "elapsed" => buf
+                                .write_fmt(format_args!("{:#}", HumanDuration(state.elapsed())))
+                                .unwrap(),
+                            "per_sec" => buf
+                                .write_fmt(format_args!("{}/s", HumanFloatCount(state.per_sec())))
+                                .unwrap(),
+                            "bytes_per_sec" => buf
+                                .write_fmt(format_args!("{}/s", HumanBytes(state.per_sec() as u64)))
+                                .unwrap(),
+                            "binary_bytes_per_sec" => buf
+                                .write_fmt(format_args!(
+                                    "{}/s",
+                                    BinaryBytes(state.per_sec() as u64)
+                                ))
+                                .unwrap(),
+                            "eta_precise" => buf
+                                .write_fmt(format_args!("{}", FormattedDuration(state.eta())))
+                                .unwrap(),
+                            "eta" => buf
+                                .write_fmt(format_args!("{:#}", HumanDuration(state.eta())))
+                                .unwrap(),
+                            "duration_precise" => buf
+                                .write_fmt(format_args!("{}", FormattedDuration(state.duration())))
+                                .unwrap(),
+                            "duration" => buf
+                                .write_fmt(format_args!("{:#}", HumanDuration(state.duration())))
+                                .unwrap(),
+                            _ => (),
+                        }
+                    };
+
+                    match width {
+                        Some(width) => {
+                            let padded = PaddedStringDisplay {
+                                str: &buf,
+                                width: *width as usize,
+                                align: *align,
+                                truncate: *truncate,
+                            };
+                            match style {
+                                Some(s) => cur
+                                    .write_fmt(format_args!("{}", s.apply_to(padded)))
+                                    .unwrap(),
+                                None => cur.write_fmt(format_args!("{padded}")).unwrap(),
+                            }
+                        }
+                        None => match style {
+                            Some(s) => cur.write_fmt(format_args!("{}", s.apply_to(&buf))).unwrap(),
+                            None => cur.push_str(&buf),
+                        },
+                    }
+                }
+                TemplatePart::Literal(s) => cur.push_str(s.expanded()),
+                TemplatePart::NewLine => {
+                    self.push_line(lines, &mut cur, state, &mut buf, target_width, &wide);
+                }
+            }
+        }
+
+        if !cur.is_empty() {
+            self.push_line(lines, &mut cur, state, &mut buf, target_width, &wide);
+        }
+    }
+
+    fn push_line(
+        &self,
+        lines: &mut Vec<String>,
+        cur: &mut String,
+        state: &ProgressState,
+        buf: &mut String,
+        target_width: u16,
+        wide: &Option<WideElement>,
+    ) {
+        let expanded = match wide {
+            Some(inner) => inner.expand(mem::take(cur), self, state, buf, target_width),
+            None => mem::take(cur),
+        };
+
+        // If there are newlines, we need to split them up
+        // and add the lines separately so that they're counted
+        // correctly on re-render.
+        for (i, line) in expanded.split('\n').enumerate() {
+            // No newlines found in this case
+            if i == 0 && line.len() == expanded.len() {
+                lines.push(expanded);
+                break;
+            }
+
+            lines.push(line.to_string());
+        }
+    }
+}
+
+struct TabRewriter<'a>(&'a mut dyn fmt::Write, usize);
+
+impl Write for TabRewriter<'_> {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        self.0
+            .write_str(s.replace('\t', &" ".repeat(self.1)).as_str())
+    }
+}
+
+#[derive(Clone, Copy)]
+enum WideElement<'a> {
+    Bar { alt_style: &'a Option<Style> },
+    Message { align: &'a Alignment },
+}
+
+impl<'a> WideElement<'a> {
+    fn expand(
+        self,
+        cur: String,
+        style: &ProgressStyle,
+        state: &ProgressState,
+        buf: &mut String,
+        width: u16,
+    ) -> String {
+        let left = (width as usize).saturating_sub(measure_text_width(&cur.replace('\x00', "")));
+        match self {
+            Self::Bar { alt_style } => cur.replace(
+                '\x00',
+                &format!(
+                    "{}",
+                    style.format_bar(state.fraction(), left, alt_style.as_ref())
+                ),
+            ),
+            WideElement::Message { align } => {
+                buf.clear();
+                buf.write_fmt(format_args!(
+                    "{}",
+                    PaddedStringDisplay {
+                        str: state.message.expanded(),
+                        width: left,
+                        align: *align,
+                        truncate: true,
+                    }
+                ))
+                .unwrap();
+
+                let trimmed = match cur.as_bytes().last() == Some(&b'\x00') {
+                    true => buf.trim_end(),
+                    false => buf,
+                };
+
+                cur.replace('\x00', trimmed)
+            }
+        }
+    }
+}
+
+#[derive(Clone, Debug)]
+struct Template {
+    parts: Vec<TemplatePart>,
+}
+
+impl Template {
+    fn from_str_with_tab_width(s: &str, tab_width: usize) -> Result<Self, TemplateError> {
+        use State::*;
+        let (mut state, mut parts, mut buf) = (Literal, vec![], String::new());
+        for c in s.chars() {
+            let new = match (state, c) {
+                (Literal, '{') => (MaybeOpen, None),
+                (Literal, '\n') => {
+                    if !buf.is_empty() {
+                        parts.push(TemplatePart::Literal(TabExpandedString::new(
+                            mem::take(&mut buf).into(),
+                            tab_width,
+                        )));
+                    }
+                    parts.push(TemplatePart::NewLine);
+                    (Literal, None)
+                }
+                (Literal, '}') => (DoubleClose, Some('}')),
+                (Literal, c) => (Literal, Some(c)),
+                (DoubleClose, '}') => (Literal, None),
+                (MaybeOpen, '{') => (Literal, Some('{')),
+                (MaybeOpen | Key, c) if c.is_ascii_whitespace() => {
+                    // If we find whitespace where the variable key is supposed to go,
+                    // backtrack and act as if this was a literal.
+                    buf.push(c);
+                    let mut new = String::from("{");
+                    new.push_str(&buf);
+                    buf.clear();
+                    parts.push(TemplatePart::Literal(TabExpandedString::new(
+                        new.into(),
+                        tab_width,
+                    )));
+                    (Literal, None)
+                }
+                (MaybeOpen, c) if c != '}' && c != ':' => (Key, Some(c)),
+                (Key, c) if c != '}' && c != ':' => (Key, Some(c)),
+                (Key, ':') => (Align, None),
+                (Key, '}') => (Literal, None),
+                (Key, '!') if !buf.is_empty() => {
+                    parts.push(TemplatePart::Placeholder {
+                        key: mem::take(&mut buf),
+                        align: Alignment::Left,
+                        width: None,
+                        truncate: true,
+                        style: None,
+                        alt_style: None,
+                    });
+                    (Width, None)
+                }
+                (Align, c) if c == '<' || c == '^' || c == '>' => {
+                    if let Some(TemplatePart::Placeholder { align, .. }) = parts.last_mut() {
+                        match c {
+                            '<' => *align = Alignment::Left,
+                            '^' => *align = Alignment::Center,
+                            '>' => *align = Alignment::Right,
+                            _ => (),
+                        }
+                    }
+
+                    (Width, None)
+                }
+                (Align, c @ '0'..='9') => (Width, Some(c)),
+                (Align | Width, '!') => {
+                    if let Some(TemplatePart::Placeholder { truncate, .. }) = parts.last_mut() {
+                        *truncate = true;
+                    }
+                    (Width, None)
+                }
+                (Align, '.') => (FirstStyle, None),
+                (Align, '}') => (Literal, None),
+                (Width, c @ '0'..='9') => (Width, Some(c)),
+                (Width, '.') => (FirstStyle, None),
+                (Width, '}') => (Literal, None),
+                (FirstStyle, '/') => (AltStyle, None),
+                (FirstStyle, '}') => (Literal, None),
+                (FirstStyle, c) => (FirstStyle, Some(c)),
+                (AltStyle, '}') => (Literal, None),
+                (AltStyle, c) => (AltStyle, Some(c)),
+                (st, c) => return Err(TemplateError { next: c, state: st }),
+            };
+
+            match (state, new.0) {
+                (MaybeOpen, Key) if !buf.is_empty() => parts.push(TemplatePart::Literal(
+                    TabExpandedString::new(mem::take(&mut buf).into(), tab_width),
+                )),
+                (Key, Align | Literal) if !buf.is_empty() => {
+                    parts.push(TemplatePart::Placeholder {
+                        key: mem::take(&mut buf),
+                        align: Alignment::Left,
+                        width: None,
+                        truncate: false,
+                        style: None,
+                        alt_style: None,
+                    });
+                }
+                (Width, FirstStyle | Literal) if !buf.is_empty() => {
+                    if let Some(TemplatePart::Placeholder { width, .. }) = parts.last_mut() {
+                        *width = Some(buf.parse().unwrap());
+                        buf.clear();
+                    }
+                }
+                (FirstStyle, AltStyle | Literal) if !buf.is_empty() => {
+                    if let Some(TemplatePart::Placeholder { style, .. }) = parts.last_mut() {
+                        *style = Some(Style::from_dotted_str(&buf));
+                        buf.clear();
+                    }
+                }
+                (AltStyle, Literal) if !buf.is_empty() => {
+                    if let Some(TemplatePart::Placeholder { alt_style, .. }) = parts.last_mut() {
+                        *alt_style = Some(Style::from_dotted_str(&buf));
+                        buf.clear();
+                    }
+                }
+                (_, _) => (),
+            }
+
+            state = new.0;
+            if let Some(c) = new.1 {
+                buf.push(c);
+            }
+        }
+
+        if matches!(state, Literal | DoubleClose) && !buf.is_empty() {
+            parts.push(TemplatePart::Literal(TabExpandedString::new(
+                buf.into(),
+                tab_width,
+            )));
+        }
+
+        Ok(Self { parts })
+    }
+
+    fn from_str(s: &str) -> Result<Self, TemplateError> {
+        Self::from_str_with_tab_width(s, DEFAULT_TAB_WIDTH)
+    }
+
+    fn set_tab_width(&mut self, new_tab_width: usize) {
+        for part in &mut self.parts {
+            if let TemplatePart::Literal(s) = part {
+                s.set_tab_width(new_tab_width);
+            }
+        }
+    }
+}
+
+#[derive(Debug)]
+pub struct TemplateError {
+    state: State,
+    next: char,
+}
+
+impl fmt::Display for TemplateError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(
+            f,
+            "TemplateError: unexpected character {:?} in state {:?}",
+            self.next, self.state
+        )
+    }
+}
+
+impl std::error::Error for TemplateError {}
+
+#[derive(Clone, Debug, PartialEq, Eq)]
+enum TemplatePart {
+    Literal(TabExpandedString),
+    Placeholder {
+        key: String,
+        align: Alignment,
+        width: Option<u16>,
+        truncate: bool,
+        style: Option<Style>,
+        alt_style: Option<Style>,
+    },
+    NewLine,
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq)]
+enum State {
+    Literal,
+    MaybeOpen,
+    DoubleClose,
+    Key,
+    Align,
+    Width,
+    FirstStyle,
+    AltStyle,
+}
+
+struct BarDisplay<'a> {
+    chars: &'a [Box<str>],
+    filled: usize,
+    cur: Option<usize>,
+    rest: console::StyledObject<RepeatedStringDisplay<'a>>,
+}
+
+impl<'a> fmt::Display for BarDisplay<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        for _ in 0..self.filled {
+            f.write_str(&self.chars[0])?;
+        }
+        if let Some(cur) = self.cur {
+            f.write_str(&self.chars[cur])?;
+        }
+        self.rest.fmt(f)
+    }
+}
+
+struct RepeatedStringDisplay<'a> {
+    str: &'a str,
+    num: usize,
+}
+
+impl<'a> fmt::Display for RepeatedStringDisplay<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        for _ in 0..self.num {
+            f.write_str(self.str)?;
+        }
+        Ok(())
+    }
+}
+
+struct PaddedStringDisplay<'a> {
+    str: &'a str,
+    width: usize,
+    align: Alignment,
+    truncate: bool,
+}
+
+impl<'a> fmt::Display for PaddedStringDisplay<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        let cols = measure_text_width(self.str);
+        let excess = cols.saturating_sub(self.width);
+        if excess > 0 && !self.truncate {
+            return f.write_str(self.str);
+        } else if excess > 0 {
+            let (start, end) = match self.align {
+                Alignment::Left => (0, self.str.len() - excess),
+                Alignment::Right => (excess, self.str.len()),
+                Alignment::Center => (
+                    excess / 2,
+                    self.str.len() - excess.saturating_sub(excess / 2),
+                ),
+            };
+
+            return f.write_str(self.str.get(start..end).unwrap_or(self.str));
+        }
+
+        let diff = self.width.saturating_sub(cols);
+        let (left_pad, right_pad) = match self.align {
+            Alignment::Left => (0, diff),
+            Alignment::Right => (diff, 0),
+            Alignment::Center => (diff / 2, diff.saturating_sub(diff / 2)),
+        };
+
+        for _ in 0..left_pad {
+            f.write_char(' ')?;
+        }
+        f.write_str(self.str)?;
+        for _ in 0..right_pad {
+            f.write_char(' ')?;
+        }
+        Ok(())
+    }
+}
+
+#[derive(PartialEq, Eq, Debug, Copy, Clone)]
+enum Alignment {
+    Left,
+    Center,
+    Right,
+}
+
+/// Trait for defining stateful or stateless formatters
+pub trait ProgressTracker: Send + Sync {
+    /// Creates a new instance of the progress tracker
+    fn clone_box(&self) -> Box<dyn ProgressTracker>;
+    /// Notifies the progress tracker of a tick event
+    fn tick(&mut self, state: &ProgressState, now: Instant);
+    /// Notifies the progress tracker of a reset event
+    fn reset(&mut self, state: &ProgressState, now: Instant);
+    /// Provides access to the progress bar display buffer for custom messages
+    fn write(&self, state: &ProgressState, w: &mut dyn fmt::Write);
+}
+
+impl Clone for Box<dyn ProgressTracker> {
+    fn clone(&self) -> Self {
+        self.clone_box()
+    }
+}
+
+impl<F> ProgressTracker for F
+where
+    F: Fn(&ProgressState, &mut dyn fmt::Write) + Send + Sync + Clone + 'static,
+{
+    fn clone_box(&self) -> Box<dyn ProgressTracker> {
+        Box::new(self.clone())
+    }
+
+    fn tick(&mut self, _: &ProgressState, _: Instant) {}
+
+    fn reset(&mut self, _: &ProgressState, _: Instant) {}
+
+    fn write(&self, state: &ProgressState, w: &mut dyn fmt::Write) {
+        (self)(state, w);
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::sync::Arc;
+
+    use super::*;
+    use crate::state::{AtomicPosition, ProgressState};
+    use std::sync::Mutex;
+
+    #[test]
+    fn test_stateful_tracker() {
+        #[derive(Debug, Clone)]
+        struct TestTracker(Arc<Mutex<String>>);
+
+        impl ProgressTracker for TestTracker {
+            fn clone_box(&self) -> Box<dyn ProgressTracker> {
+                Box::new(self.clone())
+            }
+
+            fn tick(&mut self, state: &ProgressState, _: Instant) {
+                let mut m = self.0.lock().unwrap();
+                m.clear();
+                m.push_str(format!("{} {}", state.len().unwrap(), state.pos()).as_str());
+            }
+
+            fn reset(&mut self, _state: &ProgressState, _: Instant) {
+                let mut m = self.0.lock().unwrap();
+                m.clear();
+            }
+
+            fn write(&self, _state: &ProgressState, w: &mut dyn fmt::Write) {
+                w.write_str(self.0.lock().unwrap().as_str()).unwrap();
+            }
+        }
+
+        use crate::ProgressBar;
+
+        let pb = ProgressBar::new(1);
+        pb.set_style(
+            ProgressStyle::with_template("{{ {foo} }}")
+                .unwrap()
+                .with_key("foo", TestTracker(Arc::new(Mutex::new(String::default()))))
+                .progress_chars("#>-"),
+        );
+
+        let mut buf = Vec::new();
+        let style = pb.clone().style();
+
+        style.format_state(&pb.state().state, &mut buf, 16);
+        assert_eq!(&buf[0], "{  }");
+        buf.clear();
+        pb.inc(1);
+        style.format_state(&pb.state().state, &mut buf, 16);
+        assert_eq!(&buf[0], "{ 1 1 }");
+        pb.reset();
+        buf.clear();
+        style.format_state(&pb.state().state, &mut buf, 16);
+        assert_eq!(&buf[0], "{  }");
+        pb.finish_and_clear();
+    }
+
+    use crate::state::TabExpandedString;
+
+    #[test]
+    fn test_expand_template() {
+        const WIDTH: u16 = 80;
+        let pos = Arc::new(AtomicPosition::new());
+        let state = ProgressState::new(Some(10), pos);
+        let mut buf = Vec::new();
+
+        let mut style = ProgressStyle::default_bar();
+        style.format_map.insert(
+            "foo",
+            Box::new(|_: &ProgressState, w: &mut dyn Write| write!(w, "FOO").unwrap()),
+        );
+        style.format_map.insert(
+            "bar",
+            Box::new(|_: &ProgressState, w: &mut dyn Write| write!(w, "BAR").unwrap()),
+        );
+
+        style.template = Template::from_str("{{ {foo} {bar} }}").unwrap();
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(&buf[0], "{ FOO BAR }");
+
+        buf.clear();
+        style.template = Template::from_str(r#"{ "foo": "{foo}", "bar": {bar} }"#).unwrap();
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(&buf[0], r#"{ "foo": "FOO", "bar": BAR }"#);
+    }
+
+    #[test]
+    fn test_expand_template_flags() {
+        use console::set_colors_enabled;
+        set_colors_enabled(true);
+
+        const WIDTH: u16 = 80;
+        let pos = Arc::new(AtomicPosition::new());
+        let state = ProgressState::new(Some(10), pos);
+        let mut buf = Vec::new();
+
+        let mut style = ProgressStyle::default_bar();
+        style.format_map.insert(
+            "foo",
+            Box::new(|_: &ProgressState, w: &mut dyn Write| write!(w, "XXX").unwrap()),
+        );
+
+        style.template = Template::from_str("{foo:5}").unwrap();
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(&buf[0], "XXX  ");
+
+        buf.clear();
+        style.template = Template::from_str("{foo:.red.on_blue}").unwrap();
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(&buf[0], "\u{1b}[31m\u{1b}[44mXXX\u{1b}[0m");
+
+        buf.clear();
+        style.template = Template::from_str("{foo:^5.red.on_blue}").unwrap();
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(&buf[0], "\u{1b}[31m\u{1b}[44m XXX \u{1b}[0m");
+
+        buf.clear();
+        style.template = Template::from_str("{foo:^5.red.on_blue/green.on_cyan}").unwrap();
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(&buf[0], "\u{1b}[31m\u{1b}[44m XXX \u{1b}[0m");
+    }
+
+    #[test]
+    fn align_truncation() {
+        const WIDTH: u16 = 10;
+        let pos = Arc::new(AtomicPosition::new());
+        let mut state = ProgressState::new(Some(10), pos);
+        let mut buf = Vec::new();
+
+        let style = ProgressStyle::with_template("{wide_msg}").unwrap();
+        state.message = TabExpandedString::NoTabs("abcdefghijklmnopqrst".into());
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(&buf[0], "abcdefghij");
+
+        buf.clear();
+        let style = ProgressStyle::with_template("{wide_msg:>}").unwrap();
+        state.message = TabExpandedString::NoTabs("abcdefghijklmnopqrst".into());
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(&buf[0], "klmnopqrst");
+
+        buf.clear();
+        let style = ProgressStyle::with_template("{wide_msg:^}").unwrap();
+        state.message = TabExpandedString::NoTabs("abcdefghijklmnopqrst".into());
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(&buf[0], "fghijklmno");
+    }
+
+    #[test]
+    fn wide_element_style() {
+        const CHARS: &str = "=>-";
+        const WIDTH: u16 = 8;
+        let pos = Arc::new(AtomicPosition::new());
+        // half finished
+        pos.set(2);
+        let mut state = ProgressState::new(Some(4), pos);
+        let mut buf = Vec::new();
+
+        let style = ProgressStyle::with_template("{wide_bar}")
+            .unwrap()
+            .progress_chars(CHARS);
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(&buf[0], "====>---");
+
+        buf.clear();
+        let style = ProgressStyle::with_template("{wide_bar:.red.on_blue/green.on_cyan}")
+            .unwrap()
+            .progress_chars(CHARS);
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(
+            &buf[0],
+            "\u{1b}[31m\u{1b}[44m====>\u{1b}[32m\u{1b}[46m---\u{1b}[0m\u{1b}[0m"
+        );
+
+        buf.clear();
+        let style = ProgressStyle::with_template("{wide_msg:^.red.on_blue}").unwrap();
+        state.message = TabExpandedString::NoTabs("foobar".into());
+        style.format_state(&state, &mut buf, WIDTH);
+        assert_eq!(&buf[0], "\u{1b}[31m\u{1b}[44m foobar \u{1b}[0m");
+    }
+
+    #[test]
+    fn multiline_handling() {
+        const WIDTH: u16 = 80;
+        let pos = Arc::new(AtomicPosition::new());
+        let mut state = ProgressState::new(Some(10), pos);
+        let mut buf = Vec::new();
+
+        let mut style = ProgressStyle::default_bar();
+        state.message = TabExpandedString::new("foo\nbar\nbaz".into(), 2);
+        style.template = Template::from_str("{msg}").unwrap();
+        style.format_state(&state, &mut buf, WIDTH);
+
+        assert_eq!(buf.len(), 3);
+        assert_eq!(&buf[0], "foo");
+        assert_eq!(&buf[1], "bar");
+        assert_eq!(&buf[2], "baz");
+
+        buf.clear();
+        style.template = Template::from_str("{wide_msg}").unwrap();
+        style.format_state(&state, &mut buf, WIDTH);
+
+        assert_eq!(buf.len(), 3);
+        assert_eq!(&buf[0], "foo");
+        assert_eq!(&buf[1], "bar");
+        assert_eq!(&buf[2], "baz");
+
+        buf.clear();
+        state.prefix = TabExpandedString::new("prefix\nprefix".into(), 2);
+        style.template = Template::from_str("{prefix} {wide_msg}").unwrap();
+        style.format_state(&state, &mut buf, WIDTH);
+
+        assert_eq!(buf.len(), 4);
+        assert_eq!(&buf[0], "prefix");
+        assert_eq!(&buf[1], "prefix foo");
+        assert_eq!(&buf[2], "bar");
+        assert_eq!(&buf[3], "baz");
+    }
+}