Support sending and displaying formatted messages (#10)

src/base.rs

@@ -59,7 +59,7 @@ use crate::{
     ApplicationSettings,
 };
 
-const ROOM_FETCH_DEBOUNCE: Duration = Duration::from_secs(3);
+const ROOM_FETCH_DEBOUNCE: Duration = Duration::from_secs(2);
 
 #[derive(Clone, Debug, Eq, PartialEq)]
 pub enum IambInfo {}

src/main.rs

@@ -42,6 +42,7 @@ mod commands;
 mod config;
 mod keybindings;
 mod message;
+mod util;
 mod windows;
 mod worker;
 
@@ -99,6 +100,14 @@ use modalkit::{
     },
 };
 
+const MIN_MSG_LOAD: u32 = 50;
+
+fn msg_load_req(area: Rect) -> u32 {
+    let n = area.height as u32;
+
+    n.max(MIN_MSG_LOAD)
+}
+
 struct Application {
     store: AsyncProgramStore,
     worker: Requester,
@@ -176,7 +185,7 @@ impl Application {
                 f.set_cursor(cx, cy);
             }
 
-            store.application.load_older(area.height as u32);
+            store.application.load_older(msg_load_req(area));
         })?;
 
         Ok(())
@@ -186,7 +195,8 @@ impl Application {
         loop {
             self.redraw(false, self.store.clone().lock().await.deref_mut())?;
 
-            if !poll(Duration::from_millis(500))? {
+            if !poll(Duration::from_secs(1))? {
+                // Redraw in case there's new messages to show.
                 continue;
             }
 

src/message/html.rs

@@ -0,0 +1,942 @@
+//! # Rendering for formatted bodies
+//!
+//! This module contains the code for rendering messages that contained an
+//! "org.matrix.custom.html"-formatted body.
+//!
+//! The Matrix specification recommends limiting rendered tags and attributes to a safe subset of
+//! HTML. You can read more in section 11.2.1.1, "m.room.message msgtypes":
+//!
+//!   https://spec.matrix.org/unstable/client-server-api/#mroommessage-msgtypes
+//!
+//! This isn't as important for iamb, since it isn't a browser environment, but we do still map
+//! input onto an enum of the safe list of tags to keep it easy to understand and process.
+use std::ops::Deref;
+
+use css_color_parser::Color as CssColor;
+use markup5ever_rcdom::{Handle, NodeData, RcDom};
+use unicode_segmentation::UnicodeSegmentation;
+
+use html5ever::{
+    driver::{parse_fragment, ParseOpts},
+    interface::{Attribute, QualName},
+    local_name,
+    namespace_url,
+    ns,
+    tendril::{StrTendril, TendrilSink},
+};
+
+use modalkit::tui::{
+    layout::Alignment,
+    style::{Color, Modifier as StyleModifier, Style},
+    symbols::line,
+    text::{Span, Spans, Text},
+};
+
+use crate::{
+    message::printer::TextPrinter,
+    util::{join_cell_text, space_text},
+};
+
+struct BulletIterator {
+    style: ListStyle,
+    pos: usize,
+    len: usize,
+}
+
+impl BulletIterator {
+    fn width(&self) -> usize {
+        match self.style {
+            ListStyle::Unordered => 2,
+            ListStyle::Ordered => self.len.to_string().len() + 2,
+        }
+    }
+}
+
+impl Iterator for BulletIterator {
+    type Item = String;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.pos == self.len {
+            return None;
+        }
+
+        self.pos += 1;
+
+        let bullet = match self.style {
+            ListStyle::Unordered => "- ".to_string(),
+            ListStyle::Ordered => {
+                let w = self.len.to_string().len();
+                format!("{: >w$}. ", self.pos, w = w)
+            },
+        };
+
+        return Some(bullet);
+    }
+}
+
+#[derive(Clone, Copy, Debug)]
+pub enum ListStyle {
+    Ordered,
+    Unordered,
+}
+
+impl ListStyle {
+    fn bullets(&self, len: usize) -> BulletIterator {
+        BulletIterator { style: *self, pos: 0, len }
+    }
+}
+
+pub type StyleTreeChildren = Vec<StyleTreeNode>;
+
+pub enum CellType {
+    Data,
+    Header,
+}
+
+pub struct TableRow {
+    cells: Vec<(CellType, StyleTreeNode)>,
+}
+
+impl TableRow {
+    fn columns(&self) -> usize {
+        self.cells.len()
+    }
+}
+
+pub struct TableSection {
+    rows: Vec<TableRow>,
+}
+
+impl TableSection {
+    fn columns(&self) -> usize {
+        self.rows.iter().map(TableRow::columns).max().unwrap_or(0)
+    }
+}
+
+pub struct Table {
+    caption: Option<Box<StyleTreeNode>>,
+    sections: Vec<TableSection>,
+}
+
+impl Table {
+    fn columns(&self) -> usize {
+        self.sections.iter().map(TableSection::columns).max().unwrap_or(0)
+    }
+
+    fn to_text(&self, width: usize, style: Style) -> Text {
+        let mut text = Text::default();
+        let columns = self.columns();
+        let cell_total = width.saturating_sub(columns).saturating_sub(1);
+        let cell_min = cell_total / columns;
+        let mut cell_slop = cell_total - cell_min * columns;
+        let cell_widths = (0..columns)
+            .into_iter()
+            .map(|_| {
+                let slopped = cell_slop.min(1);
+                cell_slop -= slopped;
+                cell_min + slopped
+            })
+            .collect::<Vec<_>>();
+
+        let mut nrows = 0;
+
+        if let Some(caption) = &self.caption {
+            let subw = width.saturating_sub(6);
+            let mut printer = TextPrinter::new(subw, style, true).align(Alignment::Center);
+            caption.print(&mut printer, style);
+
+            for mut line in printer.finish().lines {
+                line.0.insert(0, Span::styled("   ", style));
+                line.0.push(Span::styled("   ", style));
+                text.lines.push(line);
+            }
+        }
+
+        for section in self.sections.iter() {
+            for row in section.rows.iter() {
+                let mut ruler = String::new();
+
+                for (i, w) in cell_widths.iter().enumerate() {
+                    let cross = match (nrows, i) {
+                        (0, 0) => line::TOP_LEFT,
+                        (0, _) => line::HORIZONTAL_DOWN,
+                        (_, 0) => line::VERTICAL_RIGHT,
+                        (_, _) => line::CROSS,
+                    };
+
+                    ruler.push_str(cross);
+
+                    for _ in 0..*w {
+                        ruler.push_str(line::HORIZONTAL);
+                    }
+                }
+
+                if nrows == 0 {
+                    ruler.push_str(line::TOP_RIGHT);
+                } else {
+                    ruler.push_str(line::VERTICAL_LEFT);
+                }
+
+                text.lines.push(Spans(vec![Span::styled(ruler, style)]));
+
+                let cells = cell_widths
+                    .iter()
+                    .enumerate()
+                    .map(|(i, w)| {
+                        let text = if let Some((kind, cell)) = row.cells.get(i) {
+                            let style = match kind {
+                                CellType::Header => style.add_modifier(StyleModifier::BOLD),
+                                CellType::Data => style,
+                            };
+
+                            cell.to_text(*w, style)
+                        } else {
+                            space_text(*w, style)
+                        };
+
+                        (text, *w)
+                    })
+                    .collect();
+
+                let joined = join_cell_text(cells, Span::styled(line::VERTICAL, style));
+                text.lines.extend(joined.lines);
+
+                nrows += 1;
+            }
+        }
+
+        if nrows > 0 {
+            let mut ruler = String::new();
+
+            for (i, w) in cell_widths.iter().enumerate() {
+                let cross = if i == 0 {
+                    line::BOTTOM_LEFT
+                } else {
+                    line::HORIZONTAL_UP
+                };
+
+                ruler.push_str(cross);
+
+                for _ in 0..*w {
+                    ruler.push_str(line::HORIZONTAL);
+                }
+            }
+
+            ruler.push_str(line::BOTTOM_RIGHT);
+            text.lines.push(Spans(vec![Span::styled(ruler, style)]));
+        }
+
+        text
+    }
+}
+
+pub enum StyleTreeNode {
+    Blockquote(Box<StyleTreeNode>),
+    Break,
+    Code(Box<StyleTreeNode>, Option<String>),
+    Header(Box<StyleTreeNode>, usize),
+    Image(Option<String>),
+    List(StyleTreeChildren, ListStyle),
+    Paragraph(Box<StyleTreeNode>),
+    Reply(Box<StyleTreeNode>),
+    Ruler,
+    Style(Box<StyleTreeNode>, Style),
+    Table(Table),
+    Text(String),
+    Sequence(StyleTreeChildren),
+}
+
+impl StyleTreeNode {
+    pub fn to_text(&self, width: usize, style: Style) -> Text {
+        let mut printer = TextPrinter::new(width, style, true);
+        self.print(&mut printer, style);
+        printer.finish()
+    }
+
+    pub fn print<'a>(&'a self, printer: &mut TextPrinter<'a>, style: Style) {
+        let width = printer.width();
+
+        match self {
+            StyleTreeNode::Blockquote(child) => {
+                let mut subp = printer.sub(4);
+                child.print(&mut subp, style);
+
+                for mut line in subp.finish() {
+                    line.0.insert(0, Span::styled("    ", style));
+                    printer.push_line(line);
+                }
+            },
+            StyleTreeNode::Code(child, _) => {
+                child.print(printer, style);
+            },
+            StyleTreeNode::Header(child, level) => {
+                let style = style.add_modifier(StyleModifier::BOLD);
+                let mut hashes = "#".repeat(*level);
+                hashes.push(' ');
+
+                printer.push_str(hashes, style);
+                child.print(printer, style);
+            },
+            StyleTreeNode::Image(None) => {},
+            StyleTreeNode::Image(Some(alt)) => {
+                printer.commit();
+                printer.push_str("Image Alt: ", Style::default());
+                printer.push_str(alt, Style::default());
+                printer.commit();
+            },
+            StyleTreeNode::List(children, lt) => {
+                let mut bullets = lt.bullets(children.len());
+                let liw = bullets.width();
+
+                for child in children {
+                    let mut subp = printer.sub(liw);
+                    let mut bullet = bullets.next();
+                    child.print(&mut subp, style);
+
+                    for mut line in subp.finish() {
+                        let leading = if let Some(bullet) = bullet.take() {
+                            Span::styled(bullet, style)
+                        } else {
+                            Span::styled(" ".repeat(liw), style)
+                        };
+
+                        line.0.insert(0, leading);
+                        printer.push_line(line);
+                    }
+                }
+            },
+            StyleTreeNode::Paragraph(child) => {
+                printer.push_break();
+                child.print(printer, style);
+                printer.commit();
+            },
+            StyleTreeNode::Reply(child) => {
+                if printer.hide_reply() {
+                    return;
+                }
+
+                printer.push_break();
+                child.print(printer, style);
+                printer.commit();
+            },
+            StyleTreeNode::Ruler => {
+                printer.push_str(line::HORIZONTAL.repeat(width), style);
+            },
+            StyleTreeNode::Table(table) => {
+                let text = table.to_text(width, style);
+                printer.push_text(text);
+            },
+            StyleTreeNode::Break => {
+                printer.push_break();
+            },
+            StyleTreeNode::Text(s) => {
+                printer.push_str(s.as_str(), style);
+            },
+
+            StyleTreeNode::Style(child, patch) => child.print(printer, style.patch(*patch)),
+            StyleTreeNode::Sequence(children) => {
+                for child in children {
+                    child.print(printer, style);
+                }
+            },
+        }
+    }
+}
+
+pub struct StyleTree {
+    children: StyleTreeChildren,
+}
+
+impl StyleTree {
+    pub fn to_text(&self, width: usize, style: Style, hide_reply: bool) -> Text<'_> {
+        let mut printer = TextPrinter::new(width, style, hide_reply);
+
+        for child in self.children.iter() {
+            child.print(&mut printer, style);
+        }
+
+        printer.finish()
+    }
+}
+
+fn c2c(handles: &[Handle]) -> Vec<StyleTreeNode> {
+    handles.iter().flat_map(h2t).collect()
+}
+
+fn c2t(handles: &[Handle]) -> Box<StyleTreeNode> {
+    let node = StyleTreeNode::Sequence(c2c(handles));
+
+    Box::new(node)
+}
+
+fn get_node(hdl: &Handle, want: &str) -> Option<StyleTreeNode> {
+    let node = hdl.deref();
+
+    if let NodeData::Element { name, .. } = &node.data {
+        if name.local.as_ref() != want {
+            return None;
+        }
+
+        let c = c2c(&node.children.borrow());
+        return Some(StyleTreeNode::Sequence(c));
+    } else {
+        return None;
+    }
+}
+
+fn li2t(hdl: &Handle) -> Option<StyleTreeNode> {
+    get_node(hdl, "li")
+}
+
+fn table_cell(hdl: &Handle) -> Option<(CellType, StyleTreeNode)> {
+    if let Some(node) = get_node(hdl, "th") {
+        return Some((CellType::Header, node));
+    }
+
+    Some((CellType::Data, get_node(hdl, "td")?))
+}
+
+fn table_row(hdl: &Handle) -> Option<TableRow> {
+    let node = hdl.deref();
+
+    if let NodeData::Element { name, .. } = &node.data {
+        if name.local.as_ref() != "tr" {
+            return None;
+        }
+
+        let cells = table_cells(&node.children.borrow());
+        return Some(TableRow { cells });
+    } else {
+        return None;
+    }
+}
+
+fn table_section(hdl: &Handle) -> Option<TableSection> {
+    let node = hdl.deref();
+
+    if let NodeData::Element { name, .. } = &node.data {
+        match name.local.as_ref() {
+            "thead" | "tbody" => {
+                let rows = table_rows(&node.children.borrow());
+
+                Some(TableSection { rows })
+            },
+            _ => None,
+        }
+    } else {
+        return None;
+    }
+}
+
+fn table_cells(handles: &[Handle]) -> Vec<(CellType, StyleTreeNode)> {
+    handles.iter().filter_map(table_cell).collect()
+}
+
+fn table_rows(handles: &[Handle]) -> Vec<TableRow> {
+    handles.iter().filter_map(table_row).collect()
+}
+
+fn table_sections(handles: &[Handle]) -> Vec<TableSection> {
+    handles.iter().filter_map(table_section).collect()
+}
+
+fn lic2t(handles: &[Handle]) -> StyleTreeChildren {
+    handles.iter().filter_map(li2t).collect()
+}
+
+fn attrs_to_alt(attrs: &[Attribute]) -> Option<String> {
+    for attr in attrs {
+        if attr.name.local.as_ref() != "alt" {
+            continue;
+        }
+
+        return Some(attr.value.to_string());
+    }
+
+    return None;
+}
+
+fn attrs_to_language(attrs: &[Attribute]) -> Option<String> {
+    for attr in attrs {
+        if attr.name.local.as_ref() != "class" {
+            continue;
+        }
+
+        for class in attr.value.as_ref().unicode_words() {
+            if class.len() > 9 && class.starts_with("language-") {
+                return Some(class[9..].to_string());
+            }
+        }
+    }
+
+    return None;
+}
+
+fn attrs_to_style(attrs: &[Attribute]) -> Style {
+    let mut style = Style::default();
+
+    for attr in attrs {
+        match attr.name.local.as_ref() {
+            "data-mx-bg-color" => {
+                if let Ok(rgb) = attr.value.as_ref().parse::<CssColor>() {
+                    let color = Color::Rgb(rgb.r, rgb.g, rgb.b);
+                    style = style.bg(color);
+                }
+            },
+            "data-mx-color" | "color" => {
+                if let Ok(rgb) = attr.value.as_ref().parse::<CssColor>() {
+                    let color = Color::Rgb(rgb.r, rgb.g, rgb.b);
+                    style = style.fg(color);
+                }
+            },
+            _ => continue,
+        }
+    }
+
+    return style;
+}
+
+fn h2t(hdl: &Handle) -> StyleTreeChildren {
+    let node = hdl.deref();
+
+    let tree = match &node.data {
+        NodeData::Document => *c2t(node.children.borrow().as_slice()),
+        NodeData::Text { contents } => StyleTreeNode::Text(contents.borrow().to_string()),
+        NodeData::Element { name, attrs, .. } => {
+            match name.local.as_ref() {
+                // Message that this one replies to.
+                "mx-reply" => StyleTreeNode::Reply(c2t(&node.children.borrow())),
+
+                // Style change
+                "b" | "strong" => {
+                    let c = c2t(&node.children.borrow());
+                    let s = Style::default().add_modifier(StyleModifier::BOLD);
+
+                    StyleTreeNode::Style(c, s)
+                },
+                "font" => {
+                    let c = c2t(&node.children.borrow());
+                    let s = attrs_to_style(&attrs.borrow());
+
+                    StyleTreeNode::Style(c, s)
+                },
+                "em" | "i" => {
+                    let c = c2t(&node.children.borrow());
+                    let s = Style::default().add_modifier(StyleModifier::ITALIC);
+
+                    StyleTreeNode::Style(c, s)
+                },
+                "span" => {
+                    let c = c2t(&node.children.borrow());
+                    let s = attrs_to_style(&attrs.borrow());
+
+                    StyleTreeNode::Style(c, s)
+                },
+                "del" | "strike" => {
+                    let c = c2t(&node.children.borrow());
+                    let s = Style::default().add_modifier(StyleModifier::CROSSED_OUT);
+
+                    StyleTreeNode::Style(c, s)
+                },
+                "u" => {
+                    let c = c2t(&node.children.borrow());
+                    let s = Style::default().add_modifier(StyleModifier::UNDERLINED);
+
+                    StyleTreeNode::Style(c, s)
+                },
+
+                // Lists
+                "ol" => StyleTreeNode::List(lic2t(&node.children.borrow()), ListStyle::Ordered),
+                "ul" => StyleTreeNode::List(lic2t(&node.children.borrow()), ListStyle::Unordered),
+
+                // Headers
+                "h1" => StyleTreeNode::Header(c2t(&node.children.borrow()), 1),
+                "h2" => StyleTreeNode::Header(c2t(&node.children.borrow()), 2),
+                "h3" => StyleTreeNode::Header(c2t(&node.children.borrow()), 3),
+                "h4" => StyleTreeNode::Header(c2t(&node.children.borrow()), 4),
+                "h5" => StyleTreeNode::Header(c2t(&node.children.borrow()), 5),
+                "h6" => StyleTreeNode::Header(c2t(&node.children.borrow()), 6),
+
+                // Table
+                "table" => {
+                    let sections = table_sections(&node.children.borrow());
+                    let caption = node
+                        .children
+                        .borrow()
+                        .iter()
+                        .find_map(|hdl| get_node(hdl, "caption"))
+                        .map(Box::new);
+                    let table = Table { caption, sections };
+
+                    StyleTreeNode::Table(table)
+                },
+
+                // Code blocks.
+                "code" => {
+                    let c = c2t(&node.children.borrow());
+                    let l = attrs_to_language(&attrs.borrow());
+
+                    StyleTreeNode::Code(c, l)
+                },
+
+                // Other text blocks.
+                "blockquote" => StyleTreeNode::Blockquote(c2t(&node.children.borrow())),
+                "div" | "p" => StyleTreeNode::Paragraph(c2t(&node.children.borrow())),
+
+                // No children.
+                "hr" => StyleTreeNode::Ruler,
+                "br" => StyleTreeNode::Break,
+
+                "img" => StyleTreeNode::Image(attrs_to_alt(&attrs.borrow())),
+
+                // These don't render in any special way.
+                "a" | "details" | "html" | "pre" | "summary" | "sub" | "sup" => {
+                    *c2t(&node.children.borrow())
+                },
+
+                _ => return vec![],
+            }
+        },
+
+        // These don't render as anything.
+        NodeData::Doctype { .. } => return vec![],
+        NodeData::Comment { .. } => return vec![],
+        NodeData::ProcessingInstruction { .. } => return vec![],
+    };
+
+    vec![tree]
+}
+
+fn dom_to_style_tree(dom: RcDom) -> StyleTree {
+    StyleTree { children: h2t(&dom.document) }
+}
+
+pub fn parse_matrix_html(s: &str) -> StyleTree {
+    let dom = parse_fragment(
+        RcDom::default(),
+        ParseOpts::default(),
+        QualName::new(None, ns!(), local_name!("div")),
+        vec![],
+    )
+    .one(StrTendril::from(s));
+
+    dom_to_style_tree(dom)
+}
+
+#[cfg(test)]
+pub mod tests {
+    use super::*;
+    use crate::util::space_span;
+
+    #[test]
+    fn test_header() {
+        let bold = Style::default().add_modifier(StyleModifier::BOLD);
+
+        let s = "<h1>Header 1</h1>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("# ", bold),
+            Span::styled("Header 1", bold),
+            space_span(10, Style::default())
+        ])]);
+
+        let s = "<h2>Header 2</h2>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("## ", bold),
+            Span::styled("Header 2", bold),
+            space_span(9, Style::default())
+        ])]);
+
+        let s = "<h3>Header 3</h3>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("### ", bold),
+            Span::styled("Header 3", bold),
+            space_span(8, Style::default())
+        ])]);
+
+        let s = "<h4>Header 4</h4>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("#### ", bold),
+            Span::styled("Header 4", bold),
+            space_span(7, Style::default())
+        ])]);
+
+        let s = "<h5>Header 5</h5>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("##### ", bold),
+            Span::styled("Header 5", bold),
+            space_span(6, Style::default())
+        ])]);
+
+        let s = "<h6>Header 6</h6>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("###### ", bold),
+            Span::styled("Header 6", bold),
+            space_span(5, Style::default())
+        ])]);
+    }
+
+    #[test]
+    fn test_style() {
+        let def = Style::default();
+        let bold = def.add_modifier(StyleModifier::BOLD);
+        let italic = def.add_modifier(StyleModifier::ITALIC);
+        let strike = def.add_modifier(StyleModifier::CROSSED_OUT);
+        let underl = def.add_modifier(StyleModifier::UNDERLINED);
+        let red = def.fg(Color::Rgb(0xff, 0x00, 0x00));
+
+        let s = "<b>Bold!</b>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("Bold!", bold),
+            space_span(15, def)
+        ])]);
+
+        let s = "<strong>Bold!</strong>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("Bold!", bold),
+            space_span(15, def)
+        ])]);
+
+        let s = "<i>Italic!</i>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("Italic!", italic),
+            space_span(13, def)
+        ])]);
+
+        let s = "<em>Italic!</em>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("Italic!", italic),
+            space_span(13, def)
+        ])]);
+
+        let s = "<del>Strikethrough!</del>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("Strikethrough!", strike),
+            space_span(6, def)
+        ])]);
+
+        let s = "<strike>Strikethrough!</strike>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("Strikethrough!", strike),
+            space_span(6, def)
+        ])]);
+
+        let s = "<u>Underline!</u>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![
+            Span::styled("Underline!", underl),
+            space_span(10, def)
+        ])]);
+
+        let s = "<font color=\"#ff0000\">Red!</u>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![Span::styled("Red!", red), space_span(16, def)])]);
+
+        let s = "<font color=\"red\">Red!</u>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(20, Style::default(), false);
+        assert_eq!(text.lines, vec![Spans(vec![Span::styled("Red!", red), space_span(16, def)])]);
+    }
+
+    #[test]
+    fn test_paragraph() {
+        let s = "<p>Hello world!</p><p>Content</p><p>Goodbye world!</p>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(10, Style::default(), false);
+        assert_eq!(text.lines.len(), 7);
+        assert_eq!(text.lines[0], Spans(vec![Span::raw("Hello worl")]));
+        assert_eq!(text.lines[1], Spans(vec![Span::raw("d!"), Span::raw("        ")]));
+        assert_eq!(text.lines[2], Spans(vec![Span::raw("          ")]));
+        assert_eq!(text.lines[3], Spans(vec![Span::raw("Content"), Span::raw("   ")]));
+        assert_eq!(text.lines[4], Spans(vec![Span::raw("          ")]));
+        assert_eq!(text.lines[5], Spans(vec![Span::raw("Goodbye wo")]));
+        assert_eq!(text.lines[6], Spans(vec![Span::raw("rld!"), Span::raw("      ")]));
+    }
+
+    #[test]
+    fn test_blockquote() {
+        let s = "<blockquote>Hello world!</blockquote>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(10, Style::default(), false);
+        assert_eq!(text.lines.len(), 2);
+        assert_eq!(text.lines[0], Spans(vec![Span::raw("    "), Span::raw("Hello ")]));
+        assert_eq!(text.lines[1], Spans(vec![Span::raw("    "), Span::raw("world!")]));
+    }
+
+    #[test]
+    fn test_list_unordered() {
+        let s = "<ul><li>List Item 1</li><li>List Item 2</li><li>List Item 3</li></ul>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(8, Style::default(), false);
+        assert_eq!(text.lines.len(), 6);
+        assert_eq!(text.lines[0], Spans(vec![Span::raw("- "), Span::raw("List I")]));
+        assert_eq!(text.lines[1], Spans(vec![Span::raw("  "), Span::raw("tem 1"), Span::raw(" ")]));
+        assert_eq!(text.lines[2], Spans(vec![Span::raw("- "), Span::raw("List I")]));
+        assert_eq!(text.lines[3], Spans(vec![Span::raw("  "), Span::raw("tem 2"), Span::raw(" ")]));
+        assert_eq!(text.lines[4], Spans(vec![Span::raw("- "), Span::raw("List I")]));
+        assert_eq!(text.lines[5], Spans(vec![Span::raw("  "), Span::raw("tem 3"), Span::raw(" ")]));
+    }
+
+    #[test]
+    fn test_list_ordered() {
+        let s = "<ol><li>List Item 1</li><li>List Item 2</li><li>List Item 3</li></ol>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(9, Style::default(), false);
+        assert_eq!(text.lines.len(), 6);
+        assert_eq!(text.lines[0], Spans(vec![Span::raw("1. "), Span::raw("List I")]));
+        assert_eq!(
+            text.lines[1],
+            Spans(vec![Span::raw("   "), Span::raw("tem 1"), Span::raw(" ")])
+        );
+        assert_eq!(text.lines[2], Spans(vec![Span::raw("2. "), Span::raw("List I")]));
+        assert_eq!(
+            text.lines[3],
+            Spans(vec![Span::raw("   "), Span::raw("tem 2"), Span::raw(" ")])
+        );
+        assert_eq!(text.lines[4], Spans(vec![Span::raw("3. "), Span::raw("List I")]));
+        assert_eq!(
+            text.lines[5],
+            Spans(vec![Span::raw("   "), Span::raw("tem 3"), Span::raw(" ")])
+        );
+    }
+
+    #[test]
+    fn test_table() {
+        let s = "<table>\
+                 <thead>\
+                 <tr><th>Column 1</th><th>Column 2</th><th>Column 3</th></tr>
+                 </thead>\
+                 <tbody>\
+                 <tr><td>a</td><td>b</td><td>c</td></tr>\
+                 <tr><td>a</td><td>b</td><td>c</td></tr>\
+                 <tr><td>a</td><td>b</td><td>c</td></tr>\
+                 </tbody></table>";
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(15, Style::default(), false);
+        let bold = Style::default().add_modifier(StyleModifier::BOLD);
+        assert_eq!(text.lines.len(), 11);
+
+        // Table header
+        assert_eq!(text.lines[0].0, vec![Span::raw("┌────┬────┬───┐")]);
+        assert_eq!(text.lines[1].0, vec![
+            Span::raw("│"),
+            Span::styled("Colu", bold),
+            Span::raw("│"),
+            Span::styled("Colu", bold),
+            Span::raw("│"),
+            Span::styled("Col", bold),
+            Span::raw("│")
+        ]);
+        assert_eq!(text.lines[2].0, vec![
+            Span::raw("│"),
+            Span::styled("mn 1", bold),
+            Span::raw("│"),
+            Span::styled("mn 2", bold),
+            Span::raw("│"),
+            Span::styled("umn", bold),
+            Span::raw("│")
+        ]);
+        assert_eq!(text.lines[3].0, vec![
+            Span::raw("│"),
+            Span::raw("    "),
+            Span::raw("│"),
+            Span::raw("    "),
+            Span::raw("│"),
+            Span::styled(" 3", bold),
+            Span::styled(" ", bold),
+            Span::raw("│")
+        ]);
+
+        // First row
+        assert_eq!(text.lines[4].0, vec![Span::raw("├────┼────┼───┤")]);
+        assert_eq!(text.lines[5].0, vec![
+            Span::raw("│"),
+            Span::raw("a"),
+            Span::raw("   "),
+            Span::raw("│"),
+            Span::raw("b"),
+            Span::raw("   "),
+            Span::raw("│"),
+            Span::raw("c"),
+            Span::raw("  "),
+            Span::raw("│")
+        ]);
+
+        // Second row
+        assert_eq!(text.lines[6].0, vec![Span::raw("├────┼────┼───┤")]);
+        assert_eq!(text.lines[7].0, vec![
+            Span::raw("│"),
+            Span::raw("a"),
+            Span::raw("   "),
+            Span::raw("│"),
+            Span::raw("b"),
+            Span::raw("   "),
+            Span::raw("│"),
+            Span::raw("c"),
+            Span::raw("  "),
+            Span::raw("│")
+        ]);
+
+        // Third row
+        assert_eq!(text.lines[8].0, vec![Span::raw("├────┼────┼───┤")]);
+        assert_eq!(text.lines[9].0, vec![
+            Span::raw("│"),
+            Span::raw("a"),
+            Span::raw("   "),
+            Span::raw("│"),
+            Span::raw("b"),
+            Span::raw("   "),
+            Span::raw("│"),
+            Span::raw("c"),
+            Span::raw("  "),
+            Span::raw("│")
+        ]);
+
+        // Bottom ruler
+        assert_eq!(text.lines[10].0, vec![Span::raw("└────┴────┴───┘")]);
+    }
+
+    #[test]
+    fn test_matrix_reply() {
+        let s = "<mx-reply>This was replied to</mx-reply>This is the reply";
+
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(10, Style::default(), false);
+        assert_eq!(text.lines.len(), 4);
+        assert_eq!(text.lines[0], Spans(vec![Span::raw("This was r")]));
+        assert_eq!(text.lines[1], Spans(vec![Span::raw("eplied to"), Span::raw(" ")]));
+        assert_eq!(text.lines[2], Spans(vec![Span::raw("This is th")]));
+        assert_eq!(text.lines[3], Spans(vec![Span::raw("e reply"), Span::raw("   ")]));
+
+        let tree = parse_matrix_html(s);
+        let text = tree.to_text(10, Style::default(), true);
+        assert_eq!(text.lines.len(), 2);
+        assert_eq!(text.lines[0], Spans(vec![Span::raw("This is th")]));
+        assert_eq!(text.lines[1], Spans(vec![Span::raw("e reply"), Span::raw("   ")]));
+    }
+}

src/message/mod.rs

@@ -4,19 +4,20 @@ use std::collections::hash_map::DefaultHasher;
 use std::collections::BTreeMap;
 use std::convert::TryFrom;
 use std::hash::{Hash, Hasher};
-use std::str::Lines;
 
 use chrono::{DateTime, NaiveDateTime, Utc};
-use unicode_segmentation::UnicodeSegmentation;
 use unicode_width::UnicodeWidthStr;
 
 use matrix_sdk::ruma::{
     events::{
         room::{
             message::{
+                FormattedBody,
+                MessageFormat,
                 MessageType,
                 OriginalRoomMessageEvent,
                 RedactedRoomMessageEvent,
+                Relation,
                 RoomMessageEvent,
                 RoomMessageEventContent,
             },
@@ -33,6 +34,7 @@ use matrix_sdk::ruma::{
 
 use modalkit::tui::{
     style::{Modifier as StyleModifier, Style},
+    symbols::line::THICK_VERTICAL,
     text::{Span, Spans, Text},
 };
 
@@ -41,8 +43,13 @@ use modalkit::editing::{base::ViewportContext, cursor::Cursor};
 use crate::{
     base::{IambResult, RoomInfo},
     config::ApplicationSettings,
+    message::html::{parse_matrix_html, StyleTree},
+    util::{space_span, wrapped_text},
 };
 
+mod html;
+mod printer;
+
 pub type MessageFetchResult = IambResult<(Option<String>, Vec<RoomMessageEvent>)>;
 pub type MessageKey = (MessageTimeStamp, OwnedEventId);
 pub type Messages = BTreeMap<MessageKey, Message>;
@@ -62,65 +69,6 @@ const USER_GUTTER_EMPTY_SPAN: Span<'static> = Span {
     },
 };
 
-struct WrappedLinesIterator<'a> {
-    iter: Lines<'a>,
-    curr: Option<&'a str>,
-    width: usize,
-}
-
-impl<'a> WrappedLinesIterator<'a> {
-    fn new(input: &'a str, width: usize) -> Self {
-        WrappedLinesIterator { iter: input.lines(), curr: None, width }
-    }
-}
-
-impl<'a> Iterator for WrappedLinesIterator<'a> {
-    type Item = (&'a str, usize);
-
-    fn next(&mut self) -> Option<Self::Item> {
-        if self.curr.is_none() {
-            self.curr = self.iter.next();
-        }
-
-        if let Some(s) = self.curr.take() {
-            let width = UnicodeWidthStr::width(s);
-
-            if width <= self.width {
-                return Some((s, width));
-            } else {
-                // Find where to split the line.
-                let mut width = 0;
-                let mut idx = 0;
-
-                for (i, g) in UnicodeSegmentation::grapheme_indices(s, true) {
-                    let gw = UnicodeWidthStr::width(g);
-                    idx = i;
-
-                    if width + gw > self.width {
-                        break;
-                    }
-
-                    width += gw;
-                }
-
-                self.curr = Some(&s[idx..]);
-
-                return Some((&s[..idx], width));
-            }
-        } else {
-            return None;
-        }
-    }
-}
-
-fn wrap(input: &str, width: usize) -> WrappedLinesIterator<'_> {
-    WrappedLinesIterator::new(input, width)
-}
-
-fn space(width: usize) -> String {
-    " ".repeat(width)
-}
-
 #[derive(thiserror::Error, Debug)]
 pub enum TimeStampIntError {
     #[error("Integer conversion error: {0}")]
@@ -327,9 +275,9 @@ pub enum MessageEvent {
 }
 
 impl MessageEvent {
-    pub fn show(&self) -> Cow<'_, str> {
+    pub fn body(&self) -> Cow<'_, str> {
         match self {
-            MessageEvent::Original(ev) => show_room_content(&ev.content),
+            MessageEvent::Original(ev) => body_cow_content(&ev.content),
             MessageEvent::Redacted(ev) => {
                 let reason = ev
                     .unsigned
@@ -344,7 +292,25 @@ impl MessageEvent {
                     Cow::Borrowed("[Redacted]")
                 }
             },
-            MessageEvent::Local(content) => show_room_content(content),
+            MessageEvent::Local(content) => body_cow_content(content),
+        }
+    }
+
+    pub fn html(&self) -> Option<StyleTree> {
+        let content = match self {
+            MessageEvent::Original(ev) => &ev.content,
+            MessageEvent::Redacted(_) => return None,
+            MessageEvent::Local(content) => content,
+        };
+
+        if let MessageType::Text(content) = &content.msgtype {
+            if let Some(FormattedBody { format: MessageFormat::Html, body }) = &content.formatted {
+                Some(parse_matrix_html(body.as_str()))
+            } else {
+                None
+            }
+        } else {
+            None
         }
     }
 
@@ -360,18 +326,14 @@ impl MessageEvent {
     }
 }
 
-fn show_room_content(content: &RoomMessageEventContent) -> Cow<'_, str> {
+fn body_cow_content(content: &RoomMessageEventContent) -> Cow<'_, str> {
     let s = match &content.msgtype {
-        MessageType::Text(content) => content.body.as_ref(),
+        MessageType::Text(content) => content.body.as_str(),
+        MessageType::VerificationRequest(_) => "[Verification Request]",
         MessageType::Emote(content) => content.body.as_ref(),
         MessageType::Notice(content) => content.body.as_str(),
         MessageType::ServerNotice(content) => content.body.as_str(),
 
-        MessageType::VerificationRequest(_) => {
-            // XXX: implement
-
-            return Cow::Owned("[verification request]".into());
-        },
         MessageType::Audio(content) => {
             return Cow::Owned(format!("[Attached Audio: {}]", content.body));
         },
@@ -392,37 +354,93 @@ fn show_room_content(content: &RoomMessageEventContent) -> Cow<'_, str> {
     Cow::Borrowed(s)
 }
 
-#[derive(Clone)]
+enum MessageColumns<'a> {
+    Three(usize, Option<Span<'a>>, Option<Span<'a>>),
+    Two(usize, Option<Span<'a>>),
+    One(usize, Option<Span<'a>>),
+}
+
+impl<'a> MessageColumns<'a> {
+    fn width(&self) -> usize {
+        match self {
+            MessageColumns::Three(fill, _, _) => *fill,
+            MessageColumns::Two(fill, _) => *fill,
+            MessageColumns::One(fill, _) => *fill,
+        }
+    }
+
+    #[inline]
+    fn push_spans(&mut self, spans: Spans<'a>, style: Style, text: &mut Text<'a>) {
+        match self {
+            MessageColumns::Three(_, user, time) => {
+                let user = user.take().unwrap_or(USER_GUTTER_EMPTY_SPAN);
+                let time = time.take().unwrap_or_else(|| Span::from(""));
+
+                let mut line = vec![user];
+                line.extend(spans.0);
+                line.push(time);
+
+                text.lines.push(Spans(line))
+            },
+            MessageColumns::Two(_, opt) => {
+                let user = opt.take().unwrap_or(USER_GUTTER_EMPTY_SPAN);
+                let mut line = vec![user];
+                line.extend(spans.0);
+
+                text.lines.push(Spans(line));
+            },
+            MessageColumns::One(_, opt) => {
+                if let Some(user) = opt.take() {
+                    text.lines.push(Spans(vec![user]));
+                }
+
+                let leading = space_span(2, style);
+                let mut line = vec![leading];
+                line.extend(spans.0);
+
+                text.lines.push(Spans(line));
+            },
+        }
+    }
+
+    fn push_text(&mut self, append: Text<'a>, style: Style, text: &mut Text<'a>) {
+        for line in append.lines.into_iter() {
+            self.push_spans(line, style, text);
+        }
+    }
+}
+
 pub struct Message {
     pub event: MessageEvent,
     pub sender: OwnedUserId,
     pub timestamp: MessageTimeStamp,
     pub downloaded: bool,
+    pub html: Option<StyleTree>,
 }
 
 impl Message {
     pub fn new(event: MessageEvent, sender: OwnedUserId, timestamp: MessageTimeStamp) -> Self {
-        Message { event, sender, timestamp, downloaded: false }
+        let html = event.html();
+        let downloaded = false;
+
+        Message { event, sender, timestamp, downloaded, html }
     }
 
-    pub fn show(
-        &self,
-        prev: Option<&Message>,
-        selected: bool,
-        vwctx: &ViewportContext<MessageCursor>,
-        settings: &ApplicationSettings,
-    ) -> Text {
-        let width = vwctx.get_width();
-        let mut msg = self.event.show();
+    pub fn reply_to(&self) -> Option<OwnedEventId> {
+        let content = match &self.event {
+            MessageEvent::Local(content) => content,
+            MessageEvent::Original(ev) => &ev.content,
+            MessageEvent::Redacted(_) => return None,
+        };
 
-        if self.downloaded {
-            msg.to_mut().push_str(" \u{2705}");
+        if let Some(Relation::Reply { in_reply_to }) = &content.relates_to {
+            Some(in_reply_to.event_id.clone())
+        } else {
+            None
         }
+    }
 
-        let msg = msg.as_ref();
-
-        let mut lines = vec![];
-
+    fn get_render_style(&self, selected: bool) -> Style {
         let mut style = Style::default();
 
         if selected {
@@ -433,54 +451,109 @@ impl Message {
             style = style.add_modifier(StyleModifier::ITALIC);
         }
 
+        return style;
+    }
+
+    fn get_render_format(
+        &self,
+        prev: Option<&Message>,
+        width: usize,
+        settings: &ApplicationSettings,
+    ) -> MessageColumns {
         if USER_GUTTER + TIME_GUTTER + MIN_MSG_LEN <= width {
             let lw = width - USER_GUTTER - TIME_GUTTER;
+            let user = self.show_sender(prev, true, settings);
+            let time = self.timestamp.show();
 
-            for (i, (line, w)) in wrap(msg, lw).enumerate() {
-                let line = Span::styled(line.to_string(), style);
-                let trailing = Span::styled(space(lw.saturating_sub(w)), style);
-
-                if i == 0 {
-                    let user = self.show_sender(prev, true, settings);
-
-                    if let Some(time) = self.timestamp.show() {
-                        lines.push(Spans(vec![user, line, trailing, time]))
-                    } else {
-                        lines.push(Spans(vec![user, line, trailing]))
-                    }
-                } else {
-                    let space = USER_GUTTER_EMPTY_SPAN;
-
-                    lines.push(Spans(vec![space, line, trailing]))
-                }
-            }
+            MessageColumns::Three(lw, user, time)
         } else if USER_GUTTER + MIN_MSG_LEN <= width {
             let lw = width - USER_GUTTER;
+            let user = self.show_sender(prev, true, settings);
 
-            for (i, (line, w)) in wrap(msg, lw).enumerate() {
-                let line = Span::styled(line.to_string(), style);
-                let trailing = Span::styled(space(lw.saturating_sub(w)), style);
-
-                let prefix = if i == 0 {
-                    self.show_sender(prev, true, settings)
-                } else {
-                    USER_GUTTER_EMPTY_SPAN
-                };
-
-                lines.push(Spans(vec![prefix, line, trailing]))
-            }
+            MessageColumns::Two(lw, user)
         } else {
-            lines.push(Spans::from(self.show_sender(prev, false, settings)));
+            let lw = width.saturating_sub(2);
+            let user = self.show_sender(prev, false, settings);
 
-            for (line, _) in wrap(msg, width.saturating_sub(2)) {
-                let line = format!("  {}", line);
-                let line = Span::styled(line, style);
+            MessageColumns::One(lw, user)
+        }
+    }
 
-                lines.push(Spans(vec![line]))
+    pub fn show<'a>(
+        &'a self,
+        prev: Option<&Message>,
+        selected: bool,
+        vwctx: &ViewportContext<MessageCursor>,
+        info: &'a RoomInfo,
+        settings: &ApplicationSettings,
+    ) -> Text<'a> {
+        let width = vwctx.get_width();
+
+        let style = self.get_render_style(selected);
+        let mut fmt = self.get_render_format(prev, width, settings);
+        let mut text = Text { lines: vec![] };
+        let width = fmt.width();
+
+        // Show the message that this one replied to, if any.
+        let reply = self.reply_to().and_then(|e| info.get_event(&e));
+
+        if let Some(r) = &reply {
+            let w = width.saturating_sub(2);
+            let mut replied = r.show_msg(w, style, true);
+            let mut sender = r.sender_span(settings);
+            let sender_width = UnicodeWidthStr::width(sender.content.as_ref());
+            let trailing = w.saturating_sub(sender_width + 1);
+
+            sender.style = sender.style.patch(style);
+
+            fmt.push_spans(
+                Spans(vec![
+                    Span::styled(" ", style),
+                    Span::styled(THICK_VERTICAL, style),
+                    sender,
+                    Span::styled(":", style),
+                    space_span(trailing, style),
+                ]),
+                style,
+                &mut text,
+            );
+
+            for line in replied.lines.iter_mut() {
+                line.0.insert(0, Span::styled(THICK_VERTICAL, style));
+                line.0.insert(0, Span::styled(" ", style));
             }
+
+            fmt.push_text(replied, style, &mut text);
         }
 
-        return Text { lines };
+        // Now show the message contents, and the inlined reply if we couldn't find it above.
+        let msg = self.show_msg(width, style, reply.is_some());
+        fmt.push_text(msg, style, &mut text);
+
+        if text.lines.is_empty() {
+            // If there was nothing in the body, just show an empty message.
+            fmt.push_spans(space_span(width, style).into(), style, &mut text);
+        }
+
+        return text;
+    }
+
+    pub fn show_msg(&self, width: usize, style: Style, hide_reply: bool) -> Text {
+        if let Some(html) = &self.html {
+            html.to_text(width, style, hide_reply)
+        } else {
+            let mut msg = self.event.body();
+
+            if self.downloaded {
+                msg.to_mut().push_str(" \u{2705}");
+            }
+
+            wrapped_text(msg, width, style)
+        }
+    }
+
+    fn sender_span(&self, settings: &ApplicationSettings) -> Span {
+        settings.get_user_span(self.sender.as_ref())
     }
 
     fn show_sender(
@@ -488,11 +561,11 @@ impl Message {
         prev: Option<&Message>,
         align_right: bool,
         settings: &ApplicationSettings,
-    ) -> Span {
+    ) -> Option<Span> {
         let user = if matches!(prev, Some(prev) if self.sender == prev.sender) {
-            USER_GUTTER_EMPTY_SPAN
+            return None;
         } else {
-            settings.get_user_span(self.sender.as_ref())
+            self.sender_span(settings)
         };
 
         let Span { content, style } = user;
@@ -505,7 +578,7 @@ impl Message {
             format!("{: <width$}  ", s, width = 28)
         };
 
-        Span::styled(sender, style)
+        Span::styled(sender, style).into()
     }
 }
 
@@ -540,7 +613,7 @@ impl From<RoomMessageEvent> for Message {
 
 impl ToString for Message {
     fn to_string(&self) -> String {
-        self.event.show().into_owned()
+        self.event.body().into_owned()
     }
 }
 
@@ -549,47 +622,6 @@ pub mod tests {
     use super::*;
     use crate::tests::*;
 
-    #[test]
-    fn test_wrapped_lines_ascii() {
-        let s = "hello world!\nabcdefghijklmnopqrstuvwxyz\ngoodbye";
-
-        let mut iter = wrap(s, 100);
-        assert_eq!(iter.next(), Some(("hello world!", 12)));
-        assert_eq!(iter.next(), Some(("abcdefghijklmnopqrstuvwxyz", 26)));
-        assert_eq!(iter.next(), Some(("goodbye", 7)));
-        assert_eq!(iter.next(), None);
-
-        let mut iter = wrap(s, 5);
-        assert_eq!(iter.next(), Some(("hello", 5)));
-        assert_eq!(iter.next(), Some((" worl", 5)));
-        assert_eq!(iter.next(), Some(("d!", 2)));
-        assert_eq!(iter.next(), Some(("abcde", 5)));
-        assert_eq!(iter.next(), Some(("fghij", 5)));
-        assert_eq!(iter.next(), Some(("klmno", 5)));
-        assert_eq!(iter.next(), Some(("pqrst", 5)));
-        assert_eq!(iter.next(), Some(("uvwxy", 5)));
-        assert_eq!(iter.next(), Some(("z", 1)));
-        assert_eq!(iter.next(), Some(("goodb", 5)));
-        assert_eq!(iter.next(), Some(("ye", 2)));
-        assert_eq!(iter.next(), None);
-    }
-
-    #[test]
-    fn test_wrapped_lines_unicode() {
-        let s = "ＣＨＩＣＫＥＮ";
-
-        let mut iter = wrap(s, 14);
-        assert_eq!(iter.next(), Some((s, 14)));
-        assert_eq!(iter.next(), None);
-
-        let mut iter = wrap(s, 5);
-        assert_eq!(iter.next(), Some(("ＣＨ", 4)));
-        assert_eq!(iter.next(), Some(("ＩＣ", 4)));
-        assert_eq!(iter.next(), Some(("ＫＥ", 4)));
-        assert_eq!(iter.next(), Some(("Ｎ", 2)));
-        assert_eq!(iter.next(), None);
-    }
-
     #[test]
     fn test_mc_cmp() {
         let mc1 = MessageCursor::from(MSG1_KEY.clone());

src/message/printer.rs

@@ -0,0 +1,157 @@
+use std::borrow::Cow;
+
+use modalkit::tui::layout::Alignment;
+use modalkit::tui::style::Style;
+use modalkit::tui::text::{Span, Spans, Text};
+use unicode_width::UnicodeWidthStr;
+
+use crate::util::{space_span, take_width};
+
+pub struct TextPrinter<'a> {
+    text: Text<'a>,
+    width: usize,
+    base_style: Style,
+    hide_reply: bool,
+
+    alignment: Alignment,
+    curr_spans: Vec<Span<'a>>,
+    curr_width: usize,
+}
+
+impl<'a> TextPrinter<'a> {
+    pub fn new(width: usize, base_style: Style, hide_reply: bool) -> Self {
+        TextPrinter {
+            text: Text::default(),
+            width,
+            base_style,
+            hide_reply,
+
+            alignment: Alignment::Left,
+            curr_spans: vec![],
+            curr_width: 0,
+        }
+    }
+
+    pub fn align(mut self, alignment: Alignment) -> Self {
+        self.alignment = alignment;
+        self
+    }
+
+    pub fn hide_reply(&self) -> bool {
+        self.hide_reply
+    }
+
+    pub fn width(&self) -> usize {
+        self.width
+    }
+
+    pub fn sub(&self, indent: usize) -> Self {
+        TextPrinter {
+            text: Text::default(),
+            width: self.width.saturating_sub(indent),
+            base_style: self.base_style,
+            hide_reply: self.hide_reply,
+
+            alignment: self.alignment,
+            curr_spans: vec![],
+            curr_width: 0,
+        }
+    }
+
+    fn remaining(&self) -> usize {
+        self.width - self.curr_width
+    }
+
+    pub fn commit(&mut self) {
+        if self.curr_width > 0 {
+            self.push_break();
+        }
+    }
+
+    fn push(&mut self) {
+        self.curr_width = 0;
+        self.text.lines.push(Spans(std::mem::take(&mut self.curr_spans)));
+    }
+
+    pub fn push_break(&mut self) {
+        if self.curr_width == 0 && self.text.lines.is_empty() {
+            // Disallow leading breaks.
+            return;
+        }
+
+        let remaining = self.remaining();
+
+        if remaining > 0 {
+            match self.alignment {
+                Alignment::Left => {
+                    let tspan = space_span(remaining, self.base_style);
+                    self.curr_spans.push(tspan);
+                },
+                Alignment::Center => {
+                    let trailing = remaining / 2;
+                    let leading = remaining - trailing;
+
+                    let tspan = space_span(trailing, self.base_style);
+                    let lspan = space_span(leading, self.base_style);
+
+                    self.curr_spans.push(tspan);
+                    self.curr_spans.insert(0, lspan);
+                },
+                Alignment::Right => {
+                    let lspan = space_span(remaining, self.base_style);
+                    self.curr_spans.insert(0, lspan);
+                },
+            }
+        }
+
+        self.push();
+    }
+
+    pub fn push_str<T>(&mut self, s: T, style: Style)
+    where
+        T: Into<Cow<'a, str>>,
+    {
+        let style = self.base_style.patch(style);
+        let mut cow = s.into();
+
+        loop {
+            let sw = UnicodeWidthStr::width(cow.as_ref());
+
+            if self.curr_width + sw <= self.width {
+                // The text fits within the current line.
+                self.curr_spans.push(Span::styled(cow, style));
+                self.curr_width += sw;
+                break;
+            }
+
+            // Take a leading portion of the text that fits in the line.
+            let ((s0, w), s1) = take_width(cow, self.remaining());
+            cow = s1;
+
+            self.curr_spans.push(Span::styled(s0, style));
+            self.curr_width += w;
+
+            self.commit();
+        }
+
+        if self.curr_width == self.width {
+            // If the last bit fills the full line, start a new one.
+            self.push();
+        }
+    }
+
+    pub fn push_line(&mut self, spans: Spans<'a>) {
+        self.commit();
+        self.text.lines.push(spans);
+    }
+
+    pub fn push_text(&mut self, text: Text<'a>) {
+        self.commit();
+        self.text.lines.extend(text.lines);
+    }
+
+    pub fn finish(mut self) -> Text<'a> {
+        self.commit();
+        self.text
+    }
+}

src/util.rs

@@ -0,0 +1,191 @@
+use std::borrow::Cow;
+
+use unicode_segmentation::UnicodeSegmentation;
+use unicode_width::UnicodeWidthStr;
+
+use modalkit::tui::style::Style;
+use modalkit::tui::text::{Span, Spans, Text};
+
+pub fn split_cow(cow: Cow<'_, str>, idx: usize) -> (Cow<'_, str>, Cow<'_, str>) {
+    match cow {
+        Cow::Borrowed(s) => {
+            let s1 = Cow::Borrowed(&s[idx..]);
+            let s0 = Cow::Borrowed(&s[..idx]);
+
+            (s0, s1)
+        },
+        Cow::Owned(mut s) => {
+            let s1 = Cow::Owned(s.split_off(idx));
+            let s0 = Cow::Owned(s);
+
+            (s0, s1)
+        },
+    }
+}
+
+pub fn take_width(s: Cow<'_, str>, width: usize) -> ((Cow<'_, str>, usize), Cow<'_, str>) {
+    // Find where to split the line.
+    let mut idx = 0;
+    let mut w = 0;
+
+    for (i, g) in UnicodeSegmentation::grapheme_indices(s.as_ref(), true) {
+        let gw = UnicodeWidthStr::width(g);
+        idx = i;
+
+        if w + gw > width {
+            break;
+        }
+
+        w += gw;
+    }
+
+    let (s0, s1) = split_cow(s, idx);
+
+    ((s0, w), s1)
+}
+
+pub struct WrappedLinesIterator<'a> {
+    iter: std::vec::IntoIter<Cow<'a, str>>,
+    curr: Option<Cow<'a, str>>,
+    width: usize,
+}
+
+impl<'a> WrappedLinesIterator<'a> {
+    fn new<T>(input: T, width: usize) -> Self
+    where
+        T: Into<Cow<'a, str>>,
+    {
+        let width = width.max(2);
+
+        let cows: Vec<Cow<'a, str>> = match input.into() {
+            Cow::Borrowed(s) => s.lines().map(Cow::Borrowed).collect(),
+            Cow::Owned(s) => s.lines().map(ToOwned::to_owned).map(Cow::Owned).collect(),
+        };
+
+        WrappedLinesIterator { iter: cows.into_iter(), curr: None, width }
+    }
+}
+
+impl<'a> Iterator for WrappedLinesIterator<'a> {
+    type Item = (Cow<'a, str>, usize);
+
+    fn next(&mut self) -> Option<Self::Item> {
+        if self.curr.is_none() {
+            self.curr = self.iter.next();
+        }
+
+        if let Some(s) = self.curr.take() {
+            let width = UnicodeWidthStr::width(s.as_ref());
+
+            if width <= self.width {
+                return Some((s, width));
+            } else {
+                let (prefix, s1) = take_width(s, self.width);
+                self.curr = Some(s1);
+                return Some(prefix);
+            }
+        } else {
+            return None;
+        }
+    }
+}
+
+pub fn wrap<'a, T>(input: T, width: usize) -> WrappedLinesIterator<'a>
+where
+    T: Into<Cow<'a, str>>,
+{
+    WrappedLinesIterator::new(input, width)
+}
+
+pub fn wrapped_text<'a, T>(s: T, width: usize, style: Style) -> Text<'a>
+where
+    T: Into<Cow<'a, str>>,
+{
+    let mut text = Text::default();
+
+    for (line, w) in wrap(s, width) {
+        let space = space_span(width.saturating_sub(w), style);
+        let spans = Spans(vec![Span::styled(line, style), space]);
+
+        text.lines.push(spans);
+    }
+
+    return text;
+}
+
+pub fn space(width: usize) -> String {
+    " ".repeat(width)
+}
+
+pub fn space_span(width: usize, style: Style) -> Span<'static> {
+    Span::styled(space(width), style)
+}
+
+pub fn space_text(width: usize, style: Style) -> Text<'static> {
+    space_span(width, style).into()
+}
+
+pub fn join_cell_text<'a>(texts: Vec<(Text<'a>, usize)>, join: Span<'a>) -> Text<'a> {
+    let height = texts.iter().map(|t| t.0.height()).max().unwrap_or(0);
+    let mut text = Text { lines: vec![Spans(vec![join.clone()]); height] };
+
+    for (mut t, w) in texts.into_iter() {
+        for i in 0..height {
+            if let Some(spans) = t.lines.get_mut(i) {
+                text.lines[i].0.append(&mut spans.0);
+            } else {
+                text.lines[i].0.push(space_span(w, Style::default()));
+            }
+
+            text.lines[i].0.push(join.clone());
+        }
+    }
+
+    text
+}
+
+#[cfg(test)]
+pub mod tests {
+    use super::*;
+
+    #[test]
+    fn test_wrapped_lines_ascii() {
+        let s = "hello world!\nabcdefghijklmnopqrstuvwxyz\ngoodbye";
+
+        let mut iter = wrap(s, 100);
+        assert_eq!(iter.next(), Some((Cow::Borrowed("hello world!"), 12)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("abcdefghijklmnopqrstuvwxyz"), 26)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("goodbye"), 7)));
+        assert_eq!(iter.next(), None);
+
+        let mut iter = wrap(s, 5);
+        assert_eq!(iter.next(), Some((Cow::Borrowed("hello"), 5)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed(" worl"), 5)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("d!"), 2)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("abcde"), 5)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("fghij"), 5)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("klmno"), 5)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("pqrst"), 5)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("uvwxy"), 5)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("z"), 1)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("goodb"), 5)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("ye"), 2)));
+        assert_eq!(iter.next(), None);
+    }
+
+    #[test]
+    fn test_wrapped_lines_unicode() {
+        let s = "ＣＨＩＣＫＥＮ";
+
+        let mut iter = wrap(s, 14);
+        assert_eq!(iter.next(), Some((Cow::Borrowed(s), 14)));
+        assert_eq!(iter.next(), None);
+
+        let mut iter = wrap(s, 5);
+        assert_eq!(iter.next(), Some((Cow::Borrowed("ＣＨ"), 4)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("ＩＣ"), 4)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("ＫＥ"), 4)));
+        assert_eq!(iter.next(), Some((Cow::Borrowed("Ｎ"), 2)));
+        assert_eq!(iter.next(), None);
+    }
+}

src/windows/room/chat.rs

@@ -324,7 +324,7 @@ impl ChatState {
                     return Ok(None);
                 }
 
-                let msg = TextMessageEventContent::plain(msg);
+                let msg = TextMessageEventContent::markdown(msg);
                 let msg = MessageType::Text(msg);
 
                 let mut msg = RoomMessageEventContent::new(msg);

src/windows/room/scrollback.rs

@@ -214,7 +214,7 @@ impl ScrollbackState {
 
                 for (key, item) in info.messages.range(..=&idx).rev() {
                     let sel = selidx == key;
-                    let len = item.show(None, sel, &self.viewctx, settings).lines.len();
+                    let len = item.show(None, sel, &self.viewctx, info, settings).lines.len();
 
                     if key == &idx {
                         lines += len / 2;
@@ -236,7 +236,7 @@ impl ScrollbackState {
 
                 for (key, item) in info.messages.range(..=&idx).rev() {
                     let sel = key == selidx;
-                    let len = item.show(None, sel, &self.viewctx, settings).lines.len();
+                    let len = item.show(None, sel, &self.viewctx, info, settings).lines.len();
 
                     lines += len;
 
@@ -276,7 +276,7 @@ impl ScrollbackState {
                 break;
             }
 
-            lines += item.show(None, false, &self.viewctx, settings).height().max(1);
+            lines += item.show(None, false, &self.viewctx, info, settings).height().max(1);
 
             if lines >= self.viewctx.get_height() {
                 // We've reached the end of the viewport; move cursor into it.
@@ -431,7 +431,7 @@ impl ScrollbackState {
                 continue;
             }
 
-            if needle.is_match(msg.event.show().as_ref()) {
+            if needle.is_match(msg.event.body().as_ref()) {
                 mc = MessageCursor::from(key.clone()).into();
                 count -= 1;
             }
@@ -455,7 +455,7 @@ impl ScrollbackState {
                 break;
             }
 
-            if needle.is_match(msg.event.show().as_ref()) {
+            if needle.is_match(msg.event.body().as_ref()) {
                 mc = MessageCursor::from(key.clone()).into();
                 count -= 1;
             }
@@ -704,7 +704,7 @@ impl EditorActions<ProgramContext, ProgramStore, IambInfo> for ScrollbackState {
                     let mut yanked = EditRope::from("");
 
                     for (_, msg) in self.messages(range, info) {
-                        yanked += EditRope::from(msg.event.show().into_owned());
+                        yanked += EditRope::from(msg.event.body());
                         yanked += EditRope::from('\n');
                     }
 
@@ -1009,7 +1009,7 @@ impl ScrollActions<ProgramContext, ProgramStore, IambInfo> for ScrollbackState {
 
                 for (key, item) in info.messages.range(..=&corner_key).rev() {
                     let sel = key == cursor_key;
-                    let txt = item.show(None, sel, &self.viewctx, settings);
+                    let txt = item.show(None, sel, &self.viewctx, info, settings);
                     let len = txt.height().max(1);
                     let max = len.saturating_sub(1);
 
@@ -1035,7 +1035,7 @@ impl ScrollActions<ProgramContext, ProgramStore, IambInfo> for ScrollbackState {
             MoveDir2D::Down => {
                 for (key, item) in info.messages.range(&corner_key..) {
                     let sel = key == cursor_key;
-                    let txt = item.show(None, sel, &self.viewctx, settings);
+                    let txt = item.show(None, sel, &self.viewctx, info, settings);
                     let len = txt.height().max(1);
                     let max = len.saturating_sub(1);
 
@@ -1218,7 +1218,7 @@ impl<'a> StatefulWidget for Scrollback<'a> {
 
         for (key, item) in info.messages.range(&corner_key..) {
             let sel = key == cursor_key;
-            let txt = item.show(prev, foc && sel, &state.viewctx, settings);
+            let txt = item.show(prev, foc && sel, &state.viewctx, info, settings);
 
             prev = Some(item);