message-row: Add support for preformatted HTML element

When it is not a code block.

src/session_view/room_history/message_row/text/inline_html.rs

@@ -23,6 +23,8 @@ pub(super) struct InlineHtmlBuilder<'a> {
     single_line: bool,
     /// Whether to append an ellipsis at the end of the string.
     ellipsis: bool,
+    /// Whether whitespace should be preserved.
+    preserve_whitespace: bool,
     /// The mentions detection setting and results.
     mentions: MentionsMode<'a>,
     /// The inner string.
@@ -39,12 +41,16 @@ impl<'a> InlineHtmlBuilder<'a> {
     /// If `single_line` is set to `true`, the string will be ellipsized at the
     /// first line break.
     ///
-    /// If `ellipsis` is set to `true`, and ellipsis will be added at the end of
+    /// If `ellipsis` is set to `true`, an ellipsis will be added at the end of
     /// the string.
-    pub(super) fn new(single_line: bool, ellipsis: bool) -> Self {
+    ///
+    /// If `preserve_whitespace` is set to `true`, all whitespace will be
+    /// preserved, otherwise it will be collapsed according to the HTML spec.
+    pub(super) fn new(single_line: bool, ellipsis: bool, preserve_whitespace: bool) -> Self {
         Self {
             single_line,
             ellipsis,
+            preserve_whitespace,
             mentions: MentionsMode::default(),
             inner: String::new(),
             truncated: false,
@@ -82,7 +88,7 @@ impl<'a> InlineHtmlBuilder<'a> {
 
         if ellipsis {
             inner.append_ellipsis();
-        } else {
+        } else if !self.preserve_whitespace {
             inner.truncate_end_whitespaces();
         }
 
@@ -207,8 +213,11 @@ impl<'a> InlineHtmlBuilder<'a> {
                 if self.single_line {
                     self.truncated = true;
                 } else {
-                    // Remove whitespaces before the newline.
-                    self.inner.truncate_end_whitespaces();
+                    if !self.preserve_whitespace {
+                        // Remove whitespaces before the newline.
+                        self.inner.truncate_end_whitespaces();
+                    }
+
                     self.inner.push('\n');
                 }
             }
@@ -226,10 +235,14 @@ impl<'a> InlineHtmlBuilder<'a> {
     fn append_text_node(&mut self, text: &str, context: NodeContext) {
         // Collapse whitespaces and remove them at the beginning and end of an HTML
         // element, and after a newline.
-        let text = text.collapse_whitespaces(
-            context.is_first_child || self.inner.ends_with('\n'),
-            context.is_last_child,
-        );
+        let text = if self.preserve_whitespace {
+            text.to_owned()
+        } else {
+            text.collapse_whitespaces(
+                context.is_first_child || self.inner.ends_with('\n'),
+                context.is_last_child,
+            )
+        };
 
         if context.should_linkify {
             if let MentionsMode::WithMentions {

src/session_view/room_history/message_row/text/mod.rs

@@ -322,6 +322,7 @@ mod imp {
                     room,
                     detect_at_room,
                     ellipsize,
+                    is_preformatted: false,
                 },
                 false,
                 &mut sender_name,

src/session_view/room_history/message_row/text/tests.rs

@@ -5,7 +5,7 @@ use super::inline_html::InlineHtmlBuilder;
 #[test]
 fn text_with_no_markup() {
     let html = Html::parse("A simple text");
-    let (s, pills) = InlineHtmlBuilder::new(false, false).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(false, false, false).build_with_nodes(html.children());
 
     assert_eq!(s, "A simple text");
     assert!(pills.is_none());
@@ -14,13 +14,13 @@ fn text_with_no_markup() {
 #[test]
 fn single_line() {
     let html = Html::parse("A simple text<br>on several lines");
-    let (s, pills) = InlineHtmlBuilder::new(true, false).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(true, false, false).build_with_nodes(html.children());
 
     assert_eq!(s, "A simple text…");
     assert!(pills.is_none());
 
     let html = Html::parse("\nThis is a paragraph<br />\n\nThis is another paragraph\n");
-    let (s, pills) = InlineHtmlBuilder::new(true, false).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(true, false, false).build_with_nodes(html.children());
 
     assert_eq!(s, "This is a paragraph…");
     assert!(pills.is_none());
@@ -29,7 +29,7 @@ fn single_line() {
 #[test]
 fn add_ellipsis() {
     let html = Html::parse("A simple text");
-    let (s, pills) = InlineHtmlBuilder::new(false, true).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(false, true, false).build_with_nodes(html.children());
 
     assert_eq!(s, "A simple text…");
     assert!(pills.is_none());
@@ -38,7 +38,7 @@ fn add_ellipsis() {
 #[test]
 fn no_duplicate_ellipsis() {
     let html = Html::parse("A simple text...<br>...on several lines");
-    let (s, pills) = InlineHtmlBuilder::new(true, false).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(true, false, false).build_with_nodes(html.children());
 
     assert_eq!(s, "A simple text...");
     assert!(pills.is_none());
@@ -47,7 +47,7 @@ fn no_duplicate_ellipsis() {
 #[test]
 fn trim_end_spaces() {
     let html = Html::parse("A high-altitude text 🗻   ");
-    let (s, pills) = InlineHtmlBuilder::new(false, false).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(false, false, false).build_with_nodes(html.children());
 
     assert_eq!(s, "A high-altitude text 🗻");
     assert!(pills.is_none());
@@ -55,17 +55,27 @@ fn trim_end_spaces() {
 
 #[test]
 fn collapse_whitespace() {
-    let html = Html::parse("Hello \nyou! \nYou are <b>my \nfriend</b>.");
-    let (s, pills) = InlineHtmlBuilder::new(false, false).build_with_nodes(html.children());
+    let original = "Hello \nyou! \nYou are <b>my \nfriend</b>.";
+    let html = Html::parse(original);
 
+    let (s, pills) = InlineHtmlBuilder::new(false, false, false).build_with_nodes(html.children());
     assert_eq!(s, "Hello you! You are <b>my friend</b>.");
     assert!(pills.is_none());
 
-    let html = Html::parse(" Hello    \nyou! \n\nYou are \n<b>   my \nfriend   </b>.  ");
-    let (s, pills) = InlineHtmlBuilder::new(false, false).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(false, false, true).build_with_nodes(html.children());
+    assert_eq!(s, original);
+    assert!(pills.is_none());
+
+    let original = " Hello    \nyou! \n\nYou are \n<b>   my \nfriend   </b>.  ";
+    let html = Html::parse(original);
 
+    let (s, pills) = InlineHtmlBuilder::new(false, false, false).build_with_nodes(html.children());
     assert_eq!(s, "Hello you! You are <b>my friend</b>.");
     assert!(pills.is_none());
+
+    let (s, pills) = InlineHtmlBuilder::new(false, false, true).build_with_nodes(html.children());
+    assert_eq!(s, original);
+    assert!(pills.is_none());
 }
 
 #[test]
@@ -73,7 +83,7 @@ fn sanitize_inline_html() {
     let html = Html::parse(
         r#"A <strong>text</strong> with <a href="https://docs.local/markup"><i>markup</i></a>"#,
     );
-    let (s, pills) = InlineHtmlBuilder::new(false, false).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(false, false, false).build_with_nodes(html.children());
 
     assert_eq!(
         s,
@@ -87,7 +97,7 @@ fn escape_markup() {
     let html = Html::parse(
         r#"Go to <a href="https://docs.local?this=this&that=that">this &amp; that docs</a>"#,
     );
-    let (s, pills) = InlineHtmlBuilder::new(false, false).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(false, false, false).build_with_nodes(html.children());
 
     assert_eq!(
         s,
@@ -101,7 +111,7 @@ fn linkify() {
     let html = Html::parse(
         "The homepage is https://gnome.org, and you can contact me at contact@me.local",
     );
-    let (s, pills) = InlineHtmlBuilder::new(false, false).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(false, false, false).build_with_nodes(html.children());
 
     assert_eq!(
         s,
@@ -113,7 +123,7 @@ fn linkify() {
 #[test]
 fn do_not_linkify_inside_anchor() {
     let html = Html::parse(r#"The homepage is <a href="https://gnome.org">https://gnome.org</a>"#);
-    let (s, pills) = InlineHtmlBuilder::new(false, false).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(false, false, false).build_with_nodes(html.children());
 
     assert_eq!(
         s,
@@ -125,7 +135,7 @@ fn do_not_linkify_inside_anchor() {
 #[test]
 fn do_not_linkify_inside_code() {
     let html = Html::parse("The homepage is <code>https://gnome.org</code>");
-    let (s, pills) = InlineHtmlBuilder::new(false, false).build_with_nodes(html.children());
+    let (s, pills) = InlineHtmlBuilder::new(false, false, false).build_with_nodes(html.children());
 
     assert_eq!(s, "The homepage is <tt>https://gnome.org</tt>");
     assert!(pills.is_none());
@@ -134,7 +144,7 @@ fn do_not_linkify_inside_code() {
 #[test]
 fn emote_name() {
     let html = Html::parse("sent a beautiful picture.");
-    let (s, pills) = InlineHtmlBuilder::new(false, false)
+    let (s, pills) = InlineHtmlBuilder::new(false, false, false)
         .append_emote_with_name(&mut Some("Jun"))
         .build_with_nodes(html.children());
 

src/session_view/room_history/message_row/text/widgets.rs

@@ -19,9 +19,19 @@ use crate::{
 /// The immutable config fields to build a HTML widget tree.
 #[derive(Debug, Clone, Copy)]
 pub(super) struct HtmlWidgetConfig<'a> {
+    /// The room where the message constructed by this widget was sent.
+    ///
+    /// Used for generating mentions.
     pub(super) room: &'a Room,
+    /// Whether we should try to detect an `@room` mention in the HTML to
+    /// render.
     pub(super) detect_at_room: bool,
+    /// Whether to ellipsize the message.
     pub(super) ellipsize: bool,
+    /// Whether this is preformatted text.
+    ///
+    /// Whitespaces are untouched in preformatted text.
+    pub(super) is_preformatted: bool,
 }
 
 /// Construct a new label for displaying a message's content.
@@ -85,7 +95,7 @@ pub(super) fn widget_for_html_nodes(
                 // Include sender name before, if the child widget did not handle it.
                 if let Some(sender_name) = sender_name.take() {
                     let label = new_message_label();
-                    let (text, _) = InlineHtmlBuilder::new(false, false)
+                    let (text, _) = InlineHtmlBuilder::new(false, false, config.is_preformatted)
                         .append_emote_with_name(&mut Some(sender_name))
                         .build();
                     label.set_label(&text);
@@ -174,10 +184,11 @@ fn label_for_inline_html(
     add_ellipsis: bool,
     sender_name: &mut Option<&str>,
 ) -> Option<gtk::Widget> {
-    let (text, widgets) = InlineHtmlBuilder::new(config.ellipsize, add_ellipsis)
-        .detect_mentions(config.room, config.detect_at_room)
-        .append_emote_with_name(sender_name)
-        .build_with_nodes(nodes);
+    let (text, widgets) =
+        InlineHtmlBuilder::new(config.ellipsize, add_ellipsis, config.is_preformatted)
+            .detect_mentions(config.room, config.detect_at_room)
+            .append_emote_with_name(sender_name)
+            .build_with_nodes(nodes);
 
     if text.is_empty() {
         return None;
@@ -242,7 +253,7 @@ fn widget_for_html_block(
         }
         MatrixElement::Hr => gtk::Separator::new(gtk::Orientation::Horizontal).upcast(),
         MatrixElement::Pre => {
-            widget_for_preformatted_text(node.children(), config.ellipsize, add_ellipsis)?
+            widget_for_preformatted_text(node.children(), config, add_ellipsis, sender_name)?
         }
         MatrixElement::Details => widget_for_details(node.children(), config, add_ellipsis)?,
         element => {
@@ -350,8 +361,9 @@ impl From<OrderedListData> for ListType {
 /// Create a widget for preformatted text.
 fn widget_for_preformatted_text(
     children: Children,
-    ellipsize: bool,
+    config: HtmlWidgetConfig<'_>,
     add_ellipsis: bool,
+    sender_name: &mut Option<&str>,
 ) -> Option<gtk::Widget> {
     let children = children.collect::<Vec<_>>();
 
@@ -361,37 +373,45 @@ fn widget_for_preformatted_text(
 
     let unique_code_child = (children.len() == 1)
         .then_some(&children[0])
-        .and_then(|child| child.as_element())
-        .and_then(|element| match element.to_matrix().element {
-            MatrixElement::Code(code) => Some(code),
-            _ => None,
+        .and_then(|child| {
+            match child
+                .as_element()
+                .map(|element| element.to_matrix().element)
+            {
+                Some(MatrixElement::Code(code)) => Some((child, code)),
+                _ => None,
+            }
         });
 
-    let (children, code_language) = if let Some(code) = unique_code_child {
-        let children = children[0].children().collect::<Vec<_>>();
+    let Some((child, code)) = unique_code_child else {
+        // This is just preformatted text, we need to construct the children hierarchy.
+        let config = HtmlWidgetConfig {
+            is_preformatted: true,
+            ..config
+        };
+        let widget = widget_for_html_nodes(children, config, add_ellipsis, sender_name)?;
 
-        if children.is_empty() {
-            return None;
-        }
+        // We use the monospace font for preformatted text.
+        widget.add_css_class("monospace");
 
-        (children, code.language)
-    } else {
-        (children, None)
+        return Some(widget);
     };
 
-    let text = InlineHtmlBuilder::new(ellipsize, add_ellipsis).build_with_nodes_text(children);
+    let children = child.children().collect::<Vec<_>>();
 
-    if ellipsize {
-        // Present text as inline code.
-        let text = format!("<tt>{}</tt>", text.escape_markup());
+    if children.is_empty() {
+        return None;
+    }
 
+    let text = InlineHtmlBuilder::new(config.ellipsize, add_ellipsis, config.is_preformatted)
+        .build_with_nodes_text(children);
+
+    if config.ellipsize {
+        // Present text as inline code.
         let label = new_message_label();
-        label.set_ellipsize(if ellipsize {
-            pango::EllipsizeMode::End
-        } else {
-            pango::EllipsizeMode::None
-        });
-        label.set_label(&text);
+        label.set_ellipsize(pango::EllipsizeMode::End);
+        label.add_css_class("monospace");
+        label.set_label(&text.escape_markup());
 
         return Some(label.upcast());
     }
@@ -402,7 +422,8 @@ fn widget_for_preformatted_text(
         .build();
     crate::utils::sourceview::setup_style_scheme(&buffer);
 
-    let language = code_language
+    let language = code
+        .language
         .and_then(|lang| sourceview::LanguageManager::default().language(lang.as_ref()));
     buffer.set_language(language.as_ref());