Fix line break handling in markdown and wrap (#601)

zng-ui · Jan 22, 2025 · c5e308b · c5e308b
1 parent 0589f4e
commit c5e308b
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Showing 3 changed files with 31 additions and 16 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,5 +1,7 @@
 # Unreleased
 
+* Fix `Wrap!` ignoring child `Text!` that is only a line-break.
+* Fix soft/hard breaks in `Markdown!`.
 * Improve cache of font data to use less memory.
 
 # 0.13.7

diff --git a/crates/zng-wgt-markdown/src/lib.rs b/crates/zng-wgt-markdown/src/lib.rs
@@ -198,6 +198,11 @@ fn markdown_view_fn<'a>(md: &'a str) -> impl UiNode {
     let mut last_txt_end = '\0';
 
     for item in Parser::new_with_broken_link_callback(md, Options::all(), Some(&mut |b: BrokenLink<'a>| Some((b.reference, "".into())))) {
+        let item = match item {
+            Event::SoftBreak => Event::Text(pulldown_cmark::CowStr::Borrowed(" ")),
+            Event::HardBreak => Event::Text(pulldown_cmark::CowStr::Borrowed("\n")),
+            item => item,
+        };
         match item {
             Event::Start(tag) => match tag {
                 Tag::Paragraph => {
@@ -502,24 +507,27 @@ fn markdown_view_fn<'a>(md: &'a str) -> impl UiNode {
                     // apply `WhiteSpace::MergeAll` across texts.
                     let txt_end = txt.chars().next_back().unwrap();
 
-                    let starts_with_space = txt.chars().next().unwrap().is_whitespace();
-                    match WhiteSpace::MergeAll.transform(&txt) {
-                        std::borrow::Cow::Borrowed(_) => {
-                            if starts_with_space && last_txt_end != '\0' || !txt.is_empty() && last_txt_end.is_whitespace() {
-                                txt.to_mut().insert(0, ' ');
-                            }
-                            txt.end_mut();
-                            last_txt_end = txt_end;
-                        }
-                        std::borrow::Cow::Owned(t) => {
-                            txt = t;
-                            if !txt.is_empty() {
+                    if txt != " " && txt != "\n" {
+                        // not Soft/HardBreak
+                        let starts_with_space = txt.chars().next().unwrap().is_whitespace();
+                        match WhiteSpace::MergeAll.transform(&txt) {
+                            std::borrow::Cow::Borrowed(_) => {
                                 if starts_with_space && last_txt_end != '\0' || !txt.is_empty() && last_txt_end.is_whitespace() {
                                     txt.to_mut().insert(0, ' ');
-                                    txt.end_mut();
                                 }
+                                txt.end_mut();
                                 last_txt_end = txt_end;
                             }
+                            std::borrow::Cow::Owned(t) => {
+                                txt = t;
+                                if !txt.is_empty() {
+                                    if starts_with_space && last_txt_end != '\0' || !txt.is_empty() && last_txt_end.is_whitespace() {
+                                        txt.to_mut().insert(0, ' ');
+                                        txt.end_mut();
+                                    }
+                                    last_txt_end = txt_end;
+                                }
+                            }
                         }
                     }
 
@@ -578,8 +586,6 @@ fn markdown_view_fn<'a>(md: &'a str) -> impl UiNode {
                     inlines.push(txt);
                 }
             }
-            Event::SoftBreak => {}
-            Event::HardBreak => {}
             Event::Rule => {
                 blocks.push(rule_view(RuleFnArgs {}));
             }
@@ -590,6 +596,8 @@ fn markdown_view_fn<'a>(md: &'a str) -> impl UiNode {
             }
             Event::InlineMath(_) => {}
             Event::DisplayMath(_) => {}
+            // handled early
+            Event::SoftBreak | Event::HardBreak => unreachable!(),
         }
     }
 

diff --git a/crates/zng-wgt-wrap/src/lib.rs b/crates/zng-wgt-wrap/src/lib.rs
@@ -770,7 +770,12 @@ impl InlineLayout {
 
                 let (inline, size) = wm.measure_inline(inline_constrain, row.size.height - spacing.row, child);
 
-                if size.is_empty() {
+                let can_collapse = size.is_empty()
+                    && match &inline {
+                        Some(i) => i.first_segs.is_empty(),
+                        None => true,
+                    };
+                if can_collapse {
                     row.item_segs.push(ItemSegsInfo::new_collapsed());
                     // collapsed, continue.
                     return;