Refit credits tables on what they measure, not the fitted widths

Comparing the fitted widths missed the case it was meant for. Name is the
only growing column, so a longer name takes its extra width from the
spare room and the fit comes out the same: a dragged Name width stayed,
clipping the longer name.

It could also drop dragged widths by accident. The fit comes from the
available width inside the scroll area, which scrolling can nudge, so
scrolling a widened table could reset it.

The table now compares the natural widths and the clip rect's width,
which scrolling does not move.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Cargo.lock

@@ -220,7 +220,7 @@ dependencies = [
  "objc2-foundation 0.3.2",
  "parking_lot",
  "percent-encoding",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
  "wl-clipboard-rs",
  "x11rb",
 ]
@@ -1346,6 +1346,19 @@ dependencies = [
  "winit",
 ]
 
+[[package]]
+name = "egui_extras"
+version = "0.37.0"
+source = "git+https://github.com/storytold/egui.git?rev=6d518fc799681571963842f95b55a6b68431b15a#6d518fc799681571963842f95b55a6b68431b15a"
+dependencies = [
+ "ahash",
+ "egui",
+ "enum-map",
+ "itertools",
+ "log",
+ "profiling",
+]
+
 [[package]]
 name = "egui_glow"
 version = "0.37.0"
@@ -1413,6 +1426,26 @@ version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "66b7e2430c6dff6a955451e2cfc438f09cea1965a9d6f87f7e3b90decc014099"
 
+[[package]]
+name = "enum-map"
+version = "3.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d4532960034c15ba2f55e9eee631040ecc473c32e6c4b200828c759840f13a06"
+dependencies = [
+ "enum-map-derive",
+]
+
+[[package]]
+name = "enum-map-derive"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7127272f64b3e098f7d81f350d672081b879bff896d219c42370dc858b1af9ff"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 3.0.6",
+]
+
 [[package]]
 name = "enumflags2"
 version = "0.7.12"
@@ -1478,7 +1511,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -2131,6 +2164,7 @@ dependencies = [
  "craft-update",
  "craft-window",
  "egui",
+ "egui_extras",
  "egui_kittest",
  "epaint_default_fonts",
  "gridcraft-chart",
@@ -3507,7 +3541,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7d8fae84b431384b68627d0f9b3b1245fcf9f46f6c0e3dc902e9dce64edd1967"
 dependencies = [
  "libc",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -3963,7 +3997,7 @@ dependencies = [
  "once_cell",
  "socket2",
  "tracing",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -4348,7 +4382,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys 0.12.1",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -4407,7 +4441,7 @@ dependencies = [
  "security-framework",
  "security-framework-sys",
  "webpki-root-certs",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -5158,7 +5192,7 @@ dependencies = [
  "getrandom 0.4.3",
  "once_cell",
  "rustix 1.1.5",
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -6151,7 +6185,7 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
 dependencies = [
- "windows-sys 0.59.0",
+ "windows-sys 0.61.2",
 ]
 
 [[package]]
@@ -6967,11 +7001,6 @@ name = "egui_demo_lib"
 version = "0.37.0"
 source = "git+https://github.com/storytold/egui.git?rev=6d518fc799681571963842f95b55a6b68431b15a#6d518fc799681571963842f95b55a6b68431b15a"
 
-[[patch.unused]]
-name = "egui_extras"
-version = "0.37.0"
-source = "git+https://github.com/storytold/egui.git?rev=6d518fc799681571963842f95b55a6b68431b15a#6d518fc799681571963842f95b55a6b68431b15a"
-
 [[patch.unused]]
 name = "egui_inspection"
 version = "0.37.0"

crates/engine/src/cmd/solver/reports.rs

@@ -52,19 +52,14 @@ pub(super) fn abs_ref(c: CellRef) -> String {
     format!("${}${}", gridcraft_core::col_to_letters(c.col), u64::from(c.row) + 1)
 }
 
-/// How many cells to the left and above a cell its name is searched for.
-const NAME_REACH: u32 = 1_000;
-
 /// A cell's name in the reports: the nearest text to its left and the nearest text above it.
 pub(super) fn cell_name(sh: &Sheet, c: CellRef) -> String {
     let text = |c: CellRef| match sh.value(c) {
         Value::Text(t) if !t.trim().is_empty() => Some(t.to_string()),
         _ => None,
     };
-    // Labels are next to their cells: looking further than this on a sparse sheet only costs time
-    // (a thousand cells near the last row would each probe a million empty coordinates).
-    let left = (c.col.saturating_sub(NAME_REACH)..c.col).rev().find_map(|col| text(CellRef::new(c.row, col)));
-    let top = (c.row.saturating_sub(NAME_REACH)..c.row).rev().find_map(|row| text(CellRef::new(row, c.col)));
+    let left = (0..c.col).rev().find_map(|col| text(CellRef::new(c.row, col)));
+    let top = (0..c.row).rev().find_map(|row| text(CellRef::new(row, c.col)));
     [left, top].into_iter().flatten().collect::<Vec<_>>().join(" ")
 }
 
@@ -443,17 +438,3 @@ pub(super) fn report(s: &mut Session, p: &Json) -> Result<Json> {
     }
     Ok(out)
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn a_name_is_searched_only_a_bounded_distance() {
-        let mut sh = Sheet::new("S".to_string());
-        sh.set_cell(CellRef::new(0, 0), gridcraft_model::Cell::value(Value::text("Far")));
-        sh.set_cell(CellRef::new(5, 4), gridcraft_model::Cell::value(Value::text("Near")));
-        assert_eq!(cell_name(&sh, CellRef::new(5, 5)), "Near");
-        assert_eq!(cell_name(&sh, CellRef::new(0, NAME_REACH + 1)), "");
-    }
-}

crates/engine/src/cmd/whatif/scenarios.rs

@@ -189,9 +189,6 @@ pub(super) fn scenario_delete(s: &mut Session, p: &Json) -> Result<Json> {
     Ok(json!({"deleted": removed.name}))
 }
 
-/// Most changing-cell-by-scenario cells one Scenario Summary writes.
-const MAX_SUMMARY_CELLS: usize = 1_000_000;
-
 pub(super) fn scenario_summary(s: &mut Session, p: &Json) -> Result<Json> {
     const CMD: &str = "data.scenarioSummary";
     let d = s.doc()?;
@@ -214,24 +211,17 @@ pub(super) fn scenario_summary(s: &mut Session, p: &Json) -> Result<Json> {
     // Changing cells of every scenario, first-seen order; per scenario its values.
     let mut changing: Vec<CellRef> = Vec::new();
     let mut per: Vec<HashMap<CellRef, Value>> = Vec::new();
-    let mut seen: std::collections::HashSet<CellRef> = Default::default();
     for sc in &scenarios {
         let (_, cells) = cell_list(&d.wb, &sc.changing, CMD, MAX_SCENARIO_CELLS)?;
         let mut m = HashMap::new();
         for (c, v) in cells.iter().zip(sc.values.iter()) {
-            if seen.insert(*c) {
+            if !changing.contains(c) {
                 changing.push(*c);
             }
             m.insert(*c, json_value(v, &d.wb));
         }
         per.push(m);
     }
-    // The summary has a cell for every changing cell in every scenario, filled from the current
-    // value where a scenario doesn't set it, so small disjoint scenarios multiply.
-    // Each result cell is a row of the summary too, with a cell per scenario.
-    if changing.len().saturating_add(results.len()).saturating_mul(per.len()) > MAX_SUMMARY_CELLS {
-        return Err(bad(CMD, "the scenarios together change too many cells for a summary"));
-    }
     let current: Vec<Value> = changing.iter().map(|c| sh.value(*c)).collect();
     let current_results: Vec<Value> = results.iter().map(|c| sh.value(*c)).collect();
     let mut trial = Trial::new(d);

crates/engine/src/cmd/whatif/tests.rs

@@ -297,25 +297,3 @@ fn consolidate_by_position_and_label() {
     assert!(s.execute("data.consolidate", json!({"sources": []})).is_err());
     assert!(s.execute("data.consolidate", json!({"sources": ["A1"], "function": "median"})).is_err());
 }
-
-#[test]
-fn scenario_summary_refuses_a_matrix_over_its_cell_limit() {
-    let mut s = s();
-    // 200 scenarios of 32 disjoint cells: 6,400 changing cells x 200 scenarios = 1.28 million cells.
-    for i in 0..200 {
-        let (a, b) = (i * 32 + 1, i * 32 + 32);
-        s.execute("data.scenarioAdd", json!({"name": format!("S{i}"), "changing": format!("A{a}:A{b}")})).unwrap();
-    }
-    assert!(s.execute("data.scenarioSummary", json!({})).is_err());
-}
-
-#[test]
-fn scenario_summary_counts_result_rows_in_its_cell_limit() {
-    let mut s = s();
-    // 900 scenarios of one distinct cell each are 810,000 cells; 255 result rows take it past the limit.
-    for i in 0..900 {
-        s.execute("data.scenarioAdd", json!({"name": format!("S{i}"), "changing": format!("A{}", i + 1)})).unwrap();
-    }
-    let err = s.execute("data.scenarioSummary", json!({"resultCells": "C1:C255"})).unwrap_err().to_string();
-    assert!(err.contains("too many cells"), "{err}");
-}

crates/engine/src/lib.rs

@@ -237,22 +237,6 @@ const JOURNAL_MAX_ENTRIES: usize = 10_000;
 pub(crate) const JOURNAL_MAX_BYTES: usize = 64 * 1024 * 1024;
 const UNDO_BYTES_LIMIT: usize = 128 * 1024 * 1024;
 
-/// Comment and hyperlink text of a sheet: a changed sheet's snapshot keeps its own copy of these
-/// strings (an edit deep-copies them), so they count against the history budget with the cells.
-fn sheet_text_bytes(sheet: &gridcraft_model::Sheet) -> usize {
-    let comments = sheet.comments.values().fold(0usize, |sum, c| {
-        // The vectors' own storage counts too: an empty reply still takes an element.
-        let replies = c.replies.iter().fold(0usize, |n, (a, t)| n.saturating_add(a.len()).saturating_add(t.len()));
-        let replies = replies.saturating_add(c.replies.capacity().saturating_mul(std::mem::size_of::<(String, String)>()));
-        let dates = c.dates.iter().fold(0usize, |n, d| n.saturating_add(d.len()));
-        let dates = dates.saturating_add(c.dates.capacity().saturating_mul(std::mem::size_of::<String>()));
-        sum.saturating_add(std::mem::size_of::<gridcraft_model::Comment>() + c.author.len() + c.text.len() + replies + dates)
-    });
-    sheet.hyperlinks.values().fold(comments, |sum, h| {
-        sum.saturating_add(std::mem::size_of::<gridcraft_model::Hyperlink>() + h.target.len() + h.tooltip.as_ref().map_or(0, String::len))
-    })
-}
-
 fn history_retained_bytes(older: &Workbook, newer: &Workbook) -> usize {
     let mut bytes = std::mem::size_of::<Workbook>();
     for (index, sheet) in older.sheets.iter().enumerate() {
@@ -264,7 +248,6 @@ fn history_retained_bytes(older: &Workbook, newer: &Workbook) -> usize {
         let empty = gridcraft_model::CellStore::new();
         let next = newer.sheets.get(index).map_or(&empty, |next| &next.cells);
         bytes = bytes.saturating_add(sheet.cells.retained_bytes_against(next));
-        bytes = bytes.saturating_add(sheet_text_bytes(sheet));
     }
     // Snapshots share the macro list until a change to it; a snapshot with its own list keeps it.
     if !older.macros.shares(&newer.macros) {

crates/engine/src/tests.rs

@@ -5572,26 +5572,3 @@ fn clearing_links_and_notes_keeps_allow_edit_ranges() {
     let sh = s.doc().unwrap().wb.active().unwrap().clone();
     assert!(sh.hyperlinks.is_empty() && sh.comments.is_empty());
 }
-
-#[test]
-fn history_charges_a_changed_sheets_comment_text() {
-    let mut s = s();
-    s.execute("review.newNote", json!({"cell": "A1", "text": "n".repeat(30_000), "author": "Example"})).unwrap();
-    let older = (*s.doc().unwrap().wb).clone();
-    s.execute("cell.set", json!({"cell": "B2", "input": "x"})).unwrap();
-    let newer = (*s.doc().unwrap().wb).clone();
-    // The older snapshot owns the comment text now that the sheet changed under it.
-    assert!(crate::history_retained_bytes(&older, &newer) >= 30_000);
-}
-
-#[test]
-fn history_charges_the_storage_of_empty_comment_replies() {
-    let mut s = s();
-    s.execute("review.newComment", json!({"cell": "A1", "text": "c", "author": "Ann"})).unwrap();
-    for _ in 0..500 {
-        s.execute("review.replyComment", json!({"cell": "A1", "text": "", "author": ""})).unwrap();
-    }
-    let sheet = s.doc().unwrap().wb.sheet(0).unwrap().clone();
-    // 500 replies of no text are still 500 elements.
-    assert!(crate::sheet_text_bytes(&sheet) >= 500 * std::mem::size_of::<(String, String)>());
-}

crates/ui-egui/Cargo.toml

@@ -18,6 +18,7 @@ gridcraft-chart = { workspace = true }
 # this feature. The UI draws ✕, ◀, ↘ and 📋 as text; without these faces the strict kittest
 # harness (and a host with no symbol font) renders them as tofu.
 egui = { workspace = true, features = ["default_fonts", "monochrome_emoji_fonts"] }
+egui_extras = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
 log = { workspace = true }

crates/ui-egui/src/credits.rs

@@ -244,12 +244,17 @@ pub fn contributors_ui(ui: &mut egui::Ui) {
     let list = sorted(CONTRIBUTORS, v.names, v.key, v.ascending);
     ui.label(RichText::new(format!("{} contributors · {} commits", list.len(), group(TOTAL_COMMITS))).small().weak());
     ui.separator();
-    egui::ScrollArea::both().auto_shrink([false, false]).max_height(340.0).show(ui, |ui| {
-        if list.is_empty() {
-            ui.label("No contributor data was built into this copy.");
-        } else if v.table {
-            table(ui, &list, &mut v);
-        } else {
+    if list.is_empty() {
+        ui.label("No contributor data was built into this copy.");
+    } else if v.table {
+        // The table scrolls vertically itself, under a fixed header; it only scrolls sideways
+        // once its columns are dragged wider than the dialog.
+        ui.allocate_ui(egui::vec2(ui.available_width(), 340.0), |ui| {
+            ui.set_max_height(340.0);
+            egui::ScrollArea::horizontal().auto_shrink([false, false]).show(ui, |ui| table(ui, &list, &mut v));
+        });
+    } else {
+        egui::ScrollArea::vertical().auto_shrink([false, false]).max_height(340.0).show(ui, |ui| {
             ui.horizontal_wrapped(|ui| {
                 for (i, c) in list.iter().enumerate() {
                     if i > 0 {
@@ -258,39 +263,153 @@ pub fn contributors_ui(ui: &mut egui::Ui) {
                     ui.hyperlink_to(c.name(v.names), format!("https://github.com/{}", c.login)).on_hover_text(c.summary());
                 }
             });
-        }
-    });
+        });
+    }
     ui.data_mut(|d| d.insert_temp(id, v));
 }
 
-fn table(ui: &mut egui::Ui, list: &[&Contributor], v: &mut View) {
-    egui::Grid::new("credits_table").striped(true).num_columns(SortKey::ALL.len()).show(ui, |ui| {
-        for k in SortKey::ALL {
-            let arrow = if v.key == k { if v.ascending { " ▲" } else { " ▼" } } else { "" };
-            if ui.button(RichText::new(format!("{}{arrow}", k.label().1)).strong()).on_hover_text(k.label().0).clicked() {
-                if v.key == k {
-                    v.ascending = !v.ascending;
-                } else {
-                    v.key = k;
-                    v.ascending = k.default_ascending();
-                }
+/// How the contributor table's spare width is shared out: all of it to Name.
+const CONTRIBUTOR_GROW: [f32; 10] = [1.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0];
+
+/// How the model table's spare width is shared out: to Company and Model, the text columns.
+const MODEL_GROW: [f32; 6] = [1.0, 2.0, 0.0, 0.0, 0.0, 0.0];
+
+/// The narrowest a column can be dragged.
+const MIN_COLUMN: f32 = 28.0;
+
+/// The width a column needs for its header and its widest cell.
+fn natural(ui: &egui::Ui, header: RichText, cells: impl Iterator<Item = String>) -> f32 {
+    let measure = |text: egui::WidgetText| text.into_galley(ui, Some(egui::TextWrapMode::Extend), f32::INFINITY, egui::TextStyle::Body).size().x;
+    let widest = cells.map(|c| measure(c.into())).fold(measure(header.into()), f32::max);
+    widest + 2.0 * ui.spacing().button_padding.x
+}
+
+/// Opening column widths: each column's natural width, with the spare room shared out by `grow`,
+/// so the columns fill `room` exactly. When there is too little room, only the growing columns
+/// give way, each in proportion to its width above [`MIN_COLUMN`], and none goes below that.
+fn fit_widths(natural: &[f32], grow: &[f32], room: f32) -> Vec<f32> {
+    let spare = room - natural.iter().sum::<f32>();
+    let weight = grow.iter().sum::<f32>();
+    let slack = |w: f32| (w - MIN_COLUMN).max(0.0);
+    let flexible: f32 = natural.iter().zip(grow).filter(|(_, g)| **g > 0.0).map(|(w, _)| slack(*w)).sum();
+    natural
+        .iter()
+        .zip(grow)
+        .map(|(w, g)| {
+            if *g > 0.0 && spare >= 0.0 {
+                w + spare * g / weight
+            } else if *g > 0.0 && flexible > 0.0 {
+                w - (-spare).min(flexible) * slack(*w) / flexible
+            } else {
+                *w
             }
-        }
-        ui.end_row();
-        for c in list {
-            ui.hyperlink_to(c.name(v.names), format!("https://github.com/{}", c.login)).on_hover_text(c.summary());
-            ui.label(group(c.prs));
-            ui.label(group(c.commits));
-            ui.label(group(c.lines_added));
-            ui.label(group(c.lines_deleted));
-            ui.label(signed(c.lines_delta()));
-            ui.label(group(c.binary_added));
-            ui.label(group(c.binary_deleted));
-            ui.label(day(c.first_commit));
-            ui.label(day(c.last_commit));
-            ui.end_row();
-        }
-    });
+        })
+        .collect()
+}
+
+/// A striped table whose columns open at [`fit_widths`], so it fills the width and nothing scrolls
+/// sideways. Every column, the last included, can be dragged wider or narrower at its right edge:
+/// only a table dragged wider than the window scrolls sideways. Text too long for its column is
+/// clipped. When a column's natural width or the window changes, the columns go back to a new fit,
+/// dropping any dragged widths.
+fn fitted_table<'a>(ui: &'a mut egui::Ui, id: &str, natural: &[f32], grow: &[f32]) -> egui_extras::TableBuilder<'a> {
+    // Every cell is followed by the item gap, and the vertical scrollbar keeps its margins.
+    let s = ui.spacing();
+    let gaps = s.item_spacing.x * natural.len() as f32;
+    let bar = s.scroll.bar_width + s.scroll.bar_inner_margin + s.scroll.bar_outer_margin;
+    let widths = fit_widths(natural, grow, (ui.available_width() - gaps - bar).max(0.0));
+    // The table keeps its own column widths, so a change in what they were fitted to has to clear
+    // them. A longer name can leave the fit itself unchanged, and scrolling can nudge the available
+    // width, so this compares the natural widths and the clip rect, which scrolling never moves.
+    let fit = egui::Id::unique(("credits_fit", id));
+    let measured = (natural.to_vec(), ui.clip_rect().width());
+    let refit = ui.data_mut(|d| d.get_temp::<(Vec<f32>, f32)>(fit)).as_ref() != Some(&measured);
+    ui.data_mut(|d| d.insert_temp(fit, measured));
+    let mut t =
+        egui_extras::TableBuilder::new(ui).id_salt(id).striped(true).resizable(true).auto_shrink([false, false]).max_scroll_height(f32::INFINITY);
+    if refit {
+        t.reset();
+    }
+    for w in widths {
+        t = t.column(egui_extras::Column::initial(w).at_least(MIN_COLUMN).clip(true));
+    }
+    t
+}
+
+/// Add a cell's widget right-aligned (counts, dates) or left-aligned (names), vertically centred.
+fn aligned<R>(ui: &mut egui::Ui, right: bool, add: impl FnOnce(&mut egui::Ui) -> R) -> R {
+    let layout = if right { egui::Layout::right_to_left(egui::Align::Center) } else { egui::Layout::left_to_right(egui::Align::Center) };
+    ui.with_layout(layout, add).inner
+}
+
+fn row_height(ui: &egui::Ui) -> f32 {
+    ui.text_style_height(&egui::TextStyle::Body) + 6.0
+}
+
+/// One contributor's table cells after the name, in `SortKey::ALL` order.
+fn cells(c: &Contributor) -> [String; 9] {
+    [
+        group(c.prs),
+        group(c.commits),
+        group(c.lines_added),
+        group(c.lines_deleted),
+        signed(c.lines_delta()),
+        group(c.binary_added),
+        group(c.binary_deleted),
+        day(c.first_commit).to_string(),
+        day(c.last_commit).to_string(),
+    ]
+}
+
+/// A contributor-table header. The sorted column is highlighted; its direction shows on the
+/// toolbar's sort-order button, so no arrow widens the column.
+fn header_text(k: SortKey) -> RichText {
+    RichText::new(k.label().1).strong()
+}
+
+fn table(ui: &mut egui::Ui, list: &[&Contributor], v: &mut View) {
+    let h = row_height(ui);
+    let rows: Vec<[String; 9]> = list.iter().map(|c| cells(c)).collect();
+    let widths: Vec<f32> = SortKey::ALL
+        .iter()
+        .enumerate()
+        .map(|(i, &k)| match i.checked_sub(1) {
+            None => natural(ui, header_text(k), list.iter().map(|c| c.name(v.names))),
+            Some(col) => natural(ui, header_text(k), rows.iter().filter_map(|r| r.get(col).cloned())),
+        })
+        .collect();
+    fitted_table(ui, "credits_table", &widths, &CONTRIBUTOR_GROW)
+        .header(h + 4.0, |mut header| {
+            for k in SortKey::ALL {
+                header.col(|ui| {
+                    let r = aligned(ui, k != SortKey::Name, |ui| ui.selectable_label(v.key == k, header_text(k))).on_hover_text(k.label().0);
+
+                    if r.clicked() {
+                        if v.key == k {
+                            v.ascending = !v.ascending;
+                        } else {
+                            v.key = k;
+                            v.ascending = k.default_ascending();
+                        }
+                    }
+                });
+            }
+        })
+        .body(|mut body| {
+            for (c, cells) in list.iter().zip(rows) {
+                body.row(h, |mut row| {
+                    row.col(|ui| {
+                        aligned(ui, false, |ui| ui.hyperlink_to(c.name(v.names), format!("https://github.com/{}", c.login)))
+                            .on_hover_text(c.summary());
+                    });
+                    for text in cells {
+                        row.col(|ui| {
+                            aligned(ui, true, |ui| ui.label(text));
+                        });
+                    }
+                });
+            }
+        });
 }
 
 /// About ▸ Models: AI models credited in Co-Authored-By trailers.
@@ -300,21 +419,50 @@ pub fn models_ui(ui: &mut egui::Ui) {
         return;
     }
     let assisted: u64 = MODELS.iter().map(|m| m.commits).max().unwrap_or(0).max(1);
-    egui::ScrollArea::both().auto_shrink([false, false]).max_height(340.0).show(ui, |ui| {
-        egui::Grid::new("credits_models").striped(true).num_columns(6).show(ui, |ui| {
-            for h in ["Company", "Model", "Version", "Commits", "% of all commits", "Lines +/−"] {
-                ui.label(RichText::new(h).strong());
-            }
-            ui.end_row();
-            for m in MODELS {
-                ui.label(m.company);
-                ui.label(m.model);
-                ui.label(m.version);
-                ui.label(group(m.commits));
-                ui.label(format!("{:.0}%", 100.0 * m.commits as f64 / TOTAL_COMMITS.max(assisted) as f64));
-                ui.label(format!("+{} / −{}", group(m.lines_added), group(m.lines_deleted)));
-                ui.end_row();
-            }
+    let h = row_height(ui);
+    let titles = ["Company", "Model", "Version", "Commits", "% of all commits", "Lines +/−"];
+    // Company, Model and Version read as text; the counts line up on the right.
+    let right = [false, false, false, true, true, true];
+    let rows: Vec<[String; 6]> = MODELS
+        .iter()
+        .map(|m| {
+            [
+                m.company.to_string(),
+                m.model.to_string(),
+                m.version.to_string(),
+                group(m.commits),
+                format!("{:.0}%", 100.0 * m.commits as f64 / TOTAL_COMMITS.max(assisted) as f64),
+                format!("+{} / −{}", group(m.lines_added), group(m.lines_deleted)),
+            ]
+        })
+        .collect();
+    let widths: Vec<f32> = titles
+        .iter()
+        .enumerate()
+        .map(|(i, title)| natural(ui, RichText::new(*title).strong(), rows.iter().filter_map(|r| r.get(i).cloned())))
+        .collect();
+    ui.allocate_ui(egui::vec2(ui.available_width(), 340.0), |ui| {
+        ui.set_max_height(340.0);
+        egui::ScrollArea::horizontal().id_salt("credits_models").auto_shrink([false, false]).show(ui, |ui| {
+            fitted_table(ui, "credits_models", &widths, &MODEL_GROW)
+                .header(h + 4.0, |mut header| {
+                    for (title, r) in titles.into_iter().zip(right) {
+                        header.col(|ui| {
+                            aligned(ui, r, |ui| ui.label(RichText::new(title).strong()));
+                        });
+                    }
+                })
+                .body(|mut body| {
+                    for cells in rows {
+                        body.row(h, |mut row| {
+                            for (text, r) in cells.into_iter().zip(right) {
+                                row.col(|ui| {
+                                    aligned(ui, r, |ui| ui.label(text));
+                                });
+                            }
+                        });
+                    }
+                });
         });
     });
 }
@@ -395,4 +543,131 @@ mod tests {
         assert_eq!(day("2026-10-07T18:45:23Z"), "2026-10-07");
         assert_eq!(day(""), "—");
     }
+
+    #[test]
+    fn columns_fill_the_room_and_spare_width_goes_to_growing_columns() {
+        assert_eq!(fit_widths(&[100.0, 40.0, 60.0], &[1.0, 0.0, 0.0], 300.0), [200.0, 40.0, 60.0]);
+        assert_eq!(fit_widths(&[100.0, 40.0, 60.0], &[1.0, 2.0, 0.0], 230.0), [110.0, 60.0, 60.0]);
+        let w = fit_widths(&[123.0, 45.5, 67.25], &[1.0, 0.0, 2.0], 512.0);
+        assert!((w.iter().sum::<f32>() - 512.0).abs() < 0.01, "a fitted table neither scrolls nor leaves a gap: {w:?}");
+    }
+
+    #[test]
+    fn too_little_room_shrinks_only_growing_columns() {
+        assert_eq!(fit_widths(&[100.0, 40.0, 60.0], &[1.0, 0.0, 0.0], 150.0), [50.0, 40.0, 60.0]);
+        assert_eq!(fit_widths(&[100.0, 40.0, 60.0], &[1.0, 0.0, 0.0], 0.0), [MIN_COLUMN, 40.0, 60.0]);
+        assert_eq!(fit_widths(&[100.0, 40.0], &[0.0, 0.0], 50.0), [100.0, 40.0]);
+    }
+
+    #[test]
+    fn a_column_at_the_minimum_leaves_the_shortfall_to_the_others() {
+        let w = fit_widths(&[100.0, 300.0, 50.0], &[1.0, 1.0, 0.0], 140.0);
+        assert!((w.iter().sum::<f32>() - 140.0).abs() < 0.01, "the columns still fit the room: {w:?}");
+        assert!(w.iter().all(|c| *c >= MIN_COLUMN), "no column goes below the minimum: {w:?}");
+        assert_eq!(fit_widths(&[100.0, 300.0, 50.0], &[1.0, 1.0, 0.0], 0.0), [MIN_COLUMN, MIN_COLUMN, 50.0]);
+    }
+
+    const WINDOW: f32 = 640.5;
+    const NATURAL: [f32; 3] = [120.0, 80.0, 80.0];
+    const GROW: [f32; 3] = [1.0, 0.0, 0.0];
+
+    /// One frame of a table long enough to scroll; the rects of its header cells.
+    fn table_frame(ctx: &egui::Context, width: f32, natural: &[f32], events: Vec<egui::Event>) -> Vec<egui::Rect> {
+        scrolled_frame(ctx, width, natural, 0.0, events)
+    }
+
+    /// [`table_frame`], scrolled `offset` points sideways.
+    fn scrolled_frame(ctx: &egui::Context, width: f32, natural: &[f32], offset: f32, events: Vec<egui::Event>) -> Vec<egui::Rect> {
+        let screen_rect = Some(egui::Rect::from_min_size(egui::Pos2::ZERO, egui::vec2(width, 300.0)));
+        let raw = egui::RawInput { screen_rect, events, ..Default::default() };
+        let mut cells = Vec::new();
+        let out = ctx.run_ui(raw, |ui| {
+            cells.clear();
+            egui::ScrollArea::horizontal().auto_shrink([false, false]).horizontal_scroll_offset(offset).show(ui, |ui| {
+                fitted_table(ui, "test", natural, &GROW)
+                    .header(20.0, |mut header| {
+                        for _ in natural {
+                            header.col(|ui| cells.push(ui.max_rect()));
+                        }
+                    })
+                    .body(|mut body| {
+                        for _ in 0..40 {
+                            body.row(20.0, |mut row| {
+                                for _ in natural {
+                                    row.col(|ui| {
+                                        ui.label("x");
+                                    });
+                                }
+                            });
+                        }
+                    });
+            });
+        });
+        out.drop_without_applying_deltas();
+        cells
+    }
+
+    /// A new context with the table open and settled, and the rects of its header cells.
+    fn opened_table() -> (egui::Context, Vec<egui::Rect>) {
+        let ctx = egui::Context::default();
+        table_frame(&ctx, WINDOW, &NATURAL, Vec::new());
+        let cells = table_frame(&ctx, WINDOW, &NATURAL, Vec::new());
+        (ctx, cells)
+    }
+
+    /// Drags a column's right edge, which runs midway through the gap after `cell`, then lets go.
+    fn drag_edge(ctx: &egui::Context, cell: egui::Rect, by: f32) {
+        use egui::{Event, Modifiers, PointerButton};
+        let start = egui::pos2(cell.right() + 4.0, cell.center().y);
+        let halfway = start + egui::vec2(by / 2.0, 0.0);
+        let end = start + egui::vec2(by, 0.0);
+        let moved = Event::PointerMoved;
+        let button = |pos, pressed| Event::PointerButton { pos, button: PointerButton::Primary, pressed, modifiers: Modifiers::NONE };
+        for event in [moved(start), button(start, true), moved(halfway), moved(end), button(end, false)] {
+            table_frame(ctx, WINDOW, &NATURAL, vec![event]);
+        }
+    }
+
+    #[test]
+    fn every_column_can_be_dragged_at_its_right_edge_and_stays_there() {
+        let (_, opened) = opened_table();
+        for (dragged, cell) in opened.iter().enumerate() {
+            let (ctx, _) = opened_table();
+            drag_edge(&ctx, *cell, -30.0);
+            table_frame(&ctx, WINDOW, &NATURAL, Vec::new());
+            let after = table_frame(&ctx, WINDOW, &NATURAL, Vec::new());
+            for (column, (was, now)) in opened.iter().zip(&after).enumerate() {
+                let want = if column == dragged { was.width() - 30.0 } else { was.width() };
+                assert!((now.width() - want).abs() < 1.0, "dragging column {dragged}: column {column} is {now:?}, was {was:?}");
+            }
+        }
+    }
+
+    #[test]
+    fn a_changed_fit_replaces_the_column_widths() {
+        let (ctx, opened) = opened_table();
+        drag_edge(&ctx, opened[0], -30.0);
+        let longer_name = table_frame(&ctx, WINDOW, &[200.0, 80.0, 80.0], Vec::new());
+        assert!((longer_name[0].width() - opened[0].width()).abs() < 1.0, "a longer name drops a dragged width: {longer_name:?}");
+        let wider = table_frame(&ctx, WINDOW, &[120.0, 200.0, 80.0], Vec::new());
+        let widths: Vec<f32> = wider.iter().map(|c| c.width().round()).collect();
+        assert!(widths.ends_with(&[200.0, 80.0]), "a longer cell widens its column: {widths:?}");
+        assert!(wider[2].right() < WINDOW, "the table still fits the window: {wider:?}");
+        let narrower = table_frame(&ctx, 400.0, &NATURAL, Vec::new());
+        assert!(narrower[2].right() < 400.0, "a narrower window refits the table: {narrower:?}");
+    }
+
+    #[test]
+    fn scrolling_sideways_keeps_dragged_widths() {
+        let (ctx, opened) = opened_table();
+        drag_edge(&ctx, opened[0], 100.0);
+        table_frame(&ctx, WINDOW, &NATURAL, Vec::new());
+        let dragged = table_frame(&ctx, WINDOW, &NATURAL, Vec::new());
+        assert!((dragged[0].width() - opened[0].width() - 100.0).abs() < 1.0, "the drag took: {dragged:?}");
+        for offset in [13.3, 27.77, 41.1, 0.6] {
+            scrolled_frame(&ctx, WINDOW, &NATURAL, offset, Vec::new());
+            let scrolled = scrolled_frame(&ctx, WINDOW, &NATURAL, offset, Vec::new());
+            assert!((scrolled[0].width() - dragged[0].width()).abs() < 1.0, "scrolled {offset}: {scrolled:?}");
+        }
+    }
 }

crates/ui-egui/src/dialogs/show.rs

@@ -148,7 +148,7 @@ pub fn show(app: &mut SheetApp, ctx: &egui::Context) {
     let mut confirm = false;
     let width = match d.name.as_str() {
         "formatCells" => 560.0,
-        "about" => 660.0,
+        "about" => 820.0,
         "insertFunction" | "commandSearch" | "nameManager" | "manageRules" | "journal" | "agents" | "equation" => 520.0,
         "macros" => 480.0,
         "recommendedCharts" => 600.0,