use fraction units for typst column layouts

fixes #11578

src/resources/filters/layout/layout.lua

@@ -203,9 +203,13 @@ function layout_cells(float_or_div, cells)
       end
       rows[#rows]:insert(cell)
     end
-    -- convert width units to percentages
-    widthsToPercent(rows, layoutCols)
-
+    if _quarto.format.isTypstOutput() then
+      widthsToFraction(rows, layoutCols)
+    else
+      -- convert width units to percentages
+      widthsToPercent(rows, layoutCols)
+    end
+
   -- check for layout
   elseif layout ~= nil then
     -- parse the layout

src/resources/filters/layout/width.lua

@@ -40,12 +40,16 @@ function parseLayoutWidths(figLayout, figureCount)
     return cols:map(function(width)
       figureLayoutCount = figureLayoutCount + 1
       if type(width) == "number" then
-        if numericTotal ~= 0 then
-          width = round((width / numericTotal) * 100, 2)
-        elseif width <= 1 then
-          width = round(width * 100, 2)
+        if _quarto.format.isTypstOutput() then
+          width = tostring(width) .. "fr"
+        else
+          if numericTotal ~= 0 then
+            width = round((width / numericTotal) * 100, 2)
+          elseif width <= 1 then
+            width = round(width * 100, 2)
+          end
+          width = tostring(width) .. "%"
         end
-        width = tostring(width) .. "%"
       end
       -- negative widths are "spacers" so we need to bump our total fig count
       if isSpacerWidth(width) then
@@ -119,6 +123,41 @@ function widthsToPercent(layout, cols)
 end
 
 
+-- convert widths to typst fractions
+function widthsToFraction(layout, cols)
+
+  -- for each row
+  for _,row in ipairs(layout) do
+
+    -- initialize widths with 0 or length string
+    -- currently we assume the width unit is appropriate for the output format
+    local widths = pandoc.List()
+    for _,fig in ipairs(row) do
+      widths[#widths+1] = 0
+      local width = attribute(fig, "width", nil)
+      if width then
+        widths[#widths] = width
+      end
+    end
+
+    -- create virtual fig widths as needed and note the total width
+    local defaultWidth = "1fr"
+    for i=1,cols do
+      if (i > #widths) or widths[i] == 0 then
+        widths[i] = defaultWidth
+      end
+    end
+    -- allocate widths
+    for i,fig in ipairs(row) do
+      local width = widths[i];
+      fig.attr.attributes["width"] = width
+      fig.attr.attributes["height"] = nil
+    end
+
+  end
+end
+
+
 -- elements with a percentage width and no height have a 'layout percent'
 -- which means then should be laid out at a higher level in the tree than
 -- the individual figure element

tests/docs/smoke-all/typst/layout/fraction-layout.qmd

@@ -0,0 +1,30 @@
+---
+title: "Fraction layout"
+format:
+  typst:
+    keep-typ: true
+_quarto:
+  tests:
+    typst:
+      ensureTypstFileRegexMatches:
+        -
+          ['#grid\((\r\n?|\n)columns: \(1fr, 2fr, 2fr, 1fr, 3fr, 1fr, 1fr\), gutter: 1em, rows: 1,']
+---
+
+::: {layout="[1, 2, 2, 1, 3, 1, 1]"}
+
+![Placeholder]({{< placeholder 200 >}})
+
+![Placeholder]({{< placeholder 200 >}})
+
+![Placeholder]({{< placeholder 200 >}})
+
+![Placeholder]({{< placeholder 200 >}})
+
+![Placeholder]({{< placeholder 200 >}})
+
+![Placeholder]({{< placeholder 200 >}})
+
+![Placeholder]({{< placeholder 200 >}})
+
+:::

tests/docs/smoke-all/typst/layout/overflowing-callout-7.qmd

@@ -0,0 +1,35 @@
+---
+title: Test
+format: typst
+keep-md: true
+keep-typ: true
+_quarto:
+  tests:
+    typst:
+      ensureTypstFileRegexMatches:
+        -
+          ['#grid\((\r\n?|\n)columns: \(1fr, 1fr, 100pt, 1fr, 1fr, 1fr, 1fr\), gutter: 1em, rows: 1,']
+
+---
+
+::: {.callout-note}
+
+## Plots
+
+::: {layout-ncol=7}
+
+![]({{< placeholder format=svg >}})
+
+![]({{< placeholder format=svg >}})
+
+![]({{< placeholder format=svg >}}){width="100pt"}
+
+![]({{< placeholder format=svg >}})
+
+![]({{< placeholder format=svg >}})
+
+![]({{< placeholder format=svg >}})
+
+![]({{< placeholder format=svg >}})
+:::
+:::

tests/docs/smoke-all/typst/layout/overflowing-callout.qmd

@@ -0,0 +1,33 @@
+---
+title: Test
+format: typst
+keep-md: true
+keep-typ: true
+_quarto:
+  tests:
+    typst:
+      ensureTypstFileRegexMatches:
+        -
+          ['#grid\((\r\n?|\n)columns: \(1fr, 1fr, 1fr, 1fr, 1fr\), gutter: 1em, rows: 1,']
+---
+
+::: {.callout-note}
+
+## Plots
+
+::: {layout-ncol=5}
+
+![]({{< placeholder format=svg >}})
+
+![]({{< placeholder format=svg >}})
+
+![]({{< placeholder format=svg >}})
+
+![]({{< placeholder format=svg >}})
+
+![]({{< placeholder format=svg >}})
+:::
+
+a)  Beschreiben Sie die 5 Verteilungsformen. [5 Punkte]
+
+:::