Make grid RTL aware

library/src/layout/columns.rs

@@ -131,7 +131,7 @@ impl Layout for ColumnsNode {
                 }
 
                 let width = frame.width();
-                let x = if dir.is_positive() {
+                let x = if dir == Dir::LTR {
                     cursor
                 } else {
                     regions.first.x - cursor - width

library/src/layout/grid.rs

@@ -1,4 +1,5 @@
 use crate::prelude::*;
+use crate::text::TextNode;
 
 use super::Spacing;
 
@@ -218,6 +219,8 @@ struct GridLayouter<'a, 'v> {
     vt: &'a mut Vt<'v>,
     /// The grid cells.
     cells: &'a [Content],
+    /// Whether this is an RTL grid.
+    rtl: bool,
     /// The column tracks including gutter tracks.
     cols: Vec<TrackSizing>,
     /// The row tracks including gutter tracks.
@@ -299,6 +302,12 @@ impl<'a, 'v> GridLayouter<'a, 'v> {
         cols.pop();
         rows.pop();
 
+        // Reverse for RTL.
+        let rtl = styles.get(TextNode::DIR) == Dir::RTL;
+        if rtl {
+            cols.reverse();
+        }
+
         let full = regions.first.y;
         let rcols = vec![Abs::zero(); cols.len()];
         let lrows = vec![];
@@ -311,6 +320,7 @@ impl<'a, 'v> GridLayouter<'a, 'v> {
         Self {
             vt,
             cells,
+            rtl,
             cols,
             rows,
             regions,
@@ -680,10 +690,15 @@ impl<'a, 'v> GridLayouter<'a, 'v> {
     ///
     /// Returns `None` if it's a gutter cell.
     #[track_caller]
-    fn cell(&self, x: usize, y: usize) -> Option<&'a Content> {
+    fn cell(&self, mut x: usize, y: usize) -> Option<&'a Content> {
         assert!(x < self.cols.len());
         assert!(y < self.rows.len());
 
+        // Columns are reorded, but the cell slice is not.
+        if self.rtl {
+            x = self.cols.len() - 1 - x;
+        }
+
         // Even columns and rows are children, odd ones are gutter.
         if x % 2 == 0 && y % 2 == 0 {
             let c = 1 + self.cols.len() / 2;

tests/typ/layout/grid-rtl.typ

@@ -0,0 +1,9 @@
+// Test RTL grid.
+
+---
+#set text(dir: rtl)
+- מימין לשמאל
+
+---
+#set text(dir: rtl)
+#table(columns: 2, gutter: 5pt)[A][B][C][D]