A +Pager keeps its program's colours: the session parses what /pager is written after its directory with ghostty-vt, SGR becomes spans drawn over the plain text, every other escape is dropped, and PagerColor off pages it plain

1 files changed, 39 insertions, 1 deletions

diff --git a/src/File.zig b/src/File.zig
index 4fac0073..b3c28290 100644
--- a/src/File.zig
+++ b/src/File.zig
@@ -75,6 +75,11 @@ pub const State = struct {
     /// A +Pager pane (`pardes -`) whose text is a diff (`git diff`, `show`,
     /// `log -p`): drawn and looked at as a diff (Pane.colorAlgo).
     pager_diff: bool = false,
+    /// A +Pager's colours, as its program printed them (pager.zig): drawn
+    /// over its text by recolorSyntax, never read over 9P. ponytail: any
+    /// edit drops them (setContentSpan); shifting them through the splice,
+    /// as pane.zig's shiftOne moves dot, would keep them.
+    pager_spans: []pardes.pager.Span = &.{},
     /// Seconds of the last content change, for the filesystem's stat; zero until edited.
     mtime: u32 = 0,
     /// Non-null for a generated output buffer rather than an on-disk file.
@@ -982,6 +987,7 @@ pub fn deinit(p: *Pardes, pane: *Pane, file: *State) void {
     if (file.mini) |*mini| mini.deinit(p.gpa);
     if (file.line_starts.len > 0) p.gpa.free(file.line_starts);
     if (file.highlights.len > 0) p.tree_sitter_gpa.free(file.highlights);
+    p.gpa.free(file.pager_spans);
     locations.freeRows(p.gpa, file.location_rows);
     if (file.context_declarations.len > 0) p.tree_sitter_gpa.free(file.context_declarations);
     if (file.node_tree) |tree| syntax.freeTree(tree);
@@ -1010,6 +1016,8 @@ pub fn setContent(p: *Pardes, f: *State, new: []u8) void {
 pub fn setContentSpan(p: *Pardes, f: *State, new: []u8, span: ?Span) void {
     locations.freeRows(p.gpa, f.location_rows);
     f.location_rows = &.{};
+    p.gpa.free(f.pager_spans);
+    f.pager_spans = &.{};
     for (p.panes) |slot| if (slot) |pane| {
         if (pane.file) |*file| if (file == f) {
             for (0..pane.sel.len) |button| {
@@ -1483,7 +1491,8 @@ fn synStyle(p: *Pardes, sy: syntax.Syn) ?SynStyle {
 pub fn recolorSyntax(p: *Pardes, s: *Surface, pane: *Pane, f: *State, r: pardes.Rect, tx: u16, tw: u16, body_h: u16) void {
     const highlights = if (f.mini) |mini| mini.colors else f.highlights;
     const highlight_start = if (f.mini != null) 0 else f.highlight_start;
-    if (highlights.len == 0 and f.output == null) return;
+    const spans = f.pager_spans;
+    if (highlights.len == 0 and f.output == null and spans.len == 0) return;
     const prefix_width = gutterWidth(pane);
     const tz_recolor = tracy.zone(@src(), "synRecolor");
     defer tz_recolor.end();
@@ -1526,6 +1535,14 @@ pub fn recolorSyntax(p: *Pardes, s: *Surface, pane: *Pane, f: *State, r: pardes.
         else
             null else null;
         if (tint) |t| if (prefix_width < tw) tintRow(s, tx + @as(u16, @intCast(prefix_width)), body_y + vr, tx + tw, t.bg);
+        // A +Pager's own colours (pager.zig) on every row but one the diff
+        // look tints: an added or removed line is drawn as pardes draws a
+        // diff, and git's red and green on it would only fight the tint.
+        var span_at = if (tint != null) spans.len else std.sort.partitionPoint(pardes.pager.Span, spans, base + hs, struct {
+            fn before(at: usize, span: pardes.pager.Span) bool {
+                return span.end <= at;
+            }
+        }.before);
         var c: usize = 0;
         var screen_c: usize = 0;
         while (hs + c < limit and prefix_width + screen_c < tw) {
@@ -1562,6 +1579,27 @@ pub fn recolorSyntax(p: *Pardes, s: *Surface, pane: *Pane, f: *State, r: pardes.
                     if (style.bg != .default) cell.style.bg = style.bg;
                 }
             }
+            while (span_at < spans.len and spans[span_at].end <= idx) span_at += 1;
+            if (span_at < spans.len and spans[span_at].start <= idx) {
+                const st = spans[span_at].style;
+                var fill: usize = 0;
+                while (fill < cells and prefix_width + screen_c + fill < tw) : (fill += 1) {
+                    const cell = s.at(tx + @as(u16, @intCast(prefix_width + screen_c + fill)), body_y + vr);
+                    if (cell.default) continue;
+                    // A palette colour through the theme's sixteen, as a
+                    // terminal pane's cell; truecolor as it is.
+                    if (st.fg != .default) cell.style.fg = if (st.fg == .index) terminal.palColor(p, st.fg.index) else st.fg;
+                    if (st.bg != .default) cell.style.bg = if (st.bg == .index) terminal.palColor(p, st.bg.index) else st.bg;
+                    cell.style.bold = cell.style.bold or st.bold;
+                    cell.style.dim = st.dim;
+                    cell.style.italic = st.italic;
+                    cell.style.blink = st.blink;
+                    cell.style.reverse = st.reverse;
+                    cell.style.invisible = st.invisible;
+                    cell.style.strikethrough = st.strikethrough;
+                    if (st.ul != .off) cell.style.ul = st.ul;
+                }
+            }
             screen_c += cells;
             c = grapheme_end - hs;
         }