Let a pane's tag take a row for each line it holds

A tag that is a text can hold a newline, and the tagline, the body under it
and the pointer all assumed one row. The pane's tag now takes a row per line
(up to eight, and never the body's last row); the body starts below it, the
rows a pointer counts start the body after the tag's lines, a click on any
line puts the tag's cursor there, and a pixel shell gets a tag layer per
line. A tag of one line draws exactly as before.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 70 insertions, 10 deletions

diff --git a/test/panes.zig b/test/panes.zig
index b9fa9a88..4804c497 100644
--- a/test/panes.zig
+++ b/test/panes.zig
@@ -168,6 +168,66 @@ const TagLayerTests = struct {
     }
 };
 
+test "a tag with a newline in it is as tall as its lines, and each line is typed into and pointed at" {
+    for ([_]bool{ false, true }) |bottom| {
+        const p = try Pardes.init(std.testing.allocator, .{ .tty_only = true, .cols = 80, .rows = 14 });
+        defer p.deinit();
+        const pane = try p.setTestFile("body\n");
+        p.presentation.enabled = false;
+        p.settings.tag_bottom = bottom;
+        p.update(.tick);
+        try std.testing.expectEqual(@as(u16, 1), pane.tag_rows);
+        const height = p.rects[0].h;
+        const body_rows = pane.rows;
+        // Insert mode in a tag is a body's: Enter is a new line.
+        p.update(.{ .key = .{ .cp = ':' } });
+        p.update(.{ .key = .{ .cp = 'A' } });
+        p.update(.{ .key = .{ .cp = Key.enter } });
+        p.update(.{ .key = .{ .cp = 'S', .text = "Second" } });
+        try std.testing.expect(std.mem.endsWith(u8, Pardes.curTail(pane), "\nSecond"));
+        try std.testing.expectEqual(@as(u16, 2), pane.tag_rows);
+        // The pane keeps its height; the body gives the tag its row.
+        try std.testing.expectEqual(height, p.rects[0].h);
+        try std.testing.expectEqual(body_rows - 1, pane.rows);
+        var frame = std.heap.ArenaAllocator.init(std.testing.allocator);
+        defer frame.deinit();
+        const surface = try p.render(frame.allocator());
+        const r = p.rects[0];
+        const tag_y = p.tagTop(pane, r);
+        const x = r.x + pardes.TAG_TEXT_INSET;
+        try std.testing.expectEqualStrings("/", surface.at(x, tag_y).grapheme());
+        for ("Second", 0..) |byte, i| try std.testing.expectEqual(byte, surface.at(x + @as(u16, @intCast(i)), tag_y + 1).text[0]);
+        try std.testing.expectEqual(pardes.FontRole.tagline, surface.at(x, tag_y + 1).style.font_role);
+        // the caret is on the second line, after what was typed
+        try std.testing.expectEqual(tag_y + 1, surface.cursor.?.y);
+        try std.testing.expectEqual(x + 6, surface.cursor.?.x);
+        // the body starts under (or over) the whole tag
+        const body_y = p.bodyTop(pane, r);
+        try std.testing.expectEqual(if (bottom) r.y else r.y + 2, body_y);
+        try std.testing.expectEqualStrings("b", surface.at(r.x + config.GUTTER + panes.File.gutterWidth(pane), body_y).grapheme());
+        // a layer to a line, for a pixel shell
+        var lines: usize = 0;
+        for (p.surface.tagLayers()) |*layer| {
+            if (layer.cols == 0 or layer.kind != .pane or layer.id != 0) continue;
+            try std.testing.expectEqual(tag_y + layer.line, layer.viewport.y);
+            lines += 1;
+        }
+        try std.testing.expectEqual(@as(usize, 2), lines);
+        // a click on the second line puts the tag's cursor on it
+        p.update(.{ .key = .{ .cp = Key.escape } });
+        p.update(.{ .key = .{ .cp = ':' } });
+        ClickCursorTests.click(p, .left, x + 2, tag_y + 1);
+        try std.testing.expect(pane.focus == .tag);
+        try std.testing.expectEqual(@as(i32, 1), pane.tag.cur_row);
+        try std.testing.expectEqual(@as(i32, 2), pane.tag.cur_col);
+        // and the pane's text, a row to a screen row, has both of its lines
+        const text = try pardes.edit.paneText(p, pane);
+        try std.testing.expect(std.mem.startsWith(u8, modal.lineSlice(text, 0), "/test.txt"));
+        try std.testing.expectEqualStrings("Second", modal.lineSlice(text, 1));
+        try std.testing.expectEqualStrings("body\n", pane.file.?.content);
+    }
+}
+
 const TagNavigationTests = struct {
     fn key(p: *Pardes, cp: u21) void {
         p.update(.{ .key = .{ .cp = cp } });
@@ -521,7 +581,7 @@ const TreeContextTests = struct {
             try std.testing.expectEqual(@as(i32, 59), pane.wrapAt(visible.row).line);
             const cursor = surface.cursor orelse return error.MissingLookCursor;
             const rect = p.rects[0];
-            const y = p.bodyTop(rect);
+            const y = p.bodyTop(pane, rect);
             try std.testing.expectEqual(y + @as(u16, @intCast(visible.row)), cursor.y);
         }
     }
@@ -543,7 +603,7 @@ const TreeContextTests = struct {
         try std.testing.expectEqual(@as(i32, 7), pane.wrapAt(pane.context_rows).line);
         const rect = p.rects[0];
         const x = rect.x + config.GUTTER + panes.File.gutterWidth(pane);
-        const y = p.bodyTop(rect);
+        const y = p.bodyTop(pane, rect);
         ClickCursorTests.click(p, .left, x + 6, y);
         try std.testing.expectEqual(@as(i32, 0), pane.body.cur_row);
         try std.testing.expectEqual(@as(i32, 6), pane.body.cur_col);
@@ -552,7 +612,7 @@ const TreeContextTests = struct {
         try std.testing.expectEqual(x + 6, cursor.x);
         // Read the body top again: the click cleared the announcement band the
         // builtin above put up, and the body moved back up with it.
-        try std.testing.expectEqual(p.bodyTop(p.rects[0]), cursor.y);
+        try std.testing.expectEqual(p.bodyTop(pane, p.rects[0]), cursor.y);
         p.update(.{ .key = .{ .cp = 'i' } });
         p.update(.{ .key = .{ .cp = 'Z', .text = "Z" } });
         try std.testing.expect(std.mem.startsWith(u8, pane.file.?.content, "const ZBox = struct {"));
@@ -591,7 +651,7 @@ const TreeContextTests = struct {
         const surface = try p.render(frame.allocator());
         try std.testing.expectEqual(@as(u16, 3), pane.context_rows);
         const rect = p.rects[0];
-        const y = p.bodyTop(rect);
+        const y = p.bodyTop(pane, rect);
         var glyph_x: ?u16 = null;
         for (0..surface.cols) |col| {
             if (std.mem.eql(u8, surface.at(@intCast(col), y).grapheme(), "界")) glyph_x = @intCast(col);
@@ -605,7 +665,7 @@ const TreeContextTests = struct {
         try std.testing.expectEqual(x, cursor.x);
         // Read the body top again: the click cleared the announcement band the
         // builtin above put up, so the body moved with it.
-        try std.testing.expectEqual(p.bodyTop(p.rects[0]), cursor.y);
+        try std.testing.expectEqual(p.bodyTop(pane, p.rects[0]), cursor.y);
         panes.File.setContent(p, &pane.file.?, try p.gpa.dupe(u8, "// no enclosing declaration\n" ** 18));
         _ = try p.render(frame.allocator());
         try std.testing.expectEqual(@as(u16, 0), pane.context_rows);
@@ -664,7 +724,7 @@ const TtySelectionTests = struct {
         _ = try p.render(frame.allocator());
         const rect = p.rects[0];
         const x = rect.x + config.GUTTER;
-        const y = p.bodyTop(rect);
+        const y = p.bodyTop(pane, rect);
         JumpSelectionTests.drag(p, x + 1, y, x + 3, y);
         try std.testing.expectEqualStrings("lph", p.yank orelse return error.MissingAutomaticTtyYank);
         p.update(.{ .key = .{ .cp = p.opts.tty_toggle, .ctrl = true } });
@@ -694,7 +754,7 @@ const TtySelectionTests = struct {
             _ = try p.render(frame.allocator());
             const rect = p.rects[0];
             const x = rect.x + config.GUTTER;
-            const y = p.bodyTop(rect);
+            const y = p.bodyTop(pane, rect);
             JumpSelectionTests.drag(p, x + @as(u16, if (prompt) 0 else 1), y, x + 3, y + @as(u16, if (prompt) 0 else 1));
             const expected = if (prompt) "$ ab" else "lph\nrav";
             try std.testing.expectEqual(panes.Text.Mode.tty, pane.body.mode);
@@ -1009,7 +1069,7 @@ const JumpSelectionTests = struct {
         if (wrap) try std.testing.expectEqual(pane.wrap_line[0], pane.wrap_line[1]);
         const rect = p.rects[0];
         const x = rect.x + config.GUTTER + panes.File.gutterWidth(pane);
-        const y = p.bodyTop(rect);
+        const y = p.bodyTop(pane, rect);
         if (reverse)
             drag(p, x + last_col, y + 1, x + first_col, y)
         else
@@ -1040,7 +1100,7 @@ const JumpSelectionTests = struct {
 
         // A selection created after Back must also disappear on Forward.
         // Back announces itself, so the body sits under a notice band now.
-        const y2 = p.bodyTop(p.rects[0]);
+        const y2 = p.bodyTop(pane, p.rects[0]);
         drag(p, x + 1, y2, x + 3, y2 + 1);
         try std.testing.expect(pardes.test_api.heldSelection(p, 0) != null);
         p.update(.{ .key = .{ .cp = 'i', .ctrl = true } });
@@ -4093,7 +4153,7 @@ test "cancelled normal gestures leave no count or subprefix after mouse and focu
                 .body, .tag => {
                     const rect = p.rects[0];
                     const tag_y = if (p.settings.tag_bottom) rect.y + rect.h - pardes.BOX_H else rect.y;
-                    const body_y = p.bodyTop(rect);
+                    const body_y = p.bodyTop(pane, rect);
                     const x = if (gesture == .tag)
                         rect.x + pardes.TAG_TEXT_INSET + @as(u16, @intCast(panes.File.displayWidth(try p.tagPrefix(pane)))) + 3
                     else