From 430914371acd3fe46c31d7be900214e7ea03f657 Mon Sep 17 00:00:00 2001
From: Gabriel Schneider <gbrls@0x4200.cafe>
Date: Mon, 6 Jul 2026 14:49:20 -0300
Subject: look on path:NN centers the target line in the pane body (scroll =
 line - body/2, clamped at 0): fresh opens lay out first (computeGeom after
 placeDoc) to center with the real body height; dedup re-looks recenter the
 existing pane. look-file golden shifts accordingly; new look-center snap
 proves fresh-open centering, dedup recentering, and the top clamp.

---
 src/pardes.zig                    |  7 ++-
 test/snapshots/look-center.golden | 93 +++++++++++++++++++++++++++++++++++++++
 test/snapshots/look-center.snap   | 28 ++++++++++++
 test/snapshots/look-file.golden   | 12 ++---
 4 files changed, 133 insertions(+), 7 deletions(-)
 create mode 100644 test/snapshots/look-center.golden
 create mode 100644 test/snapshots/look-center.snap

diff --git a/src/pardes.zig b/src/pardes.zig
index c4893b25..5b677250 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -2631,7 +2631,7 @@ pub const Pardes = struct {
                         if (slot) |tt| if (tt.file) |*ff| if (std.mem.eql(u8, ff.path, target.path)) {
                             p.active = i;
                             if (target.line > 0 and target.line <= fileLineCount(ff.content)) {
-                                const next = target.line - 1;
+                                const next = (target.line - 1) -| tt.rows / 2; // center, clamp at top
                                 if (next != ff.scroll) {
                                     ff.scroll = next;
                                     ff.syntax_dirty = true;
@@ -2643,6 +2643,11 @@ pub const Pardes = struct {
                     const free = p.freeSlot() orelse return;
                     const nt = p.openFileView(free, target.path, target.line) catch return;
                     p.placeDoc(id, free, nt);
+                    // center the target line: the pane's real body height only
+                    // exists after placement, so lay out now and pull the
+                    // scroll up by half a body (line 0 opens stay at the top)
+                    p.computeGeom();
+                    nt.file.?.scroll -|= @max(1, p.rects[free].h -| BOX_H) / 2;
                 },
                 .image => |target| {
                     for (p.panes, 0..) |slot, i| {
diff --git a/test/snapshots/look-center.golden b/test/snapshots/look-center.golden
new file mode 100644
index 00000000..f2fe15a4
--- /dev/null
+++ b/test/snapshots/look-center.golden
@@ -0,0 +1,93 @@
+== snap center-open grid=100x30 cursor=7,6
+|Kill Newcol Tutor Debug Colors NextColor Dump
+|  nm /tmp/pardes-snap/look-center/cwd/big.txt Save  nm /tmp/pardes-snap/look-center/cwd Del
+|    96 line 96
+|    97 line 97                                      big.txt
+|    98 line 98
+|    99 line 99
+|   100 line 100
+|   101 line 101
+|   102 line 102
+|   103 line 103
+|   104 line 104
+|  nm /tmp/pardes-snap/look-center/cwd Del
+|
+|  big.txt
+|
+|
+|
+|    big.txt:100 big.txt:150 big.txt:2
+|
+|
+|
+|  nm /tmp/pardes-snap/look-center/cwd Del
+|
+|  big.txt
+|
+|
+|
+|
+|
+|
+== snap center-dedup grid=100x30 cursor=4,17
+|Kill Newcol Tutor Debug Colors NextColor Dump
+|  nm /tmp/pardes-snap/look-center/cwd/big.txt Save  nm /tmp/pardes-snap/look-center/cwd Del
+|   146 line 146
+|   147 line 147                                     big.txt
+|   148 line 148
+|   149 line 149
+|   150 line 150
+|   151 line 151
+|   152 line 152
+|   153 line 153
+|   154 line 154
+|  nm /tmp/pardes-snap/look-center/cwd Del
+|
+|  big.txt
+|
+|
+|
+|    big.txt:100 big.txt:150 big.txt:2
+|
+|
+|
+|  nm /tmp/pardes-snap/look-center/cwd Del
+|
+|  big.txt
+|
+|
+|
+|
+|
+|
+== snap center-clamp grid=100x30 cursor=4,17
+|Kill Newcol Tutor Debug Colors NextColor Dump
+|  nm /tmp/pardes-snap/look-center/cwd/big.txt Save  nm /tmp/pardes-snap/look-center/cwd Del
+|     1 line 1
+|     2 line 2                                       big.txt
+|     3 line 3
+|     4 line 4
+|     5 line 5
+|     6 line 6
+|     7 line 7
+|     8 line 8
+|     9 line 9
+|  nm /tmp/pardes-snap/look-center/cwd Del
+|
+|  big.txt
+|
+|
+|
+|    big.txt:100 big.txt:150 big.txt:2
+|
+|
+|
+|  nm /tmp/pardes-snap/look-center/cwd Del
+|
+|  big.txt
+|
+|
+|
+|
+|
+|
diff --git a/test/snapshots/look-center.snap b/test/snapshots/look-center.snap
new file mode 100644
index 00000000..db575844
--- /dev/null
+++ b/test/snapshots/look-center.snap
@@ -0,0 +1,28 @@
+# a look on path:NN opens the file with the target line CENTERED in the body
+# (scroll = line - body/2): fresh open at a deep line, then dedup re-looks at
+# the same path re-center the existing pane, and a look near line 1 clamps
+# the scroll at 0 (no negative scroll)
+lines big.txt 200
+start 30 100
+wait 8000 big.txt
+stable 700 20000
+press left 5 8
+release left 5 8
+stable 400 5000
+key i
+text big.txt:100 big.txt:150 big.txt:2
+key esc
+settle 700
+stable 400 5000
+press right 7 8
+release right 7 8
+stable 700 15000
+snap center-open
+press right 18 18
+release right 18 18
+stable 700 15000
+snap center-dedup
+press right 30 18
+release right 30 18
+stable 700 15000
+snap center-clamp
diff --git a/test/snapshots/look-file.golden b/test/snapshots/look-file.golden
index 4f6d4a71..5e8166c7 100644
--- a/test/snapshots/look-file.golden
+++ b/test/snapshots/look-file.golden
@@ -1,15 +1,15 @@
-== snap file-open grid=100x30 cursor=7,2
+== snap file-open grid=100x30 cursor=7,6
 |Kill Newcol Tutor Debug Colors NextColor Dump
 |  nm /tmp/pardes-snap/look-file/cwd/big.txt Save D  nm /tmp/pardes-snap/look-file/cwd Del
+|    36 line 36
+|    37 line 37                                      big.txt
+|    38 line 38
+|    39 line 39
 |    40 line 40
-|    41 line 41                                      big.txt
+|    41 line 41
 |    42 line 42
 |    43 line 43
 |    44 line 44
-|    45 line 45
-|    46 line 46
-|    47 line 47
-|    48 line 48
 |  nm /tmp/pardes-snap/look-file/cwd Del
 |
 |  big.txt
-- 
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