panes can shrink to just their tagline: border-drag clamps drop from MINH to BOX_H (the tag row doubles as the re-enlarge handle; the gutter move box wins over the handle so a tag-only pane stays movable), a hidden body's pty/vt is never resized so re-enlarging restores it intact, and cursor/modal-selection paints never land on the tag row. New shrinktag.snap; tutor updated.

2 files changed, 26 insertions, 12 deletions

diff --git a/src/pardes.zig b/src/pardes.zig
index c6513392..c14154e5 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -3577,7 +3577,17 @@ pub const Pardes = struct {
                         return;
                     }
                     if (mrow < TOPBAR_H) return; // topbar: left click deliberately inert
-                    // resize handles first: a pane's own trailing edge (v: the
+                    // the layout box (gutter cells of the tag row) wins over
+                    // the resize handles: a tag-only pane's single row IS its
+                    // pair's h-handle, and the box must stay grabbable to move
+                    if (hovered) |mid| {
+                        const mr = p.rects[mid];
+                        if (mcol < mr.x + GUTTER and mrow < mr.y + BOX_H) {
+                            p.drag = .{ .move = .{ .id = mid, .cur_x = mcol, .cur_y = mrow } };
+                            return;
+                        }
+                    }
+                    // resize handles next: a pane's own trailing edge (v: the
                     // left column's last col; h: the upper pane's last row)
                     for (0..p.ncol -| 1) |c| {
                         if (mcol == p.col_x[c] + p.col_w[c] -| 1) {
@@ -3598,9 +3608,7 @@ pub const Pardes = struct {
                     const id = hovered orelse return;
                     const r = p.rects[id];
                     const pane = p.panes[id] orelse return;
-                    if (mcol < r.x + GUTTER and mrow < r.y + BOX_H) {
-                        p.drag = .{ .move = .{ .id = id, .cur_x = mcol, .cur_y = mrow } };
-                    } else if (mcol < r.x + GUTTER) {
+                    if (mcol < r.x + GUTTER) {
                         // gutter scrollbar: a left click scrolls UP to that row
                         p.active = id;
                         pane.scrollBy(-(@as(i32, mrow) - @as(i32, r.y + BOX_H)));
@@ -3687,8 +3695,9 @@ pub const Pardes = struct {
                 if (k + 1 < p.col_n[cc]) {
                     const a = p.rects[p.col_terms[cc][k]];
                     const b = p.rects[p.col_terms[cc][k + 1]];
-                    const lo = a.y + MINH;
-                    const hi = a.y +| a.h +| b.h -| MINH;
+                    // either pane may shrink to just its tag row (BOX_H)
+                    const lo = a.y + BOX_H - 1;
+                    const hi = a.y +| a.h +| b.h -| (BOX_H + 1);
                     d.cur_y = if (lo <= hi) std.math.clamp(mrow, lo, hi) else mrow;
                 } else d.cur_y = mrow;
             },
@@ -3737,7 +3746,7 @@ pub const Pardes = struct {
                     const rb = p.rects[p.col_terms[cc][k + 1]];
                     const combined: f32 = @floatFromInt(ra.h + rb.h);
                     var nt: f32 = @floatFromInt((d.cur_y + 1) -| ra.y);
-                    nt = std.math.clamp(nt, @as(f32, MINH), @max(@as(f32, MINH), combined - MINH));
+                    nt = std.math.clamp(nt, @as(f32, BOX_H), @max(@as(f32, BOX_H), combined - BOX_H));
                     const pair = a.vweight + b.vweight;
                     a.vweight = pair * (nt / combined);
                     b.vweight = pair - a.vweight;
@@ -4602,7 +4611,10 @@ pub const Pardes = struct {
             const r = p.rects[id];
             const cols = @max(1, r.w -| GUTTER);
             const rows = @max(1, r.h -| BOX_H); // the tag steals the top row
-            if (cols != pane.cols or rows != pane.rows) {
+            // a pane shrunk to just its tag keeps its last real grid: no
+            // pty/vt reflow while the body is hidden, so re-enlarging brings
+            // it back exactly as it was
+            if ((cols != pane.cols or rows != pane.rows) and r.h > BOX_H) {
                 // doc panes have no pty/emulator grid to reflow; just record
                 // the size so bodyText renders the right number of rows
                 if (pane.isTerminal()) {
@@ -4999,7 +5011,7 @@ pub const Pardes = struct {
         if (pane.mode == .normal and pane.msel.active) {
             const lo = @min(pane.msel.r0, pane.msel.r1) - off + @as(i32, BOX_H);
             const hi = @max(pane.msel.r0, pane.msel.r1) - off + @as(i32, BOX_H);
-            var row: u16 = 0;
+            var row: u16 = BOX_H; // never paint the tag row
             while (row < r.h) : (row += 1) {
                 if (@as(i32, row) < lo or @as(i32, row) > hi) continue;
                 var col: u16 = if (pane.file != null) PREFIX_W else 0;
@@ -5019,7 +5031,7 @@ pub const Pardes = struct {
             var ar: i32 = bnd.lo_row;
             while (ar <= bnd.hi_row) : (ar += 1) {
                 const prow = ar - off + @as(i32, BOX_H);
-                if (prow < 0 or prow >= @as(i32, r.h)) continue;
+                if (prow < BOX_H or prow >= @as(i32, r.h)) continue;
                 const cstart: i32 = if (ar == bnd.lo_row) bnd.lo_col - vhs + vpfx else vpfx;
                 const cend: i32 = if (ar == bnd.hi_row) bnd.hi_col - vhs + vpfx else @as(i32, tw) - 1;
                 var col: i32 = @max(cstart, vpfx);
@@ -5050,7 +5062,7 @@ pub const Pardes = struct {
                     pane.renderedCol(crow, ccol, coff)
                 else
                     ccol;
-                if (prow >= 0 and cx >= 0 and prow < r.h and cx < tw)
+                if (prow >= BOX_H and cx >= 0 and prow < r.h and cx < tw)
                     s.cursor = .{ .x = tx + @as(u16, @intCast(cx)), .y = r.y + @as(u16, @intCast(prow)), .bar = pane.mode == .insert };
             } else if (cur.y + BOX_H < r.h and cur.x < tw) {
                 s.cursor = .{ .x = tx + cur.x, .y = r.y + cur.y + BOX_H, .bar = pane.mode == .insert };
diff --git a/src/tutor.txt b/src/tutor.txt
index 0b78da72..50b92558 100644
--- a/src/tutor.txt
+++ b/src/tutor.txt
@@ -106,7 +106,9 @@
  last row above the next tag) IS the resize handle: hover it and a dashed
  line overlays that edge (keeping the underlying colors) to mark the drag.
    - drag a column's right edge to resize it against its neighbour
-   - drag a window's bottom edge to resize it against the one below
+   - drag a window's bottom edge to resize it against the one below;
+     either window may shrink to just its tagline (the tag row then IS
+     the handle) — re-enlarging brings the body back intact
    - drag the accent box (top-left of a pane; indigo-purple, brighter
      when the pane is focused) to MOVE a window between columns / reorder
    - the scrollbar is the gutter below the box: left-click scrolls UP