horizontal scroll for file panes (terminals wrap at pty width — nothing to scroll): pane.hscroll cuts content columns after the lineno gutter in bodyText (post edit-splice, so typed runs shift with the text), no scrollbar. Drivers: horizontal wheel (new wheel_left/right Mouse.Buttons, SGR 66/67 via vaxis on the tty, SDL wheel.x on the gui, ±4 cols, clamped at 0, right overscroll allowed) and keyboard movement — ensureCursorVisible grew the horizontal mirror of the scrolloff reconcile, so $ pulls the view right with 3 columns of margin and 0 reels it home; the wheel never moves the cursor. Shifted alongside: syntax recolor pass, modal cursor paint (hidden when off-view), vsel highlight, click->content-col mapping, cursorWordSel. Byte columns like the rest of the file-pane code. New hscroll.snap golden: wheel shift with fixed gutter, left clamp, $ margin follow, 0 home. 30/30.

2 files changed, 198 insertions, 0 deletions

diff --git a/test/snapshots/hscroll.golden b/test/snapshots/hscroll.golden
new file mode 100644
index 00000000..3eed48f8
--- /dev/null
+++ b/test/snapshots/hscroll.golden
@@ -0,0 +1,155 @@
+== snap opened grid=60x30 cursor=7,2
+|Kill Newcol Tutor Debug Colors NextColor Dump
+|  NOR /tmp/pardes-snap/hscroll  NOR /tmp/pardes-snap/hscroll
+|     1 short1 END_A_MARKER_WAY
+|                                wide.txt
+|
+|
+|
+|╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌╌
+|  NOR /tmp/pardes-snap/hscroll
+|
+|  wide.txt
+|
+|
+|
+|    wide.txt
+|
+|  NOR /tmp/pardes-snap/hscroll
+|
+|  wide.txt
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+== snap wheeled grid=60x30 cursor=7,2
+|Kill Newcol Tutor Debug Colors NextColor Dump
+|  NOR /tmp/pardes-snap/hscroll  NOR /tmp/pardes-snap/hscroll
+|     1 ND_A_MARKER_WAY_OUT_RIG
+|                                wide.txt
+|
+|
+|
+|
+|  NOR /tmp/pardes-snap/hscroll
+|
+|  wide.txt
+|
+|
+|
+|    wide.txt
+|
+|  NOR /tmp/pardes-snap/hscroll
+|
+|  wide.txt
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+== snap clamped grid=60x30 cursor=7,2
+|Kill Newcol Tutor Debug Colors NextColor Dump
+|  NOR /tmp/pardes-snap/hscroll  NOR /tmp/pardes-snap/hscroll
+|     1 short1 END_A_MARKER_WAY
+|                                wide.txt
+|
+|
+|
+|
+|  NOR /tmp/pardes-snap/hscroll
+|
+|  wide.txt
+|
+|
+|
+|    wide.txt
+|
+|  NOR /tmp/pardes-snap/hscroll
+|
+|  wide.txt
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+== snap dollar grid=60x30 cursor=26,2
+|Kill Newcol Tutor Debug Colors NextColor Dump
+|  NOR /tmp/pardes-snap/hscroll  NOR /tmp/pardes-snap/hscroll
+|     1 padpadpadpadpad_TAIL
+|                                wide.txt
+|
+|
+|
+|
+|  NOR /tmp/pardes-snap/hscroll
+|
+|  wide.txt
+|
+|
+|
+|    wide.txt
+|
+|  NOR /tmp/pardes-snap/hscroll
+|
+|  wide.txt
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+== snap zero grid=60x30 cursor=7,2
+|Kill Newcol Tutor Debug Colors NextColor Dump
+|  NOR /tmp/pardes-snap/hscroll  NOR /tmp/pardes-snap/hscroll
+|     1 short1 END_A_MARKER_WAY
+|                                wide.txt
+|
+|
+|
+|
+|  NOR /tmp/pardes-snap/hscroll
+|
+|  wide.txt
+|
+|
+|
+|    wide.txt
+|
+|  NOR /tmp/pardes-snap/hscroll
+|
+|  wide.txt
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
+|
diff --git a/test/snapshots/hscroll.snap b/test/snapshots/hscroll.snap
new file mode 100644
index 00000000..37a1b647
--- /dev/null
+++ b/test/snapshots/hscroll.snap
@@ -0,0 +1,43 @@
+# horizontal scroll, file panes only (terminals wrap at pty width): the
+# horizontal wheel shifts the content window (gutter stays put, no scrollbar),
+# and keyboard movement keeps the scrolloff margin sideways — $ on a long
+# line pulls the view right, 0 snaps it back. Overscroll right is allowed;
+# a cursor move reels it in.
+file wide.txt short1 END_A_MARKER_WAY_OUT_RIGHT_padpadpadpadpadpadpadpadpadpadpadpadpadpad_TAIL
+start 30 60 -n 3
+wait 8000 wide.txt
+stable 700 20000
+# open wide.txt: click a body spot, type the name, look it
+press left 5 8
+release left 5 8
+stable 400 5000
+key i
+text wide.txt
+key esc
+settle 700
+stable 400 5000
+press right 7 8
+release right 7 8
+stable 700 15000
+snap opened
+# wheel right over the file pane: content shifts, line numbers stay
+send \x1b[<66;10;3M
+send \x1b[<66;10;3M
+stable 400 5000
+snap wheeled
+# wheel back left past the start clamps at column 0
+send \x1b[<67;10;3M
+send \x1b[<67;10;3M
+send \x1b[<67;10;3M
+stable 400 5000
+snap clamped
+# $ walks the cursor to the line end: the view follows with the margin
+key g g
+stable 400 5000
+key $
+stable 400 5000
+snap dollar
+# 0 back to column zero: the view snaps home
+key 0
+stable 400 5000
+snap zero