From 94018de3e803d6a7098d41e51998ca7bf95a824e Mon Sep 17 00:00:00 2001
From: Stefan Haller <stefan@haller-berlin.de>
Date: Sat, 8 Aug 2026 18:57:12 +0200
Subject: [PATCH] Route all view origin writes through SetOriginX and
 SetOriginY

Several methods assigned v.ox and v.oy directly: SetOrigin, CopyContent,
the wrap/autoscroll branches in draw, FocusPoint, and
Scroll{Up,Down,Left,Right}. Funnelling them all through SetOriginX and
SetOriginY gives a single place to observe (or set a breakpoint on)
every change to a view's scroll position, which makes debugging scroll
behaviour much easier.

This means those call sites now also get the setters' `< 0` clamps, but
that is behaviour-preserving in every case: each assigned value is
already >= 0. calculateNewOrigin never returns a negative number;
CopyContent copies origins that are themselves always >= 0; and the draw
and scroll writes are all guarded (or fed only non-negative amounts) so
the result can't go below zero.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
---
 pkg/gocui/view.go | 29 +++++++++++------------------
 1 file changed, 11 insertions(+), 18 deletions(-)

diff --git a/pkg/gocui/view.go b/pkg/gocui/view.go
index 787d11475..81ab0acab 100644
--- a/pkg/gocui/view.go
+++ b/pkg/gocui/view.go
@@ -402,7 +402,7 @@ func (v *View) FocusPoint(cx int, cy int, scrollIntoView bool) {
 
 	if scrollIntoView {
 		height := v.InnerHeight()
-		v.oy = calculateNewOrigin(cy, v.oy, lineCount, height)
+		v.SetOriginY(calculateNewOrigin(cy, v.oy, lineCount, height))
 	}
 
 	v.cx = cx
@@ -707,15 +707,8 @@ func (v *View) CursorY() int {
 // implement Horizontal and Vertical scrolling with just incrementing
 // or decrementing ox and oy.
 func (v *View) SetOrigin(x, y int) {
-	if x < 0 {
-		x = 0
-	}
-	if y < 0 {
-		y = 0
-	}
-
-	v.ox = x
-	v.oy = y
+	v.SetOriginX(x)
+	v.SetOriginY(y)
 }
 
 func (v *View) SetOriginX(x int) {
@@ -1166,8 +1159,8 @@ func (v *View) CopyContent(from *View) {
 	// their contents.
 	v.lines = slices.Clone(from.lines)
 	v.viewLines = slices.Clone(from.viewLines)
-	v.ox = from.ox
-	v.oy = from.oy
+	v.SetOriginX(from.ox)
+	v.SetOriginY(from.oy)
 	v.cx = from.cx
 	v.cy = from.cy
 }
@@ -1335,14 +1328,14 @@ func (v *View) draw(isWindowFocused bool) {
 		if maxX == 0 {
 			return
 		}
-		v.ox = 0
+		v.SetOriginX(0)
 	}
 
 	v.refreshViewLinesIfNeeded()
 
 	visibleViewLinesHeight := v.viewLineLengthIgnoringTrailingBlankLines()
 	if v.Autoscroll && visibleViewLinesHeight > maxY {
-		v.oy = visibleViewLinesHeight - maxY
+		v.SetOriginY(visibleViewLinesHeight - maxY)
 	}
 
 	if len(v.viewLines) == 0 {
@@ -1989,7 +1982,7 @@ func (v *View) ScrollUp(amount int) {
 	}
 
 	if amount != 0 {
-		v.oy -= amount
+		v.SetOriginY(v.oy - amount)
 		v.cy += amount
 
 		v.clearHover()
@@ -2001,7 +1994,7 @@ func (v *View) ScrollUp(amount int) {
 func (v *View) ScrollDown(amount int) {
 	adjustedAmount := v.adjustDownwardScrollAmount(amount)
 	if adjustedAmount > 0 {
-		v.oy += adjustedAmount
+		v.SetOriginY(v.oy + adjustedAmount)
 		v.cy -= adjustedAmount
 
 		v.clearHover()
@@ -2015,7 +2008,7 @@ func (v *View) ScrollLeft(amount int) {
 		newOx = 0
 	}
 	if newOx != v.ox {
-		v.ox = newOx
+		v.SetOriginX(newOx)
 
 		v.clearHover()
 	}
@@ -2023,7 +2016,7 @@ func (v *View) ScrollLeft(amount int) {
 
 // not applying any limits to this
 func (v *View) ScrollRight(amount int) {
-	v.ox += amount
+	v.SetOriginX(v.ox + amount)
 
 	v.clearHover()
 }