Fix annoying UI stalls after refresh (e.g. background fetch) when the reflog is very long

go.mod

@@ -18,7 +18,7 @@ require (
 	github.com/integrii/flaggy v1.4.0
 	github.com/jesseduffield/generics v0.0.0-20250517122708-b0b4a53a6f5c
 	github.com/jesseduffield/go-git/v5 v5.14.1-0.20250407170251-e1a013310ccd
-	github.com/jesseduffield/gocui v0.3.1-0.20251223143206-950739ccd44a
+	github.com/jesseduffield/gocui v0.3.1-0.20251223144240-29fe12e8d53f
 	github.com/jesseduffield/lazycore v0.0.0-20221012050358-03d2e40243c5
 	github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0
 	github.com/karimkhaleel/jsonschema v0.0.0-20231001195015-d933f0d94ea3

go.sum

@@ -194,8 +194,8 @@ github.com/jesseduffield/generics v0.0.0-20250517122708-b0b4a53a6f5c h1:tC2Paiis
 github.com/jesseduffield/generics v0.0.0-20250517122708-b0b4a53a6f5c/go.mod h1:F2fEBk0ddf6ixrBrJjY7phfQ3hL9rXG0uSjvwYe50bE=
 github.com/jesseduffield/go-git/v5 v5.14.1-0.20250407170251-e1a013310ccd h1:ViKj6qth8FgcIWizn9KiACWwPemWSymx62OPN0tHT+Q=
 github.com/jesseduffield/go-git/v5 v5.14.1-0.20250407170251-e1a013310ccd/go.mod h1:lRhCiBr6XjQrvcQVa+UYsy/99d3wMXn/a0nSQlhnhlA=
-github.com/jesseduffield/gocui v0.3.1-0.20251223143206-950739ccd44a h1:XRsyqrSljes4TlaPczQViIAA4xqdnB0fKEEpZdqWWTA=
-github.com/jesseduffield/gocui v0.3.1-0.20251223143206-950739ccd44a/go.mod h1:sLIyZ2J42R6idGdtemZzsiR3xY5EF0KsvYEGh3dQv3s=
+github.com/jesseduffield/gocui v0.3.1-0.20251223144240-29fe12e8d53f h1:5ArylWehV98WTxJM7AcSa53YNskEFpHHv+VePONQn58=
+github.com/jesseduffield/gocui v0.3.1-0.20251223144240-29fe12e8d53f/go.mod h1:sLIyZ2J42R6idGdtemZzsiR3xY5EF0KsvYEGh3dQv3s=
 github.com/jesseduffield/lazycore v0.0.0-20221012050358-03d2e40243c5 h1:CDuQmfOjAtb1Gms6a1p5L2P8RhbLUq5t8aL7PiQd2uY=
 github.com/jesseduffield/lazycore v0.0.0-20221012050358-03d2e40243c5/go.mod h1:qxN4mHOAyeIDLP7IK7defgPClM/z1Kze8VVQiaEjzsQ=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=

pkg/gui/context/list_context_trait.go

@@ -21,6 +21,9 @@ type ListContextTrait struct {
 	// If this is true, we only render the visible lines of the list. Useful for lists that can
 	// get very long, because it can save a lot of memory
 	renderOnlyVisibleLines bool
+	// If renderOnlyVisibleLines is true, needRerenderVisibleLines indicates whether we need to
+	// rerender the visible lines e.g. because the scroll position changed
+	needRerenderVisibleLines bool
 }
 
 func (self *ListContextTrait) IsListContext() {}
@@ -50,8 +53,8 @@ func (self *ListContextTrait) FocusLine(scrollIntoView bool) {
 			self.refreshViewport()
 		} else if self.renderOnlyVisibleLines {
 			newOrigin, _ := self.GetViewTrait().ViewPortYBounds()
-			if oldOrigin != newOrigin {
-				self.HandleRender()
+			if oldOrigin != newOrigin || self.needRerenderVisibleLines {
+				self.refreshViewport()
 			}
 		}
 		return nil
@@ -102,10 +105,10 @@ func (self *ListContextTrait) HandleRender() {
 		if self.getNonModelItems != nil {
 			totalLength += len(self.getNonModelItems())
 		}
-		self.GetViewTrait().SetContentLineCount(totalLength)
 		startIdx, length := self.GetViewTrait().ViewPortYBounds()
 		content := self.renderLines(startIdx, startIdx+length)
-		self.GetViewTrait().SetViewPortContentAndClearEverythingElse(content)
+		self.GetViewTrait().SetViewPortContentAndClearEverythingElse(totalLength, content)
+		self.needRerenderVisibleLines = false
 	} else {
 		content := self.renderLines(-1, -1)
 		self.GetViewTrait().SetContent(content)
@@ -142,6 +145,10 @@ func (self *ListContextTrait) RenderOnlyVisibleLines() bool {
 	return self.renderOnlyVisibleLines
 }
 
+func (self *ListContextTrait) SetNeedRerenderVisibleLines() {
+	self.needRerenderVisibleLines = true
+}
+
 func (self *ListContextTrait) TotalContentHeight() int {
 	result := self.list.Len()
 	if self.getNonModelItems != nil {

pkg/gui/context/reflog_commits_context.go

@@ -26,9 +26,14 @@ func NewReflogCommitsContext(c *ContextCommon) *ReflogCommitsContext {
 		},
 	)
 
-	getDisplayStrings := func(_ int, _ int) [][]string {
+	getDisplayStrings := func(startIdx int, endIdx int) [][]string {
+		commits := viewModel.GetItems()
+		if startIdx >= len(commits) {
+			return nil
+		}
+
 		return presentation.GetReflogCommitListDisplayStrings(
-			viewModel.GetItems(),
+			commits[startIdx:endIdx],
 			c.State().GetRepoState().GetScreenMode() != types.SCREEN_NORMAL,
 			c.Modes().CherryPicking.SelectedHashSet(),
 			c.Modes().Diffing.Ref,
@@ -43,18 +48,20 @@ func NewReflogCommitsContext(c *ContextCommon) *ReflogCommitsContext {
 		FilteredListViewModel: viewModel,
 		ListContextTrait: &ListContextTrait{
 			Context: NewSimpleContext(NewBaseContext(NewBaseContextOpts{
-				View:                       c.Views().ReflogCommits,
-				WindowName:                 "commits",
-				Key:                        REFLOG_COMMITS_CONTEXT_KEY,
-				Kind:                       types.SIDE_CONTEXT,
-				Focusable:                  true,
-				NeedsRerenderOnWidthChange: types.NEEDS_RERENDER_ON_WIDTH_CHANGE_WHEN_SCREEN_MODE_CHANGES,
+				View:                        c.Views().ReflogCommits,
+				WindowName:                  "commits",
+				Key:                         REFLOG_COMMITS_CONTEXT_KEY,
+				Kind:                        types.SIDE_CONTEXT,
+				Focusable:                   true,
+				NeedsRerenderOnWidthChange:  types.NEEDS_RERENDER_ON_WIDTH_CHANGE_WHEN_SCREEN_MODE_CHANGES,
+				NeedsRerenderOnHeightChange: true,
 			})),
 			ListRenderer: ListRenderer{
 				list:              viewModel,
 				getDisplayStrings: getDisplayStrings,
 			},
-			c: c,
+			c:                      c,
+			renderOnlyVisibleLines: true,
 		},
 	}
 }

pkg/gui/context/view_trait.go

@@ -34,13 +34,9 @@ func (self *ViewTrait) SetViewPortContent(content string) {
 	self.view.OverwriteLines(y, content)
 }
 
-func (self *ViewTrait) SetViewPortContentAndClearEverythingElse(content string) {
+func (self *ViewTrait) SetViewPortContentAndClearEverythingElse(lineCount int, content string) {
 	_, y := self.view.Origin()
-	self.view.OverwriteLinesAndClearEverythingElse(y, content)
-}
-
-func (self *ViewTrait) SetContentLineCount(lineCount int) {
-	self.view.SetContentLineCount(lineCount)
+	self.view.OverwriteLinesAndClearEverythingElse(lineCount, y, content)
 }
 
 func (self *ViewTrait) SetContent(content string) {

pkg/gui/controllers/list_controller.go

@@ -178,6 +178,13 @@ func (self *ListController) handlePageChange(delta int) error {
 		}
 	}
 
+	// Since we already scrolled the view above, the normal mechanism that
+	// ListContextTrait.FocusLine uses for deciding whether rerendering is needed won't work. It is
+	// based on checking whether the origin was changed by the call to FocusPoint in that function,
+	// but since we scrolled the view directly above, the origin has already been updated. So we
+	// must tell it explicitly to rerender.
+	self.context.SetNeedRerenderVisibleLines()
+
 	// Since we are maintaining the scroll position ourselves above, there's no point in passing
 	// ScrollSelectionIntoView=true here.
 	self.context.HandleFocus(types.OnFocusOpts{})

pkg/gui/types/context.go

@@ -182,6 +182,7 @@ type IListContext interface {
 	IsListContext() // used for type switch
 	RangeSelectEnabled() bool
 	RenderOnlyVisibleLines() bool
+	SetNeedRerenderVisibleLines()
 
 	IndexForGotoBottom() int
 }
@@ -205,8 +206,7 @@ type IViewTrait interface {
 	SetRangeSelectStart(yIdx int)
 	CancelRangeSelect()
 	SetViewPortContent(content string)
-	SetViewPortContentAndClearEverythingElse(content string)
-	SetContentLineCount(lineCount int)
+	SetViewPortContentAndClearEverythingElse(lineCount int, content string)
 	SetContent(content string)
 	SetFooter(value string)
 	SetOriginX(value int)

vendor/modules.txt

@@ -221,7 +221,7 @@ github.com/jesseduffield/go-git/v5/utils/merkletrie/internal/frame
 github.com/jesseduffield/go-git/v5/utils/merkletrie/noder
 github.com/jesseduffield/go-git/v5/utils/sync
 github.com/jesseduffield/go-git/v5/utils/trace
-# github.com/jesseduffield/gocui v0.3.1-0.20251223143206-950739ccd44a
+# github.com/jesseduffield/gocui v0.3.1-0.20251223144240-29fe12e8d53f
 ## explicit; go 1.12
 github.com/jesseduffield/gocui
 # github.com/jesseduffield/lazycore v0.0.0-20221012050358-03d2e40243c5