fix glitchy render of stale data when flicking through files and directories

go.mod

@@ -18,7 +18,7 @@ require (
 	github.com/integrii/flaggy v1.4.0
 	github.com/jesseduffield/generics v0.0.0-20220320043834-727e535cbe68
 	github.com/jesseduffield/go-git/v5 v5.1.2-0.20201006095850-341962be15a4
-	github.com/jesseduffield/gocui v0.3.1-0.20221001154429-72c39318a83d
+	github.com/jesseduffield/gocui v0.3.1-0.20221003033055-3b1444b7ce1c
 	github.com/jesseduffield/kill v0.0.0-20220618033138-bfbe04675d10
 	github.com/jesseduffield/minimal/gitignore v0.3.3-0.20211018110810-9cde264e6b1e
 	github.com/jesseduffield/yaml v2.1.0+incompatible

go.sum

@@ -72,8 +72,8 @@ github.com/jesseduffield/generics v0.0.0-20220320043834-727e535cbe68 h1:EQP2Tv8T
 github.com/jesseduffield/generics v0.0.0-20220320043834-727e535cbe68/go.mod h1:+LLj9/WUPAP8LqCchs7P+7X0R98HiFujVFANdNaxhGk=
 github.com/jesseduffield/go-git/v5 v5.1.2-0.20201006095850-341962be15a4 h1:GOQrmaE8i+KEdB8NzAegKYd4tPn/inM0I1uo0NXFerg=
 github.com/jesseduffield/go-git/v5 v5.1.2-0.20201006095850-341962be15a4/go.mod h1:nGNEErzf+NRznT+N2SWqmHnDnF9aLgANB1CUNEan09o=
-github.com/jesseduffield/gocui v0.3.1-0.20221001154429-72c39318a83d h1:OTUa2dO3IvnY53QWCABkKJK9v5yvs3+uv3RMbG698S0=
-github.com/jesseduffield/gocui v0.3.1-0.20221001154429-72c39318a83d/go.mod h1:znJuCDnF2Ph40YZSlBwdX/4GEofnIoWLGdT4mK5zRAU=
+github.com/jesseduffield/gocui v0.3.1-0.20221003033055-3b1444b7ce1c h1:mbOoXlqOzc243zNV71pDxeiEof8IRRw2ZJzVXm/RLjc=
+github.com/jesseduffield/gocui v0.3.1-0.20221003033055-3b1444b7ce1c/go.mod h1:znJuCDnF2Ph40YZSlBwdX/4GEofnIoWLGdT4mK5zRAU=
 github.com/jesseduffield/kill v0.0.0-20220618033138-bfbe04675d10 h1:jmpr7KpX2+2GRiE91zTgfq49QvgiqB0nbmlwZ8UnOx0=
 github.com/jesseduffield/kill v0.0.0-20220618033138-bfbe04675d10/go.mod h1:aA97kHeNA+sj2Hbki0pvLslmE4CbDyhBeSSTUUnOuVo=
 github.com/jesseduffield/minimal/gitignore v0.3.3-0.20211018110810-9cde264e6b1e h1:uw/oo+kg7t/oeMs6sqlAwr85ND/9cpO3up3VxphxY0U=

pkg/gui/main_panels.go

@@ -27,11 +27,35 @@ func (gui *Gui) runTaskForView(view *gocui.View, task types.UpdateTask) error {
 }
 
 func (gui *Gui) moveMainContextPairToTop(pair types.MainContextPair) {
-	gui.setWindowContext(pair.Main)
-	gui.moveToTopOfWindow(pair.Main)
+	gui.moveMainContextToTop(pair.Main)
 	if pair.Secondary != nil {
-		gui.setWindowContext(pair.Secondary)
-		gui.moveToTopOfWindow(pair.Secondary)
+		gui.moveMainContextToTop(pair.Secondary)
+	}
+}
+
+func (gui *Gui) moveMainContextToTop(context types.Context) {
+	gui.setWindowContext(context)
+
+	view := context.GetView()
+
+	topView := gui.topViewInWindow(context.GetWindowName())
+	if topView == nil {
+		gui.Log.Error("unexpected: topView is nil")
+		return
+	}
+
+	if topView != view {
+		// We need to copy the content to avoid a flicker effect: If we're flicking
+		// through files in the files panel, we use a different view to render the
+		// files vs the directories, and if you select dir A, then file B, then dir
+		// C, you'll briefly see dir A's contents again before the view is updated.
+		// So here we're copying the content from the top window to avoid that
+		// flicker effect.
+		gui.g.CopyContent(topView, view)
+
+		if err := gui.g.SetViewOnTopOf(view.Name(), topView.Name()); err != nil {
+			gui.Log.Error(err)
+		}
 	}
 }
 

pkg/gui/window.go

@@ -3,6 +3,7 @@ package gui
 import (
 	"fmt"
 
+	"github.com/jesseduffield/gocui"
 	"github.com/jesseduffield/lazygit/pkg/gui/context"
 	"github.com/jesseduffield/lazygit/pkg/gui/types"
 	"github.com/samber/lo"
@@ -70,28 +71,42 @@ func (gui *Gui) resetWindowContext(c types.Context) {
 	}
 }
 
-func (gui *Gui) moveToTopOfWindow(context types.Context) {
+// moves given context's view to the top of the window and returns
+// true if the view was not already on top.
+func (gui *Gui) moveToTopOfWindow(context types.Context) bool {
 	view := context.GetView()
 	if view == nil {
-		return
+		return false
 	}
 
 	window := context.GetWindowName()
 
+	topView := gui.topViewInWindow(window)
+
+	if view.Name() == topView.Name() {
+		return false
+	} else {
+		if err := gui.g.SetViewOnTopOf(view.Name(), topView.Name()); err != nil {
+			gui.Log.Error(err)
+		}
+
+		return true
+	}
+}
+
+func (gui *Gui) topViewInWindow(windowName string) *gocui.View {
 	// now I need to find all views in that same window, via contexts. And I guess then I need to find the index of the highest view in that list.
-	viewNamesInWindow := gui.viewNamesInWindow(window)
+	viewNamesInWindow := gui.viewNamesInWindow(windowName)
 
 	// The views list is ordered highest-last, so we're grabbing the last view of the window
-	topView := view
+	var topView *gocui.View
 	for _, currentView := range gui.g.Views() {
 		if lo.Contains(viewNamesInWindow, currentView.Name()) {
 			topView = currentView
 		}
 	}
 
-	if err := gui.g.SetViewOnTopOf(view.Name(), topView.Name()); err != nil {
-		gui.Log.Error(err)
-	}
+	return topView
 }
 
 func (gui *Gui) viewNamesInWindow(windowName string) []string {

vendor/github.com/jesseduffield/gocui/gui.go

@@ -403,6 +403,21 @@ func (g *Gui) SetViewOnTopOf(toMove string, other string) error {
 	return nil
 }
 
+// replaces the content in toView with the content in fromView
+func (g *Gui) CopyContent(fromView *View, toView *View) {
+	g.Mutexes.ViewsMutex.Lock()
+	defer g.Mutexes.ViewsMutex.Unlock()
+
+	toView.clear()
+
+	toView.lines = fromView.lines
+	toView.viewLines = fromView.viewLines
+	toView.ox = fromView.ox
+	toView.oy = fromView.oy
+	toView.cx = fromView.cx
+	toView.cy = fromView.cy
+}
+
 // Views returns all the views in the GUI.
 func (g *Gui) Views() []*View {
 	return g.views

vendor/modules.txt

@@ -172,7 +172,7 @@ github.com/jesseduffield/go-git/v5/utils/merkletrie/filesystem
 github.com/jesseduffield/go-git/v5/utils/merkletrie/index
 github.com/jesseduffield/go-git/v5/utils/merkletrie/internal/frame
 github.com/jesseduffield/go-git/v5/utils/merkletrie/noder
-# github.com/jesseduffield/gocui v0.3.1-0.20221001154429-72c39318a83d
+# github.com/jesseduffield/gocui v0.3.1-0.20221003033055-3b1444b7ce1c
 ## explicit; go 1.12
 github.com/jesseduffield/gocui
 # github.com/jesseduffield/kill v0.0.0-20220618033138-bfbe04675d10