add scrollbars

14 files changed, 270 insertions, 116 deletions

diff --git a/go.mod b/go.mod
index f53f2645e..73124a6d1 100644
--- a/go.mod
+++ b/go.mod
@@ -16,7 +16,7 @@ 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 v0.3.1-0.20220415005542-2eb424ce3d0a
+	github.com/jesseduffield/gocui v0.3.1-0.20220416053910-5b19e175bc67
 	github.com/jesseduffield/minimal/gitignore v0.3.3-0.20211018110810-9cde264e6b1e
 	github.com/jesseduffield/yaml v2.1.0+incompatible
 	github.com/kardianos/osext v0.0.0-20190222173326-2bc1f35cddc0
diff --git a/go.sum b/go.sum
index 7dbd3f1b8..0a5b19b6c 100644
--- a/go.sum
+++ b/go.sum
@@ -70,8 +70,8 @@ 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 v0.3.1-0.20220415005542-2eb424ce3d0a h1:Fd8B7eZJfwK0cFzqz2gEFLEDiY0iwJTm6oBbPRHONxA=
-github.com/jesseduffield/gocui v0.3.1-0.20220415005542-2eb424ce3d0a/go.mod h1:znJuCDnF2Ph40YZSlBwdX/4GEofnIoWLGdT4mK5zRAU=
+github.com/jesseduffield/gocui v0.3.1-0.20220416053910-5b19e175bc67 h1:6NIOoR4LMuNEkP6e9P6GVZkzgYZ7rqpfM+LieKqubnA=
+github.com/jesseduffield/gocui v0.3.1-0.20220416053910-5b19e175bc67/go.mod h1:znJuCDnF2Ph40YZSlBwdX/4GEofnIoWLGdT4mK5zRAU=
 github.com/jesseduffield/minimal/gitignore v0.3.3-0.20211018110810-9cde264e6b1e h1:uw/oo+kg7t/oeMs6sqlAwr85ND/9cpO3up3VxphxY0U=
 github.com/jesseduffield/minimal/gitignore v0.3.3-0.20211018110810-9cde264e6b1e/go.mod h1:u60qdFGXRd36jyEXxetz0vQceQIxzI13lIo3EFUDf4I=
 github.com/jesseduffield/yaml v2.1.0+incompatible h1:HWQJ1gIv2zHKbDYNp0Jwjlj24K8aqpFHnMCynY1EpmE=
diff --git a/pkg/gui/context/view_trait.go b/pkg/gui/context/view_trait.go
index 4c0cd9e05..8f2a2e99e 100644
--- a/pkg/gui/context/view_trait.go
+++ b/pkg/gui/context/view_trait.go
@@ -3,7 +3,6 @@ package context
 import (
 	"github.com/jesseduffield/gocui"
 	"github.com/jesseduffield/lazygit/pkg/gui/types"
-	"github.com/jesseduffield/lazygit/pkg/utils"
 )
 
 const HORIZONTAL_SCROLL_FACTOR = 3
@@ -43,20 +42,31 @@ func (self *ViewTrait) SetOriginX(value int) {
 	_ = self.view.SetOriginX(value)
 }
 
-// tells us the bounds of line indexes shown in the view currently
+// tells us the start of line indexes shown in the view currently as well as the capacity of lines shown in the viewport.
 func (self *ViewTrait) ViewPortYBounds() (int, int) {
-	_, min := self.view.Origin()
-	max := self.view.InnerHeight() + 1
-	return min, max
+	_, start := self.view.Origin()
+	length := self.view.InnerHeight() + 1
+	return start, length
 }
 
 func (self *ViewTrait) ScrollLeft() {
-	newOriginX := utils.Max(self.view.OriginX()-self.view.InnerWidth()/HORIZONTAL_SCROLL_FACTOR, 0)
-	_ = self.view.SetOriginX(newOriginX)
+	self.view.ScrollLeft(self.horizontalScrollAmount())
 }
 
 func (self *ViewTrait) ScrollRight() {
-	_ = self.view.SetOriginX(self.view.OriginX() + self.view.InnerWidth()/HORIZONTAL_SCROLL_FACTOR)
+	self.view.ScrollRight(self.horizontalScrollAmount())
+}
+
+func (self *ViewTrait) horizontalScrollAmount() int {
+	return self.view.InnerWidth() / HORIZONTAL_SCROLL_FACTOR
+}
+
+func (self *ViewTrait) ScrollUp() {
+	self.view.ScrollUp(1)
+}
+
+func (self *ViewTrait) ScrollDown() {
+	self.view.ScrollDown(1)
 }
 
 // this returns the amount we'll scroll if we want to scroll by a page.
diff --git a/pkg/gui/context/viewport_list_context_trait.go b/pkg/gui/context/viewport_list_context_trait.go
index ab9b04fb8..b89dea832 100644
--- a/pkg/gui/context/viewport_list_context_trait.go
+++ b/pkg/gui/context/viewport_list_context_trait.go
@@ -15,8 +15,8 @@ type ViewportListContextTrait struct {
 func (self *ViewportListContextTrait) FocusLine() {
 	self.ListContextTrait.FocusLine()
 
-	min, max := self.GetViewTrait().ViewPortYBounds()
-	displayStrings := self.ListContextTrait.getDisplayStrings(min, max)
+	startIdx, length := self.GetViewTrait().ViewPortYBounds()
+	displayStrings := self.ListContextTrait.getDisplayStrings(startIdx, length)
 	content := utils.RenderDisplayStrings(displayStrings)
 	self.GetViewTrait().SetViewPortContent(content)
 }
diff --git a/pkg/gui/controllers/list_controller.go b/pkg/gui/controllers/list_controller.go
index 0f64228bb..7da05710e 100644
--- a/pkg/gui/controllers/list_controller.go
+++ b/pkg/gui/controllers/list_controller.go
@@ -43,14 +43,42 @@ func (self *ListController) HandleNextLine() error {
 }
 
 func (self *ListController) HandleScrollLeft() error {
-	return self.scroll(self.context.GetViewTrait().ScrollLeft)
+	return self.scrollHorizontal(self.context.GetViewTrait().ScrollLeft)
 }
 
 func (self *ListController) HandleScrollRight() error {
-	return self.scroll(self.context.GetViewTrait().ScrollRight)
+	return self.scrollHorizontal(self.context.GetViewTrait().ScrollRight)
 }
 
-func (self *ListController) scroll(scrollFunc func()) error {
+func (self *ListController) HandleScrollUp() error {
+	self.context.GetViewTrait().ScrollUp()
+
+	// we only need to do a line change if our line has been pushed out of the viewport, because
+	// at the moment much logic depends on the selected line always being visible
+	if !self.isSelectedLineInViewPort() {
+		return self.handleLineChange(-1)
+	}
+
+	return nil
+}
+
+func (self *ListController) HandleScrollDown() error {
+	self.context.GetViewTrait().ScrollDown()
+
+	if !self.isSelectedLineInViewPort() {
+		return self.handleLineChange(1)
+	}
+
+	return nil
+}
+
+func (self *ListController) isSelectedLineInViewPort() bool {
+	selectedLineIdx := self.context.GetList().GetSelectedLineIdx()
+	startIdx, length := self.context.GetViewTrait().ViewPortYBounds()
+	return selectedLineIdx >= startIdx && selectedLineIdx < startIdx+length
+}
+
+func (self *ListController) scrollHorizontal(scrollFunc func()) error {
 	scrollFunc()
 
 	return self.context.HandleFocus()
@@ -157,7 +185,7 @@ func (self *ListController) GetMouseKeybindings(opts types.KeybindingsOpts) []*g
 			ViewName:  self.context.GetViewName(),
 			ToContext: string(self.context.GetKey()),
 			Key:       gocui.MouseWheelUp,
-			Handler:   func(gocui.ViewMouseBindingOpts) error { return self.HandlePrevLine() },
+			Handler:   func(gocui.ViewMouseBindingOpts) error { return self.HandleScrollUp() },
 		},
 		{
 			ViewName:  self.context.GetViewName(),
@@ -169,7 +197,7 @@ func (self *ListController) GetMouseKeybindings(opts types.KeybindingsOpts) []*g
 			ViewName:  self.context.GetViewName(),
 			ToContext: string(self.context.GetKey()),
 			Key:       gocui.MouseWheelDown,
-			Handler:   func(gocui.ViewMouseBindingOpts) error { return self.HandleNextLine() },
+			Handler:   func(gocui.ViewMouseBindingOpts) error { return self.HandleScrollDown() },
 		},
 	}
 }
diff --git a/pkg/gui/extras_panel.go b/pkg/gui/extras_panel.go
index 462a5118e..6033f8516 100644
--- a/pkg/gui/extras_panel.go
+++ b/pkg/gui/extras_panel.go
@@ -46,15 +46,15 @@ func (gui *Gui) handleFocusCommandLog() error {
 func (gui *Gui) scrollUpExtra() error {
 	gui.Views.Extras.Autoscroll = false
 
-	return gui.scrollUpView(gui.Views.Extras)
+	gui.scrollUpView(gui.Views.Extras)
+
+	return nil
 }
 
 func (gui *Gui) scrollDownExtra() error {
 	gui.Views.Extras.Autoscroll = false
 
-	if err := gui.scrollDownView(gui.Views.Extras); err != nil {
-		return err
-	}
+	gui.scrollDownView(gui.Views.Extras)
 
 	return nil
 }
diff --git a/pkg/gui/global_handlers.go b/pkg/gui/global_handlers.go
index e76c9f1a6..97cf4650d 100644
--- a/pkg/gui/global_handlers.go
+++ b/pkg/gui/global_handlers.go
@@ -2,7 +2,6 @@ package gui
 
 import (
 	"fmt"
-	"math"
 	"strings"
 
 	"github.com/jesseduffield/gocui"
@@ -63,56 +62,17 @@ func (gui *Gui) prevScreenMode() error {
 	return gui.rerenderViewsWithScreenModeDependentContent()
 }
 
-func (gui *Gui) scrollUpView(view *gocui.View) error {
-	ox, oy := view.Origin()
-	newOy := int(math.Max(0, float64(oy-gui.c.UserConfig.Gui.ScrollHeight)))
-	return view.SetOrigin(ox, newOy)
+func (gui *Gui) scrollUpView(view *gocui.View) {
+	view.ScrollUp(gui.c.UserConfig.Gui.ScrollHeight)
 }
 
-func (gui *Gui) scrollDownView(view *gocui.View) error {
-	ox, oy := view.Origin()
-	scrollHeight := gui.linesToScrollDown(view)
-	if scrollHeight > 0 {
-		if err := view.SetOrigin(ox, oy+scrollHeight); err != nil {
-			return err
-		}
-	}
+func (gui *Gui) scrollDownView(view *gocui.View) {
+	scrollHeight := gui.c.UserConfig.Gui.ScrollHeight
+	view.ScrollDown(scrollHeight)
 
 	if manager, ok := gui.viewBufferManagerMap[view.Name()]; ok {
 		manager.ReadLines(scrollHeight)
 	}
-	return nil
-}
-
-func (gui *Gui) linesToScrollDown(view *gocui.View) int {
-	_, oy := view.Origin()
-	y := oy
-	canScrollPastBottom := gui.c.UserConfig.Gui.ScrollPastBottom
-	if !canScrollPastBottom {
-		_, sy := view.Size()
-		y += sy
-	}
-	scrollHeight := gui.c.UserConfig.Gui.ScrollHeight
-	scrollableLines := view.ViewLinesHeight() - y
-	if scrollableLines < 0 {
-		return 0
-	}
-
-	// margin is about how many lines must still appear if you scroll
-	// all the way down. In practice every file ends in a newline so it will really
-	// just show a single line
-	margin := 1
-	if canScrollPastBottom {
-		margin = 2
-	}
-	if scrollableLines-margin < scrollHeight {
-		scrollHeight = scrollableLines - margin
-	}
-	if oy+scrollHeight < 0 {
-		return 0
-	} else {
-		return scrollHeight
-	}
 }
 
 func (gui *Gui) scrollUpMain() error {
@@ -120,7 +80,9 @@ func (gui *Gui) scrollUpMain() error {
 		gui.State.Panels.Merging.UserVerticalScrolling = true
 	}
 
-	return gui.scrollUpView(gui.Views.Main)
+	gui.scrollUpView(gui.Views.Main)
+
+	return nil
 }
 
 func (gui *Gui) scrollDownMain() error {
@@ -128,7 +90,9 @@ func (gui *Gui) scrollDownMain() error {
 		gui.State.Panels.Merging.UserVerticalScrolling = true
 	}
 
-	return gui.scrollDownView(gui.Views.Main)
+	gui.scrollDownView(gui.Views.Main)
+
+	return nil
 }
 
 func (gui *Gui) scrollLeftMain() error {
@@ -153,11 +117,15 @@ func (gui *Gui) scrollRight(view *gocui.View) {
 }
 
 func (gui *Gui) scrollUpSecondary() error {
-	return gui.scrollUpView(gui.Views.Secondary)
+	gui.scrollUpView(gui.Views.Secondary)
+
+	return nil
 }
 
 func (gui *Gui) scrollDownSecondary() error {
-	return gui.scrollDownView(gui.Views.Secondary)
+	gui.scrollDownView(gui.Views.Secondary)
+
+	return nil
 }
 
 func (gui *Gui) scrollUpConfirmationPanel() error {
@@ -165,7 +133,9 @@ func (gui *Gui) scrollUpConfirmationPanel() error {
 		return nil
 	}
 
-	return gui.scrollUpView(gui.Views.Confirmation)
+	gui.scrollUpView(gui.Views.Confirmation)
+
+	return nil
 }
 
 func (gui *Gui) scrollDownConfirmationPanel() error {
@@ -173,7 +143,9 @@ func (gui *Gui) scrollDownConfirmationPanel() error {
 		return nil
 	}
 
-	return gui.scrollDownView(gui.Views.Confirmation)
+	gui.scrollDownView(gui.Views.Confirmation)
+
+	return nil
 }
 
 func (gui *Gui) handleRefresh() error {
diff --git a/pkg/gui/gui.go b/pkg/gui/gui.go
index 17ca26f41..23b8ae8ca 100644
--- a/pkg/gui/gui.go
+++ b/pkg/gui/gui.go
@@ -661,11 +661,13 @@ func (gui *Gui) createAllViews() error {
 	gui.Views.Secondary.Wrap = true
 	gui.Views.Secondary.FgColor = theme.GocuiDefaultTextColor
 	gui.Views.Secondary.IgnoreCarriageReturns = true
+	gui.Views.Secondary.CanScrollPastBottom = gui.c.UserConfig.Gui.ScrollPastBottom
 
 	gui.Views.Main.Title = gui.c.Tr.DiffTitle
 	gui.Views.Main.Wrap = true
 	gui.Views.Main.FgColor = theme.GocuiDefaultTextColor
 	gui.Views.Main.IgnoreCarriageReturns = true
+	gui.Views.Main.CanScrollPastBottom = gui.c.UserConfig.Gui.ScrollPastBottom
 
 	gui.Views.Limit.Title = gui.c.Tr.NotEnoughSpace
 	gui.Views.Limit.Wrap = true
diff --git a/pkg/gui/tasks_adapter.go b/pkg/gui/tasks_adapter.go
index d619c58ba..745cc3760 100644
--- a/pkg/gui/tasks_adapter.go
+++ b/pkg/gui/tasks_adapter.go
@@ -98,21 +98,15 @@ func (gui *Gui) getManager(view *gocui.View) *tasks.ViewBufferManager {
 			},
 			func() {
 				// Need to check if the content of the view is well past the origin.
-				// It would be better to use .ViewLinesHeight here (given it considers
-				// wrapping) but when this function is called they haven't been written to yet.
-				linesHeight := view.LinesHeight()
-				_, height := view.Size()
+				linesHeight := view.ViewLinesHeight()
 				_, originY := view.Origin()
 				if linesHeight < originY {
-					newOriginY := linesHeight - height
-					if newOriginY < 0 {
-						newOriginY = 0
-					}
+					newOriginY := linesHeight
+
 					err := view.SetOrigin(0, newOriginY)
 					if err != nil {
 						panic(err)
 					}
-
 				}
 
 				view.FlushStaleCells()
diff --git a/pkg/gui/types/context.go b/pkg/gui/types/context.go
index 6f026fe73..253bb62ef 100644
--- a/pkg/gui/types/context.go
+++ b/pkg/gui/types/context.go
@@ -85,6 +85,8 @@ type IViewTrait interface {
 	ViewPortYBounds() (int, int)
 	ScrollLeft()
 	ScrollRight()
+	ScrollUp()
+	ScrollDown()
 	PageDelta() int
 	SelectedLineIdx() int
 }
diff --git a/vendor/github.com/jesseduffield/gocui/gui.go b/vendor/github.com/jesseduffield/gocui/gui.go
index ba8d93ce2..58e396492 100644
--- a/vendor/github.com/jesseduffield/gocui/gui.go
+++ b/vendor/github.com/jesseduffield/gocui/gui.go
@@ -743,6 +743,8 @@ func (g *Gui) drawFrameEdges(v *View, fgColor, bgColor Attribute) error {
 			}
 		}
 	}
+
+	showScrollbar, realScrollbarStart, realScrollbarEnd := calcRealScrollbarStartEnd(v)
 	for y := v.y0 + 1; y < v.y1 && y < g.maxY; y++ {
 		if y < 0 {
 			continue
@@ -753,7 +755,9 @@ func (g *Gui) drawFrameEdges(v *View, fgColor, bgColor Attribute) error {
 			}
 		}
 		if v.x1 > -1 && v.x1 < g.maxX {
-			if err := g.SetRune(v.x1, y, runeV, fgColor, bgColor); err != nil {
+			runeToPrint := calcScrollbarRune(showScrollbar, realScrollbarStart, realScrollbarEnd, v.y0+1, v.y1-1, y, runeV)
+
+			if err := g.SetRune(v.x1, y, runeToPrint, fgColor, bgColor); err != nil {
 				return err
 			}
 		}
@@ -761,6 +765,44 @@ func (g *Gui) drawFrameEdges(v *View, fgColor, bgColor Attribute) error {
 	return nil
 }
 
+func calcScrollbarRune(showScrollbar bool, scrollbarStart int, scrollbarEnd int, rangeStart int, rangeEnd int, position int, runeV rune) rune {
+	if !showScrollbar {
+		return runeV
+	} else if position == rangeStart {
+		return '▲'
+	} else if position == rangeEnd {
+		return '▼'
+	} else if position > scrollbarStart && position < scrollbarEnd {
+		return '█'
+	} else if position > rangeStart && position < rangeEnd {
+		// keeping this as a separate branch in case we later want to render something different here.
+		return runeV
+	} else {
+		return runeV
+	}
+}
+
+func calcRealScrollbarStartEnd(v *View) (bool, int, int) {
+	height := v.InnerHeight() + 1
+	fullHeight := v.ViewLinesHeight() - v.scrollMargin()
+
+	if v.CanScrollPastBottom {
+		fullHeight += height
+	}
+
+	if height < 2 || height >= fullHeight {
+		return false, 0, 0
+	}
+
+	originY := v.OriginY()
+	scrollbarStart, scrollbarHeight := calcScrollbar(fullHeight, height, originY, height-1)
+	top := v.y0 + 1
+	realScrollbarStart := top + scrollbarStart
+	realScrollbarEnd := realScrollbarStart + scrollbarHeight
+
+	return true, realScrollbarStart, realScrollbarEnd
+}
+
 func cornerRune(index byte) rune {
 	return []rune{' ', '│', '│', '│', '─', '┘', '┐', '┤', '─', '└', '┌', '├', '├', '┴', '┬', '┼'}[index]
 }
@@ -1014,6 +1056,40 @@ func (g *Gui) draw(v *View) error {
 	if !v.Visible || v.y1 < v.y0 {
 		return nil
 	}
+
+	if g.Cursor {
+		if curview := g.currentView; curview != nil {
+			vMaxX, vMaxY := curview.Size()
+			if curview.cx < 0 {
+				curview.cx = 0
+			} else if curview.cx >= vMaxX {
+				curview.cx = vMaxX - 1
+			}
+			if curview.cy < 0 {
+				curview.cy = 0
+			} else if curview.cy >= vMaxY {
+				curview.cy = vMaxY - 1
+			}
+
+			gMaxX, gMaxY := g.Size()
+			cx, cy := curview.x0+curview.cx+1, curview.y0+curview.cy+1
+			// This test probably doesn't need to be here.
+			// tcell is hiding cursor by setting coordinates outside of screen.
+			// Keeping it here for now, as I'm not 100% sure :)
+			if cx >= 0 && cx < gMaxX && cy >= 0 && cy < gMaxY {
+				Screen.ShowCursor(cx, cy)
+			} else {
+				Screen.HideCursor()
+			}
+		}
+	} else {
+		Screen.HideCursor()
+	}
+
+	if err := v.draw(); err != nil {
+		return err
+	}
+
 	if v.Frame {
 		var fgColor, bgColor, frameColor Attribute
 		if g.Highlight && v == g.currentView {
@@ -1057,38 +1133,6 @@ func (g *Gui) draw(v *View) error {
 		}
 	}
 
-	if g.Cursor {
-		if curview := g.currentView; curview != nil {
-			vMaxX, vMaxY := curview.Size()
-			if curview.cx < 0 {
-				curview.cx = 0
-			} else if curview.cx >= vMaxX {
-				curview.cx = vMaxX - 1
-			}
-			if curview.cy < 0 {
-				curview.cy = 0
-			} else if curview.cy >= vMaxY {
-				curview.cy = vMaxY - 1
-			}
-
-			gMaxX, gMaxY := g.Size()
-			cx, cy := curview.x0+curview.cx+1, curview.y0+curview.cy+1
-			// This test probably doesn't need to be here.
-			// tcell is hiding cursor by setting coordinates outside of screen.
-			// Keeping it here for now, as I'm not 100% sure :)
-			if cx >= 0 && cx < gMaxX && cy >= 0 && cy < gMaxY {
-				Screen.ShowCursor(cx, cy)
-			} else {
-				Screen.HideCursor()
-			}
-		}
-	} else {
-		Screen.HideCursor()
-	}
-
-	if err := v.draw(); err != nil {
-		return err
-	}
 	return nil
 }
 
diff --git a/vendor/github.com/jesseduffield/gocui/scrollbar.go b/vendor/github.com/jesseduffield/gocui/scrollbar.go
new file mode 100644
index 000000000..3bdb4a45c
--- /dev/null
+++ b/vendor/github.com/jesseduffield/gocui/scrollbar.go
@@ -0,0 +1,33 @@
+package gocui
+
+import "math"
+
+// returns start and height of scrollbar
+// `max` is the maximum possible value of `position`
+func calcScrollbar(listSize int, pageSize int, position int, scrollAreaSize int) (int, int) {
+	height := calcScrollbarHeight(listSize, pageSize, scrollAreaSize)
+	// assume we can't scroll past the last item
+	maxPosition := listSize - pageSize
+	if maxPosition <= 0 {
+		return 0, height
+	}
+	if position == maxPosition {
+		return scrollAreaSize - height, height
+	}
+	// we only want to show the scrollbar at the top or bottom positions if we're at the end. Hence the .Ceil (for moving the scrollbar once we scroll down) and the -1 (for pretending there's a smaller range than we actually have, with the above condition ensuring we snap to the bottom once we're at the end of the list)
+	start := int(math.Ceil(((float64(position) / float64(maxPosition)) * float64(scrollAreaSize-height-1))))
+	return start, height
+}
+
+func calcScrollbarHeight(listSize int, pageSize int, scrollAreaSize int) int {
+	if pageSize >= listSize {
+		return scrollAreaSize
+	}
+	height := int((float64(pageSize) / float64(listSize)) * float64(scrollAreaSize))
+	minHeight := 2
+	if height < minHeight {
+		return minHeight
+	}
+
+	return height
+}
diff --git a/vendor/github.com/jesseduffield/gocui/view.go b/vendor/github.com/jesseduffield/gocui/view.go
index d2c2b75f1..8051cce72 100644
--- a/vendor/github.com/jesseduffield/gocui/view.go
+++ b/vendor/github.com/jesseduffield/gocui/view.go
@@ -158,6 +158,9 @@ type View struct {
 
 	// something like '1 of 20' for a list view
 	Footer string
+
+	// if true, the user can scroll all the way past the last item until it appears at the top of the view
+	CanScrollPastBottom bool
 }
 
 // call this in the event of a view resize, or if you want to render new content
@@ -1287,3 +1290,69 @@ func (v *View) OverwriteLines(y int, content string) {
 	lines := strings.Replace(content, "\n", "\x1b[K\n", -1)
 	v.writeString(lines)
 }
+
+func (v *View) ScrollUp(amount int) {
+	newOy := v.oy - amount
+	if newOy < 0 {
+		newOy = 0
+	}
+	v.oy = newOy
+}
+
+// ensures we don't scroll past the end of the view's content
+func (v *View) ScrollDown(amount int) {
+	adjustedAmount := v.adjustDownwardScrollAmount(amount)
+	if adjustedAmount > 0 {
+		v.oy += adjustedAmount
+	}
+}
+
+func (v *View) ScrollLeft(amount int) {
+	newOx := v.ox - amount
+	if newOx < 0 {
+		newOx = 0
+	}
+	v.ox = newOx
+}
+
+// not applying any limits to this
+func (v *View) ScrollRight(amount int) {
+	v.ox += amount
+}
+
+func (v *View) adjustDownwardScrollAmount(scrollHeight int) int {
+	_, oy := v.Origin()
+	y := oy
+	if !v.CanScrollPastBottom {
+		_, sy := v.Size()
+		y += sy
+	}
+	scrollableLines := v.ViewLinesHeight() - y
+	if scrollableLines < 0 {
+		return 0
+	}
+
+	margin := v.scrollMargin()
+	if scrollableLines-margin < scrollHeight {
+		scrollHeight = scrollableLines - margin
+	}
+	if oy+scrollHeight < 0 {
+		return 0
+	} else {
+		return scrollHeight
+	}
+}
+
+// scrollMargin is about how many lines must still appear if you scroll
+// all the way down. We'll subtract this from the total amount of scrollable lines
+func (v *View) scrollMargin() int {
+	if v.CanScrollPastBottom {
+		// Setting to 2 because of the newline at the end of the file that we're likely showing.
+		// If we want to scroll past bottom outside the context of reading a file's contents,
+		// we should make this into a field on the view to be configured by the client.
+		// For now we're hardcoding it.
+		return 2
+	} else {
+		return 0
+	}
+}
diff --git a/vendor/modules.txt b/vendor/modules.txt
index a7f378b45..68bceb9b0 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -169,7 +169,7 @@ 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 v0.3.1-0.20220415005542-2eb424ce3d0a
+# github.com/jesseduffield/gocui v0.3.1-0.20220416053910-5b19e175bc67
 ## explicit; go 1.12
 github.com/jesseduffield/gocui
 # github.com/jesseduffield/minimal/gitignore v0.3.3-0.20211018110810-9cde264e6b1e