support scrolling left and right

16 files changed, 140 insertions, 17 deletions

diff --git a/docs/Config.md b/docs/Config.md
index 96200e75d..a43bd273f 100644
--- a/docs/Config.md
+++ b/docs/Config.md
@@ -107,6 +107,8 @@ keybinding:
     nextPage: '.' # go to previous page in list
     gotoTop: '<' # go to top of list
     gotoBottom: '>' # go to bottom of list
+    scrollLeft: 'H' # scroll left within list view
+    scrollRight: 'L' # scroll right within list view
     prevBlock: '<left>' # goto the previous block / panel
     nextBlock: '<right>' # goto the next block / panel
     prevBlock-alt: 'h' # goto the previous block / panel
diff --git a/go.mod b/go.mod
index 73704f54b..cbc8d1731 100644
--- a/go.mod
+++ b/go.mod
@@ -20,7 +20,7 @@ require (
 	github.com/imdario/mergo v0.3.11
 	github.com/integrii/flaggy v1.4.0
 	github.com/jesseduffield/go-git/v5 v5.1.2-0.20201006095850-341962be15a4
-	github.com/jesseduffield/gocui v0.3.1-0.20211102081536-e4eee64f4d13
+	github.com/jesseduffield/gocui v0.3.1-0.20211102093457-be3a05cf7131
 	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 332984b7c..faf1b80ec 100644
--- a/go.sum
+++ b/go.sum
@@ -71,8 +71,8 @@ github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 h1:BQSFePA1RWJOl
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99/go.mod h1:1lJo3i6rXxKeerYnT8Nvf0QmHCRC1n8sfWVwXF2Frvo=
 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 v0.3.1-0.20211102081536-e4eee64f4d13 h1:JB1nYX2l3s9aBtw4Ymc7KXp/Hk3IukO4u+APok6WWjo=
-github.com/jesseduffield/gocui v0.3.1-0.20211102081536-e4eee64f4d13/go.mod h1:znJuCDnF2Ph40YZSlBwdX/4GEofnIoWLGdT4mK5zRAU=
+github.com/jesseduffield/gocui v0.3.1-0.20211102093457-be3a05cf7131 h1:gojgTjfrDjDtpjcFeY/IVPGufQPOi/gTgg3wQ9FESmc=
+github.com/jesseduffield/gocui v0.3.1-0.20211102093457-be3a05cf7131/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/config/user_config.go b/pkg/config/user_config.go
index 4ded99304..2d391b5fb 100644
--- a/pkg/config/user_config.go
+++ b/pkg/config/user_config.go
@@ -125,6 +125,8 @@ type KeybindingUniversalConfig struct {
 	NextItemAlt                  string   `yaml:"nextItem-alt"`
 	PrevPage                     string   `yaml:"prevPage"`
 	NextPage                     string   `yaml:"nextPage"`
+	ScrollLeft                   string   `yaml:"scrollLeft"`
+	ScrollRight                  string   `yaml:"scrollRight"`
 	GotoTop                      string   `yaml:"gotoTop"`
 	GotoBottom                   string   `yaml:"gotoBottom"`
 	PrevBlock                    string   `yaml:"prevBlock"`
@@ -382,6 +384,8 @@ func GetDefaultConfig() *UserConfig {
 				NextItemAlt:                  "j",
 				PrevPage:                     ",",
 				NextPage:                     ".",
+				ScrollLeft:                   "H",
+				ScrollRight:                  "L",
 				GotoTop:                      "<",
 				GotoBottom:                   ">",
 				PrevBlock:                    "<left>",
diff --git a/pkg/gui/context.go b/pkg/gui/context.go
index 79db5dc26..66e28fc35 100644
--- a/pkg/gui/context.go
+++ b/pkg/gui/context.go
@@ -399,6 +399,8 @@ func (gui *Gui) onViewFocusLost(oldView *gocui.View, newView *gocui.View) error
 		return nil
 	}
 
+	_ = oldView.SetOriginX(0)
+
 	if oldView == gui.Views.CommitFiles && newView != gui.Views.Main && newView != gui.Views.Secondary && newView != gui.Views.Search {
 		gui.resetWindowForView(gui.Views.CommitFiles)
 		if err := gui.deactivateContext(gui.State.Contexts.CommitFiles); err != nil {
diff --git a/pkg/gui/global_handlers.go b/pkg/gui/global_handlers.go
index b55d6e3a8..c104c1664 100644
--- a/pkg/gui/global_handlers.go
+++ b/pkg/gui/global_handlers.go
@@ -10,6 +10,8 @@ import (
 	"github.com/jesseduffield/lazygit/pkg/utils"
 )
 
+const HORIZONTAL_SCROLL_FACTOR = 3
+
 // these views need to be re-rendered when the screen mode changes. The commits view,
 // for example, will show authorship information in half and full screen mode.
 func (gui *Gui) rerenderViewsWithScreenModeDependentContent() error {
@@ -114,7 +116,7 @@ func (gui *Gui) linesToScrollDown(view *gocui.View) int {
 
 func (gui *Gui) scrollUpMain() error {
 	if gui.canScrollMergePanel() {
-		gui.State.Panels.Merging.UserScrolling = true
+		gui.State.Panels.Merging.UserVerticalScrolling = true
 	}
 
 	return gui.scrollUpView(gui.Views.Main)
@@ -122,12 +124,33 @@ func (gui *Gui) scrollUpMain() error {
 
 func (gui *Gui) scrollDownMain() error {
 	if gui.canScrollMergePanel() {
-		gui.State.Panels.Merging.UserScrolling = true
+		gui.State.Panels.Merging.UserVerticalScrolling = true
 	}
 
 	return gui.scrollDownView(gui.Views.Main)
 }
 
+func (gui *Gui) scrollLeftMain() error {
+	gui.scrollLeft(gui.Views.Main)
+
+	return nil
+}
+
+func (gui *Gui) scrollRightMain() error {
+	gui.scrollRight(gui.Views.Main)
+
+	return nil
+}
+
+func (gui *Gui) scrollLeft(view *gocui.View) {
+	newOriginX := utils.Max(view.OriginX()-view.InnerWidth()/HORIZONTAL_SCROLL_FACTOR, 0)
+	_ = view.SetOriginX(newOriginX)
+}
+
+func (gui *Gui) scrollRight(view *gocui.View) {
+	_ = view.SetOriginX(view.OriginX() + view.InnerWidth()/HORIZONTAL_SCROLL_FACTOR)
+}
+
 func (gui *Gui) scrollUpSecondary() error {
 	return gui.scrollUpView(gui.Views.Secondary)
 }
diff --git a/pkg/gui/gui.go b/pkg/gui/gui.go
index 76df52959..496ded841 100644
--- a/pkg/gui/gui.go
+++ b/pkg/gui/gui.go
@@ -145,9 +145,9 @@ type LblPanelState struct {
 type MergingPanelState struct {
 	*mergeconflicts.State
 
-	// UserScrolling tells us if the user has started scrolling through the file themselves
+	// UserVerticalScrolling tells us if the user has started scrolling through the file themselves
 	// in which case we won't auto-scroll to a conflict.
-	UserScrolling bool
+	UserVerticalScrolling bool
 }
 
 type filePanelState struct {
@@ -403,8 +403,8 @@ func (gui *Gui) resetState(filterPath string, reuseState bool) {
 			Menu:           &menuPanelState{listPanelState: listPanelState{SelectedLineIdx: 0}, OnPress: nil},
 			Suggestions:    &suggestionsPanelState{listPanelState: listPanelState{SelectedLineIdx: 0}},
 			Merging: &MergingPanelState{
-				State:         mergeconflicts.NewState(),
-				UserScrolling: false,
+				State:                 mergeconflicts.NewState(),
+				UserVerticalScrolling: false,
 			},
 		},
 		Ptmx: nil,
diff --git a/pkg/gui/keybindings.go b/pkg/gui/keybindings.go
index d441c496c..8dbcfee7e 100644
--- a/pkg/gui/keybindings.go
+++ b/pkg/gui/keybindings.go
@@ -1428,6 +1428,20 @@ func (gui *Gui) GetInitialKeybindings() []*Binding {
 		},
 		{
 			ViewName:    "main",
+			Contexts:    []string{string(MAIN_PATCH_BUILDING_CONTEXT_KEY), string(MAIN_STAGING_CONTEXT_KEY), string(MAIN_MERGING_CONTEXT_KEY)},
+			Key:         gui.getKey(config.Universal.ScrollLeft),
+			Handler:     gui.scrollLeftMain,
+			Description: gui.Tr.LcScrollLeft,
+		},
+		{
+			ViewName:    "main",
+			Contexts:    []string{string(MAIN_PATCH_BUILDING_CONTEXT_KEY), string(MAIN_STAGING_CONTEXT_KEY), string(MAIN_MERGING_CONTEXT_KEY)},
+			Key:         gui.getKey(config.Universal.ScrollRight),
+			Handler:     gui.scrollRightMain,
+			Description: gui.Tr.LcScrollRight,
+		},
+		{
+			ViewName:    "main",
 			Contexts:    []string{string(MAIN_STAGING_CONTEXT_KEY)},
 			Key:         gui.getKey(config.Files.CommitChanges),
 			Handler:     gui.handleCommitPress,
diff --git a/pkg/gui/line_by_line_panel.go b/pkg/gui/line_by_line_panel.go
index 8c793375b..809416451 100644
--- a/pkg/gui/line_by_line_panel.go
+++ b/pkg/gui/line_by_line_panel.go
@@ -174,7 +174,7 @@ func (gui *Gui) focusSelection(state *LblPanelState) error {
 	newOrigin := state.CalculateOrigin(origin, bufferHeight)
 
 	gui.g.Update(func(*gocui.Gui) error {
-		if err := stagingView.SetOrigin(0, newOrigin); err != nil {
+		if err := stagingView.SetOriginY(newOrigin); err != nil {
 			return err
 		}
 
diff --git a/pkg/gui/list_context.go b/pkg/gui/list_context.go
index 290ac3a37..56e229273 100644
--- a/pkg/gui/list_context.go
+++ b/pkg/gui/list_context.go
@@ -30,6 +30,8 @@ type IListContext interface {
 	OnRender() error
 	handlePrevLine() error
 	handleNextLine() error
+	handleScrollLeft() error
+	handleScrollRight() error
 	handleLineChange(change int) error
 	handleNextPage() error
 	handleGotoTop() error
@@ -69,7 +71,7 @@ func (self *ListContext) FocusLine() {
 	}
 
 	// we need a way of knowing whether we've rendered to the view yet.
-	view.FocusPoint(0, self.GetPanelState().GetSelectedLineIdx())
+	view.FocusPoint(view.OriginX(), self.GetPanelState().GetSelectedLineIdx())
 	if self.RenderSelection {
 		_, originY := view.Origin()
 		displayStrings := self.GetDisplayStrings(originY, view.InnerHeight())
@@ -117,6 +119,13 @@ func (self *ListContext) HandleFocusLost() error {
 		return self.OnFocusLost()
 	}
 
+	view, err := self.Gui.g.View(self.ViewName)
+	if err != nil {
+		return nil
+	}
+
+	_ = view.SetOriginX(0)
+
 	return nil
 }
 
@@ -150,8 +159,44 @@ func (self *ListContext) handleNextLine() error {
 	return self.handleLineChange(1)
 }
 
+func (self *ListContext) handleScrollLeft() error {
+	if self.ignoreKeybinding() {
+		return nil
+	}
+
+	// get the view, move the origin
+	view, err := self.Gui.g.View(self.ViewName)
+	if err != nil {
+		return nil
+	}
+
+	self.Gui.scrollLeft(view)
+
+	return self.HandleFocus()
+}
+
+func (self *ListContext) handleScrollRight() error {
+	if self.ignoreKeybinding() {
+		return nil
+	}
+
+	// get the view, move the origin
+	view, err := self.Gui.g.View(self.ViewName)
+	if err != nil {
+		return nil
+	}
+
+	self.Gui.scrollRight(view)
+
+	return self.HandleFocus()
+}
+
+func (self *ListContext) ignoreKeybinding() bool {
+	return !self.Gui.isPopupPanel(self.ViewName) && self.Gui.popupPanelFocused()
+}
+
 func (self *ListContext) handleLineChange(change int) error {
-	if !self.Gui.isPopupPanel(self.ViewName) && self.Gui.popupPanelFocused() {
+	if self.ignoreKeybinding() {
 		return nil
 	}
 
@@ -195,7 +240,7 @@ func (self *ListContext) handlePrevPage() error {
 }
 
 func (self *ListContext) handleClick() error {
-	if !self.Gui.isPopupPanel(self.ViewName) && self.Gui.popupPanelFocused() {
+	if self.ignoreKeybinding() {
 		return nil
 	}
 
diff --git a/pkg/gui/list_context_config.go b/pkg/gui/list_context_config.go
index 3e19eaf75..814e4677d 100644
--- a/pkg/gui/list_context_config.go
+++ b/pkg/gui/list_context_config.go
@@ -402,6 +402,8 @@ func (gui *Gui) getListContextKeyBindings() []*Binding {
 			{ViewName: listContext.GetViewName(), Tag: "navigation", Contexts: []string{string(listContext.GetKey())}, Key: gui.getKey(keybindingConfig.Universal.GotoTop), Modifier: gocui.ModNone, Handler: listContext.handleGotoTop, Description: gui.Tr.LcGotoTop},
 			{ViewName: listContext.GetViewName(), Tag: "navigation", Contexts: []string{string(listContext.GetKey())}, Key: gocui.MouseWheelDown, Modifier: gocui.ModNone, Handler: listContext.handleNextLine},
 			{ViewName: listContext.GetViewName(), Contexts: []string{string(listContext.GetKey())}, Key: gocui.MouseLeft, Modifier: gocui.ModNone, Handler: listContext.handleClick},
+			{ViewName: listContext.GetViewName(), Tag: "navigation", Contexts: []string{string(listContext.GetKey())}, Key: gui.getKey(keybindingConfig.Universal.ScrollLeft), Modifier: gocui.ModNone, Handler: listContext.handleScrollLeft},
+			{ViewName: listContext.GetViewName(), Tag: "navigation", Contexts: []string{string(listContext.GetKey())}, Key: gui.getKey(keybindingConfig.Universal.ScrollRight), Modifier: gocui.ModNone, Handler: listContext.handleScrollRight},
 		}...)
 
 		// the commits panel needs to lazyload things so it has a couple of its own handlers
diff --git a/pkg/gui/merge_panel.go b/pkg/gui/merge_panel.go
index c0c55de6c..f9e2de55c 100644
--- a/pkg/gui/merge_panel.go
+++ b/pkg/gui/merge_panel.go
@@ -203,7 +203,7 @@ func (gui *Gui) catSelectedFile() (string, error) {
 }
 
 func (gui *Gui) scrollToConflict() error {
-	if gui.State.Panels.Merging.UserScrolling {
+	if gui.State.Panels.Merging.UserVerticalScrolling {
 		return nil
 	}
 
@@ -315,5 +315,5 @@ func (gui *Gui) withMergeConflictLock(f func() error) error {
 }
 
 func (gui *Gui) takeOverMergeConflictScrolling() {
-	gui.State.Panels.Merging.UserScrolling = false
+	gui.State.Panels.Merging.UserVerticalScrolling = false
 }
diff --git a/pkg/gui/view_helpers.go b/pkg/gui/view_helpers.go
index f853f2942..e77fbf751 100644
--- a/pkg/gui/view_helpers.go
+++ b/pkg/gui/view_helpers.go
@@ -323,6 +323,7 @@ func (gui *Gui) globalOptionsMap() map[string]string {
 		gui.getKeyDisplay(keybindingConfig.Universal.Quit):       gui.Tr.LcQuit,
 		gui.getKeyDisplay(keybindingConfig.Universal.OptionMenu): gui.Tr.LcMenu,
 		fmt.Sprintf("%s-%s", gui.getKeyDisplay(keybindingConfig.Universal.JumpToBlock[0]), gui.getKeyDisplay(keybindingConfig.Universal.JumpToBlock[len(keybindingConfig.Universal.JumpToBlock)-1])): gui.Tr.LcJump,
+		fmt.Sprintf("%s/%s", gui.getKeyDisplay(keybindingConfig.Universal.ScrollLeft), gui.getKeyDisplay(keybindingConfig.Universal.ScrollRight)):                                                    gui.Tr.LcScrollLeftRight,
 	}
 }
 
diff --git a/pkg/i18n/english.go b/pkg/i18n/english.go
index 8f39948a0..b7c38d7ac 100644
--- a/pkg/i18n/english.go
+++ b/pkg/i18n/english.go
@@ -271,6 +271,9 @@ type TranslationSet struct {
 	LcStashOptions                      string
 	NotARepository                      string
 	LcJump                              string
+	LcScrollLeftRight                   string
+	LcScrollLeft                        string
+	LcScrollRight                       string
 	DiscardPatch                        string
 	DiscardPatchConfirm                 string
 	CantPatchWhileRebasingError         string
@@ -802,6 +805,9 @@ func englishTranslationSet() TranslationSet {
 		LcStashOptions:                      "Stash options",
 		NotARepository:                      "Error: must be run inside a git repository",
 		LcJump:                              "jump to panel",
+		LcScrollLeftRight:                   "scroll left/right",
+		LcScrollLeft:                        "scroll left",
+		LcScrollRight:                       "scroll right",
 		DiscardPatch:                        "Discard Patch",
 		DiscardPatchConfirm:                 "You can only build a patch from one commit/stash-entry at a time. Discard current patch?",
 		CantPatchWhileRebasingError:         "You cannot build a patch or run patch commands while in a merging or rebasing state",
diff --git a/vendor/github.com/jesseduffield/gocui/view.go b/vendor/github.com/jesseduffield/gocui/view.go
index 9fc923800..4edc5a58d 100644
--- a/vendor/github.com/jesseduffield/gocui/view.go
+++ b/vendor/github.com/jesseduffield/gocui/view.go
@@ -475,9 +475,33 @@ func (v *View) SetOrigin(x, y int) error {
 	return nil
 }
 
+func (v *View) SetOriginX(x int) error {
+	if x < 0 {
+		return ErrInvalidPoint
+	}
+	v.ox = x
+	return nil
+}
+
+func (v *View) SetOriginY(y int) error {
+	if y < 0 {
+		return ErrInvalidPoint
+	}
+	v.oy = y
+	return nil
+}
+
 // Origin returns the origin position of the view.
 func (v *View) Origin() (x, y int) {
-	return v.ox, v.oy
+	return v.OriginX(), v.OriginY()
+}
+
+func (v *View) OriginX() int {
+	return v.ox
+}
+
+func (v *View) OriginY() int {
+	return v.oy
 }
 
 // SetWritePos sets the write position of the view's internal buffer.
diff --git a/vendor/modules.txt b/vendor/modules.txt
index ee620b0f6..66d582ce3 100644
--- a/vendor/modules.txt
+++ b/vendor/modules.txt
@@ -161,7 +161,7 @@ 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 v0.3.1-0.20211102081536-e4eee64f4d13
+# github.com/jesseduffield/gocui v0.3.1-0.20211102093457-be3a05cf7131
 ## explicit
 github.com/jesseduffield/gocui
 # github.com/jesseduffield/minimal/gitignore v0.3.3-0.20211018110810-9cde264e6b1e