Add gui.tabWidth config (#4291)

- **PR Description**

This adds a config `gui.tabWidth` that can be used to change the tab
width from the default of 4 to a different number. It affects everything
that's shown in the main view, but is probably mostly relevant for
diffs.

When using a pager, the pager needs to be configured separately for the
same tab width.

This may often be different for different repos, so it may make sense to
put it in a repo-local config file.

In some cases this may still not be flexible enough, e.g. in
multi-language projects that use different tab widths for the different
file types; but it's better than before and was easy to do...

Addresses #4290.

docs/Config.md

@@ -47,6 +47,10 @@ gui:
   # One of: 'margin' (default) | 'jump'
   scrollOffBehavior: margin
 
+  # The number of spaces per tab; used for everything that's shown in the main view, but probably mostly relevant for diffs.
+  # Note that when using a pager, the pager has its own tab width setting, so you need to pass it separately in the pager command.
+  tabWidth: 4
+
   # If true, capture mouse events.
   # When mouse events are captured, it's a little harder to select text: e.g. requiring you to hold the option key when on macOS.
   mouseEvents: true

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 v5.1.2-0.20221018185014-fdd53fef665d
-	github.com/jesseduffield/gocui v0.3.1-0.20250210123912-aba68ae65951
+	github.com/jesseduffield/gocui v0.3.1-0.20250220081214-b376cb0857ac
 	github.com/jesseduffield/kill v0.0.0-20250101124109-e216ddbe133a
 	github.com/jesseduffield/lazycore v0.0.0-20221012050358-03d2e40243c5
 	github.com/jesseduffield/minimal/gitignore v0.3.3-0.20211018110810-9cde264e6b1e

go.sum

@@ -188,8 +188,8 @@ 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 v5.1.2-0.20221018185014-fdd53fef665d h1:bO+OmbreIv91rCe8NmscRwhFSqkDJtzWCPV4Y+SQuXE=
 github.com/jesseduffield/go-git/v5 v5.1.2-0.20221018185014-fdd53fef665d/go.mod h1:nGNEErzf+NRznT+N2SWqmHnDnF9aLgANB1CUNEan09o=
-github.com/jesseduffield/gocui v0.3.1-0.20250210123912-aba68ae65951 h1:7/3M0yosAM9/aLAjTfzSJWhsWjT860ZVe4T76RPwE2k=
-github.com/jesseduffield/gocui v0.3.1-0.20250210123912-aba68ae65951/go.mod h1:sLIyZ2J42R6idGdtemZzsiR3xY5EF0KsvYEGh3dQv3s=
+github.com/jesseduffield/gocui v0.3.1-0.20250220081214-b376cb0857ac h1:vUNTiVEB9Bz16pTJ5kNgb/1HhnWdSA1P0GfFLUJeITI=
+github.com/jesseduffield/gocui v0.3.1-0.20250220081214-b376cb0857ac/go.mod h1:sLIyZ2J42R6idGdtemZzsiR3xY5EF0KsvYEGh3dQv3s=
 github.com/jesseduffield/kill v0.0.0-20250101124109-e216ddbe133a h1:UDeJ3EBk04bXDLOPvuqM3on8HvyJfISw0+UMqW+0a4g=
 github.com/jesseduffield/kill v0.0.0-20250101124109-e216ddbe133a/go.mod h1:FSWDLKT0NQpntbDd1H3lbz51fhCVlMzy/J0S6nM727Q=
 github.com/jesseduffield/lazycore v0.0.0-20221012050358-03d2e40243c5 h1:CDuQmfOjAtb1Gms6a1p5L2P8RhbLUq5t8aL7PiQd2uY=

pkg/config/user_config.go

@@ -64,6 +64,9 @@ type GuiConfig struct {
 	ScrollOffMargin int `yaml:"scrollOffMargin"`
 	// One of: 'margin' (default) | 'jump'
 	ScrollOffBehavior string `yaml:"scrollOffBehavior"`
+	// The number of spaces per tab; used for everything that's shown in the main view, but probably mostly relevant for diffs.
+	// Note that when using a pager, the pager has its own tab width setting, so you need to pass it separately in the pager command.
+	TabWidth int `yaml:"tabWidth" jsonschema:"minimum=1"`
 	// If true, capture mouse events.
 	// When mouse events are captured, it's a little harder to select text: e.g. requiring you to hold the option key when on macOS.
 	MouseEvents bool `yaml:"mouseEvents"`
@@ -693,6 +696,7 @@ func GetDefaultConfig() *UserConfig {
 			ScrollPastBottom:         true,
 			ScrollOffMargin:          2,
 			ScrollOffBehavior:        "margin",
+			TabWidth:                 4,
 			MouseEvents:              true,
 			SkipDiscardChangeWarning: false,
 			SkipStashWarning:         false,

pkg/gui/controllers/helpers/confirmation_helper.go

@@ -56,8 +56,8 @@ func (self *ConfirmationHelper) DeactivateConfirmationPrompt() {
 	self.clearConfirmationViewKeyBindings()
 }
 
-func getMessageHeight(wrap bool, editable bool, message string, width int) int {
-	wrappedLines, _, _ := utils.WrapViewLinesToWidth(wrap, editable, message, width)
+func getMessageHeight(wrap bool, editable bool, message string, width int, tabWidth int) int {
+	wrappedLines, _, _ := utils.WrapViewLinesToWidth(wrap, editable, message, width, tabWidth)
 	return len(wrappedLines)
 }
 
@@ -265,7 +265,7 @@ func (self *ConfirmationHelper) resizeMenu(parentPopupContext types.Context) {
 	if selectedItem != nil {
 		tooltip = self.TooltipForMenuItem(selectedItem)
 	}
-	tooltipHeight := getMessageHeight(true, false, tooltip, contentWidth) + 2 // plus 2 for the frame
+	tooltipHeight := getMessageHeight(true, false, tooltip, contentWidth, self.c.Views().Menu.TabWidth) + 2 // plus 2 for the frame
 	_, _ = self.c.GocuiGui().SetView(self.c.Views().Tooltip.Name(), x0, tooltipTop, x1, tooltipTop+tooltipHeight-1, 0)
 }
 
@@ -276,7 +276,7 @@ func (self *ConfirmationHelper) layoutMenuPrompt(contentWidth int) int {
 	var promptLines []string
 	prompt := self.c.Contexts().Menu.GetPrompt()
 	if len(prompt) > 0 {
-		promptLines, _, _ = utils.WrapViewLinesToWidth(true, false, prompt, contentWidth)
+		promptLines, _, _ = utils.WrapViewLinesToWidth(true, false, prompt, contentWidth, self.c.Views().Menu.TabWidth)
 		promptLines = append(promptLines, "")
 	}
 	self.c.Contexts().Menu.SetPromptLines(promptLines)
@@ -305,17 +305,18 @@ func (self *ConfirmationHelper) resizeConfirmationPanel(parentPopupContext types
 	}
 	panelWidth := self.getPopupPanelWidth()
 	contentWidth := panelWidth - 2 // minus 2 for the frame
-	prompt := self.c.Views().Confirmation.Buffer()
+	confirmationView := self.c.Views().Confirmation
+	prompt := confirmationView.Buffer()
 	wrap := true
-	editable := self.c.Views().Confirmation.Editable
+	editable := confirmationView.Editable
 	if editable {
-		prompt = self.c.Views().Confirmation.TextArea.GetContent()
+		prompt = confirmationView.TextArea.GetContent()
 		wrap = false
 	}
-	panelHeight := getMessageHeight(wrap, editable, prompt, contentWidth) + suggestionsViewHeight
+	panelHeight := getMessageHeight(wrap, editable, prompt, contentWidth, confirmationView.TabWidth) + suggestionsViewHeight
 	x0, y0, x1, y1 := self.getPopupPanelDimensionsAux(panelWidth, panelHeight, parentPopupContext)
 	confirmationViewBottom := y1 - suggestionsViewHeight
-	_, _ = self.c.GocuiGui().SetView(self.c.Views().Confirmation.Name(), x0, y0, x1, confirmationViewBottom, 0)
+	_, _ = self.c.GocuiGui().SetView(confirmationView.Name(), x0, y0, x1, confirmationViewBottom, 0)
 
 	suggestionsViewTop := confirmationViewBottom + 1
 	_, _ = self.c.GocuiGui().SetView(self.c.Views().Suggestions.Name(), x0, suggestionsViewTop, x1, suggestionsViewTop+suggestionsViewHeight, 0)
@@ -325,7 +326,7 @@ func (self *ConfirmationHelper) ResizeCommitMessagePanels(parentPopupContext typ
 	panelWidth := self.getPopupPanelWidth()
 	content := self.c.Views().CommitDescription.TextArea.GetContent()
 	summaryViewHeight := 3
-	panelHeight := getMessageHeight(false, true, content, panelWidth)
+	panelHeight := getMessageHeight(false, true, content, panelWidth, self.c.Views().CommitDescription.TabWidth)
 	minHeight := 7
 	if panelHeight < minHeight {
 		panelHeight = minHeight

pkg/gui/patch_exploring/state.go

@@ -323,6 +323,6 @@ func (s *State) CalculateOrigin(currentOrigin int, bufferHeight int, numLines in
 
 func wrapPatchLines(diff string, view *gocui.View) ([]int, []int) {
 	_, viewLineIndices, patchLineIndices := utils.WrapViewLinesToWidth(
-		view.Wrap, view.Editable, strings.TrimSuffix(diff, "\n"), view.InnerWidth())
+		view.Wrap, view.Editable, strings.TrimSuffix(diff, "\n"), view.InnerWidth(), view.TabWidth)
 	return viewLineIndices, patchLineIndices
 }

pkg/gui/views.go

@@ -203,6 +203,7 @@ func (gui *Gui) configureViewProperties() {
 
 	for _, view := range []*gocui.View{gui.Views.Main, gui.Views.Secondary, gui.Views.Staging, gui.Views.StagingSecondary, gui.Views.PatchBuilding, gui.Views.PatchBuildingSecondary, gui.Views.MergeConflicts} {
 		view.CanScrollPastBottom = gui.c.UserConfig().Gui.ScrollPastBottom
+		view.TabWidth = gui.c.UserConfig().Gui.TabWidth
 	}
 
 	gui.Views.CommitDescription.FgColor = theme.GocuiDefaultTextColor

pkg/utils/lines.go

@@ -109,7 +109,7 @@ func ScanLinesAndTruncateWhenLongerThanBuffer(maxBufferSize int) func(data []byt
 // - the line indices of the original lines, indexed by the wrapped line indices
 // If wrap is false, the text is returned as is.
 // This code needs to behave the same as `gocui.lineWrap` does.
-func WrapViewLinesToWidth(wrap bool, editable bool, text string, width int) ([]string, []int, []int) {
+func WrapViewLinesToWidth(wrap bool, editable bool, text string, width int, tabWidth int) ([]string, []int, []int) {
 	if !editable {
 		text = strings.TrimSuffix(text, "\n")
 	}
@@ -126,14 +126,18 @@ func WrapViewLinesToWidth(wrap bool, editable bool, text string, width int) ([]s
 	wrappedLineIndices := make([]int, 0, len(lines))
 	originalLineIndices := make([]int, 0, len(lines))
 
+	if tabWidth < 1 {
+		tabWidth = 4
+	}
+
 	for originalLineIdx, line := range lines {
 		wrappedLineIndices = append(wrappedLineIndices, len(wrappedLines))
 
 		// convert tabs to spaces
 		for i := 0; i < len(line); i++ {
 			if line[i] == '\t' {
-				numSpaces := 4 - (i % 4)
-				line = line[:i] + "    "[:numSpaces] + line[i+1:]
+				numSpaces := tabWidth - (i % tabWidth)
+				line = line[:i] + strings.Repeat(" ", numSpaces) + line[i+1:]
 				i += numSpaces - 1
 			}
 		}

pkg/utils/lines_test.go

@@ -173,6 +173,7 @@ func TestWrapViewLinesToWidth(t *testing.T) {
 		editable                     bool
 		text                         string
 		width                        int
+		tabWidth                     int
 		expectedWrappedLines         []string
 		expectedWrappedLinesIndices  []int
 		expectedOriginalLinesIndices []int
@@ -353,14 +354,25 @@ func TestWrapViewLinesToWidth(t *testing.T) {
 			},
 		},
 		{
-			name:  "Tabs",
-			wrap:  true,
-			text:  "\ta\tbb\tccc\tdddd\teeeee",
-			width: 50,
+			name:     "Tabs, width 4",
+			wrap:     true,
+			text:     "\ta\tbb\tccc\tdddd\teeeee",
+			width:    50,
+			tabWidth: 4,
 			expectedWrappedLines: []string{
 				"    a   bb  ccc dddd    eeeee",
 			},
 		},
+		{
+			name:     "Tabs, width 8",
+			wrap:     true,
+			text:     "\ta\tbb\tccc\tdddddddd\teeeee",
+			width:    100,
+			tabWidth: 8,
+			expectedWrappedLines: []string{
+				"        a       bb      ccc     dddddddd        eeeee",
+			},
+		},
 		{
 			name:  "Multiple lines",
 			wrap:  true,
@@ -425,7 +437,11 @@ func TestWrapViewLinesToWidth(t *testing.T) {
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			wrappedLines, wrappedLinesIndices, originalLinesIndices := WrapViewLinesToWidth(tt.wrap, tt.editable, tt.text, tt.width)
+			tabWidth := tt.tabWidth
+			if tabWidth == 0 {
+				tabWidth = 4
+			}
+			wrappedLines, wrappedLinesIndices, originalLinesIndices := WrapViewLinesToWidth(tt.wrap, tt.editable, tt.text, tt.width, tabWidth)
 			assert.Equal(t, tt.expectedWrappedLines, wrappedLines)
 			if tt.expectedWrappedLinesIndices != nil {
 				assert.Equal(t, tt.expectedWrappedLinesIndices, wrappedLinesIndices)
@@ -436,6 +452,7 @@ func TestWrapViewLinesToWidth(t *testing.T) {
 
 			// As a sanity check, also test that gocui's line wrapping behaves the same way
 			view := gocui.NewView("", 0, 0, tt.width+1, 1000, gocui.OutputNormal)
+			view.TabWidth = tabWidth
 			assert.Equal(t, tt.width, view.InnerWidth())
 			view.Wrap = tt.wrap
 			view.Editable = tt.editable

schema/config.json

@@ -46,6 +46,12 @@
           "description": "One of: 'margin' (default) | 'jump'",
           "default": "margin"
         },
+        "tabWidth": {
+          "type": "integer",
+          "minimum": 1,
+          "description": "The number of spaces per tab; used for everything that's shown in the main view, but probably mostly relevant for diffs.\nNote that when using a pager, the pager has its own tab width setting, so you need to pass it separately in the pager command.",
+          "default": 4
+        },
         "mouseEvents": {
           "type": "boolean",
           "description": "If true, capture mouse events.\nWhen mouse events are captured, it's a little harder to select text: e.g. requiring you to hold the option key when on macOS.",

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

@@ -195,6 +195,9 @@ type View struct {
 	// if true, the view will underline hyperlinks only when the cursor is on
 	// them; otherwise, they will always be underlined
 	UnderlineHyperLinksOnlyOnHover bool
+
+	// number of spaces per \t character, defaults to 4
+	TabWidth int
 }
 
 type pos struct {
@@ -424,6 +427,7 @@ func NewView(name string, x0, y0, x1, y1 int, mode OutputMode) *View {
 		searcher:          &searcher{},
 		TextArea:          &TextArea{},
 		rangeSelectStartY: -1,
+		TabWidth:          4,
 	}
 
 	v.FgColor, v.BgColor = ColorDefault, ColorDefault
@@ -923,9 +927,12 @@ func (v *View) parseInput(ch rune, x int, _ int) (bool, []cell) {
 			return truncateLine, nil
 		} else if ch == '\t' {
 			// fill tab-sized space
-			const tabStop = 4
+			tabWidth := v.TabWidth
+			if tabWidth < 1 {
+				tabWidth = 4
+			}
 			ch = ' '
-			repeatCount = tabStop - (x % tabStop)
+			repeatCount = tabWidth - (x % tabWidth)
 		}
 		c := cell{
 			fgColor:   v.ei.curFgColor,

vendor/modules.txt

@@ -171,7 +171,7 @@ 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 v0.3.1-0.20250210123912-aba68ae65951
+# github.com/jesseduffield/gocui v0.3.1-0.20250220081214-b376cb0857ac
 ## explicit; go 1.12
 github.com/jesseduffield/gocui
 # github.com/jesseduffield/kill v0.0.0-20250101124109-e216ddbe133a