feat(gui): add side panel auto-width option

docs/Config.md

@@ -72,6 +72,12 @@ gui:
   # 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
 
+  # Automatically adjust the width of the side panel to fit the longest visible filename. 
+  # The width is capped at a half of the total screen width to prevent the panel from becoming excessively large. 
+  # This is useful for projects with deeply nested file structures. 
+  sidePanelAutoWidth: false
+
+
   # If true, do not show a warning when amending a commit.
   skipAmendWarning: false
 

pkg/config/user_config.go

@@ -151,6 +151,8 @@ type GuiConfig struct {
 	CommitAuthorShortLength int `yaml:"commitAuthorShortLength"`
 	// Length of author name in expanded commits view. 2 means show initials only.
 	CommitAuthorLongLength int `yaml:"commitAuthorLongLength"`
+	// Automatically adjust side panel width to fit the longest filename (capped at a screen percentage). Defaults to false.
+	SidePanelAutoWidth bool `yaml:"sidePanelAutoWidth"`
 	// Length of commit hash in commits view. 0 shows '*' if NF icons aren't on.
 	CommitHashLength int `yaml:"commitHashLength" jsonschema:"minimum=0"`
 	// If true, show commit hashes alongside branch names in the branches view.

pkg/gui/controllers/helpers/refresh_helper.go

@@ -4,6 +4,7 @@ import (
 	"strings"
 	"sync"
 	"time"
+	"unicode/utf8"
 
 	"github.com/jesseduffield/generics/set"
 	"github.com/jesseduffield/gocui"
@@ -531,7 +532,6 @@ func (self *RefreshHelper) refreshFilesAndSubmodules() error {
 
 func (self *RefreshHelper) refreshStateFiles() error {
 	fileTreeViewModel := self.c.Contexts().Files.FileTreeViewModel
-
 	prevConflictFileCount := 0
 	if self.c.UserConfig().Git.AutoStageResolvedConflicts {
 		// If git thinks any of our files have inline merge conflicts, but they actually don't,
@@ -570,10 +570,17 @@ func (self *RefreshHelper) refreshStateFiles() error {
 		})
 
 	conflictFileCount := 0
+	requiredContentWidth := 0
 	for _, file := range files {
 		if file.HasMergeConflicts {
 			conflictFileCount++
 		}
+		if len(file.Names()) > 0 {
+			fileNameLen := utf8.RuneCountInString(file.Names()[0])
+			if fileNameLen > requiredContentWidth {
+				requiredContentWidth = fileNameLen
+			}
+		}
 	}
 
 	if self.c.Git().Status.WorkingTreeState().Any() && conflictFileCount == 0 && prevConflictFileCount > 0 {
@@ -582,7 +589,6 @@ func (self *RefreshHelper) refreshStateFiles() error {
 
 	fileTreeViewModel.RWMutex.Lock()
 
-	// only taking over the filter if it hasn't already been set by the user.
 	if conflictFileCount > 0 && prevConflictFileCount == 0 {
 		if fileTreeViewModel.GetFilter() == filetree.DisplayAll {
 			fileTreeViewModel.SetStatusFilter(filetree.DisplayConflicted)
@@ -596,6 +602,8 @@ func (self *RefreshHelper) refreshStateFiles() error {
 	self.c.Model().Files = files
 	fileTreeViewModel.SetTree()
 	fileTreeViewModel.RWMutex.Unlock()
+	self.c.Model().SidePanelAutoWidth = requiredContentWidth
+	self.refreshView(self.c.Contexts().Files)
 
 	return nil
 }

pkg/gui/controllers/helpers/window_arrangement_helper.go

@@ -72,6 +72,8 @@ type WindowArrangementArgs struct {
 	InSearchPrompt bool
 	// One of '' (not searching), 'Search: ', and 'Filter: '
 	SearchPrefix string
+	// Proportional width of the side panel, as a float between 0.1 and 0.9. Defaults to 0.33.
+	SidePanelAutoWidth int
 }
 
 func (self *WindowArrangementHelper) GetWindowDimensions(informationStr string, appStatus string) map[string]boxlayout.Dimensions {
@@ -101,6 +103,7 @@ func (self *WindowArrangementHelper) GetWindowDimensions(informationStr string,
 		IsAnyModeActive:     self.modeHelper.IsAnyModeActive(),
 		InSearchPrompt:      repoState.InSearchPrompt(),
 		SearchPrefix:        searchPrefix,
+		SidePanelAutoWidth:  self.c.Model().SidePanelAutoWidth,
 	}
 
 	return GetWindowDimensions(args)
@@ -138,18 +141,25 @@ func GetWindowDimensions(args WindowArrangementArgs) map[string]boxlayout.Dimens
 		infoSectionSize = 1
 	}
 
+	sidePanelBox := &boxlayout.Box{
+		Direction:           boxlayout.ROW,
+		ConditionalChildren: sidePanelChildren(args),
+	}
+
+	if args.UserConfig.Gui.SidePanelAutoWidth && args.SidePanelAutoWidth > 0 {
+		sidePanelBox.Size = min(args.Width/2, args.SidePanelAutoWidth)
+	} else {
+		sidePanelBox.Weight = sideSectionWeight
+	}
+
 	root := &boxlayout.Box{
 		Direction: boxlayout.ROW,
 		Children: []*boxlayout.Box{
 			{
 				Direction: sidePanelsDirection,
 				Weight:    1,
 				Children: []*boxlayout.Box{
-					{
-						Direction:           boxlayout.ROW,
-						Weight:              sideSectionWeight,
-						ConditionalChildren: sidePanelChildren(args),
-					},
+					sidePanelBox,
 					{
 						Direction: boxlayout.ROW,
 						Weight:    mainSectionWeight,

pkg/gui/filetree/file_tree.go

@@ -170,7 +170,8 @@ func (self *FileTree) SetTree() {
 	filesForDisplay := self.getFilesForDisplay()
 	showRootItem := self.common.UserConfig().Gui.ShowRootItemInFileTree
 	if self.showTree {
-		self.tree = BuildTreeFromFiles(filesForDisplay, showRootItem)
+		tree := BuildTreeFromFiles(filesForDisplay, showRootItem)
+		self.tree = tree
 	} else {
 		self.tree = BuildFlatTreeFromFiles(filesForDisplay, showRootItem)
 	}

pkg/gui/filetree/file_tree_view_model.go

@@ -220,3 +220,29 @@ func (self *FileTreeViewModel) ExpandAll() {
 		self.SetSelectedLineIdx(index)
 	}
 }
+
+// func (self *FileTreeViewModel) GetRequiredWidth() int {
+//     maxWidth := 0
+//     // We need a recursive function to walk the tree
+//     var traverse func(node *Node[models.File], depth int)
+//     traverse = func(node *Node[models.File], depth int) {
+//         if node != nil {
+//             // Calculate the width of the indentation string (e.g., "  ├─ ")
+//             indentationWidth := getIndentationWidth(depth) // You'll need to figure out how lazygit calculates this
+//
+//             // Calculate the total width for this line
+//             lineLength := utf8.RuneCountInString(node.GetFile().Name) + indentationWidth
+//             if lineLength > maxWidth {
+//                 maxWidth = lineLength
+//             }
+//
+//             // Recurse for all children
+//             for _, child := range node.Children {
+//                 traverse(child, depth+1)
+//             }
+//         }
+//     }
+//
+//     traverse(self.GetRoot(), 0)
+//     return maxWidth
+// }

pkg/gui/types/common.go

@@ -318,6 +318,12 @@ type Model struct {
 	Authors map[string]*models.Author
 
 	HashPool *utils.StringPool
+
+	// SidePanelAutoWidth stores the required width to display the longest file name
+	// in the files panel without truncation. This value is calculated whenever the
+	// file state is refreshed and is used by the layout manager to conditionally
+	// set a fixed size for the side panel.
+	SidePanelAutoWidth int
 }
 
 type Mutexes struct {