properly resolve cyclic dependency

22 files changed, 768 insertions, 641 deletions

diff --git a/pkg/commands/git_commands/working_tree.go b/pkg/commands/git_commands/working_tree.go
index c40f75693..4e97913fb 100644
--- a/pkg/commands/git_commands/working_tree.go
+++ b/pkg/commands/git_commands/working_tree.go
@@ -10,7 +10,6 @@ import (
 	"github.com/jesseduffield/lazygit/pkg/commands/loaders"
 	"github.com/jesseduffield/lazygit/pkg/commands/models"
 	"github.com/jesseduffield/lazygit/pkg/commands/oscommands"
-	"github.com/jesseduffield/lazygit/pkg/gui/filetree"
 	"github.com/jesseduffield/lazygit/pkg/utils"
 )
 
@@ -160,12 +159,18 @@ func (self *WorkingTreeCommands) DiscardAllFileChanges(file *models.File) error
 	return self.DiscardUnstagedFileChanges(file)
 }
 
-func (self *WorkingTreeCommands) DiscardAllDirChanges(node *filetree.FileNode) error {
+type IFileNode interface {
+	ForEachFile(cb func(*models.File) error) error
+	GetFilePathsMatching(test func(*models.File) bool) []string
+	GetPath() string
+}
+
+func (self *WorkingTreeCommands) DiscardAllDirChanges(node IFileNode) error {
 	// this could be more efficient but we would need to handle all the edge cases
 	return node.ForEachFile(self.DiscardAllFileChanges)
 }
 
-func (self *WorkingTreeCommands) DiscardUnstagedDirChanges(node *filetree.FileNode) error {
+func (self *WorkingTreeCommands) DiscardUnstagedDirChanges(node IFileNode) error {
 	if err := self.RemoveUntrackedDirFiles(node); err != nil {
 		return err
 	}
@@ -178,9 +183,9 @@ func (self *WorkingTreeCommands) DiscardUnstagedDirChanges(node *filetree.FileNo
 	return nil
 }
 
-func (self *WorkingTreeCommands) RemoveUntrackedDirFiles(node *filetree.FileNode) error {
-	untrackedFilePaths := node.GetPathsMatching(
-		func(n *filetree.FileNode) bool { return n.File != nil && !n.File.GetIsTracked() },
+func (self *WorkingTreeCommands) RemoveUntrackedDirFiles(node IFileNode) error {
+	untrackedFilePaths := node.GetFilePathsMatching(
+		func(file *models.File) bool { return !file.GetIsTracked() },
 	)
 
 	for _, path := range untrackedFilePaths {
diff --git a/pkg/gui/commit_files_panel.go b/pkg/gui/commit_files_panel.go
index 7e1ecd130..61f3b72b8 100644
--- a/pkg/gui/commit_files_panel.go
+++ b/pkg/gui/commit_files_panel.go
@@ -8,11 +8,11 @@ import (
 
 func (gui *Gui) getSelectedCommitFileNode() *filetree.CommitFileNode {
 	selectedLine := gui.State.Panels.CommitFiles.SelectedLineIdx
-	if selectedLine == -1 || selectedLine > gui.State.CommitFileManager.GetItemsLength()-1 {
+	if selectedLine == -1 || selectedLine > gui.State.CommitFileTreeViewModel.GetItemsLength()-1 {
 		return nil
 	}
 
-	return gui.State.CommitFileManager.GetItemAtIndex(selectedLine)
+	return gui.State.CommitFileTreeViewModel.GetItemAtIndex(selectedLine)
 }
 
 func (gui *Gui) getSelectedCommitFile() *models.CommitFile {
@@ -42,7 +42,7 @@ func (gui *Gui) commitFilesRenderToMain() error {
 		return nil
 	}
 
-	to := gui.State.CommitFileManager.GetParent()
+	to := gui.State.CommitFileTreeViewModel.GetParent()
 	from, reverse := gui.getFromAndReverseArgsForDiff(to)
 
 	cmdObj := gui.Git.WorkingTree.ShowFileDiffCmdObj(from, to, reverse, node.GetPath(), false)
@@ -64,7 +64,7 @@ func (gui *Gui) handleCheckoutCommitFile() error {
 	}
 
 	gui.logAction(gui.Tr.Actions.CheckoutFile)
-	if err := gui.Git.WorkingTree.CheckoutFile(gui.State.CommitFileManager.GetParent(), node.GetPath()); err != nil {
+	if err := gui.Git.WorkingTree.CheckoutFile(gui.State.CommitFileTreeViewModel.GetParent(), node.GetPath()); err != nil {
 		return gui.surfaceError(err)
 	}
 
@@ -111,7 +111,8 @@ func (gui *Gui) refreshCommitFilesView() error {
 	if err != nil {
 		return gui.surfaceError(err)
 	}
-	gui.State.CommitFileManager.SetFiles(files, to)
+	gui.State.CommitFileTreeViewModel.SetParent(to)
+	gui.State.CommitFileTreeViewModel.SetFiles(files)
 
 	return gui.postRefreshUpdate(gui.State.Contexts.CommitFiles)
 }
@@ -154,7 +155,7 @@ func (gui *Gui) handleToggleFileForPatch() error {
 		// if there is any file that hasn't been fully added we'll fully add everything,
 		// otherwise we'll remove everything
 		adding := node.AnyFile(func(file *models.CommitFile) bool {
-			return gui.Git.Patch.PatchManager.GetFileStatus(file.Name, gui.State.CommitFileManager.GetParent()) != patch.WHOLE
+			return gui.Git.Patch.PatchManager.GetFileStatus(file.Name, gui.State.CommitFileTreeViewModel.GetParent()) != patch.WHOLE
 		})
 
 		err := node.ForEachFile(func(file *models.CommitFile) error {
@@ -176,7 +177,7 @@ func (gui *Gui) handleToggleFileForPatch() error {
 		return gui.postRefreshUpdate(gui.State.Contexts.CommitFiles)
 	}
 
-	if gui.Git.Patch.PatchManager.Active() && gui.Git.Patch.PatchManager.To != gui.State.CommitFileManager.GetParent() {
+	if gui.Git.Patch.PatchManager.Active() && gui.Git.Patch.PatchManager.To != gui.State.CommitFileTreeViewModel.GetParent() {
 		return gui.ask(askOpts{
 			title:  gui.Tr.DiscardPatch,
 			prompt: gui.Tr.DiscardPatchConfirm,
@@ -224,7 +225,7 @@ func (gui *Gui) enterCommitFile(opts OnFocusOpts) error {
 		return gui.pushContext(gui.State.Contexts.PatchBuilding, opts)
 	}
 
-	if gui.Git.Patch.PatchManager.Active() && gui.Git.Patch.PatchManager.To != gui.State.CommitFileManager.GetParent() {
+	if gui.Git.Patch.PatchManager.Active() && gui.Git.Patch.PatchManager.To != gui.State.CommitFileTreeViewModel.GetParent() {
 		return gui.ask(askOpts{
 			title:  gui.Tr.DiscardPatch,
 			prompt: gui.Tr.DiscardPatchConfirm,
@@ -244,7 +245,7 @@ func (gui *Gui) handleToggleCommitFileDirCollapsed() error {
 		return nil
 	}
 
-	gui.State.CommitFileManager.ToggleCollapsed(node.GetPath())
+	gui.State.CommitFileTreeViewModel.ToggleCollapsed(node.GetPath())
 
 	if err := gui.postRefreshUpdate(gui.State.Contexts.CommitFiles); err != nil {
 		gui.Log.Error(err)
@@ -275,12 +276,12 @@ func (gui *Gui) switchToCommitFilesContext(refName string, canRebase bool, conte
 func (gui *Gui) handleToggleCommitFileTreeView() error {
 	path := gui.getSelectedCommitFilePath()
 
-	gui.State.CommitFileManager.ToggleShowTree()
+	gui.State.CommitFileTreeViewModel.ToggleShowTree()
 
 	// find that same node in the new format and move the cursor to it
 	if path != "" {
-		gui.State.CommitFileManager.ExpandToPath(path)
-		index, found := gui.State.CommitFileManager.GetIndexForPath(path)
+		gui.State.CommitFileTreeViewModel.ExpandToPath(path)
+		index, found := gui.State.CommitFileTreeViewModel.GetIndexForPath(path)
 		if found {
 			gui.State.Contexts.CommitFiles.GetPanelState().SetSelectedLineIdx(index)
 		}
diff --git a/pkg/gui/files_panel.go b/pkg/gui/files_panel.go
index 4201afb11..c62da8e21 100644
--- a/pkg/gui/files_panel.go
+++ b/pkg/gui/files_panel.go
@@ -21,7 +21,7 @@ func (gui *Gui) getSelectedFileNode() *filetree.FileNode {
 		return nil
 	}
 
-	return gui.State.FileManager.GetItemAtIndex(selectedLine)
+	return gui.State.FileTreeViewModel.GetItemAtIndex(selectedLine)
 }
 
 func (gui *Gui) getSelectedFile() *models.File {
@@ -129,7 +129,7 @@ func (gui *Gui) refreshFilesAndSubmodules() error {
 // specific functions
 
 func (gui *Gui) stagedFiles() []*models.File {
-	files := gui.State.FileManager.GetAllFiles()
+	files := gui.State.FileTreeViewModel.GetAllFiles()
 	result := make([]*models.File, 0)
 	for _, file := range files {
 		if file.HasStagedChanges {
@@ -140,7 +140,7 @@ func (gui *Gui) stagedFiles() []*models.File {
 }
 
 func (gui *Gui) trackedFiles() []*models.File {
-	files := gui.State.FileManager.GetAllFiles()
+	files := gui.State.FileTreeViewModel.GetAllFiles()
 	result := make([]*models.File, 0, len(files))
 	for _, file := range files {
 		if file.Tracked {
@@ -244,7 +244,7 @@ func (gui *Gui) handleFilePress() error {
 }
 
 func (gui *Gui) allFilesStaged() bool {
-	for _, file := range gui.State.FileManager.GetAllFiles() {
+	for _, file := range gui.State.FileTreeViewModel.GetAllFiles() {
 		if file.HasUnstagedChanges {
 			return false
 		}
@@ -378,7 +378,7 @@ func (gui *Gui) handleCommitPress() error {
 		return gui.surfaceError(err)
 	}
 
-	if gui.State.FileManager.GetItemsLength() == 0 {
+	if gui.State.FileTreeViewModel.GetItemsLength() == 0 {
 		return gui.createErrorPanel(gui.Tr.NoFilesStagedTitle)
 	}
 
@@ -433,7 +433,7 @@ func (gui *Gui) promptToStageAllAndRetry(retry func() error) error {
 }
 
 func (gui *Gui) handleAmendCommitPress() error {
-	if gui.State.FileManager.GetItemsLength() == 0 {
+	if gui.State.FileTreeViewModel.GetItemsLength() == 0 {
 		return gui.createErrorPanel(gui.Tr.NoFilesStagedTitle)
 	}
 
@@ -459,7 +459,7 @@ func (gui *Gui) handleAmendCommitPress() error {
 // handleCommitEditorPress - handle when the user wants to commit changes via
 // their editor rather than via the popup panel
 func (gui *Gui) handleCommitEditorPress() error {
-	if gui.State.FileManager.GetItemsLength() == 0 {
+	if gui.State.FileTreeViewModel.GetItemsLength() == 0 {
 		return gui.createErrorPanel(gui.Tr.NoFilesStagedTitle)
 	}
 
@@ -498,9 +498,9 @@ func (gui *Gui) handleStatusFilterPressed() error {
 	return gui.createMenu(gui.Tr.FilteringMenuTitle, menuItems, createMenuOptions{showCancel: true})
 }
 
-func (gui *Gui) setStatusFiltering(filter filetree.FileManagerDisplayFilter) error {
+func (gui *Gui) setStatusFiltering(filter filetree.FileTreeDisplayFilter) error {
 	state := gui.State
-	state.FileManager.SetDisplayFilter(filter)
+	state.FileTreeViewModel.SetDisplayFilter(filter)
 	return gui.handleRefreshFiles()
 }
 
@@ -555,31 +555,31 @@ func (gui *Gui) refreshStateFiles() error {
 
 	selectedNode := gui.getSelectedFileNode()
 
-	prevNodes := gui.State.FileManager.GetAllItems()
+	prevNodes := gui.State.FileTreeViewModel.GetAllItems()
 	prevSelectedLineIdx := gui.State.Panels.Files.SelectedLineIdx
 
 	files := gui.Git.Loaders.Files.
 		GetStatusFiles(loaders.GetStatusFileOptions{})
 
 	// for when you stage the old file of a rename and the new file is in a collapsed dir
-	state.FileManager.RWMutex.Lock()
+	state.FileTreeViewModel.RWMutex.Lock()
 	for _, file := range files {
 		if selectedNode != nil && selectedNode.Path != "" && file.PreviousName == selectedNode.Path {
-			state.FileManager.ExpandToPath(file.Name)
+			state.FileTreeViewModel.ExpandToPath(file.Name)
 		}
 	}
 
-	state.FileManager.SetFiles(files)
-	state.FileManager.RWMutex.Unlock()
+	state.FileTreeViewModel.SetFiles(files)
+	state.FileTreeViewModel.RWMutex.Unlock()
 
 	if err := gui.fileWatcher.addFilesToFileWatcher(files); err != nil {
 		return err
 	}
 
 	if selectedNode != nil {
-		newIdx := gui.findNewSelectedIdx(prevNodes[prevSelectedLineIdx:], state.FileManager.GetAllItems())
+		newIdx := gui.findNewSelectedIdx(prevNodes[prevSelectedLineIdx:], state.FileTreeViewModel.GetAllItems())
 		if newIdx != -1 && newIdx != prevSelectedLineIdx {
-			newNode := state.FileManager.GetItemAtIndex(newIdx)
+			newNode := state.FileTreeViewModel.GetItemAtIndex(newIdx)
 			// when not in tree mode, we show merge conflict files at the top, so you
 			// can work through them one by one without having to sift through a large
 			// set of files. If you have just fixed the merge conflicts of a file, we
@@ -588,7 +588,7 @@ func (gui *Gui) refreshStateFiles() error {
 			// conflicts: the user in this case would rather work on the next file
 			// with merge conflicts, which will have moved up to fill the gap left by
 			// the last file, meaning the cursor doesn't need to move at all.
-			leaveCursor := !state.FileManager.InTreeMode() && newNode != nil &&
+			leaveCursor := !state.FileTreeViewModel.InTreeMode() && newNode != nil &&
 				selectedNode.File != nil && selectedNode.File.HasMergeConflicts &&
 				newNode.File != nil && !newNode.File.HasMergeConflicts
 
@@ -598,7 +598,7 @@ func (gui *Gui) refreshStateFiles() error {
 		}
 	}
 
-	gui.refreshSelectedLine(state.Panels.Files, state.FileManager.GetItemsLength())
+	gui.refreshSelectedLine(state.Panels.Files, state.FileTreeViewModel.GetItemsLength())
 	return nil
 }
 
@@ -871,7 +871,7 @@ func (gui *Gui) openFile(filename string) error {
 }
 
 func (gui *Gui) anyFilesWithMergeConflicts() bool {
-	for _, file := range gui.State.FileManager.GetAllFiles() {
+	for _, file := range gui.State.FileTreeViewModel.GetAllFiles() {
 		if file.HasMergeConflicts {
 			return true
 		}
@@ -939,7 +939,7 @@ func (gui *Gui) handleToggleDirCollapsed() error {
 		return nil
 	}
 
-	gui.State.FileManager.ToggleCollapsed(node.GetPath())
+	gui.State.FileTreeViewModel.ToggleCollapsed(node.GetPath())
 
 	if err := gui.postRefreshUpdate(gui.State.Contexts.Files); err != nil {
 		gui.Log.Error(err)
@@ -952,12 +952,12 @@ func (gui *Gui) handleToggleFileTreeView() error {
 	// get path of currently selected file
 	path := gui.getSelectedPath()
 
-	gui.State.FileManager.ToggleShowTree()
+	gui.State.FileTreeViewModel.ToggleShowTree()
 
 	// find that same node in the new format and move the cursor to it
 	if path != "" {
-		gui.State.FileManager.ExpandToPath(path)
-		index, found := gui.State.FileManager.GetIndexForPath(path)
+		gui.State.FileTreeViewModel.ExpandToPath(path)
+		index, found := gui.State.FileTreeViewModel.GetIndexForPath(path)
 		if found {
 			gui.filesListContext().GetPanelState().SetSelectedLineIdx(index)
 		}
diff --git a/pkg/gui/filetree/README.md b/pkg/gui/filetree/README.md
new file mode 100644
index 000000000..d2d16ace6
--- /dev/null
+++ b/pkg/gui/filetree/README.md
@@ -0,0 +1,22 @@
+## FileTree Package
+
+This package handles the representation of file trees. There are two ways to render files: one is to render them flat, so something like this:
+
+```
+dir1/file1
+dir1/file2
+file3
+```
+
+And the other is to render them as a tree
+
+```
+dir1/
+  file1
+  file2
+file3
+```
+
+Internally we represent each of the above as a tree, but with the flat approach there's just a single root node and every path is a direct child of that root. Viewing in 'tree' mode (as opposed to 'flat' mode) allows for collapsing and expanding directories, and lets you perform actions on directories e.g. staging a whole directory. But it takes up more vertical space and sometimes you just want to have a flat view where you can go flick through your files one by one to see the diff.
+
+This package is not concerned about rendering the tree: only representing its internal state.
diff --git a/pkg/gui/filetree/commit_file_manager.go b/pkg/gui/filetree/commit_file_manager.go
deleted file mode 100644
index 852a67b09..000000000
--- a/pkg/gui/filetree/commit_file_manager.go
+++ /dev/null
@@ -1,118 +0,0 @@
-package filetree
-
-import (
-	"github.com/jesseduffield/lazygit/pkg/commands/models"
-	"github.com/jesseduffield/lazygit/pkg/commands/patch"
-	"github.com/sirupsen/logrus"
-)
-
-type CommitFileManager struct {
-	files          []*models.CommitFile
-	tree           *CommitFileNode
-	showTree       bool
-	log            *logrus.Entry
-	collapsedPaths CollapsedPaths
-	// parent is the identifier of the parent object e.g. a commit SHA if this commit file is for a commit, or a stash entry ref like 'stash@{1}'
-	parent string
-}
-
-func (m *CommitFileManager) GetParent() string {
-	return m.parent
-}
-
-func NewCommitFileManager(files []*models.CommitFile, log *logrus.Entry, showTree bool) *CommitFileManager {
-	return &CommitFileManager{
-		files:          files,
-		log:            log,
-		showTree:       showTree,
-		collapsedPaths: CollapsedPaths{},
-	}
-}
-
-func (m *CommitFileManager) ExpandToPath(path string) {
-	m.collapsedPaths.ExpandToPath(path)
-}
-
-func (m *CommitFileManager) ToggleShowTree() {
-	m.showTree = !m.showTree
-	m.SetTree()
-}
-
-func (m *CommitFileManager) GetItemAtIndex(index int) *CommitFileNode {
-	// need to traverse the three depth first until we get to the index.
-	return m.tree.GetNodeAtIndex(index+1, m.collapsedPaths) // ignoring root
-}
-
-func (m *CommitFileManager) GetIndexForPath(path string) (int, bool) {
-	index, found := m.tree.GetIndexForPath(path, m.collapsedPaths)
-	return index - 1, found
-}
-
-func (m *CommitFileManager) GetAllItems() []*CommitFileNode {
-	if m.tree == nil {
-		return nil
-	}
-
-	return m.tree.Flatten(m.collapsedPaths)[1:] // ignoring root
-}
-
-func (m *CommitFileManager) GetItemsLength() int {
-	return m.tree.Size(m.collapsedPaths) - 1 // ignoring root
-}
-
-func (m *CommitFileManager) GetAllFiles() []*models.CommitFile {
-	return m.files
-}
-
-func (m *CommitFileManager) SetFiles(files []*models.CommitFile, parent string) {
-	m.files = files
-	m.parent = parent
-
-	m.SetTree()
-}
-
-func (m *CommitFileManager) SetTree() {
-	if m.showTree {
-		m.tree = BuildTreeFromCommitFiles(m.files)
-	} else {
-		m.tree = BuildFlatTreeFromCommitFiles(m.files)
-	}
-}
-
-func (m *CommitFileManager) IsCollapsed(path string) bool {
-	return m.collapsedPaths.IsCollapsed(path)
-}
-
-func (m *CommitFileManager) ToggleCollapsed(path string) {
-	m.collapsedPaths.ToggleCollapsed(path)
-}
-
-func (m *CommitFileManager) Render(diffName string, patchManager *patch.PatchManager) []string {
-	// can't rely on renderAux to check for nil because an interface won't be nil if its concrete value is nil
-	if m.tree == nil {
-		return []string{}
-	}
-
-	return renderAux(m.tree, m.collapsedPaths, "", -1, func(n INode, depth int) string {
-		castN := n.(*CommitFileNode)
-
-		// This is a little convoluted because we're dealing with either a leaf or a non-leaf.
-		// But this code actually applies to both. If it's a leaf, the status will just
-		// be whatever status it is, but if it's a non-leaf it will determine its status
-		// based on the leaves of that subtree
-		var status patch.PatchStatus
-		if castN.EveryFile(func(file *models.CommitFile) bool {
-			return patchManager.GetFileStatus(file.Name, m.parent) == patch.WHOLE
-		}) {
-			status = patch.WHOLE
-		} else if castN.EveryFile(func(file *models.CommitFile) bool {
-			return patchManager.GetFileStatus(file.Name, m.parent) == patch.UNSELECTED
-		}) {
-			status = patch.UNSELECTED
-		} else {
-			status = patch.PART
-		}
-
-		return getCommitFileLine(castN.NameAtDepth(depth), diffName, castN.File, status)
-	})
-}
diff --git a/pkg/gui/filetree/commit_file_node.go b/pkg/gui/filetree/commit_file_node.go
index 173281035..14960ee30 100644
--- a/pkg/gui/filetree/commit_file_node.go
+++ b/pkg/gui/filetree/commit_file_node.go
@@ -11,6 +11,8 @@ type CommitFileNode struct {
 	CompressionLevel int    // equal to the number of forward slashes you'll see in the path when it's rendered in tree mode
 }
 
+var _ INode = &CommitFileNode{}
+
 // methods satisfying ListItem interface
 
 func (s *CommitFileNode) ID() string {
@@ -23,6 +25,10 @@ func (s *CommitFileNode) Description() string {
 
 // methods satisfying INode interface
 
+func (s *CommitFileNode) IsNil() bool {
+	return s == nil
+}
+
 func (s *CommitFileNode) IsLeaf() bool {
 	return s.File != nil
 }
@@ -139,13 +145,6 @@ func (s *CommitFileNode) Compress() {
 	compressAux(s)
 }
 
-// This ignores the root
-func (node *CommitFileNode) GetPathsMatching(test func(*CommitFileNode) bool) []string {
-	return getPathsMatching(node, func(n INode) bool {
-		return test(n.(*CommitFileNode))
-	})
-}
-
 func (s *CommitFileNode) GetLeaves() []*CommitFileNode {
 	leaves := getLeaves(s)
 	castLeaves := make([]*CommitFileNode, len(leaves))
diff --git a/pkg/gui/filetree/commit_file_tree_view_model.go b/pkg/gui/filetree/commit_file_tree_view_model.go
new file mode 100644
index 000000000..301396462
--- /dev/null
+++ b/pkg/gui/filetree/commit_file_tree_view_model.go
@@ -0,0 +1,101 @@
+package filetree
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/commands/models"
+	"github.com/sirupsen/logrus"
+)
+
+type CommitFileTreeViewModel struct {
+	files          []*models.CommitFile
+	tree           *CommitFileNode
+	showTree       bool
+	log            *logrus.Entry
+	collapsedPaths CollapsedPaths
+	// parent is the identifier of the parent object e.g. a commit SHA if this commit file is for a commit, or a stash entry ref like 'stash@{1}'
+	parent string
+}
+
+func (self *CommitFileTreeViewModel) GetParent() string {
+	return self.parent
+}
+
+func (self *CommitFileTreeViewModel) SetParent(parent string) {
+	self.parent = parent
+}
+
+func NewCommitFileTreeViewModel(files []*models.CommitFile, log *logrus.Entry, showTree bool) *CommitFileTreeViewModel {
+	viewModel := &CommitFileTreeViewModel{
+		log:            log,
+		showTree:       showTree,
+		collapsedPaths: CollapsedPaths{},
+	}
+
+	viewModel.SetFiles(files)
+
+	return viewModel
+}
+
+func (self *CommitFileTreeViewModel) ExpandToPath(path string) {
+	self.collapsedPaths.ExpandToPath(path)
+}
+
+func (self *CommitFileTreeViewModel) ToggleShowTree() {
+	self.showTree = !self.showTree
+	self.SetTree()
+}
+
+func (self *CommitFileTreeViewModel) GetItemAtIndex(index int) *CommitFileNode {
+	// need to traverse the three depth first until we get to the index.
+	return self.tree.GetNodeAtIndex(index+1, self.collapsedPaths) // ignoring root
+}
+
+func (self *CommitFileTreeViewModel) GetIndexForPath(path string) (int, bool) {
+	index, found := self.tree.GetIndexForPath(path, self.collapsedPaths)
+	return index - 1, found
+}
+
+func (self *CommitFileTreeViewModel) GetAllItems() []*CommitFileNode {
+	if self.tree == nil {
+		return nil
+	}
+
+	return self.tree.Flatten(self.collapsedPaths)[1:] // ignoring root
+}
+
+func (self *CommitFileTreeViewModel) GetItemsLength() int {
+	return self.tree.Size(self.collapsedPaths) - 1 // ignoring root
+}
+
+func (self *CommitFileTreeViewModel) GetAllFiles() []*models.CommitFile {
+	return self.files
+}
+
+func (self *CommitFileTreeViewModel) SetFiles(files []*models.CommitFile) {
+	self.files = files
+
+	self.SetTree()
+}
+
+func (self *CommitFileTreeViewModel) SetTree() {
+	if self.showTree {
+		self.tree = BuildTreeFromCommitFiles(self.files)
+	} else {
+		self.tree = BuildFlatTreeFromCommitFiles(self.files)
+	}
+}
+
+func (self *CommitFileTreeViewModel) IsCollapsed(path string) bool {
+	return self.collapsedPaths.IsCollapsed(path)
+}
+
+func (self *CommitFileTreeViewModel) ToggleCollapsed(path string) {
+	self.collapsedPaths.ToggleCollapsed(path)
+}
+
+func (self *CommitFileTreeViewModel) Tree() INode {
+	return self.tree
+}
+
+func (self *CommitFileTreeViewModel) CollapsedPaths() CollapsedPaths {
+	return self.collapsedPaths
+}
diff --git a/pkg/gui/filetree/constants.go b/pkg/gui/filetree/constants.go
deleted file mode 100644
index d510650e2..000000000
--- a/pkg/gui/filetree/constants.go
+++ /dev/null
@@ -1,9 +0,0 @@
-package filetree
-
-const EXPANDED_ARROW = "▼"
-const COLLAPSED_ARROW = "►"
-
-const INNER_ITEM = "├─ "
-const LAST_ITEM = "└─ "
-const NESTED = "│  "
-const NOTHING = "   "
diff --git a/pkg/gui/filetree/file_manager.go b/pkg/gui/filetree/file_manager.go
deleted file mode 100644
index b028ef961..000000000
--- a/pkg/gui/filetree/file_manager.go
+++ /dev/null
@@ -1,140 +0,0 @@
-package filetree
-
-import (
-	"sync"
-
-	"github.com/jesseduffield/lazygit/pkg/commands/models"
-	"github.com/sirupsen/logrus"
-)
-
-type FileManagerDisplayFilter int
-
-const (
-	DisplayAll FileManagerDisplayFilter = iota
-	DisplayStaged
-	DisplayUnstaged
-)
-
-type FileManager struct {
-	files          []*models.File
-	tree           *FileNode
-	showTree       bool
-	log            *logrus.Entry
-	filter         FileManagerDisplayFilter
-	collapsedPaths CollapsedPaths
-	sync.RWMutex
-}
-
-func NewFileManager(files []*models.File, log *logrus.Entry, showTree bool) *FileManager {
-	return &FileManager{
-		files:          files,
-		log:            log,
-		showTree:       showTree,
-		filter:         DisplayAll,
-		collapsedPaths: CollapsedPaths{},
-		RWMutex:        sync.RWMutex{},
-	}
-}
-
-func (m *FileManager) InTreeMode() bool {
-	return m.showTree
-}
-
-func (m *FileManager) ExpandToPath(path string) {
-	m.collapsedPaths.ExpandToPath(path)
-}
-
-func (m *FileManager) GetFilesForDisplay() []*models.File {
-	files := m.files
-	if m.filter == DisplayAll {
-		return files
-	}
-
-	result := make([]*models.File, 0)
-	if m.filter == DisplayStaged {
-		for _, file := range files {
-			if file.HasStagedChanges {
-				result = append(result, file)
-			}
-		}
-	} else {
-		for _, file := range files {
-			if !file.HasStagedChanges {
-				result = append(result, file)
-			}
-		}
-	}
-
-	return result
-}
-
-func (m *FileManager) SetDisplayFilter(filter FileManagerDisplayFilter) {
-	m.filter = filter
-	m.SetTree()
-}
-
-func (m *FileManager) ToggleShowTree() {
-	m.showTree = !m.showTree
-	m.SetTree()
-}
-
-func (m *FileManager) GetItemAtIndex(index int) *FileNode {
-	// need to traverse the three depth first until we get to the index.
-	return m.tree.GetNodeAtIndex(index+1, m.collapsedPaths) // ignoring root
-}
-
-func (m *FileManager) GetIndexForPath(path string) (int, bool) {
-	index, found := m.tree.GetIndexForPath(path, m.collapsedPaths)
-	return index - 1, found
-}
-
-func (m *FileManager) GetAllItems() []*FileNode {
-	if m.tree == nil {
-		return nil
-	}
-
-	return m.tree.Flatten(m.collapsedPaths)[1:] // ignoring root
-}
-
-func (m *FileManager) GetItemsLength() int {
-	return m.tree.Size(m.collapsedPaths) - 1 // ignoring root
-}
-
-func (m *FileManager) GetAllFiles() []*models.File {
-	return m.files
-}
-
-func (m *FileManager) SetFiles(files []*models.File) {
-	m.files = files
-
-	m.SetTree()
-}
-
-func (m *FileManager) SetTree() {
-	filesForDisplay := m.GetFilesForDisplay()
-	if m.showTree {
-		m.tree = BuildTreeFromFiles(filesForDisplay)
-	} else {
-		m.tree = BuildFlatTreeFromFiles(filesForDisplay)
-	}
-}
-
-func (m *FileManager) IsCollapsed(path string) bool {
-	return m.collapsedPaths.IsCollapsed(path)
-}
-
-func (m *FileManager) ToggleCollapsed(path string) {
-	m.collapsedPaths.ToggleCollapsed(path)
-}
-
-func (m *FileManager) Render(diffName string, submoduleConfigs []*models.SubmoduleConfig) []string {
-	// can't rely on renderAux to check for nil because an interface won't be nil if its concrete value is nil
-	if m.tree == nil {
-		return []string{}
-	}
-
-	return renderAux(m.tree, m.collapsedPaths, "", -1, func(n INode, depth int) string {
-		castN := n.(*FileNode)
-		return getFileLine(castN.GetHasUnstagedChanges(), castN.GetHasStagedChanges(), castN.NameAtDepth(depth), diffName, submoduleConfigs, castN.File)
-	})
-}
diff --git a/pkg/gui/filetree/file_manager_test.go b/pkg/gui/filetree/file_manager_test.go
deleted file mode 100644
index 83ba5b086..000000000
--- a/pkg/gui/filetree/file_manager_test.go
+++ /dev/null
@@ -1,156 +0,0 @@
-package filetree
-
-import (
-	"testing"
-
-	"github.com/gookit/color"
-	"github.com/jesseduffield/lazygit/pkg/commands/models"
-	"github.com/stretchr/testify/assert"
-	"github.com/xo/terminfo"
-)
-
-func init() {
-	color.ForceSetColorLevel(terminfo.ColorLevelNone)
-}
-
-func TestRender(t *testing.T) {
-	scenarios := []struct {
-		name           string
-		root           *FileNode
-		collapsedPaths map[string]bool
-		expected       []string
-	}{
-		{
-			name:     "nil node",
-			root:     nil,
-			expected: []string{},