deal with the fact that a nil wrapped in an interface is not equal to nil

pkg/gui/branches_panel.go

@@ -463,8 +463,8 @@ func (gui *Gui) currentBranch() *commands.Branch {
 func (gui *Gui) handleNewBranchOffCurrentItem() error {
 	context := gui.currentSideContext()
 
-	item := context.GetSelectedItem()
+	item, ok := context.GetSelectedItem()
-	if item == nil {
+	if !ok {
 		return nil
 	}
 

pkg/gui/cherry_picking.go

@@ -35,11 +35,12 @@ func (gui *Gui) handleCopyCommit() error {
 		return err
 	}
 
-	commit, ok := context.SelectedItem().(*commands.Commit)
+	item, ok := context.SelectedItem()
 	if !ok {
-		gui.Log.Error("type cast failed for handling copy commit")
+		return nil
 	}
-	if commit == nil {
+	commit, ok := item.(*commands.Commit)
+	if !ok {
 		return nil
 	}
 
@@ -114,26 +115,24 @@ func (gui *Gui) handleCopyCommitRange() error {
 		return err
 	}
 
-	commit, ok := context.SelectedItem().(*commands.Commit)
+	commitShaMap := gui.cherryPickedCommitShaMap()
-	if !ok {
+	commitsList := gui.commitsListForContext()
-		gui.Log.Error("type cast failed for handling copy commit")
+	selectedLineIdx := context.GetPanelState().GetSelectedLineIdx()
-	}
+
-	if commit == nil {
+	if selectedLineIdx > len(commitsList)-1 {
 		return nil
 	}
 
-	commitShaMap := gui.cherryPickedCommitShaMap()
-
 	// find the last commit that is copied that's above our position
 	// if there are none, startIndex = 0
 	startIndex := 0
-	for index, commit := range gui.commitsListForContext()[0:context.GetPanelState().GetSelectedLineIdx()] {
+	for index, commit := range commitsList[0:selectedLineIdx] {
 		if commitShaMap[commit.Sha] {
 			startIndex = index
 		}
 	}
 
-	for index := startIndex; index <= context.GetPanelState().GetSelectedLineIdx(); index++ {
+	for index := startIndex; index <= selectedLineIdx; index++ {
 		gui.addCommitToCherryPickedCommits(index)
 	}
 

pkg/gui/context.go

@@ -45,8 +45,6 @@ type Context interface {
 	GetWindowName() string
 	SetWindowName(string)
 	GetKey() string
-	GetSelectedItemId() string
-	GetSelectedItem() ListItem
 	SetParentContext(Context)
 	GetParentContext() Context
 }
@@ -64,10 +62,6 @@ func (c BasicContext) SetWindowName(windowName string) {
 	panic("can't set window name on basic context")
 }
 
-func (c BasicContext) GetSelectedItem() ListItem {
-	return nil
-}
-
 func (c BasicContext) GetWindowName() string {
 	// TODO: fix this up
 	return c.GetViewName()
@@ -81,11 +75,6 @@ func (c BasicContext) GetParentContext() Context {
 	panic("can't get parent context on basic context")
 }
 
-// TODO: think about whether we need this on the Context interface or if it should just be on the ListContext struct
-func (c BasicContext) GetSelectedItemId() string {
-	return ""
-}
-
 func (c BasicContext) HandleRender() error {
 	if c.OnRender != nil {
 		return c.OnRender()
@@ -534,7 +523,12 @@ func (gui *Gui) currentSideContext() *ListContext {
 		context := stack[len(stack)-1-i]
 
 		if context.GetKind() == SIDE_CONTEXT {
-			return context.(*ListContext)
+			// not all side contexts are list contexts (e.g. the status panel)
+			listContext, ok := context.(*ListContext)
+			if !ok {
+				return nil
+			}
+			return listContext
 		}
 	}
 
@@ -694,11 +688,17 @@ func (gui *Gui) getCurrentSideView() *gocui.View {
 	return view
 }
 
-func (gui *Gui) getSideContextSelectedItem() ListItem {
+func (gui *Gui) getSideContextSelectedItemId() string {
 	currentSideContext := gui.currentSideContext()
 	if currentSideContext == nil {
-		return nil
+		return ""
 	}
 
-	return currentSideContext.GetSelectedItem()
+	item, ok := currentSideContext.GetSelectedItem()
+
+	if ok {
+		return item.ID()
+	}
+
+	return ""
 }

pkg/gui/diffing.go

@@ -60,8 +60,8 @@ func (gui *Gui) currentDiffTerminals() []string {
 		if context == nil {
 			return nil
 		}
-		item := context.GetSelectedItem()
+		item, ok := context.GetSelectedItem()
-		if item == nil {
+		if !ok {
 			return nil
 		}
 		return []string{item.ID()}
@@ -79,11 +79,7 @@ func (gui *Gui) currentDiffTerminal() string {
 func (gui *Gui) currentlySelectedFilename() string {
 	switch gui.currentContextKey() {
 	case FILES_CONTEXT_KEY, COMMIT_FILES_CONTEXT_KEY:
-		item := gui.getSideContextSelectedItem()
+		return gui.getSideContextSelectedItemId()
-		if item == nil {
-			return ""
-		}
-		return item.ID()
 	default:
 		return ""
 	}

pkg/gui/global_handlers.go

@@ -181,11 +181,11 @@ func (gui *Gui) fetch(canPromptForCredentials bool) (err error) {
 
 func (gui *Gui) handleCopySelectedSideContextItemToClipboard() error {
 	// important to note that this assumes we've selected an item in a side context
-	item := gui.getSideContextSelectedItem()
+	itemId := gui.getSideContextSelectedItemId()
 
-	if item == nil {
+	if itemId == "" {
 		return nil
 	}
 
-	return gui.OSCommand.CopyToClipboard(item.ID())
+	return gui.OSCommand.CopyToClipboard(itemId)
 }

pkg/gui/list_context.go

@@ -21,8 +21,10 @@ type ListContext struct {
 	OnFocus             func() error
 	OnFocusLost         func() error
 	OnClickSelectedItem func() error
-	SelectedItem        func() ListItem
+
-	GetPanelState       func() IListPanelState
+	// have to return whether item is nil because you can't work it out on the calling end once the pointer is wrapped in an interface (unless you want to use reflection)
+	SelectedItem  func() (ListItem, bool)
+	GetPanelState func() IListPanelState
 
 	Gui               *Gui
 	RendersToMainView bool
@@ -40,7 +42,7 @@ type ListItem interface {
 	Description() string
 }
 
-func (lc *ListContext) GetSelectedItem() ListItem {
+func (lc *ListContext) GetSelectedItem() (ListItem, bool) {
 	return lc.SelectedItem()
 }
 
@@ -72,9 +74,9 @@ func (lc *ListContext) GetParentContext() Context {
 }
 
 func (lc *ListContext) GetSelectedItemId() string {
-	item := lc.SelectedItem()
+	item, ok := lc.SelectedItem()
 
-	if item == nil {
+	if !ok {
 		return ""
 	}
 
@@ -277,8 +279,11 @@ func (gui *Gui) filesListContext() *ListContext {
 		GetDisplayStrings: func() [][]string {
 			return presentation.GetFileListDisplayStrings(gui.State.Files, gui.State.Modes.Diffing.Ref)
 		},
-		Contains:     CONTAINS_NOTHING,
+		Contains: CONTAINS_NOTHING,
-		SelectedItem: func() ListItem { return gui.getSelectedFile() },
+		SelectedItem: func() (ListItem, bool) {
+			item := gui.getSelectedFile()
+			return item, item != nil
+		},
 	}
 }
 
@@ -295,8 +300,11 @@ func (gui *Gui) branchesListContext() *ListContext {
 		GetDisplayStrings: func() [][]string {
 			return presentation.GetBranchListDisplayStrings(gui.State.Branches, gui.State.ScreenMode != SCREEN_NORMAL, gui.State.Modes.Diffing.Ref)
 		},
-		Contains:     CONTAINS_COMMITS,
+		Contains: CONTAINS_COMMITS,
-		SelectedItem: func() ListItem { return gui.getSelectedBranch() },
+		SelectedItem: func() (ListItem, bool) {
+			item := gui.getSelectedBranch()
+			return item, item != nil
+		},
 	}
 }
 
@@ -314,8 +322,11 @@ func (gui *Gui) remotesListContext() *ListContext {
 		GetDisplayStrings: func() [][]string {
 			return presentation.GetRemoteListDisplayStrings(gui.State.Remotes, gui.State.Modes.Diffing.Ref)
 		},
-		Contains:     CONTAINS_BRANCHES,
+		Contains: CONTAINS_BRANCHES,
-		SelectedItem: func() ListItem { return gui.getSelectedRemote() },
+		SelectedItem: func() (ListItem, bool) {
+			item := gui.getSelectedRemote()
+			return item, item != nil
+		},
 	}
 }
 
@@ -332,8 +343,11 @@ func (gui *Gui) remoteBranchesListContext() *ListContext {
 		GetDisplayStrings: func() [][]string {
 			return presentation.GetRemoteBranchListDisplayStrings(gui.State.RemoteBranches, gui.State.Modes.Diffing.Ref)
 		},
-		Contains:     CONTAINS_COMMITS,
+		Contains: CONTAINS_COMMITS,
-		SelectedItem: func() ListItem { return gui.getSelectedRemoteBranch() },
+		SelectedItem: func() (ListItem, bool) {
+			item := gui.getSelectedRemoteBranch()
+			return item, item != nil
+		},
 	}
 }
 
@@ -350,8 +364,11 @@ func (gui *Gui) tagsListContext() *ListContext {
 		GetDisplayStrings: func() [][]string {
 			return presentation.GetTagListDisplayStrings(gui.State.Tags, gui.State.Modes.Diffing.Ref)
 		},
-		Contains:     CONTAINS_COMMITS,
+		Contains: CONTAINS_COMMITS,
-		SelectedItem: func() ListItem { return gui.getSelectedTag() },
+		SelectedItem: func() (ListItem, bool) {
+			item := gui.getSelectedTag()
+			return item, item != nil
+		},
 	}
 }
 
@@ -369,8 +386,11 @@ func (gui *Gui) branchCommitsListContext() *ListContext {
 		GetDisplayStrings: func() [][]string {
 			return presentation.GetCommitListDisplayStrings(gui.State.Commits, gui.State.ScreenMode != SCREEN_NORMAL, gui.cherryPickedCommitShaMap(), gui.State.Modes.Diffing.Ref)
 		},
-		Contains:     CONTAINS_FILES,
+		Contains: CONTAINS_FILES,
-		SelectedItem: func() ListItem { return gui.getSelectedLocalCommit() },
+		SelectedItem: func() (ListItem, bool) {
+			item := gui.getSelectedLocalCommit()
+			return item, item != nil
+		},
 	}
 }
 
@@ -387,8 +407,11 @@ func (gui *Gui) reflogCommitsListContext() *ListContext {
 		GetDisplayStrings: func() [][]string {
 			return presentation.GetReflogCommitListDisplayStrings(gui.State.FilteredReflogCommits, gui.State.ScreenMode != SCREEN_NORMAL, gui.cherryPickedCommitShaMap(), gui.State.Modes.Diffing.Ref)
 		},
-		Contains:     CONTAINS_FILES,
+		Contains: CONTAINS_FILES,
-		SelectedItem: func() ListItem { return gui.getSelectedReflogCommit() },
+		SelectedItem: func() (ListItem, bool) {
+			item := gui.getSelectedReflogCommit()
+			return item, item != nil
+		},
 	}
 }
 
@@ -406,8 +429,11 @@ func (gui *Gui) subCommitsListContext() *ListContext {
 			gui.Log.Warn("getting display strings for sub commits")
 			return presentation.GetCommitListDisplayStrings(gui.State.SubCommits, gui.State.ScreenMode != SCREEN_NORMAL, gui.cherryPickedCommitShaMap(), gui.State.Modes.Diffing.Ref)
 		},
-		Contains:     CONTAINS_COMMITS,
+		Contains: CONTAINS_COMMITS,
-		SelectedItem: func() ListItem { return gui.getSelectedSubCommit() },
+		SelectedItem: func() (ListItem, bool) {
+			item := gui.getSelectedSubCommit()
+			return item, item != nil
+		},
 	}
 }
 
@@ -424,8 +450,11 @@ func (gui *Gui) stashListContext() *ListContext {
 		GetDisplayStrings: func() [][]string {
 			return presentation.GetStashEntryListDisplayStrings(gui.State.StashEntries, gui.State.Modes.Diffing.Ref)
 		},
-		Contains:     CONTAINS_FILES,
+		Contains: CONTAINS_FILES,
-		SelectedItem: func() ListItem { return gui.getSelectedStashEntry() },
+		SelectedItem: func() (ListItem, bool) {
+			item := gui.getSelectedStashEntry()
+			return item, item != nil
+		},
 	}
 }
 
@@ -443,8 +472,11 @@ func (gui *Gui) commitFilesListContext() *ListContext {
 		GetDisplayStrings: func() [][]string {
 			return presentation.GetCommitFileListDisplayStrings(gui.State.CommitFiles, gui.State.Modes.Diffing.Ref)
 		},
-		Contains:     CONTAINS_NOTHING,
+		Contains: CONTAINS_NOTHING,
-		SelectedItem: func() ListItem { return gui.getSelectedCommitFile() },
+		SelectedItem: func() (ListItem, bool) {
+			item := gui.getSelectedCommitFile()
+			return item, item != nil
+		},
 	}
 }