Extract a ListRenderer struct

I'm doing this not so much because it's a great abstraction, but just because it
will make it much easier to write tests for it.

pkg/gui/context/branches_context.go

@@ -45,9 +45,11 @@ func NewBranchesContext(c *ContextCommon) *BranchesContext {
 				Kind:       types.SIDE_CONTEXT,
 				Focusable:  true,
 			})),
-			list:              viewModel,
-			getDisplayStrings: getDisplayStrings,
-			c:                 c,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
+			c: c,
 		},
 	}
 

pkg/gui/context/commit_files_context.go

@@ -54,9 +54,11 @@ func NewCommitFilesContext(c *ContextCommon) *CommitFilesContext {
 					Transient:  true,
 				}),
 			),
-			list:              viewModel,
-			getDisplayStrings: getDisplayStrings,
-			c:                 c,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
+			c: c,
 		},
 	}
 

pkg/gui/context/list_context_trait.go

@@ -4,17 +4,13 @@ import (
 	"fmt"
 
 	"github.com/jesseduffield/lazygit/pkg/gui/types"
-	"github.com/jesseduffield/lazygit/pkg/utils"
 )
 
 type ListContextTrait struct {
 	types.Context
+	ListRenderer
 
-	c                 *ContextCommon
-	list              types.IList
-	getDisplayStrings func(startIdx int, endIdx int) [][]string
-	// Alignment for each column. If nil, the default is left alignment
-	getColumnAlignments func() []utils.Alignment
+	c *ContextCommon
 	// Some contexts, like the commit context, will highlight the path from the selected commit
 	// to its parents, because it's ambiguous otherwise. For these, we need to refresh the viewport
 	// so that we show the highlighted path.
@@ -26,10 +22,6 @@ type ListContextTrait struct {
 
 func (self *ListContextTrait) IsListContext() {}
 
-func (self *ListContextTrait) GetList() types.IList {
-	return self.list
-}
-
 func (self *ListContextTrait) FocusLine() {
 	// Doing this at the end of the layout function because we need the view to be
 	// resized before we focus the line, otherwise if we're in accordion mode
@@ -57,16 +49,6 @@ func (self *ListContextTrait) FocusLine() {
 	}
 }
 
-func (self *ListContextTrait) renderLines(startIdx int, endIdx int) string {
-	var columnAlignments []utils.Alignment
-	if self.getColumnAlignments != nil {
-		columnAlignments = self.getColumnAlignments()
-	}
-	return utils.RenderDisplayStrings(
-		self.getDisplayStrings(startIdx, utils.Min(endIdx, self.list.Len())),
-		columnAlignments)
-}
-
 func (self *ListContextTrait) refreshViewport() {
 	startIdx, length := self.GetViewTrait().ViewPortYBounds()
 	content := self.renderLines(startIdx, startIdx+length)

pkg/gui/context/list_renderer.go

@@ -0,0 +1,27 @@
+package context
+
+import (
+	"github.com/jesseduffield/lazygit/pkg/gui/types"
+	"github.com/jesseduffield/lazygit/pkg/utils"
+)
+
+type ListRenderer struct {
+	list              types.IList
+	getDisplayStrings func(startIdx int, endIdx int) [][]string
+	// Alignment for each column. If nil, the default is left alignment
+	getColumnAlignments func() []utils.Alignment
+}
+
+func (self *ListRenderer) GetList() types.IList {
+	return self.list
+}
+
+func (self *ListRenderer) renderLines(startIdx int, endIdx int) string {
+	var columnAlignments []utils.Alignment
+	if self.getColumnAlignments != nil {
+		columnAlignments = self.getColumnAlignments()
+	}
+	return utils.RenderDisplayStrings(
+		self.getDisplayStrings(startIdx, utils.Min(endIdx, self.list.Len())),
+		columnAlignments)
+}

pkg/gui/context/local_commits_context.go

@@ -74,8 +74,10 @@ func NewLocalCommitsContext(c *ContextCommon) *LocalCommitsContext {
 				Kind:       types.SIDE_CONTEXT,
 				Focusable:  true,
 			})),
-			list:                    viewModel,
-			getDisplayStrings:       getDisplayStrings,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
 			c:                       c,
 			refreshViewportOnChange: true,
 		},

pkg/gui/context/menu_context.go

@@ -34,10 +34,12 @@ func NewMenuContext(
 				Focusable:             true,
 				HasUncontrolledBounds: true,
 			})),
-			getDisplayStrings:   viewModel.GetDisplayStrings,
-			list:                viewModel,
-			c:                   c,
-			getColumnAlignments: func() []utils.Alignment { return viewModel.columnAlignment },
+			ListRenderer: ListRenderer{
+				list:                viewModel,
+				getDisplayStrings:   viewModel.GetDisplayStrings,
+				getColumnAlignments: func() []utils.Alignment { return viewModel.columnAlignment },
+			},
+			c: c,
 		},
 	}
 }

pkg/gui/context/reflog_commits_context.go

@@ -49,9 +49,11 @@ func NewReflogCommitsContext(c *ContextCommon) *ReflogCommitsContext {
 				Kind:       types.SIDE_CONTEXT,
 				Focusable:  true,
 			})),
-			list:              viewModel,
-			getDisplayStrings: getDisplayStrings,
-			c:                 c,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
+			c: c,
 		},
 	}
 }

pkg/gui/context/remote_branches_context.go

@@ -43,9 +43,11 @@ func NewRemoteBranchesContext(
 				Focusable:  true,
 				Transient:  true,
 			})),
-			list:              viewModel,
-			getDisplayStrings: getDisplayStrings,
-			c:                 c,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
+			c: c,
 		},
 	}
 }

pkg/gui/context/remotes_context.go

@@ -38,9 +38,11 @@ func NewRemotesContext(c *ContextCommon) *RemotesContext {
 				Kind:       types.SIDE_CONTEXT,
 				Focusable:  true,
 			})),
-			list:              viewModel,
-			getDisplayStrings: getDisplayStrings,
-			c:                 c,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
+			c: c,
 		},
 	}
 }

pkg/gui/context/stash_context.go

@@ -40,9 +40,11 @@ func NewStashContext(
 				Kind:       types.SIDE_CONTEXT,
 				Focusable:  true,
 			})),
-			list:              viewModel,
-			getDisplayStrings: getDisplayStrings,
-			c:                 c,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
+			c: c,
 		},
 	}
 }

pkg/gui/context/sub_commits_context.go

@@ -93,8 +93,10 @@ func NewSubCommitsContext(
 				Focusable:  true,
 				Transient:  true,
 			})),
-			list:                    viewModel,
-			getDisplayStrings:       getDisplayStrings,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
 			c:                       c,
 			refreshViewportOnChange: true,
 		},

pkg/gui/context/submodules_context.go

@@ -35,9 +35,11 @@ func NewSubmodulesContext(c *ContextCommon) *SubmodulesContext {
 				Kind:       types.SIDE_CONTEXT,
 				Focusable:  true,
 			})),
-			list:              viewModel,
-			getDisplayStrings: getDisplayStrings,
-			c:                 c,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
+			c: c,
 		},
 	}
 }

pkg/gui/context/suggestions_context.go

@@ -54,9 +54,11 @@ func NewSuggestionsContext(
 				Focusable:             true,
 				HasUncontrolledBounds: true,
 			})),
-			list:              viewModel,
-			getDisplayStrings: getDisplayStrings,
-			c:                 c,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
+			c: c,
 		},
 	}
 }

pkg/gui/context/tags_context.go

@@ -40,9 +40,11 @@ func NewTagsContext(
 				Kind:       types.SIDE_CONTEXT,
 				Focusable:  true,
 			})),
-			list:              viewModel,
-			getDisplayStrings: getDisplayStrings,
-			c:                 c,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
+			c: c,
 		},
 	}
 }

pkg/gui/context/working_tree_context.go

@@ -41,9 +41,11 @@ func NewWorkingTreeContext(c *ContextCommon) *WorkingTreeContext {
 				Kind:       types.SIDE_CONTEXT,
 				Focusable:  true,
 			})),
-			list:              viewModel,
-			getDisplayStrings: getDisplayStrings,
-			c:                 c,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
+			c: c,
 		},
 	}
 

pkg/gui/context/worktrees_context.go

@@ -38,9 +38,11 @@ func NewWorktreesContext(c *ContextCommon) *WorktreesContext {
 				Kind:       types.SIDE_CONTEXT,
 				Focusable:  true,
 			})),
-			list:              viewModel,
-			getDisplayStrings: getDisplayStrings,
-			c:                 c,
+			ListRenderer: ListRenderer{
+				list:              viewModel,
+				getDisplayStrings: getDisplayStrings,
+			},
+			c: c,
 		},
 	}
 }