Use gitsigns.nvim to display inline diffs in the "diff1_inline" layout.

Author: sindrets

lua/diffview/actions.lua

@@ -9,6 +9,7 @@ local utils = lazy.require("diffview.utils") ---@module "diffview.utils"
 local vcs_utils = lazy.require("diffview.vcs.utils") ---@module "diffview.vcs.utils"
 
 local Diff1 = lazy.access("diffview.scene.layouts.diff_1", "Diff1") ---@type Diff1|LazyModule
+local Diff1Inline = lazy.access("diffview.scene.layouts.diff_1_inline", "Diff1Inline") ---@type Diff1Inline|LazyModule
 local Diff2Hor = lazy.access("diffview.scene.layouts.diff_2_hor", "Diff2Hor") ---@type Diff2Hor|LazyModule
 local Diff2Ver = lazy.access("diffview.scene.layouts.diff_2_ver", "Diff2Ver") ---@type Diff2Ver|LazyModule
 local Diff3 = lazy.access("diffview.scene.layouts.diff_3", "Diff3") ---@type Diff3|LazyModule
@@ -406,6 +407,7 @@ function M.cycle_layout()
     standard = {
       Diff2Hor.__get(),
       Diff2Ver.__get(),
+      Diff1Inline.__get(),
     },
     merge_tool = {
       Diff3Hor.__get(),

lua/diffview/config.lua

@@ -4,6 +4,7 @@ local actions = require("diffview.actions")
 local lazy = require("diffview.lazy")
 
 local Diff1 = lazy.access("diffview.scene.layouts.diff_1", "Diff1") ---@type Diff1|LazyModule
+local Diff1Inline = lazy.access("diffview.scene.layouts.diff_1_inline", "Diff1Inline") ---@type Diff1Inline|LazyModule
 local Diff2 = lazy.access("diffview.scene.layouts.diff_2", "Diff2") ---@type Diff2|LazyModule
 local Diff2Hor = lazy.access("diffview.scene.layouts.diff_2_hor", "Diff2Hor") ---@type Diff2Hor|LazyModule
 local Diff2Ver = lazy.access("diffview.scene.layouts.diff_2_ver", "Diff2Ver") ---@type Diff2Ver|LazyModule
@@ -293,6 +294,7 @@ function M.get_log_options(single_file, t)
 end
 
 ---@alias LayoutName "diff1_plain"
+---       | "diff1_inline"
 ---       | "diff2_horizontal"
 ---       | "diff2_vertical"
 ---       | "diff3_horizontal"
@@ -302,6 +304,7 @@ end
 
 local layout_map = {
   diff1_plain = Diff1,
+  diff_1_inline = Diff1Inline,
   diff2_horizontal = Diff2Hor,
   diff2_vertical = Diff2Ver,
   diff3_horizontal = Diff3Hor,
@@ -480,7 +483,7 @@ function M.setup(user_config)
   do
     -- Validate layouts
     local view = M._config.view
-    local standard_layouts = { "diff2_horizontal", "diff2_vertical", -1 }
+    local standard_layouts = { "diff2_horizontal", "diff2_vertical", "diff1_inline", -1 }
     local merge_layuots = {
       "diff1_plain",
       "diff3_horizontal",

lua/diffview/scene/file_entry.lua

@@ -120,6 +120,7 @@ function FileEntry:convert_layout(target_layout)
   end
 
   self.layout = target_layout({
+    parent = self,
     a = utils.tbl_access(self.layout, "a.file") or create_file(self.revs.a, "a"),
     b = utils.tbl_access(self.layout, "b.file") or create_file(self.revs.b, "b"),
     c = utils.tbl_access(self.layout, "c.file") or create_file(self.revs.c, "c"),
@@ -203,7 +204,7 @@ function FileEntry.with_layout(layout_class, opt)
     }) --[[@as vcs.File ]]
   end
 
-  return FileEntry({
+  local entry = FileEntry({
     adapter = opt.adapter,
     path = opt.path,
     oldpath = opt.oldpath,
@@ -212,13 +213,17 @@ function FileEntry.with_layout(layout_class, opt)
     kind = opt.kind,
     commit = opt.commit,
     revs = opt.revs,
-    layout = layout_class({
-      a = create_file(opt.revs.a, "a"),
-      b = create_file(opt.revs.b, "b"),
-      c = create_file(opt.revs.c, "c"),
-      d = create_file(opt.revs.d, "d"),
-    }),
   })
+
+  entry.layout = layout_class({
+    parent = entry,
+    a = create_file(opt.revs.a, "a"),
+    b = create_file(opt.revs.b, "b"),
+    c = create_file(opt.revs.c, "c"),
+    d = create_file(opt.revs.d, "d"),
+  })
+
+  return entry
 end
 
 M.FileEntry = FileEntry

lua/diffview/scene/layout.lua

@@ -8,13 +8,15 @@ local api = vim.api
 local M = {}
 
 ---@class Layout : diffview.Object
+---@field parent FileEntry
 ---@field windows Window[]
 ---@field emitter EventEmitter
 ---@field pivot_producer fun(): integer?
 local Layout = oop.create_class("Layout")
 
 function Layout:init(opt)
   opt = opt or {}
+  self.parent = opt.parent
   self.windows = opt.windows or {}
   self.emitter = opt.emitter or EventEmitter()
 

lua/diffview/scene/layouts/diff_1.lua

@@ -1,5 +1,5 @@
-local lazy = require("diffview.lazy")
 local Layout = require("diffview.scene.layout").Layout
+local lazy = require("diffview.lazy")
 local oop = require("diffview.oop")
 
 local Diff3 = lazy.access("diffview.scene.layouts.diff_3", "Diff3") ---@type Diff3|LazyModule

lua/diffview/scene/layouts/diff_1_inline.lua

@@ -0,0 +1,16 @@
+local Diff1 = require("diffview.scene.layouts.diff_1").Diff1
+local lazy = require("diffview.lazy")
+local oop = require("diffview.oop")
+
+local M = {}
+
+---@class Diff1Inline : Diff1
+local Diff1Inline = oop.create_class("Diff1Inline", Diff1)
+
+---@param opt Diff1.init.Opt
+function Diff1Inline:init(opt)
+  Diff1Inline:super().init(self, opt)
+end
+
+M.Diff1Inline = Diff1Inline
+return M

lua/diffview/scene/window.lua

@@ -1,7 +1,9 @@
 local lazy = require("diffview.lazy")
 local oop = require("diffview.oop")
 
+local Diff1 = lazy.access("diffview.scene.layouts.diff_1", "Diff1") ---@type Diff1|LazyModule
 local File = lazy.access("diffview.vcs.file", "File") ---@type vcs.File|LazyModule
+local GitAdapter = lazy.access("diffview.vcs.adapters.git", "GitAdapter") ---@type GitAdapter|LazyModule
 local RevType = lazy.access("diffview.vcs.rev", "RevType") ---@type RevType|LazyModule
 local config = lazy.require("diffview.config") ---@module "diffview.config"
 local lib = lazy.require("diffview.lib") ---@module "diffview.lib"
@@ -62,6 +64,12 @@ function Window:is_focused()
   return self:is_valid() and api.nvim_get_current_win() == self.id
 end
 
+function Window:is_file_open()
+  return self:is_valid()
+      and self.file:is_valid()
+      and api.nvim_win_get_buf(self.id) == self.file.bufnr
+end
+
 ---@param callback fun(file: vcs.File)
 function Window:load_file(callback)
   assert(self.file)
@@ -87,11 +95,25 @@ function Window:open_file(callback)
         self:_save_winopts()
       end
 
-      self:apply_file_winopts()
+      local winopt_overrides
+      local base_rev = utils.tbl_access(self, "parent.parent.revs.a") --[[@as Rev? ]]
+      local use_inline_diff = self.file.kind ~= "conflicting"
+          and self.parent:instanceof(Diff1.__get())
+          and self.file.adapter:instanceof(GitAdapter.__get())
+
+      if use_inline_diff then
+        winopt_overrides = { foldmethod = "manual", diff = false }
+      end
+
+      self:apply_file_winopts(winopt_overrides)
       self.file:attach_buffer(false, {
         keymaps = config.get_layout_keymaps(self.parent),
         disable_diagnostics = self.file.kind == "conflicting"
             and config.get_config().view.merge_tool.disable_diagnostics,
+        inline_diff = {
+          enabled = use_inline_diff,
+          base = base_rev and base_rev:object_name(),
+        }
       })
 
       api.nvim_win_call(self.id, function()
@@ -163,11 +185,16 @@ function Window:_restore_winopts()
   end
 end
 
-function Window:apply_file_winopts()
+---@param overrides WindowOptions?
+function Window:apply_file_winopts(overrides)
   assert(self.file)
   if self.file.winopts then
+    if overrides then
+      utils.set_local(self.id, vim.tbl_extend("force", self.file.winopts, overrides))
+    else
     utils.set_local(self.id, self.file.winopts)
   end
+  end
 end
 
 function Window:apply_null_winopts()