feat(ProjectDiffScreen): Jump to file position on quit

The diff view is a projection of the file's state. Quitting from the diff pane now jumps to the corresponding file position, keeping context stable.

Author: MaxFangX

lua/vgit/features/screens/ProjectDiffScreen/init.lua

@@ -821,6 +821,31 @@ function ProjectDiffScreen:create()
   return true
 end
 
+-- Called when quit key is pressed. Returns true if quit was handled.
+function ProjectDiffScreen:on_quit()
+  local diff_component = self.scene:get('current')
+  if not diff_component:is_focused() then
+    return false
+  end
+
+  local filepath = self.model:get_filepath()
+  if not filepath then
+    return false
+  end
+
+  local file_lnum = self.diff_view:get_file_lnum()
+  loop.free_textlock()
+
+  self:destroy()
+  fs.open(filepath)
+
+  if file_lnum then
+    Window(0):set_lnum(file_lnum):position_cursor('center')
+  end
+
+  return true
+end
+
 function ProjectDiffScreen:destroy()
   -- Clean up timer handles from debounced keymap handlers
   loop.close_debounced_handlers(self.diff_keymaps)

lua/vgit/ui/screen_manager.lua

@@ -120,9 +120,10 @@ function screen_manager.create(screen_name, ...)
       {
         mode = 'n',
         key = scene_setting:get('keymaps').quit,
-        handler = function()
+        handler = loop.coroutine(function()
+          if screen.on_quit and screen:on_quit() then return end
           screen_manager.destroy_active_screen()
-        end
+        end)
       }
     })
   end

lua/vgit/ui/views/DiffView.lua

@@ -500,6 +500,28 @@ function DiffView:get_hunk_under_cursor()
   if selected then return hunks[selected], selected end
 end
 
+-- Returns the actual file line number for the current cursor position.
+-- For removed lines (which don't exist in the file), returns the closest
+-- valid line number above.
+function DiffView:get_file_lnum()
+  local lines_changes = self.state.current_lines_changes
+  if not lines_changes or #lines_changes == 0 then return nil end
+
+  local lnum = self.scene:get('current'):get_lnum()
+  if lnum > #lines_changes then lnum = #lines_changes end
+
+  -- Search current line and above for a valid line number
+  for i = lnum, 1, -1 do
+    local entry = lines_changes[i]
+    if entry and entry.line_number then
+      local file_lnum = tonumber(entry.line_number:match('%d+'))
+      if file_lnum then return file_lnum end
+    end
+  end
+
+  return nil
+end
+
 function DiffView:set_lnum(lnum, position)
   if self.props.layout_type() == 'split' then self.scene:get('previous'):set_lnum(lnum):position_cursor(position) end
   self.scene:get('current'):set_lnum(lnum):position_cursor(position)