Allow using neighboring window operations in the stack layout

docs/changelog.rst

@@ -21,6 +21,10 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 
 - Fix turning off cursor blink via escape codes not working (:iss:`3808`)
 
+- Allow using neighboring window operations in the stack layout. The previous
+  window is considered the left and top neighbor and the next window is
+  considered the bottom and right neighbor (:iss:`3778`)
+
 
 0.21.2 [2021-06-28]
 ----------------------

kitty/layout/stack.py

@@ -2,9 +2,10 @@
 # vim:fileencoding=utf-8
 # License: GPLv3 Copyright: 2020, Kovid Goyal <kovid at kovidgoyal.net>
 
+from kitty.typing import WindowType
 from kitty.window_list import WindowList
 
-from .base import Layout
+from .base import Layout, NeighborsMap
 
 
 class Stack(Layout):
@@ -17,3 +18,12 @@ class Stack(Layout):
         active_group = all_windows.active_group
         for group in all_windows.iter_all_layoutable_groups():
             self.layout_single_window_group(group, add_blank_rects=group is active_group)
+
+    def neighbors_for_window(self, window: WindowType, all_windows: WindowList) -> NeighborsMap:
+        wg = all_windows.group_for_window(window)
+        assert wg is not None
+        groups = tuple(all_windows.iter_all_layoutable_groups())
+        idx = groups.index(wg)
+        before = [] if wg is groups[0] else [groups[idx-1].id]
+        after = [] if wg is groups[-1] else [groups[idx+1].id]
+        return {'top': before, 'left': before, 'right': after, 'bottom': after}