Fix #2688

docs/changelog.rst

@@ -12,6 +12,9 @@ To update |kitty|, :doc:`follow the instructions <binary>`.
 - Tall and Fat layouts: Add a ``mirrored`` option to put the full size window
   on the opposite edge of the screen (:iss:`2654`)
 
+- Tall and Fat layouts: Add mappable actions to increase or decrease the number
+  of full size windows (:iss:`2688`)
+
 - Add an option :opt:`confirm_os_window_close` to ask for confirmation
   when closing an OS window with multiple kitty windows.
 

docs/layouts.rst

@@ -67,6 +67,13 @@ for the options is shown below::
     │              │               │
     └──────────────┴───────────────┘
 
+In addition, you can map keys to increase or decrease the number of full size
+windows, for example::
+
+   map ctrl+[ layout_action decrease_num_full_size_windows
+   map ctrl+] layout_action increase_num_full_size_windows
+
+
 The Fat Layout
 ----------------
 

kitty/layout/tall.py

@@ -3,7 +3,7 @@
 # License: GPLv3 Copyright: 2020, Kovid Goyal <kovid at kovidgoyal.net>
 
 from itertools import islice, repeat
-from typing import Dict, Generator, List, Tuple
+from typing import Dict, Generator, List, Optional, Sequence, Tuple
 
 from kitty.conf.utils import to_bool
 from kitty.typing import EdgeLiteral, WindowType
@@ -209,6 +209,15 @@ class Tall(Layout):
             else:
                 yield self.only_between_border
 
+    def layout_action(self, action_name: str, args: Sequence[str], all_windows: WindowList) -> Optional[bool]:
+        if action_name == 'increase_num_full_size_windows':
+            self.layout_opts.full_size += 1
+            return True
+        if action_name == 'decrease_num_full_size_windows':
+            if self.layout_opts.full_size > 1:
+                self.layout_opts.full_size -= 1
+                return True
+
 
 class Fat(Tall):