Splits layout: A new value for :option:launch --location to auto-select the split axis when splitting existing windows.

docs/changelog.rst

@@ -87,6 +87,9 @@ Detailed list of changes
 - macOS: Add a new service ``Open with kitty`` to open file types that are not
   recognized by the system (:pull:`4641`)
 
+- Splits layout: A new value for :option:`launch --location` to auto-select the split axis when splitting existing windows.
+  Wide windows are split side-by-side and tall windows are split one-above-the-other
+
 - Fix a regression in the previous release that broke :opt:`active_tab_foreground` (:iss:`4620`)
 
 - Fix :ac:`show_last_command_output` not working when the output is stored

docs/layouts.rst

@@ -138,6 +138,11 @@ define a few extra key bindings in :file:`kitty.conf`::
     # the two windows are placed side by side
     map F6 launch --location=vsplit
 
+    # Create a new window splitting the space used by the existing one so that
+    # the two windows are placed side by side if the existing window is wide or
+    # one above the other if the existing window is tall.
+    map F4 launch --location=split
+
     # Rotate the current split, chaging its split axis from vertical to
     # horizontal or vice versa
     map F7 layout_action rotate

kitty/launch.py

@@ -102,16 +102,17 @@ kitty remote control feature with :code:`kitty @launch --copy-env`.
 --location
 type=choices
 default=default
-choices=first,after,before,neighbor,last,vsplit,hsplit,default
+choices=first,after,before,neighbor,last,vsplit,hsplit,split,default
 Where to place the newly created window when it is added to a tab which
 already has existing windows in it. :code:`after` and :code:`before` place the new
 window before or after the active window. :code:`neighbor` is a synonym for :code:`after`.
 Also applies to creating a new tab, where the value of :code:`after`
 will cause the new tab to be placed next to the current tab instead of at the end.
-The values of :code:`vsplit` and :code:`hsplit` are only used by the :code:`splits`
+The values of :code:`vsplit`, :code:`hsplit` and :code:`split` are only used by the
-layout and control if the new window is placed in a vertical or horizontal split
+:code:`splits` layout and control if the new window is placed in a vertical,
-with the currently active window. The default is to place the window in a
+horizontal or automatic split with the currently active window. The default is
-layout dependent manner, typically, after the currently active window.
+to place the window in a layout dependent manner, typically, after the
+currently active window.
 
 
 --allow-remote-control

kitty/layout/splits.py

@@ -450,12 +450,11 @@ class Splits(Layout):
     ) -> None:
         horizontal = self.default_axis_is_horizontal
         after = True
-        if location is not None:
         if location == 'vsplit':
             horizontal = True
         elif location == 'hsplit':
             horizontal = False
-            if location in ('before', 'first'):
+        elif location in ('before', 'first'):
             after = False
         aw = all_windows.active_window
         if aw is not None:
@@ -464,6 +463,10 @@ class Splits(Layout):
             group_id = ag.id
             pair = self.pairs_root.pair_for_window(group_id)
             if pair is not None:
+                if location == 'split':
+                    wwidth = aw.geometry.right - aw.geometry.left
+                    wheight = aw.geometry.bottom - aw.geometry.top
+                    horizontal = wwidth >= wheight
                 target_group = all_windows.add_window(window, next_to=aw, before=not after)
                 pair.split_and_add(group_id, target_group.id, horizontal, after)
                 return