kitty: Add custom kitten for relative resize

kitty/.config/kitty/kitty.conf

@@ -80,12 +80,11 @@ map cmd+shift+l move_window right
 
 # Resize windows
 map cmd+r start_resizing_window
-map cmd+ctrl+h resize_window narrower
-map cmd+ctrl+j resize_window shorter
-map cmd+ctrl+k resize_window taller
-map cmd+ctrl+l resize_window wider
-map cmd+shift+0 remote_control resize-window --axis reset
-
+map cmd+ctrl+0 remote_control resize-window --axis reset
+map cmd+ctrl+h kitten relative_resize.py left
+map cmd+ctrl+j kitten relative_resize.py down
+map cmd+ctrl+k kitten relative_resize.py up
+map cmd+ctrl+l kitten relative_resize.py right
 
 # Split specific:
 # Rotate the current split, chaging its split axis from vertical to

kitty/.config/kitty/relative_resize.py

@@ -0,0 +1,32 @@
+from kittens.tui.handler import result_handler
+
+def main(args):
+    pass
+
+@result_handler(no_ui=True)
+def handle_result(args, result, target_window_id, boss):
+    window = boss.window_id_map.get(target_window_id)
+    if window is None:
+        return
+
+    direction = args[1]
+
+    neighbor_direction = direction
+    if direction == 'up':
+        neighbor_direction = 'top'
+    if direction == 'down':
+        neighbor_direction = 'bottom'
+
+    neighbor = boss.active_tab.neighboring_group_id(neighbor_direction)
+
+    if direction == 'left' or direction == 'right':
+        if neighbor is None:
+            boss.active_tab.resize_window('narrower', 1)
+        else:
+            boss.active_tab.resize_window('wider', 1)
+
+    if direction == 'up' or direction == 'down':
+        if neighbor is None:
+            boss.active_tab.resize_window('shorter', 1)
+        else:
+            boss.active_tab.resize_window('taller', 1)