Make the resize step size configurable

README.asciidoc

@@ -347,11 +347,12 @@ you want to enable/disable, see link:kitty/kitty.conf[kitty.conf] for examples.
 You can resize windows inside layouts. Press {sc_start_resizing_window} to
 enter resizing mode. Then use the `W/N` (Wider/Narrower) and `T/S`
 (Taller/Shorter) keys to change the window size.  Press the `0` key to rest the
-layout to default sizes. Any other key will exit resize mode.  In a given
-window layout only some operations may be possible for a particular window. For
-example, in the Tall layout you can make the first window wider/narrower, but
-not taller/shorter. Note that what you are resizing is actually not a window,
-but a row/column in the layout, all windows in that row/column will be resized.
+layout to default sizes. Press the `Ctrl` modifier to double the step size. Any
+other key will exit resize mode.  In a given window layout only some operations
+may be possible for a particular window. For example, in the Tall layout you
+can make the first window wider/narrower, but not taller/shorter. Note that
+what you are resizing is actually not a window, but a row/column in the layout,
+all windows in that row/column will be resized.
 
 Some layouts take options to control their behavior. For example, the `fat` and `tall`
 layouts accept the `bias` option to control how the available space is split up. To specify the

kitty/boss.py

@@ -19,8 +19,8 @@
     appname, config_dir, editor, set_boss, supports_primary_selection
 )
 from .fast_data_types import (
-    GLFW_KEY_0, GLFW_KEY_W, GLFW_KEY_N, GLFW_KEY_S, ChildMonitor,
-    create_os_window, current_os_window, destroy_global_data,
+    GLFW_KEY_0, GLFW_KEY_N, GLFW_KEY_S, GLFW_KEY_W, GLFW_MOD_CONTROL,
+    ChildMonitor, create_os_window, current_os_window, destroy_global_data,
     destroy_sprite_map, get_clipboard_string, glfw_post_empty_event,
     layout_sprite_map, mark_os_window_for_close, set_clipboard_string,
     set_dpi_from_os_window, set_in_sequence_mode, show_window,
@@ -425,7 +425,9 @@ def handle_resize_keypress(self, key, mods, os_window_id, tab_id, window_id):
             tab.reset_window_sizes()
             return
         is_horizontal = key in (GLFW_KEY_W, GLFW_KEY_N)
-        increment = 0.05
+        increment = self.opts.window_resize_step_cells if is_horizontal else self.opts.window_resize_step_lines
+        if mods == GLFW_MOD_CONTROL:
+            increment *= 2
         if key in (GLFW_KEY_N, GLFW_KEY_S):
             increment *= -1
         tab.resize_window_by(window_id, increment, is_horizontal)

kitty/config.py

@@ -366,6 +366,8 @@ def url_style(x):
     'kitty_mod': to_modifiers,
     'clear_all_shortcuts': to_bool,
     'clipboard_control': lambda x: frozenset(x.lower().split()),
+    'window_resize_step_cells': int,
+    'window_resize_step_lines': int,
 }
 
 for name in (

kitty/keys.c

@@ -88,6 +88,7 @@ handle_resize_key(int key, int action, int mods) {
         call_boss(handle_resize_keypress, "iiKKK", key, mods, global_state.currently_resizing.os_window_id, global_state.currently_resizing.tab_id, global_state.currently_resizing.window_id);
         return true;
     }
+    if (key == GLFW_KEY_LEFT_CONTROL || key == GLFW_KEY_RIGHT_CONTROL) return true;
     return false;
 }
 

kitty/kitty.conf

@@ -192,6 +192,12 @@ initial_window_height  400
 # For a list of available layouts, see the README.
 enabled_layouts *
 
+# The step size (in units of cell width/cell height) to use when resizing
+# windows. The cells value is used for horizontal resizing and the lines value
+# for vertical resizing.
+window_resize_step_cells 2
+window_resize_step_lines 2
+
 # The width (in pts) of window borders. Will be rounded to the nearest number of pixels based on screen resolution.
 # Note that borders are displayed only when more than one window is visible. They are meant to separate multiple windows.
 window_border_width 1

kitty/layout.py

@@ -102,7 +102,13 @@ def __init__(self, os_window_id, tab_id, margin_width, padding_width, border_wid
     def initialize_sub_class(self):
         pass
 
-    def apply_bias(self, idx, increment, num_windows, is_horizontal):
+    def bias_increment_for_cell(self, is_horizontal):
+        self._set_dimensions()
+        if is_horizontal:
+            return (cell_width + 1) / central.width
+        return (cell_height + 1) / central.height
+
+    def apply_bias(self, idx, increment_as_percent, num_windows, is_horizontal):
         return False
 
     def remove_all_biases(self):
@@ -235,10 +241,12 @@ def set_active_window(self, all_windows, active_window_idx):
         self.set_active_window_in_os_window(active_window_idx)
         return active_window_idx
 
-    def __call__(self, all_windows, active_window_idx):
+    def _set_dimensions(self):
         global central, cell_width, cell_height
         central, tab_bar, vw, vh, cell_width, cell_height = viewport_for_window(self.os_window_id)
 
+    def __call__(self, all_windows, active_window_idx):
+        self._set_dimensions()
         active_window = all_windows[active_window_idx]
         overlaid_windows, windows = process_overlaid_windows(all_windows)
         if overlaid_windows:

kitty/tabs.py

@@ -164,7 +164,8 @@ def goto_layout(self, layout_name):
         self.relayout()
 
     def resize_window_by(self, window_id, increment, is_horizontal):
-        if self.current_layout.modify_size_of_window(self.windows, window_id, increment, is_horizontal):
+        increment_as_percent = self.current_layout.bias_increment_for_cell(is_horizontal) * increment
+        if self.current_layout.modify_size_of_window(self.windows, window_id, increment_as_percent, is_horizontal):
             self.relayout()
         else:
             ring_bell(self.os_window_id)