Add a configurable keyboard shortcut and remote command to set the font size to a specific value

Fixes #388

kitty/boss.py

@@ -288,19 +288,16 @@ class Boss:
                 tm.resize()
 
     def increase_font_size(self):
-        self.change_font_size(
+        self.set_font_size(
             min(
                 self.opts.font_size * 5, self.current_font_size +
                 self.opts.font_size_delta))
 
     def decrease_font_size(self):
-        self.change_font_size(
-            max(
-                MINIMUM_FONT_SIZE, self.current_font_size -
-                self.opts.font_size_delta))
+        self.set_font_size(self.current_font_size - self.opts.font_size_delta)
 
     def restore_font_size(self):
-        self.change_font_size(self.opts.font_size)
+        self.set_font_size(self.opts.font_size)
 
     def _change_font_size(self, new_size=None, on_dpi_change=False):
         if new_size is not None:
@@ -318,7 +315,8 @@ class Boss:
             tm.refresh_sprite_positions()
         glfw_post_empty_event()
 
-    def change_font_size(self, new_size):
+    def set_font_size(self, new_size):
+        new_size = max(MINIMUM_FONT_SIZE, new_size)
         if new_size == self.current_font_size:
             return
         self._change_font_size(new_size)

kitty/config.py

@@ -113,6 +113,8 @@ def parse_key_action(action):
         args = (max(0, int(rest)), )
     elif func == 'goto_layout':
         args = [rest]
+    elif func == 'set_font_size':
+        args = (float(rest),)
     elif func in shlex_actions:
         args = shlex.split(rest)
     return KeyAction(func, args)
@@ -351,7 +353,7 @@ def parse_config(lines, check_keys=True):
 
 Options, defaults = init_config(default_config_path, parse_config)
 actions = frozenset(a.func for a in defaults.keymap.values()) | frozenset(
-    'combine send_text goto_tab goto_layout new_tab_with_cwd new_window_with_cwd new_os_window_with_cwd'.
+    'combine send_text goto_tab goto_layout set_font_size new_tab_with_cwd new_window_with_cwd new_os_window_with_cwd'.
     split()
 )
 no_op_actions = frozenset({'noop', 'no-op', 'no_op'})

kitty/kitty.conf

@@ -354,6 +354,7 @@ map ctrl+shift+,        move_tab_backward
 # Miscellaneous
 map ctrl+shift+equal    increase_font_size
 map ctrl+shift+minus    decrease_font_size
+# map ctrl+shift+f6     set_font_size 20.0
 map ctrl+shift+backspace restore_font_size
 map ctrl+shift+f11      toggle_fullscreen
 map ctrl+shift+u        input_unicode_character

kitty/remote_control.py

@@ -16,10 +16,11 @@ from .tabs import SpecialWindow
 from .utils import non_blocking_read, parse_address_spec, read_with_timeout
 
 
-def cmd(short_desc, desc=None, options_spec=None, no_response=False):
+def cmd(short_desc, desc=None, options_spec=None, no_response=False, argspec='...'):
 
     def w(func):
         func.short_desc = short_desc
+        func.argspec = argspec
         func.desc = desc or short_desc
         func.name = func.__name__[4:].replace('_', '-')
         func.options_spec = options_spec
@@ -31,7 +32,7 @@ def cmd(short_desc, desc=None, options_spec=None, no_response=False):
 
 
 def parse_subcommand_cli(func, args):
-    opts, items = parse_args(args[1:], (func.options_spec or '\n').format, '...', func.desc, '{} @ {}'.format(appname, func.name))
+    opts, items = parse_args(args[1:], (func.options_spec or '\n').format, func.argspec, func.desc, '{} @ {}'.format(appname, func.name))
     return opts, items
 
 
@@ -42,7 +43,8 @@ def parse_subcommand_cli(func, args):
     ' of |_ tabs|. Each tab has its own |_ id|, a |_ title| and a list of |_ windows|.'
     ' Each window has an |_ id|, |_ title|, |_ current working directory|, |_ process id (PID)| and'
     ' |_ command-line| of the process running in the window.\n\n'
-    'You can use these criteria to select windows/tabs for the other commands.'.format(appname=appname)
+    'You can use these criteria to select windows/tabs for the other commands.'.format(appname=appname),
+    argspec=''
 )
 def cmd_ls(global_opts, opts, args):
     pass
@@ -54,6 +56,19 @@ def ls(boss, window):
     return data
 
 
+@cmd(
+    'Set the font size in all windows',
+    'Sets the font size to the specified size, in pts.',
+    argspec='FONT_SIZE'
+)
+def cmd_set_font_size(global_opts, opts, args):
+    return {'size': float(args[0])}
+
+
+def set_font_size(boss, window, payload):
+    boss.set_font_size(payload['size'])
+
+
 MATCH_WINDOW_OPTION = '''\
 --match -m
 The window to match. Match specifications are of the form: