Add support for multi-key shortcuts

Fixes #338

kitty/boss.py

@@ -19,11 +19,11 @@ from .fast_data_types import (
     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, show_window, toggle_fullscreen,
-    viewport_for_window
+    set_dpi_from_os_window, set_in_sequence_mode, show_window,
+    toggle_fullscreen, viewport_for_window
 )
 from .fonts.render import prerender, resize_fonts, set_font_family
-from .keys import get_shortcut
+from .keys import get_shortcut, shortcut_matches
 from .remote_control import handle_cmd
 from .session import create_session
 from .tabs import SpecialWindow, SpecialWindowInstance, TabManager
@@ -79,6 +79,7 @@ class Boss:
 
     def __init__(self, os_window_id, opts, args, cached_values):
         self.window_id_map = WeakValueDictionary()
+        self.pending_sequences = None
         self.cached_values = cached_values
         self.os_window_map = {}
         self.cursor_blinking = True
@@ -352,8 +353,37 @@ class Boss:
     def dispatch_special_key(self, key, scancode, action, mods):
         # Handles shortcuts, return True if the key was consumed
         key_action = get_shortcut(self.opts.keymap, mods, key, scancode)
-        self.current_key_press_info = key, scancode, action, mods
-        return self.dispatch_action(key_action)
+        if key_action is None:
+            sequences = get_shortcut(self.opts.sequence_map, mods, key, scancode)
+            if sequences:
+                self.pending_sequences = sequences
+                set_in_sequence_mode(True)
+                return True
+        else:
+            self.current_key_press_info = key, scancode, action, mods
+            return self.dispatch_action(key_action)
+
+    def process_sequence(self, key, scancode, action, mods):
+        if not self.pending_sequences:
+            set_in_sequence_mode(False)
+
+        remaining = {}
+        matched_action = None
+        for seq, key_action in self.pending_sequences.items():
+            if shortcut_matches(seq[0], mods, key, scancode):
+                seq = seq[1:]
+                if seq:
+                    remaining[seq] = key_action
+                else:
+                    matched_action = key_action
+
+        if remaining:
+            self.pending_sequences = remaining
+        else:
+            self.pending_sequences = None
+            set_in_sequence_mode(False)
+            if matched_action is not None:
+                self.dispatch_action(matched_action)
 
     def default_bg_changed_for(self, window_id):
         w = self.window_id_map.get(window_id)

kitty/config.py

@@ -120,16 +120,36 @@ def parse_key_action(action):
     return KeyAction(func, args)
 
 
-def parse_key(val, keymap):
+all_key_actions = set()
+sequence_sep = '>'
+
+
+def parse_key(val, keymap, sequence_map):
     sc, action = val.partition(' ')[::2]
-    sc, action = sc.strip(), action.strip()
+    sc, action = sc.strip().strip(sequence_sep), action.strip()
     if not sc or not action:
         return
-    mods, key = parse_shortcut(sc)
-    if key is None:
-        log_error('Shortcut: {} has unknown key, ignoring'.format(
-            val))
-        return
+    is_sequence = sequence_sep in sc
+    if is_sequence:
+        trigger = None
+        rest = []
+        for part in sc.split(sequence_sep):
+            mods, key = parse_shortcut(part)
+            if key is None:
+                log_error('Shortcut: {} has unknown key, ignoring'.format(
+                    sc))
+                return
+            if trigger is None:
+                trigger = mods, key
+            else:
+                rest.append((mods, key))
+        rest = tuple(rest)
+    else:
+        mods, key = parse_shortcut(sc)
+        if key is None:
+            log_error('Shortcut: {} has unknown key, ignoring'.format(
+                sc))
+            return
     try:
         paction = parse_key_action(action)
     except Exception:
@@ -137,7 +157,12 @@ def parse_key(val, keymap):
             action))
     else:
         if paction is not None:
-            keymap[(mods, key)] = paction
+            all_key_actions.add(paction.func)
+            if is_sequence:
+                s = sequence_map.setdefault(trigger, {})
+                s[rest] = paction
+            else:
+                keymap[(mods, key)] = paction
 
 
 def parse_symbol_map(val):
@@ -177,7 +202,7 @@ def parse_send_text_bytes(text):
                             ).encode('utf-8')
 
 
-def parse_send_text(val, keymap):
+def parse_send_text(val, keymap, sequence_map):
     parts = val.split(' ')
 
     def abort(msg):
@@ -190,7 +215,7 @@ def parse_send_text(val, keymap):
     mode, sc = parts[:2]
     text = ' '.join(parts[2:])
     key_str = '{} send_text {} {}'.format(sc, mode, text)
-    return parse_key(key_str, keymap)
+    return parse_key(key_str, keymap, sequence_map)
 
 
 def to_modifiers(val):
@@ -317,14 +342,14 @@ for a in ('active', 'inactive'):
 
 def special_handling(key, val, ans):
     if key == 'map':
-        parse_key(val, ans['keymap'])
+        parse_key(val, ans['keymap'], ans['sequence_map'])
         return True
     if key == 'symbol_map':
         ans['symbol_map'].update(parse_symbol_map(val))
         return True
     if key == 'send_text':
         # For legacy compatibility
-        parse_send_text(val, ans['keymap'])
+        parse_send_text(val, ans['keymap'], ans['sequence_map'])
         return True
 
 
@@ -337,6 +362,7 @@ default_config_path = os.path.join(
 def parse_config(lines, check_keys=True):
     ans = {
         'keymap': {},
+        'sequence_map': {},
         'symbol_map': {},
     }
     parse_config_base(
@@ -351,7 +377,7 @@ 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(
+actions = frozenset(all_key_actions) | frozenset(
     'combine send_text goto_tab goto_layout set_font_size new_tab_with_cwd new_window_with_cwd new_os_window_with_cwd'.
     split()
 )
@@ -370,6 +396,20 @@ def merge_keymaps(defaults, newvals):
     return ans
 
 
+def merge_sequence_maps(defaults, newvals):
+    ans = {t: r.copy() for t, r in defaults.items()}
+    for trigger, rest_map in newvals.items():
+        s = ans.setdefault(trigger, {})
+        for k, v in rest_map.items():
+            f = v.func
+            if f in no_op_actions:
+                s.pop(k, None)
+                continue
+            if f in actions:
+                s[k] = v
+    return {k: v for k, v in ans.items() if v}
+
+
 def merge_dicts(defaults, newvals):
     ans = defaults.copy()
     ans.update(newvals)
@@ -383,6 +423,8 @@ def merge_configs(defaults, vals):
             newvals = vals.get(k, {})
             if k == 'keymap':
                 ans['keymap'] = merge_keymaps(v, newvals)
+            elif k == 'sequence_map':
+                ans['sequence_map'] = merge_sequence_maps(v, newvals)
             else:
                 ans[k] = merge_dicts(v, newvals)
         else:

kitty/keys.c

@@ -101,6 +101,10 @@ void
 on_key_input(int key, int scancode, int action, int mods, const char* text, int state UNUSED) {
     Window *w = active_window();
     if (!w) return;
+    if (global_state.in_sequence_mode) {
+        if (action != GLFW_RELEASE) call_boss(process_sequence, "iiii", key, scancode, action, mods);
+        return;
+    }
     Screen *screen = w->render_data.screen;
     bool has_text = text && !is_ascii_control_char(text[0]);
 #ifdef __APPLE__

kitty/keys.py

@@ -251,6 +251,10 @@ def get_shortcut(keymap, mods, key, scancode):
     return keymap.get((mods & 0b1111, key))
 
 
+def shortcut_matches(s, mods, key, scancode):
+    return s[0] & 0b1111 == mods & 0b1111 and s[1] == key
+
+
 def generate_key_table():
     # To run this, use: python3 . -c "from kitty.keys import *; generate_key_table()"
     import os

kitty/kitty.conf

@@ -323,6 +323,12 @@ term xterm-kitty
 # For example:
 # map ctrl+shift+e combine : new_window : next_layout
 # this will create a new window and switch to the next available layout
+#
+# You can use multi-key shortcuts using the syntax shown below:
+# map key1>key2>key3 action
+# For example:
+# map ctrl+f>2 set_font_size 20
+# this will change the font size to 20 points when you press ctrl+f and then 3
 
 # Clipboard {{{
 map ctrl+shift+v        paste_from_clipboard

kitty/state.c

@@ -284,6 +284,7 @@ os_window_regions(OSWindow *os_window, Region *central, Region *tab_bar) {
 #define KKI(name) PYWRAP1(name) { id_type a, b; unsigned int c; PA("KKI", &a, &b, &c); name(a, b, c); Py_RETURN_NONE; }
 #define KKII(name) PYWRAP1(name) { id_type a, b; unsigned int c, d; PA("KKII", &a, &b, &c, &d); name(a, b, c, d); Py_RETURN_NONE; }
 #define KK5I(name) PYWRAP1(name) { id_type a, b; unsigned int c, d, e, f, g; PA("KKIIIII", &a, &b, &c, &d, &e, &f, &g); name(a, b, c, d, e, f, g); Py_RETURN_NONE; }
+#define BOOL_SET(name) PYWRAP1(set_##name) { global_state.name = PyObject_IsTrue(args); Py_RETURN_NONE; }
 
 static inline color_type
 color_as_int(PyObject *color) {
@@ -367,6 +368,8 @@ PYWRAP1(set_options) {
 
     GA(keymap); set_special_keys(ret);
     Py_DECREF(ret); if (PyErr_Occurred()) return NULL;
+    GA(sequence_map); set_special_keys(ret);
+    Py_DECREF(ret); if (PyErr_Occurred()) return NULL;
 
 #define read_adjust(name) { \
     PyObject *al = PyObject_GetAttrString(opts, #name); \
@@ -386,6 +389,8 @@ PYWRAP1(set_options) {
     Py_RETURN_NONE;
 }
 
+BOOL_SET(in_sequence_mode)
+
 PYWRAP1(set_tab_bar_render_data) {
     ScreenRenderData d = {0};
     id_type os_window_id;
@@ -555,6 +560,7 @@ KK5I(add_borders_rect)
 static PyMethodDef module_methods[] = {
     MW(current_os_window, METH_NOARGS),
     MW(set_options, METH_VARARGS),
+    MW(set_in_sequence_mode, METH_O),
     MW(handle_for_window_id, METH_VARARGS),
     MW(set_logical_dpi, METH_VARARGS),
     MW(pt_to_px, METH_O),

kitty/state.h

@@ -132,6 +132,7 @@ typedef struct {
     bool is_wayland;
     bool debug_gl, debug_font_fallback;
     bool has_pending_resizes;
+    bool in_sequence_mode;
 } GlobalState;
 
 extern GlobalState global_state;